init

.gitignore

@@ -0,0 +1,8 @@
+.env
+.git
+.svn
+.idea
+.vscode
+*.log
+gitmod.sh
+*_test.go

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 茂名聚合科技有限公司
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,25 @@
+<h1>
+<a href="https://www.dtapp.net/">Golang Ip</a>
+</h1>
+
+📦 Golang Ip库组件
+
+[comment]: <> (go)
+[![godoc](https://pkg.go.dev/badge/github.com/dtapps/goip?status.svg)](https://pkg.go.dev/github.com/dtapps/goip)
+[![goproxy.cn](https://goproxy.cn/stats/github.com/dtapps/goip/badges/download-count.svg)](https://goproxy.cn/stats/github.com/dtapps/goip)
+[![goreportcard.com](https://goreportcard.com/badge/github.com/dtapps/goip)](https://goreportcard.com/report/github.com/dtapps/goip)
+[![deps.dev](https://img.shields.io/badge/deps-go-red.svg)](https://deps.dev/go/github.com%2Fdtapps%2Fgoip)
+
+#### 安装使用
+
+```go
+go get -v -u github.com/dtapps/goip
+```
+
+#### 导入
+
+```go
+import (
+    "github.com/dtapps/goip"
+)
+```

analyse.go

@@ -0,0 +1,89 @@
+package goip
+
+import (
+	"strconv"
+)
+
+var (
+	ipv4 = "IPV4"
+	ipv6 = "IPV6"
+)
+
+type AnalyseResult struct {
+	IP       string `json:"ip,omitempty"`       // 输入的ip地址
+	Country  string `json:"country,omitempty"`  // 国家或地区
+	Province string `json:"province,omitempty"` // 省份
+	City     string `json:"city,omitempty"`     // 城市
+	Area     string `json:"area,omitempty"`     // 区域
+	Isp      string `json:"isp,omitempty"`      // 运营商
+}
+
+func (app *App) Analyse(item string) AnalyseResult {
+	isIp := app.isIpv4OrIpv6(item)
+	switch isIp {
+	case ipv4:
+		info := app.V4db.Find(item)
+		search, err := app.V4Region.MemorySearch(item)
+		if err != nil {
+			return AnalyseResult{
+				IP:      info.IP,
+				Country: info.Country,
+				Area:    info.Area,
+			}
+		} else {
+			return AnalyseResult{
+				IP:       search.IP,
+				Country:  search.Country,
+				Province: search.Province,
+				City:     search.City,
+				Isp:      info.Area,
+			}
+		}
+	case ipv6:
+		info := app.V6db.Find(item)
+		return AnalyseResult{
+			IP:       info.IP,
+			Country:  info.Country,
+			Province: info.Province,
+			City:     info.City,
+			Area:     info.Area,
+			Isp:      info.Isp,
+		}
+	default:
+		return AnalyseResult{}
+	}
+}
+
+// CheckIpv4 检查数据是不是IPV4
+func (app *App) CheckIpv4(ips string) bool {
+	if len(ips) > 3 {
+		return false
+	}
+	nums, err := strconv.Atoi(ips)
+	if err != nil {
+		return false
+	}
+	if nums < 0 || nums > 255 {
+		return false
+	}
+	if len(ips) > 1 && ips[0] == '0' {
+		return false
+	}
+	return true
+}
+
+// CheckIpv6 检测是不是IPV6
+func (app *App) CheckIpv6(ips string) bool {
+	if ips == "" {
+		return true
+	}
+	if len(ips) > 4 {
+		return false
+	}
+	for _, val := range ips {
+		if !((val >= '0' && val <= '9') || (val >= 'a' && val <= 'f') || (val >= 'A' && val <= 'F')) {
+			return false
+		}
+	}
+	return true
+}

app.go

@@ -0,0 +1,60 @@
+package goip
+
+import (
+	"github.com/dtapps/goip/ip2region"
+	v4 "github.com/dtapps/goip/v4"
+	v6 "github.com/dtapps/goip/v6"
+	"log"
+	"strings"
+)
+
+type App struct {
+	V4Region ip2region.Ip2Region // IPV4
+	V4db     v4.Pointer          // IPV4
+	V6db     v6.Pointer          // IPV6
+}
+
+func (app *App) InitIPData() {
+	v4Num := app.V4db.InitIPV4Data()
+	log.Printf("IPV4 库加载完成 共加载:%d 条 IP 记录\n", v4Num)
+	v6Num := app.V6db.InitIPV4Data()
+	log.Printf("IPV6 库加载完成 共加载:%d 条 IP 记录\n", v6Num)
+}
+
+func (app *App) Ipv4(ip string) (res v4.Result, resInfo ip2region.IpInfo) {
+	res = app.V4db.Find(ip)
+	resInfo, _ = app.V4Region.MemorySearch(ip)
+	return res, resInfo
+}
+
+func (app *App) Ipv6(ip string) (res v6.Result) {
+	res = app.V6db.Find(ip)
+	return res
+}
+
+func (app *App) isIpv4OrIpv6(ip string) string {
+	if len(ip) < 7 {
+		return ""
+	}
+	arrIpv4 := strings.Split(ip, ".")
+	if len(arrIpv4) == 4 {
+		//. 判断IPv4
+		for _, val := range arrIpv4 {
+			if !app.CheckIpv4(val) {
+				return ""
+			}
+		}
+		return ipv4
+	}
+	arrIpv6 := strings.Split(ip, ":")
+	if len(arrIpv6) == 8 {
+		// 判断Ipv6
+		for _, val := range arrIpv6 {
+			if !app.CheckIpv6(val) {
+				return "Neither"
+			}
+		}
+		return ipv6
+	}
+	return ""
+}

go.mod

@@ -0,0 +1,15 @@
+module github.com/dtapps/goip
+
+go 1.18
+
+require (
+	github.com/dtapps/gostring v1.0.0
+	github.com/saracen/go7z v0.0.0-20191010121135-9c09b6bd7fda
+	golang.org/x/text v0.3.7
+)
+
+require (
+	github.com/saracen/go7z-fixtures v0.0.0-20190623165746-aa6b8fba1d2f // indirect
+	github.com/saracen/solidblock v0.0.0-20190426153529-45df20abab6f // indirect
+	github.com/ulikunitz/xz v0.5.10 // indirect
+)

go.sum

@@ -0,0 +1,13 @@
+github.com/dtapps/gostring v1.0.0 h1:UQyCCfpz+395yTzuKAa0SrmQ3ky/rCv1FkX9t6GyOx4=
+github.com/dtapps/gostring v1.0.0/go.mod h1:BYYnZHrmwpFXkLpd9rQyV5YcChovVreacfcjyMKEwoU=
+github.com/saracen/go7z v0.0.0-20191010121135-9c09b6bd7fda h1:h+YpzUB/bGVJcLqW+d5GghcCmE/A25KbzjXvWJQi/+o=
+github.com/saracen/go7z v0.0.0-20191010121135-9c09b6bd7fda/go.mod h1:MSotTrCv1PwoR8QgU1JurEx+lNNbtr25I+m0zbLyAGw=
+github.com/saracen/go7z-fixtures v0.0.0-20190623165746-aa6b8fba1d2f h1:PF9WV5j/x6MT+x/sauUHd4objCvJbZb0wdxZkHSdd5A=
+github.com/saracen/go7z-fixtures v0.0.0-20190623165746-aa6b8fba1d2f/go.mod h1:6Ff0ADODZ6S3gYepgZ2w7OqFrTqtFcfwDUhmm8jsUhs=
+github.com/saracen/solidblock v0.0.0-20190426153529-45df20abab6f h1:1cJITU3JUI8qNS5T0BlXwANsVdyoJQHQ4hvOxbunPCw=
+github.com/saracen/solidblock v0.0.0-20190426153529-45df20abab6f/go.mod h1:LyBTue+RWeyIfN3ZJ4wVxvDuvlGJtDgCLgCb6HCPgps=
+github.com/ulikunitz/xz v0.5.10 h1:t92gobL9l3HE202wg3rlk19F6X+JOxl9BBrCCMYEYd8=
+github.com/ulikunitz/xz v0.5.10/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e h1:FDhOuMEY4JVRztM/gsbk+IKUQ8kj74bxZrgw87eMMVc=

ip2region/ip2region.go

@@ -0,0 +1,162 @@
+package ip2region
+
+import (
+	_ "embed"
+	"errors"
+	"github.com/dtapps/gostring"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	IndexBlockLength = 12
+)
+
+type Ip2Region struct {
+	// db file handler
+	dbFileHandler *os.File
+
+	//header block info
+
+	headerSip []int64
+	headerPtr []int64
+	headerLen int64
+
+	// super block index info
+	firstIndexPtr int64
+	lastIndexPtr  int64
+	totalBlocks   int64
+
+	// for memory mode only
+	// the original db binary string
+
+	dbFile string
+}
+
+//go:embed ip2region.db
+var dbBinStr []byte
+
+type IpInfo struct {
+	IP       string `json:"ip,omitempty"`       // 输入的ip地址
+	CityID   int64  `json:"city_id,omitempty"`  // 城市ID
+	Country  string `json:"country,omitempty"`  // 国家
+	Region   string `json:"region,omitempty"`   // 区域
+	Province string `json:"province,omitempty"` // 省份
+	City     string `json:"city,omitempty"`     // 城市
+	ISP      string `json:"isp,omitempty"`      // 运营商
+}
+
+func (ip IpInfo) String() string {
+	return ip.IP + "|" + strconv.FormatInt(ip.CityID, 10) + "|" + ip.Country + "|" + ip.Region + "|" + ip.Province + "|" + ip.City + "|" + ip.ISP
+}
+
+// 获取Ip信息
+func getIpInfo(ipStr string, cityId int64, line []byte) (ipInfo IpInfo) {
+
+	lineSlice := strings.Split(string(line), "|")
+	length := len(lineSlice)
+	ipInfo.CityID = cityId
+	if length < 5 {
+		for i := 0; i <= 5-length; i++ {
+			lineSlice = append(lineSlice, "")
+		}
+	}
+
+	if lineSlice[0] != "0" {
+		ipInfo.Country = gostring.SpaceAndLineBreak(lineSlice[0])
+	}
+	if lineSlice[1] != "0" {
+		ipInfo.Region = gostring.SpaceAndLineBreak(lineSlice[1])
+	}
+	if lineSlice[2] != "0" {
+		ipInfo.Province = gostring.SpaceAndLineBreak(lineSlice[2])
+	}
+	if lineSlice[3] != "0" {
+		ipInfo.City = gostring.SpaceAndLineBreak(lineSlice[3])
+	}
+	if lineSlice[4] != "0" {
+		ipInfo.ISP = gostring.SpaceAndLineBreak(lineSlice[4])
+	}
+
+	ipInfo.IP = ipStr
+	return ipInfo
+}
+
+// MemorySearch memory算法：整个数据库全部载入内存，单次查询都在0.1x毫秒内
+func (r *Ip2Region) MemorySearch(ipStr string) (ipInfo IpInfo, err error) {
+
+	ipInfo.IP = ipStr
+
+	if r.totalBlocks == 0 {
+
+		if err != nil {
+
+			return ipInfo, err
+		}
+
+		r.firstIndexPtr = getLong(dbBinStr, 0)
+		r.lastIndexPtr = getLong(dbBinStr, 4)
+		r.totalBlocks = (r.lastIndexPtr-r.firstIndexPtr)/IndexBlockLength + 1
+	}
+
+	ip, err := ip2long(ipStr)
+	if err != nil {
+		return ipInfo, err
+	}
+
+	h := r.totalBlocks
+	var dataPtr, l int64
+	for l <= h {
+
+		m := (l + h) >> 1
+		p := r.firstIndexPtr + m*IndexBlockLength
+		sip := getLong(dbBinStr, p)
+		if ip < sip {
+			h = m - 1
+		} else {
+			eip := getLong(dbBinStr, p+4)
+			if ip > eip {
+				l = m + 1
+			} else {
+				dataPtr = getLong(dbBinStr, p+8)
+				break
+			}
+		}
+	}
+	if dataPtr == 0 {
+		return ipInfo, errors.New("not found")
+	}
+
+	dataLen := (dataPtr >> 24) & 0xFF
+	dataPtr = dataPtr & 0x00FFFFFF
+	ipInfo = getIpInfo(ipStr, getLong(dbBinStr, dataPtr), dbBinStr[(dataPtr)+4:dataPtr+dataLen])
+	return ipInfo, nil
+
+}
+
+func getLong(b []byte, offset int64) int64 {
+
+	val := int64(b[offset]) |
+		int64(b[offset+1])<<8 |
+		int64(b[offset+2])<<16 |
+		int64(b[offset+3])<<24
+
+	return val
+
+}
+
+func ip2long(IpStr string) (int64, error) {
+	bits := strings.Split(IpStr, ".")
+	if len(bits) != 4 {
+		return 0, errors.New("ip format error")
+	}
+
+	var sum int64
+	for i, n := range bits {
+		bit, _ := strconv.ParseInt(n, 10, 64)
+		sum += bit << uint(24-8*i)
+	}
+
+	return sum, nil
+}

v4/download.go

@@ -0,0 +1,58 @@
+package v4
+
+import (
+	"bytes"
+	"compress/zlib"
+	"encoding/binary"
+	"io/ioutil"
+	"net/http"
+)
+
+// 解密key
+// https://zhangzifan.com/update-qqwry-dat.html
+func getKey() (uint32, error) {
+	resp, err := http.Get("https://update.cz88.net/ip/copywrite.rar")
+	if err != nil {
+		return 0, err
+	}
+	defer resp.Body.Close()
+
+	if body, err := ioutil.ReadAll(resp.Body); err != nil {
+		return 0, err
+	} else {
+		// @see https://stackoverflow.com/questions/34078427/how-to-read-packed-binary-data-in-go
+		return binary.LittleEndian.Uint32(body[5*4:]), nil
+	}
+}
+
+// 在线获取内容
+func getOnline() ([]byte, error) {
+	resp, err := http.Get("https://update.cz88.net/ip/qqwry.rar")
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if body, err := ioutil.ReadAll(resp.Body); err != nil {
+		return nil, err
+	} else {
+		if key, err := getKey(); err != nil {
+			return nil, err
+		} else {
+			for i := 0; i < 0x200; i++ {
+				key = key * 0x805
+				key++
+				key = key & 0xff
+
+				body[i] = byte(uint32(body[i]) ^ key)
+			}
+
+			reader, err := zlib.NewReader(bytes.NewReader(body))
+			if err != nil {
+				return nil, err
+			}
+
+			return ioutil.ReadAll(reader)
+		}
+	}
+}

v4/ipv4.go

@@ -0,0 +1,201 @@
+package v4
+
+import (
+	_ "embed"
+	"encoding/binary"
+	"errors"
+	"github.com/dtapps/gostring"
+	"golang.org/x/text/encoding/simplifiedchinese"
+	"io/ioutil"
+	"log"
+	"net"
+)
+
+var (
+	header  []byte
+	country []byte
+	area    []byte
+	offset  uint32
+	start   uint32
+	end     uint32
+)
+
+//go:embed qqwry.dat
+var dat []byte
+
+type Pointer struct {
+	Offset   uint32
+	ItemLen  uint32
+	IndexLen uint32
+}
+
+// Result 返回
+type Result struct {
+	IP      string `json:"ip,omitempty"`      // 输入的ip地址
+	Country string `json:"country,omitempty"` // 国家或地区
+	Area    string `json:"area,omitempty"`    // 区域
+}
+
+// InitIPV4Data 加载
+func (q *Pointer) InitIPV4Data() int64 {
+	buf := dat[0:8]
+	start := binary.LittleEndian.Uint32(buf[:4])
+	end := binary.LittleEndian.Uint32(buf[4:])
+
+	return int64((end-start)/7 + 1)
+}
+
+// ReadData 从文件中读取数据
+func (q *Pointer) readData(length uint32) (rs []byte) {
+	end := q.Offset + length
+	dataNum := uint32(len(dat))
+	if q.Offset > dataNum {
+		return nil
+	}
+
+	if end > dataNum {
+		end = dataNum
+	}
+	rs = dat[q.Offset:end]
+	q.Offset = end
+	return rs
+}
+
+// Find ip地址查询对应归属地信息
+func (q *Pointer) Find(ip string) (res Result) {
+
+	// 赋值
+	res.IP = ip
+	if net.ParseIP("61.241.55.180").To4() == nil {
+		// 不是ip地址
+		return res
+	}
+
+	q.Offset = 0
+
+	// 偏移
+	offset = q.searchIndex(binary.BigEndian.Uint32(net.ParseIP(ip).To4()))
+	if offset <= 0 {
+		return
+	}
+
+	q.Offset = offset + q.ItemLen
+
+	country, area = q.getAddr()
+
+	enc := simplifiedchinese.GBK.NewDecoder()
+
+	res.Country, _ = enc.String(string(country))
+	res.Country = gostring.SpaceAndLineBreak(res.Country)
+
+	res.Area, _ = enc.String(string(area))
+
+	// Delete CZ88.NET (防止不相关的信息产生干扰）
+	if res.Area == " CZ88.NET" || res.Area == "" {
+		res.Area = ""
+	} else {
+		res.Area = " " + res.Area
+	}
+
+	res.Area = gostring.SpaceAndLineBreak(res.Area)
+
+	return
+}
+
+// 获取地址信息
+func (q *Pointer) getAddr() ([]byte, []byte) {
+	mode := q.readData(1)[0]
+	if mode == 0x01 {
+		// [IP][0x01][国家和地区信息的绝对偏移地址]
+		q.Offset = byteToUInt32(q.readData(3))
+		return q.getAddr()
+	}
+	// [IP][0x02][信息的绝对偏移][...] or [IP][国家][...]
+	_offset := q.Offset - 1
+	c1 := q.readArea(_offset)
+	if mode == 0x02 {
+		q.Offset = 4 + _offset
+	} else {
+		q.Offset = _offset + uint32(1+len(c1))
+	}
+	c2 := q.readArea(q.Offset)
+	return c1, c2
+}
+
+// 读取区
+func (q *Pointer) readArea(offset uint32) []byte {
+	q.Offset = offset
+	mode := q.readData(1)[0]
+	if mode == 0x01 || mode == 0x02 {
+		return q.readArea(byteToUInt32(q.readData(3)))
+	}
+	q.Offset = offset
+	return q.readString()
+}
+
+// 读取字符串
+func (q *Pointer) readString() []byte {
+	data := make([]byte, 0)
+	for {
+		buf := q.readData(1)
+		if buf[0] == 0 {
+			break
+		}
+		data = append(data, buf[0])
+	}
+	return data
+}
+
+// 搜索索引
+func (q *Pointer) searchIndex(ip uint32) uint32 {
+	q.ItemLen = 4
+	q.IndexLen = 7
+	header = dat[0:8]
+	start = binary.LittleEndian.Uint32(header[:4])
+	end = binary.LittleEndian.Uint32(header[4:])
+
+	buf := make([]byte, q.IndexLen)
+
+	for {
+		mid := start + q.IndexLen*(((end-start)/q.IndexLen)>>1)
+		buf = dat[mid : mid+q.IndexLen]
+		_ip := binary.LittleEndian.Uint32(buf[:q.ItemLen])
+
+		if end-start == q.IndexLen {
+			if ip >= binary.LittleEndian.Uint32(dat[end:end+q.ItemLen]) {
+				buf = dat[end : end+q.IndexLen]
+			}
+			return byteToUInt32(buf[q.ItemLen:])
+		}
+
+		if _ip > ip {
+			end = mid
+		} else if _ip < ip {
+			start = mid
+		} else if _ip == ip {
+			return byteToUInt32(buf[q.ItemLen:])
+		}
+	}
+}
+
+// 字节转UInt32
+func byteToUInt32(data []byte) uint32 {
+	i := uint32(data[0]) & 0xff
+	i |= (uint32(data[1]) << 8) & 0xff00
+	i |= (uint32(data[2]) << 16) & 0xff0000
+	return i
+}
+
+// OnlineDownload 在线下载
+func (q *Pointer) OnlineDownload() (err error) {
+	tmpData, err := getOnline()
+	if err != nil {
+		return errors.New("下载失败")
+	}
+	if err := ioutil.WriteFile("./qqwry.dat", tmpData, 0644); err == nil {
+		log.Printf("已下载最新 纯真 IPv4数据库 %s ", "./qqwry.dat")
+	} else {
+		return errors.New("保存失败")
+	}
+	return nil
+}

v6/download.go

@@ -0,0 +1,81 @@
+package v6
+
+import (
+	"github.com/saracen/go7z"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+)
+
+func getOnline() (data []byte, err error) {
+	resp, err := http.Get("https://ip.zxinc.org/ip.7z")
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	file7z, err := ioutil.TempFile("", "*")
+	if err != nil {
+		return nil, err
+	}
+	defer os.Remove(file7z.Name())
+
+	if err := ioutil.WriteFile(file7z.Name(), body, 0644); err == nil {
+		return Un7z(file7z.Name())
+	}
+	return
+}
+
+func Un7z(filePath string) (data []byte, err error) {
+	sz, err := go7z.OpenReader(filePath)
+	if err != nil {
+		return nil, err
+	}
+	defer sz.Close()
+
+	fileNoNeed, err := ioutil.TempFile("", "*")
+	if err != nil {
+		return nil, err
+	}
+	fileNeed, err := ioutil.TempFile("", "*")
+	if err != nil {
+		return nil, err
+	}
+
+	if err != nil {
+		return nil, err
+	}
+	for {
+		hdr, err := sz.Next()
+		if err == io.EOF {
+			break // End of archive
+		}
+		if err != nil {
+			return nil, err
+		}
+
+		if hdr.Name == "ipv6wry.db" {
+			if _, err := io.Copy(fileNeed, sz); err != nil {
+				log.Fatalln("ZX ipv6数据库解压出错：", err.Error())
+			}
+		} else {
+			if _, err := io.Copy(fileNoNeed, sz); err != nil {
+				log.Fatalln("ZX ipv6数据库解压出错：", err.Error())
+			}
+		}
+	}
+	err = fileNoNeed.Close()
+	if err != nil {
+		return nil, err
+	}
+	defer os.Remove(fileNoNeed.Name())
+	defer os.Remove(fileNeed.Name())
+	return ioutil.ReadFile(fileNeed.Name())
+}

v6/ipv6.go

@@ -0,0 +1,226 @@
+package v6
+
+import (
+	_ "embed"
+	"encoding/binary"
+	"errors"
+	"github.com/dtapps/gostring"
+	"io/ioutil"
+	"log"
+	"math/big"
+	"net"
+	"strings"
+)
+
+var (
+	header  []byte
+	country []byte
+	area    []byte
+	v6ip    uint64
+	offset  uint32
+	start   uint32
+	end     uint32
+)
+
+type Result struct {
+	IP       string `json:"ip,omitempty"`       // 输入的ip地址
+	Country  string `json:"country,omitempty"`  // 国家
+	Province string `json:"province,omitempty"` // 省份
+	City     string `json:"city,omitempty"`     // 城市
+	Area     string `json:"area,omitempty"`     // 区域
+	Isp      string `json:"isp,omitempty"`      // 运营商
+}
+
+//go:embed ipv6wry.db
+var dat []byte
+
+type Pointer struct {
+	Offset   uint32
+	ItemLen  uint32
+	IndexLen uint32
+}
+
+// InitIPV4Data 加载
+func (q *Pointer) InitIPV4Data() int64 {
+	buf := dat[0:8]
+	start := binary.LittleEndian.Uint32(buf[:4])
+	end := binary.LittleEndian.Uint32(buf[4:])
+
+	return int64((end-start)/7 + 1)
+}
+
+// ReadData 从文件中读取数据
+func (q *Pointer) readData(length uint32) (rs []byte) {
+	end := q.Offset + length
+	dataNum := uint32(len(dat))
+	if q.Offset > dataNum {
+		return nil
+	}
+
+	if end > dataNum {
+		end = dataNum
+	}
+	rs = dat[q.Offset:end]
+	q.Offset = end
+	return rs
+}
+
+// Find ip地址查询对应归属地信息
+func (q *Pointer) Find(ip string) (res Result) {
+
+	res = Result{}
+	res.IP = ip
+	q.Offset = 0
+
+	tp := big.NewInt(0)
+	op := big.NewInt(0)
+	tp.SetBytes(net.ParseIP(ip).To16())
+	op.SetString("18446744073709551616", 10)
+	op.Div(tp, op)
+	tp.SetString("FFFFFFFFFFFFFFFF", 16)
+	op.And(op, tp)
+
+	v6ip = op.Uint64()
+	offset = q.searchIndex(v6ip)
+	q.Offset = offset
+
+	country, area = q.getAddr()
+
+	// 解析地区数据
+	info := strings.Split(string(country), "\t")
+	if len(info) > 0 {
+		i := 1
+		for {
+			if i > len(info) {
+				break
+			}
+			switch i {
+			case 1:
+				res.Country = info[i-1]
+				res.Country = gostring.SpaceAndLineBreak(res.Country)
+			case 2:
+				res.Province = info[i-1]
+				res.Province = gostring.SpaceAndLineBreak(res.Province)
+			case 3:
+				res.City = info[i-1]
+				res.City = gostring.SpaceAndLineBreak(res.City)
+			case 4:
+				res.Area = info[i-1]
+				res.Area = gostring.SpaceAndLineBreak(res.Area)
+			}
+			i++ // 自增
+		}
+	} else {
+		res.Country = string(country)
+		res.Country = gostring.SpaceAndLineBreak(res.Country)
+	}
+	// 运营商
+	res.Isp = string(area)
+
+	// Delete ZX (防止不相关的信息产生干扰）
+	if res.Isp == "ZX" || res.Isp == "" {
+		res.Isp = ""
+	} else {
+		res.Isp = " " + res.Isp
+	}
+
+	res.Isp = gostring.SpaceAndLineBreak(res.Isp)
+
+	return
+}
+
+func (q *Pointer) getAddr() ([]byte, []byte) {
+	mode := q.readData(1)[0]
+	if mode == 0x01 {
+		// [IP][0x01][国家和地区信息的绝对偏移地址]
+		q.Offset = byteToUInt32(q.readData(3))
+		return q.getAddr()
+	}
+	// [IP][0x02][信息的绝对偏移][...] or [IP][国家][...]
+	_offset := q.Offset - 1
+	c1 := q.readArea(_offset)
+	if mode == 0x02 {
+		q.Offset = 4 + _offset
+	} else {
+		q.Offset = _offset + uint32(1+len(c1))
+	}
+	c2 := q.readArea(q.Offset)
+	return c1, c2
+}
+
+func (q *Pointer) readArea(offset uint32) []byte {
+	q.Offset = offset
+	mode := q.readData(1)[0]
+	if mode == 0x01 || mode == 0x02 {
+		return q.readArea(byteToUInt32(q.readData(3)))
+	}
+	q.Offset = offset
+	return q.readString()
+}
+
+func (q *Pointer) readString() []byte {
+	data := make([]byte, 0)
+	for {
+		buf := q.readData(1)
+		if buf[0] == 0 {
+			break
+		}
+		data = append(data, buf[0])
+	}
+	return data
+}
+
+func (q *Pointer) searchIndex(ip uint64) uint32 {
+
+	q.ItemLen = 8
+	q.IndexLen = 11
+
+	header = dat[8:24]
+	start = binary.LittleEndian.Uint32(header[8:])
+	counts := binary.LittleEndian.Uint32(header[:8])
+	end = start + counts*q.IndexLen
+
+	buf := make([]byte, q.IndexLen)
+
+	for {
+		mid := start + q.IndexLen*(((end-start)/q.IndexLen)>>1)
+		buf = dat[mid : mid+q.IndexLen]
+		_ip := binary.LittleEndian.Uint64(buf[:q.ItemLen])
+
+		if end-start == q.IndexLen {
+			if ip >= binary.LittleEndian.Uint64(dat[end:end+q.ItemLen]) {
+				buf = dat[end : end+q.IndexLen]
+			}
+			return byteToUInt32(buf[q.ItemLen:])
+		}
+
+		if _ip > ip {
+			end = mid
+		} else if _ip < ip {
+			start = mid
+		} else if _ip == ip {
+			return byteToUInt32(buf[q.ItemLen:])
+		}
+	}
+}
+
+func byteToUInt32(data []byte) uint32 {
+	i := uint32(data[0]) & 0xff
+	i |= (uint32(data[1]) << 8) & 0xff00
+	i |= (uint32(data[2]) << 16) & 0xff0000
+	return i
+}
+
+// OnlineDownload 在线下载
+func (q *Pointer) OnlineDownload() (err error) {
+	tmpData, err := getOnline()
+	if err != nil {
+		return errors.New("下载失败")
+	}
+	if err := ioutil.WriteFile("./ipv6wry.db", tmpData, 0644); err == nil {
+		log.Printf("已下载最新 ZX IPv6数据库 %s ", "./ipv6wry.db")
+	} else {
+		return errors.New("保存失败")
+	}
+	return nil
+}

vendor/github.com/dtapps/gostring/.gitignore

@@ -0,0 +1,8 @@
+.env
+.git
+.svn
+.idea
+.vscode
+*.log
+gitmod.sh
+*_test.go

vendor/github.com/dtapps/gostring/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 茂名聚合科技有限公司
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/dtapps/gostring/README.md

@@ -0,0 +1,25 @@
+<h1>
+<a href="https://www.dtapp.net/">Golang String</a>
+</h1>
+
+📦 Golang 字符串组件
+
+[comment]: <> (go)
+[![godoc](https://pkg.go.dev/badge/github.com/dtapps/gostring?status.svg)](https://pkg.go.dev/github.com/dtapps/gostring)
+[![goproxy.cn](https://goproxy.cn/stats/github.com/dtapps/gostring/badges/download-count.svg)](https://goproxy.cn/stats/github.com/dtapps/gostring)
+[![goreportcard.com](https://goreportcard.com/badge/github.com/dtapps/gostring)](https://goreportcard.com/report/github.com/dtapps/gostring)
+[![deps.dev](https://img.shields.io/badge/deps-go-red.svg)](https://deps.dev/go/github.com%2Fdtapps%2Fgostring)
+
+#### 安装使用
+
+```go
+go get -v -u github.com/dtapps/gostring
+```
+
+#### 导入
+
+```go
+import (
+    "github.com/dtapps/gostring"
+)
+```

vendor/github.com/dtapps/gostring/gostring.go

@@ -0,0 +1,140 @@
+package gostring
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+// ToFloat64 string到float64
+func ToFloat64(s string) float64 {
+	i, _ := strconv.ParseFloat(s, 64)
+	return i
+}
+
+// ToInt string到int
+func ToInt(s string) int {
+	i, _ := strconv.Atoi(s)
+	return i
+}
+
+// ToInt64 string到int64
+func ToInt64(s string) int64 {
+	i, err := strconv.ParseInt(s, 10, 64)
+	if err == nil {
+		return i
+	}
+	return int64(ToFloat64(s))
+}
+
+// ToUint string到uint64
+func ToUint(s string) uint {
+	i, err := strconv.ParseUint(s, 10, 64)
+	if err == nil {
+		return uint(i)
+	}
+	return 0
+}
+
+// ToUint64 string到uint64
+func ToUint64(s string) uint64 {
+	i, err := strconv.ParseUint(s, 10, 64)
+	if err == nil {
+		return i
+	}
+	return 0
+}
+
+// Replace 字符串替换
+func Replace(str, old, new string) string {
+	return strings.Replace(str, old, new, -1)
+}
+
+func HmacSha256Hex(key, strToSign string) string {
+	hasHer := hmac.New(sha256.New, []byte(key))
+	hasHer.Write([]byte(strToSign))
+	return hex.EncodeToString(hasHer.Sum(nil))
+}
+
+// Space 去除空格
+func Space(str string) string {
+	return strings.Replace(str, " ", "", -1)
+}
+
+// LineBreak 去除换行符
+func LineBreak(str string) string {
+	return strings.Replace(str, "\n", "", -1)
+}
+
+// SpaceAndLineBreak 去除空格和去除换行符
+func SpaceAndLineBreak(str string) string {
+	return LineBreak(Space(str))
+}
+
+// TrimLastChar 删除字符串中的最后一个
+func TrimLastChar(s string) string {
+	r, size := utf8.DecodeLastRuneInString(s)
+	if r == utf8.RuneError && (size == 0 || size == 1) {
+		size = 0
+	}
+	return s[:len(s)-size]
+}
+
+// Split 字符串分隔
+func Split(s string, sep string) []string {
+	return strings.Split(s, sep)
+}
+
+// Contains 判断字符串是否包含某个字符
+func Contains(s, substr string) bool {
+	return strings.Contains(s, substr)
+}
+
+func NumericalToString(value interface{}) (string, bool) {
+	var val string
+
+	switch value.(type) {
+	default:
+		return "0", false
+	case int:
+		intVal, _ := value.(int)
+		val = strconv.FormatInt(int64(intVal), 10)
+	case int8:
+		intVal, _ := value.(int8)
+		val = strconv.FormatInt(int64(intVal), 10)
+	case int16:
+		intVal, _ := value.(int16)
+		val = strconv.FormatInt(int64(intVal), 10)
+	case int32:
+		intVal, _ := value.(int32)
+		val = strconv.FormatInt(int64(intVal), 10)
+	case int64:
+		intVal, _ := value.(int64)
+		val = strconv.FormatInt(int64(intVal), 10)
+	case uint:
+		intVal, _ := value.(uint)
+		val = strconv.FormatUint(uint64(intVal), 10)
+	case uint8:
+		intVal, _ := value.(uint8)
+		val = strconv.FormatUint(uint64(intVal), 10)
+	case uint16:
+		intVal, _ := value.(uint16)
+		val = strconv.FormatUint(uint64(intVal), 10)
+	case uint32:
+		intVal, _ := value.(uint32)
+		val = strconv.FormatUint(uint64(intVal), 10)
+	case uint64:
+		intVal, _ := value.(uint64)
+		val = strconv.FormatUint(intVal, 10)
+	case float32:
+		floatVal, _ := value.(float32)
+		val = strconv.FormatFloat(float64(floatVal), 'f', -1, 32)
+	case float64:
+		floatVal, _ := value.(float64)
+		val = strconv.FormatFloat(floatVal, 'f', -1, 64)
+	}
+	return val, true
+}

vendor/github.com/saracen/go7z/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Arran Walker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/saracen/go7z/README.md

@@ -0,0 +1,68 @@
+# go7z
+
+A native Go 7z archive reader.
+
+Features:
+- Development in early stages.
+- Very little tests.
+- Medium probability of crashes.
+- Medium probability of using all memory.
+- Decompresses:
+  - [LZMA](https://github.com/ulikunitz/xz)
+  - [LZMA2](https://github.com/ulikunitz/xz)
+  - Delta
+  - BCJ2
+  - bzip2
+  - deflate
+
+## Usage
+Extracting an archive:
+
+```
+package main
+
+import (
+	"io"
+	"os"
+
+	"github.com/saracen/go7z"
+)
+
+func main() {
+	sz, err := go7z.OpenReader("hello.7z")
+	if err != nil {
+		panic(err)
+	}
+	defer sz.Close()
+
+	for {
+		hdr, err := sz.Next()
+		if err == io.EOF {
+			break // End of archive
+		}
+		if err != nil {
+			panic(err)
+		}
+
+		// If empty stream (no contents) and isn't specifically an empty file...
+		// then it's a directory.
+		if hdr.IsEmptyStream && !hdr.IsEmptyFile {
+			if err := os.MkdirAll(hdr.Name, os.ModePerm); err != nil {
+				panic(err)
+			}
+			continue
+		}
+
+		// Create file
+		f, err := os.Create(hdr.Name)
+		if err != nil {
+			panic(err)
+		}
+		defer f.Close()
+
+		if _, err := io.Copy(f, sz); err != nil {
+			panic(err)
+		}
+	}
+}
+```

vendor/github.com/saracen/go7z/filters/aes.go

@@ -0,0 +1,132 @@
+package filters
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/sha256"
+	"encoding/binary"
+	"hash"
+	"io"
+	"strings"
+	"unicode/utf16"
+)
+
+var km keyManager
+
+func init() {
+	km.cache = make(map[string][]byte)
+	km.hasher = sha256.New()
+}
+
+// AESDecrypter is an AES-256 decryptor.
+type AESDecrypter struct {
+	r    io.Reader
+	rbuf bytes.Buffer
+	cbc  cipher.BlockMode
+	buf  [aes.BlockSize]byte
+}
+
+type keyManager struct {
+	hasher hash.Hash
+	cache  map[string][]byte
+}
+
+func (km *keyManager) Key(power int, salt []byte, password string) []byte {
+	var cacheKey strings.Builder
+	cacheKey.WriteString(password)
+	cacheKey.Write(salt)
+	cacheKey.WriteByte(byte(power))
+
+	key, ok := km.cache[cacheKey.String()]
+	if ok {
+		return key
+	}
+
+	b := bytes.NewBuffer(nil)
+	for _, p := range utf16.Encode([]rune(password)) {
+		binary.Write(b, binary.LittleEndian, p)
+	}
+
+	if power == 0x3f {
+		key = km.stretch(salt, b.Bytes())
+	} else {
+		key = km.sha256Stretch(power, salt, b.Bytes())
+	}
+
+	km.cache[cacheKey.String()] = key
+	return key
+}
+
+func (km *keyManager) stretch(salt, password []byte) []byte {
+	var key [aes.BlockSize]byte
+
+	var pos int
+	for pos = 0; pos < len(salt); pos++ {
+		key[pos] = salt[pos]
+	}
+	for i := 0; i < len(password) && pos < len(key); i++ {
+		key[pos] = password[i]
+		pos++
+	}
+	for ; pos < len(key); pos++ {
+		key[pos] = 0
+	}
+	return key[:]
+}
+
+func (km *keyManager) sha256Stretch(power int, salt, password []byte) []byte {
+	var temp [8]byte
+	for round := 0; round < 1<<power; round++ {
+		km.hasher.Write(salt)
+		km.hasher.Write(password)
+		km.hasher.Write(temp[:])
+
+		for i := 0; i < 8; i++ {
+			temp[i]++
+			if temp[i] != 0 {
+				break
+			}
+		}
+	}
+
+	defer km.hasher.Reset()
+	return km.hasher.Sum(nil)
+}
+
+// NewAESDecrypter returns a new AES-256 decryptor.
+func NewAESDecrypter(r io.Reader, power int, salt, iv []byte, password string) (*AESDecrypter, error) {
+	key := km.Key(power, salt, password)
+
+	cb, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	var aesiv [aes.BlockSize]byte
+	copy(aesiv[:], iv)
+
+	return &AESDecrypter{
+		r:   r,
+		cbc: cipher.NewCBCDecrypter(cb, aesiv[:]),
+	}, nil
+}
+
+func (d *AESDecrypter) Read(p []byte) (int, error) {
+	for d.rbuf.Len() < len(p) {
+		_, err := d.r.Read(d.buf[:])
+		if err != nil {
+			return 0, err
+		}
+
+		d.cbc.CryptBlocks(d.buf[:], d.buf[:])
+
+		_, err = d.rbuf.Write(d.buf[:])
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	n, err := d.rbuf.Read(p)
+	return n, err
+}

vendor/github.com/saracen/go7z/filters/bcj2.go

@@ -0,0 +1,210 @@
+package filters
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/binary"
+	"io"
+)
+
+type rangeDecoder struct {
+	r      io.Reader
+	nrange uint
+	code   uint
+}
+
+func newRangeDecoder(r io.Reader) (*rangeDecoder, error) {
+	rd := &rangeDecoder{
+		r:      r,
+		nrange: 0xffffffff,
+	}
+
+	for i := 0; i < 5; i++ {
+		b, err := rd.ReadByte()
+		if err != nil {
+			return nil, err
+		}
+
+		rd.code = (rd.code << 8) | uint(b)
+	}
+	return rd, nil
+}
+
+func (rd *rangeDecoder) ReadByte() (byte, error) {
+	var b [1]byte
+	_, err := rd.r.Read(b[:])
+	return b[0], err
+}
+
+const (
+	numMoveBits          = 5
+	numbitModelTotalBits = 11
+	bitModelTotal        = uint(1) << numbitModelTotalBits
+
+	numTopBits = 24
+	topValue   = uint(1 << numTopBits)
+)
+
+type statusDecoder struct {
+	prob uint
+}
+
+func newStatusDecoder() *statusDecoder {
+	return &statusDecoder{prob: bitModelTotal / 2}
+}
+
+func (sd *statusDecoder) Decode(decoder *rangeDecoder) (uint, error) {
+	var err error
+	var b byte
+
+	newBound := (decoder.nrange >> numbitModelTotalBits) * sd.prob
+	if decoder.code < newBound {
+		decoder.nrange = newBound
+		sd.prob += (bitModelTotal - sd.prob) >> numMoveBits
+		if decoder.nrange < topValue {
+			if b, err = decoder.ReadByte(); err != nil {
+				return 0, err
+			}
+			decoder.code = (decoder.code << 8) | uint(b)
+			decoder.nrange <<= 8
+		}
+		return 0, nil
+	}
+
+	decoder.nrange -= newBound
+	decoder.code -= newBound
+	sd.prob -= sd.prob >> numMoveBits
+	if decoder.nrange < topValue {
+		if b, err = decoder.ReadByte(); err != nil {
+			return 0, err
+		}
+		decoder.code = (decoder.code << 8) | uint(b)
+		decoder.nrange <<= 8
+	}
+	return 1, nil
+}
+
+// BCJ2Decoder is a BCJ2 decoder.
+type BCJ2Decoder struct {
+	main *bufio.Reader
+	call io.Reader
+	jump io.Reader
+
+	rangeDecoder  *rangeDecoder
+	statusDecoder []*statusDecoder
+
+	written  int64
+	finished bool
+
+	prevByte byte
+
+	buf *bytes.Buffer
+}
+
+// NewBCJ2Decoder returns a new BCJ2 decoder.
+func NewBCJ2Decoder(main, call, jump, rangedecoder io.Reader, limit int64) (*BCJ2Decoder, error) {
+	rd, err := newRangeDecoder(rangedecoder)
+	if err != nil {
+		return nil, err
+	}
+
+	decoder := &BCJ2Decoder{
+		main:          bufio.NewReader(main),
+		call:          call,
+		jump:          jump,
+		rangeDecoder:  rd,
+		statusDecoder: make([]*statusDecoder, 256+2),
+		buf:           new(bytes.Buffer),
+	}
+	decoder.buf.Grow(1 << 16)
+
+	for i := range decoder.statusDecoder {
+		decoder.statusDecoder[i] = newStatusDecoder()
+	}
+
+	return decoder, nil
+}
+
+func (d *BCJ2Decoder) isJcc(b0, b1 byte) bool {
+	return b0 == 0x0f && (b1&0xf0) == 0x80
+}
+
+func (d *BCJ2Decoder) isJ(b0, b1 byte) bool {
+	return (b1&0xfe) == 0xe8 || d.isJcc(b0, b1)
+}
+
+func (d *BCJ2Decoder) index(b0, b1 byte) int {
+	switch b1 {
+	case 0xe8:
+		return int(b0)
+	case 0xe9:
+		return 256
+	}
+	return 257
+}
+
+func (d *BCJ2Decoder) Read(p []byte) (int, error) {
+	err := d.read()
+	if err != nil && err != io.EOF {
+		return 0, err
+	}
+
+	return d.buf.Read(p)
+}
+
+func (d *BCJ2Decoder) read() error {
+	b := byte(0)
+
+	var err error
+	for i := 0; i < d.buf.Cap(); i++ {
+		b, err = d.main.ReadByte()
+		if err != nil {
+			return err
+		}
+
+		d.written++
+		if err = d.buf.WriteByte(b); err != nil {
+			return err
+		}
+
+		if d.isJ(d.prevByte, b) {
+			break
+		}
+		d.prevByte = b
+	}
+
+	if d.buf.Len() == d.buf.Cap() {
+		return nil
+	}
+
+	bit, err := d.statusDecoder[d.index(d.prevByte, b)].Decode(d.rangeDecoder)
+	if err != nil {
+		return err
+	}
+
+	if bit == 1 {
+		var r io.Reader
+		if b == 0xe8 {
+			r = d.call
+		} else {
+			r = d.jump
+		}
+
+		var dest uint32
+		if err = binary.Read(r, binary.BigEndian, &dest); err != nil {
+			return err
+		}
+
+		dest -= uint32(d.written + 4)
+		if err = binary.Write(d.buf, binary.LittleEndian, dest); err != nil {
+			return err
+		}
+
+		d.prevByte = byte(dest >> 24)
+		d.written += 4
+	} else {
+		d.prevByte = b
+	}
+
+	return nil
+}

vendor/github.com/saracen/go7z/filters/delta.go

@@ -0,0 +1,45 @@
+package filters
+
+import "io"
+
+const deltaStateSize = 256
+
+// DeltaDecoder is a Delta decoder.
+type DeltaDecoder struct {
+	state [deltaStateSize]byte
+	r     io.Reader
+	delta uint
+}
+
+// NewDeltaDecoder returns a new Delta decoder.
+func NewDeltaDecoder(r io.Reader, delta uint, limit int64) (*DeltaDecoder, error) {
+	return &DeltaDecoder{r: r, delta: delta}, nil
+}
+
+func (d *DeltaDecoder) Read(p []byte) (int, error) {
+	n, err := d.r.Read(p)
+	if err != nil {
+		return n, err
+	}
+
+	var buf [deltaStateSize]byte
+	copy(buf[:], d.state[:d.delta])
+
+	var i, j uint
+	for i = 0; i < uint(n); {
+		for j = 0; j < d.delta && i < uint(n); i++ {
+			p[i] = buf[j] + p[i]
+			buf[j] = p[i]
+			j++
+		}
+	}
+
+	if j == d.delta {
+		j = 0
+	}
+
+	copy(d.state[:], buf[j:d.delta])
+	copy(d.state[d.delta-j:], buf[:j])
+
+	return n, err
+}

vendor/github.com/saracen/go7z/fuzz.go

@@ -0,0 +1,32 @@
+// +build gofuzz
+
+package go7z
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+)
+
+func Fuzz(data []byte) int {
+	sz := new(Reader)
+	if err := sz.init(bytes.NewReader(data), int64(len(data)), true); err != nil {
+		return 0
+	}
+
+	for {
+		_, err := sz.Next()
+		if err == io.EOF {
+			return 0
+		}
+		if err != nil {
+			return 0
+		}
+
+		if _, err = io.Copy(ioutil.Discard, sz); err != nil {
+			return 0
+		}
+	}
+
+	return 1
+}

vendor/github.com/saracen/go7z/headers/digests.go

@@ -0,0 +1,25 @@
+package headers
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+// ReadDigests reads an array of uint32 CRCs.
+func ReadDigests(r io.Reader, length int) ([]uint32, error) {
+	defined, _, err := ReadOptionalBoolVector(r, length)
+	if err != nil {
+		return nil, err
+	}
+
+	crcs := make([]uint32, length)
+	for i := range defined {
+		if defined[i] {
+			if err := binary.Read(r, binary.LittleEndian, &crcs[i]); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	return crcs, nil
+}

vendor/github.com/saracen/go7z/headers/files_info.go

@@ -0,0 +1,159 @@
+package headers
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"time"
+	"unicode/utf16"
+)
+
+// ErrInvalidFileCount is returned when the file count read from the stream
+// exceeds the caller supplied maxFileCount.
+var ErrInvalidFileCount = errors.New("invalid file count")
+
+// FileInfo is a structure containing the information of an archived file.
+type FileInfo struct {
+	Name   string
+	Attrib uint32
+
+	IsEmptyStream bool
+	IsEmptyFile   bool
+
+	// Flag indicating a file should be removed upon extraction.
+	IsAntiFile bool
+
+	CreatedAt  time.Time
+	AccessedAt time.Time
+	ModifiedAt time.Time
+}
+
+// ReadFilesInfo reads the files info structure.
+func ReadFilesInfo(r io.Reader, maxFileCount int) ([]*FileInfo, error) {
+	numFiles, err := ReadNumberInt(r)
+	if err != nil {
+		return nil, err
+	}
+	if numFiles > maxFileCount {
+		return nil, ErrInvalidFileCount
+	}
+
+	fileInfo := make([]*FileInfo, numFiles)
+	for i := range fileInfo {
+		fileInfo[i] = &FileInfo{}
+	}
+
+	var numEmptyStreams int
+	for {
+		id, err := ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+
+		if id == k7zEnd {
+			return fileInfo, nil
+		}
+
+		size, err := ReadNumber(r)
+		if err != nil {
+			return nil, err
+		}
+
+		switch id {
+		case k7zEmptyStream:
+			var emptyStreams []bool
+			emptyStreams, numEmptyStreams, err = ReadBoolVector(r, numFiles)
+			if err != nil {
+				return nil, err
+			}
+			for i, fi := range fileInfo {
+				fi.IsEmptyStream = emptyStreams[i]
+			}
+
+		case k7zEmptyFile, k7zAnti:
+			files, _, err := ReadBoolVector(r, numEmptyStreams)
+			if err != nil {
+				return nil, err
+			}
+
+			idx := 0
+			for _, fi := range fileInfo {
+				if fi.IsEmptyStream {
+					switch id {
+					case k7zEmptyFile:
+						fi.IsEmptyFile = files[idx]
+					case k7zAnti:
+						fi.IsAntiFile = files[idx]
+					}
+					idx++
+				}
+			}
+
+		case k7zStartPos:
+			return nil, ErrUnexpectedPropertyID
+
+		case k7zCTime, k7zATime, k7zMTime:
+			times, err := ReadDateTimeVector(r, numFiles)
+			if err != nil {
+				return nil, err
+			}
+			for i, fi := range fileInfo {
+				switch id {
+				case k7zCTime:
+					fi.CreatedAt = times[i]
+				case k7zATime:
+					fi.AccessedAt = times[i]
+				case k7zMTime:
+					fi.ModifiedAt = times[i]
+				}
+			}
+
+		case k7zName:
+			external, err := ReadByte(r)
+			if err != nil {
+				return nil, err
+			}
+
+			switch external {
+			case 0:
+				for _, fi := range fileInfo {
+					var rune uint16
+					var name []uint16
+					for {
+						if err = binary.Read(r, binary.LittleEndian, &rune); err != nil {
+							return nil, err
+						}
+
+						if rune == 0 {
+							break
+						}
+						name = append(name, rune)
+					}
+					fi.Name = string(utf16.Decode(name))
+				}
+
+			default:
+				return nil, ErrAdditionalStreamsNotImplemented
+			}
+
+		case k7zWinAttributes:
+			attributes, err := ReadAttributeVector(r, numFiles)
+			if err != nil {
+				return nil, err
+			}
+			for i, fi := range fileInfo {
+				fi.Attrib = attributes[i]
+			}
+
+		case k7zDummy:
+			for i := uint64(0); i < size; i++ {
+				if _, err = ReadByte(r); err != nil {
+					return nil, err
+				}
+			}
+
+		default:
+			return nil, ErrUnexpectedPropertyID
+		}
+	}
+}

vendor/github.com/saracen/go7z/headers/folder.go

@@ -0,0 +1,240 @@
+package headers
+
+import (
+	"errors"
+	"io"
+)
+
+const (
+	// MaxInOutStreams is the maximum allowed stream inputs/outputs into/out
+	// of a coder.
+	MaxInOutStreams = 4
+
+	// MaxPropertyDataSize is the size in bytes supported for coder property data.
+	MaxPropertyDataSize = 128
+
+	// MaxCodersInFolder is the maximum number of coders allowed to be
+	// specified in a folder.
+	MaxCodersInFolder = 4
+
+	// MaxPackedStreamsInFolder is the maximum number of packed streams allowed
+	// to be in a folder.
+	MaxPackedStreamsInFolder = 4
+)
+
+var (
+	// ErrInvalidStreamCount is the error returned when the input/output stream
+	// count for a coder is <= 0 || > MaxInOutStreams.
+	ErrInvalidStreamCount = errors.New("invalid in/out stream count")
+
+	// ErrInvalidPropertyDataSize is the error returned when the property data
+	// size is <= 0 || > MaxInOutStreams.
+	ErrInvalidPropertyDataSize = errors.New("invalid property data size")
+
+	// ErrInvalidCoderInFolderCount is the error returned when the number of
+	// coders in a folder is <= 0 || > MaxCodersInFolder.
+	ErrInvalidCoderInFolderCount = errors.New("invalid coder in folder count")
+
+	// ErrInvalidPackedStreamsCount is the error returned when the number of
+	// packed streams exceeds MaxPackedStreamsInFolder
+	ErrInvalidPackedStreamsCount = errors.New("invalid packed streams count")
+)
+
+// Folder is a structure containing information on how a solid block was
+// constructed.
+type Folder struct {
+	CoderInfo     []*CoderInfo
+	BindPairsInfo []*BindPairsInfo
+	PackedIndices []int
+	UnpackSizes   []uint64
+	UnpackCRC     uint32
+}
+
+// NumInStreamsTotal is the sum of inputs required by all codecs.
+func (f *Folder) NumInStreamsTotal() int {
+	var count int
+	for i := range f.CoderInfo {
+		count += f.CoderInfo[i].NumInStreams
+	}
+	return count
+}
+
+// NumOutStreamsTotal is the sum of outputs required by all codecs.
+func (f *Folder) NumOutStreamsTotal() int {
+	var count int
+	for i := range f.CoderInfo {
+		count += f.CoderInfo[i].NumOutStreams
+	}
+	return count
+}
+
+// FindBindPairForInStream returns the index of a bindpair by an in index.
+func (f *Folder) FindBindPairForInStream(inStreamIndex int) int {
+	for i := range f.BindPairsInfo {
+		if f.BindPairsInfo[i].InIndex == inStreamIndex {
+			return i
+		}
+	}
+	return -1
+}
+
+// FindBindPairForOutStream returns the index of a bindpair by an out index.
+func (f *Folder) FindBindPairForOutStream(outStreamIndex int) int {
+	for i := range f.BindPairsInfo {
+		if f.BindPairsInfo[i].OutIndex == outStreamIndex {
+			return i
+		}
+	}
+	return -1
+}
+
+// UnpackSize returns the final unpacked size of the folder.
+func (f *Folder) UnpackSize() uint64 {
+	for i := range f.UnpackSizes {
+		if f.FindBindPairForOutStream(i) < 0 {
+			return f.UnpackSizes[i]
+		}
+	}
+	return 0
+}
+
+// ReadFolder reads a folder structure.
+func ReadFolder(r io.Reader) (*Folder, error) {
+	var err error
+
+	folder := &Folder{}
+
+	numCoders, err := ReadNumberInt(r)
+	if err != nil {
+		return nil, err
+	}
+	if numCoders == 0 || numCoders > MaxCodersInFolder {
+		return nil, ErrInvalidCoderInFolderCount
+	}
+
+	folder.CoderInfo = make([]*CoderInfo, numCoders)
+	for i := range folder.CoderInfo {
+		if folder.CoderInfo[i], err = ReadCoderInfo(r); err != nil {
+			return nil, err
+		}
+	}
+
+	folder.BindPairsInfo = make([]*BindPairsInfo, numCoders-1)
+	for i := range folder.BindPairsInfo {
+		if folder.BindPairsInfo[i], err = ReadBindPairsInfo(r); err != nil {
+			return nil, err
+		}
+	}
+
+	numInStreamsTotal := folder.NumInStreamsTotal()
+	numPackedStreams := numInStreamsTotal - len(folder.BindPairsInfo)
+	if numPackedStreams > 1 {
+		if numPackedStreams > MaxPackedStreamsInFolder {
+			return nil, ErrInvalidPackedStreamsCount
+		}
+
+		folder.PackedIndices = make([]int, numPackedStreams)
+		for i := range folder.PackedIndices {
+			if folder.PackedIndices[i], err = ReadNumberInt(r); err != nil {
+				return nil, err
+			}
+		}
+	} else if numPackedStreams == 1 {
+		for i := 0; i < numInStreamsTotal; i++ {
+			if folder.FindBindPairForInStream(i) < 0 {
+				folder.PackedIndices = []int{i}
+				break
+			}
+		}
+	}
+
+	return folder, nil
+}
+
+// CoderInfo is a structure holding information about a codec.
+type CoderInfo struct {
+	CodecID       uint32
+	Properties    []byte
+	NumInStreams  int
+	NumOutStreams int
+}
+
+// ReadCoderInfo reads a coder info structure.
+func ReadCoderInfo(r io.Reader) (*CoderInfo, error) {
+	attributes, err := ReadByte(r)
+	if err != nil {
+		return nil, err
+	}
+
+	coderInfo := &CoderInfo{}
+
+	codecIDSize := attributes & 0x0f
+	isComplexCoder := attributes&0x10 > 0
+	hasAttributes := attributes&0x20 > 0
+
+	if codecIDSize > 0 {
+		b := make([]byte, codecIDSize)
+		if _, err = r.Read(b); err != nil {
+			return nil, err
+		}
+		for i := codecIDSize; i > 0; i-- {
+			coderInfo.CodecID |= uint32(b[i-1]) << ((codecIDSize - i) * 8)
+		}
+	}
+
+	coderInfo.NumInStreams = 1
+	coderInfo.NumOutStreams = 1
+	if isComplexCoder {
+		if coderInfo.NumInStreams, err = ReadNumberInt(r); err != nil {
+			return nil, err
+		}
+		if coderInfo.NumInStreams == 0 || coderInfo.NumInStreams > MaxInOutStreams {
+			return nil, ErrInvalidStreamCount
+		}
+
+		if coderInfo.NumOutStreams, err = ReadNumberInt(r); err != nil {
+			return nil, err
+		}
+		if coderInfo.NumOutStreams == 0 || coderInfo.NumOutStreams > MaxInOutStreams {
+			return nil, ErrInvalidStreamCount
+		}
+	}
+
+	if hasAttributes {
+		size, err := ReadNumberInt(r)
+		if err != nil {
+			return nil, err
+		}
+		if size <= 0 || size > MaxPropertyDataSize {
+			return nil, ErrInvalidPropertyDataSize
+		}
+
+		coderInfo.Properties = make([]byte, size)
+		if _, err = r.Read(coderInfo.Properties); err != nil {
+			return nil, err
+		}
+	}
+
+	return coderInfo, nil
+}
+
+// BindPairsInfo is a structure that binds the in and out indexes of a codec.
+type BindPairsInfo struct {
+	InIndex  int
+	OutIndex int
+}
+
+// ReadBindPairsInfo reads a bindpairs info structure.
+func ReadBindPairsInfo(r io.Reader) (*BindPairsInfo, error) {
+	bindPairsInfo := &BindPairsInfo{}
+
+	var err error
+	if bindPairsInfo.InIndex, err = ReadNumberInt(r); err != nil {
+		return nil, err
+	}
+	if bindPairsInfo.OutIndex, err = ReadNumberInt(r); err != nil {
+		return nil, err
+	}
+
+	return bindPairsInfo, nil
+}

vendor/github.com/saracen/go7z/headers/header.go

@@ -0,0 +1,152 @@
+package headers
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"hash/crc32"
+	"io"
+)
+
+const (
+	// SignatureHeader size is the size of the signature header.
+	SignatureHeaderSize = 32
+
+	// MaxHeaderSize is the maximum header size.
+	MaxHeaderSize = int64(1 << 62) // 4 exbibyte
+)
+
+var (
+	// MagicBytes is the magic bytes used in the 7z signature.
+	MagicBytes = [6]byte{0x37, 0x7A, 0xBC, 0xAF, 0x27, 0x1C}
+
+	// ErrInvalidSignatureHeader is returned when signature header is invalid.
+	ErrInvalidSignatureHeader = errors.New("invalid signature header")
+)
+
+// SignatureHeader is the structure found at the top of 7z files.
+type SignatureHeader struct {
+	Signature [6]byte
+
+	ArchiveVersion struct {
+		Major byte
+		Minor byte
+	}
+
+	StartHeaderCRC uint32
+
+	StartHeader struct {
+		NextHeaderOffset int64
+		NextHeaderSize   int64
+		NextHeaderCRC    uint32
+	}
+}
+
+// ReadSignatureHeader reads the signature header.
+func ReadSignatureHeader(r io.Reader) (*SignatureHeader, error) {
+	var raw [SignatureHeaderSize]byte
+	_, err := r.Read(raw[:])
+	if err != nil {
+		return nil, err
+	}
+
+	var header SignatureHeader
+	copy(header.Signature[:], raw[:6])
+	if bytes.Compare(header.Signature[:], MagicBytes[:]) != 0 {
+		return nil, ErrInvalidSignatureHeader
+	}
+
+	header.ArchiveVersion.Major = raw[6]
+	header.ArchiveVersion.Minor = raw[7]
+	header.StartHeaderCRC = binary.LittleEndian.Uint32(raw[8:])
+	header.StartHeader.NextHeaderOffset = int64(binary.LittleEndian.Uint64(raw[12:]))
+	header.StartHeader.NextHeaderSize = int64(binary.LittleEndian.Uint64(raw[20:]))
+	header.StartHeader.NextHeaderCRC = binary.LittleEndian.Uint32(raw[28:])
+
+	if header.StartHeader.NextHeaderSize < 0 || header.StartHeader.NextHeaderSize > MaxHeaderSize {
+		return &header, ErrInvalidSignatureHeader
+	}
+	if crc32.ChecksumIEEE(raw[12:]) != header.StartHeaderCRC {
+		err = ErrChecksumMismatch
+	}
+	return &header, err
+}
+
+// Header is structure containing file and stream information.
+type Header struct {
+	MainStreamsInfo *StreamsInfo
+	FilesInfo       []*FileInfo
+}
+
+// ReadPackedStreamsForHeaders reads either a header or encoded header structure.
+func ReadPackedStreamsForHeaders(r *io.LimitedReader) (header *Header, encodedHeader *StreamsInfo, err error) {
+	id, err := ReadByte(r)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	switch id {
+	case k7zHeader:
+		if header, err = ReadHeader(r); err != nil && err != io.EOF {
+			return nil, nil, err
+		}
+
+	case k7zEncodedHeader:
+		if encodedHeader, err = ReadStreamsInfo(r); err != nil {
+			return nil, nil, err
+		}
+
+	case k7zEnd:
+		if header == nil && encodedHeader == nil {
+			return nil, nil, ErrUnexpectedPropertyID
+		}
+		break
+
+	default:
+		return nil, nil, ErrUnexpectedPropertyID
+	}
+
+	return header, encodedHeader, nil
+}
+
+// ReadHeader reads a header structure.
+func ReadHeader(r *io.LimitedReader) (*Header, error) {
+	header := &Header{}
+
+	for {
+		id, err := ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+
+		switch id {
+		case k7zArchiveProperties:
+			return nil, ErrArchivePropertiesNotImplemented
+
+		case k7zAdditionalStreamsInfo:
+			return nil, ErrAdditionalStreamsNotImplemented
+
+		case k7zMainStreamsInfo:
+			if header.MainStreamsInfo, err = ReadStreamsInfo(r); err != nil {
+				return nil, err
+			}
+
+		case k7zFilesInfo:
+			// Limit the maximum amount of FileInfos that get allocated to size
+			// of the remaining header / 3
+			if header.FilesInfo, err = ReadFilesInfo(r, int(r.N)/3); err != nil {
+				return nil, err
+			}
+
+		case k7zEnd:
+			if header.MainStreamsInfo == nil {
+				return nil, ErrUnexpectedPropertyID
+			}
+
+			return header, nil
+
+		default:
+			return nil, ErrUnexpectedPropertyID
+		}
+	}
+}

vendor/github.com/saracen/go7z/headers/pack_info.go

@@ -0,0 +1,51 @@
+package headers
+
+import "io"
+
+// PackInfo contains the pack stream sizes of the folders.
+type PackInfo struct {
+	PackPos   uint64
+	PackSizes []uint64
+}
+
+// ReadPackInfo reads a pack info structure.
+func ReadPackInfo(r io.Reader) (*PackInfo, error) {
+	packInfo := &PackInfo{}
+
+	var err error
+	if packInfo.PackPos, err = ReadNumber(r); err != nil {
+		return nil, err
+	}
+
+	numPackStreams, err := ReadNumberInt(r)
+	if err != nil {
+		return nil, err
+	}
+
+	for {
+		id, err := ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+
+		switch id {
+		case k7zSize:
+			packInfo.PackSizes = make([]uint64, numPackStreams+1)
+			for i := 0; i < numPackStreams; i++ {
+				packInfo.PackSizes[i], err = ReadNumber(r)
+				if err != nil {
+					return nil, err
+				}
+			}
+
+		case k7zCRC:
+			return nil, ErrPackInfoCRCsNotImplemented
+
+		case k7zEnd:
+			return packInfo, nil
+
+		default:
+			return nil, ErrUnexpectedPropertyID
+		}
+	}
+}

vendor/github.com/saracen/go7z/headers/primitive.go

@@ -0,0 +1,262 @@
+package headers
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"time"
+)
+
+const (
+	k7zEnd = iota
+	k7zHeader
+	k7zArchiveProperties
+	k7zAdditionalStreamsInfo
+	k7zMainStreamsInfo
+	k7zFilesInfo
+	k7zPackInfo
+	k7zUnpackInfo
+	k7zSubStreamsInfo
+	k7zSize
+	k7zCRC
+	k7zFolder
+	k7zCodersUnpackSize
+	k7zNumUnpackStream
+	k7zEmptyStream
+	k7zEmptyFile
+	k7zAnti
+	k7zName
+	k7zCTime
+	k7zATime
+	k7zMTime
+	k7zWinAttributes
+	k7zComment
+	k7zEncodedHeader
+	k7zStartPos
+	k7zDummy
+)
+
+const MaxNumber = 0x7FFFFFFF
+
+var (
+	// ErrUnexpectedPropertyID is returned when we read a property id that was
+	// either unexpected, or we don't support.
+	ErrUnexpectedPropertyID = errors.New("unexpected property id")
+
+	// ErrAdditionalStreamsNotImplemented is returned for archives using
+	// additional streams. These were apparently used in older versions of 7zip.
+	ErrAdditionalStreamsNotImplemented = errors.New("additional streams are not implemented")
+
+	// ErrArchivePropertiesNotImplemented is returned if archive properties
+	// structure is found. So far, this hasn't been used in any verison of 7zip.
+	ErrArchivePropertiesNotImplemented = errors.New("archive properties are not implemented")
+
+	// ErrChecksumMismatch is returned when a CRC check fails.
+	ErrChecksumMismatch = errors.New("checksum mismatch")
+
+	// ErrPackInfoCRCsNotImplemented is returned if a CRC property id is
+	// encountered whilst reading packinfo.
+	ErrPackInfoCRCsNotImplemented = errors.New("packinfo crcs are not implemented")
+
+	// ErrInvalidNumber is returned when a number read exceeds 0x7FFFFFFF
+	ErrInvalidNumber = errors.New("invalid number")
+)
+
+// ReadByte reads a single byte.
+func ReadByte(r io.Reader) (byte, error) {
+	var val [1]byte
+	_, err := r.Read(val[:])
+	return val[0], err
+}
+
+// ReadByteExpect reads a byte to be expected, errors if unexpected.
+func ReadByteExpect(r io.Reader, val byte) error {
+	value, err := ReadByte(r)
+	if err != nil {
+		return err
+	}
+	if value != val {
+		return ErrUnexpectedPropertyID
+	}
+	return nil
+}
+
+// ReadNumber reads a 7z encoded uint64.
+func ReadNumber(r io.Reader) (uint64, error) {
+	first, err := ReadByte(r)
+	if err != nil {
+		return 0, err
+	}
+
+	var value uint64
+	mask := byte(0x80)
+	for i := uint64(0); i < 8; i++ {
+		if first&mask == 0 {
+			hp := uint64(first) & (uint64(mask) - 1)
+			value += hp << (i * 8)
+			return value, nil
+		}
+
+		val, err := ReadByte(r)
+		if err != nil {
+			return 0, err
+		}
+
+		value |= uint64(val) << (8 * i)
+		mask >>= 1
+	}
+
+	return value, nil
+}
+
+// ReadNumberInt is the same as ReadNumber, but cast to int.
+func ReadNumberInt(r io.Reader) (int, error) {
+	u64, err := ReadNumber(r)
+	if u64 > MaxNumber {
+		return 0, ErrInvalidNumber
+	}
+
+	return int(u64), err
+}
+
+// ReadUint32 reads a uint32.
+func ReadUint32(r io.Reader) (uint32, error) {
+	var v uint32
+	return v, binary.Read(r, binary.LittleEndian, &v)
+}
+
+// ReadUint64 reads a uint64.
+func ReadUint64(r io.Reader) (uint64, error) {
+	var v uint64
+	return v, binary.Read(r, binary.LittleEndian, &v)
+}
+
+// ReadBoolVector reads a vector of boolean values.
+func ReadBoolVector(r io.Reader, length int) ([]bool, int, error) {
+	var b byte
+	var mask byte
+	var err error
+	v := make([]bool, length)
+
+	count := 0
+	for i := range v {
+		if mask == 0 {
+			b, err = ReadByte(r)
+			if err != nil {
+				return nil, 0, err
+			}
+			mask = 0x80
+		}
+		v[i] = (b & mask) != 0
+		mask >>= 1
+		if v[i] {
+			count++
+		}
+	}
+
+	return v, count, nil
+}
+
+// ReadOptionalBoolVector reads a vector of boolean values if they're available,
+// otherwise it returns an array of booleans all being true.
+func ReadOptionalBoolVector(r io.Reader, length int) ([]bool, int, error) {
+	allDefined, err := ReadByte(r)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	if allDefined == 0 {
+		return ReadBoolVector(r, length)
+	}
+
+	defined := make([]bool, length)
+	for i := range defined {
+		defined[i] = true
+	}
+
+	return defined, length, nil
+}
+
+// ReadNumberVector returns a vector of 7z encoded int64s.
+func ReadNumberVector(r io.Reader, numFiles int) ([]*int64, error) {
+	defined, _, err := ReadOptionalBoolVector(r, numFiles)
+	if err != nil {
+		return nil, err
+	}
+
+	external, err := ReadByte(r)
+	if err != nil {
+		return nil, err
+	}
+	if external != 0 {
+		return nil, ErrAdditionalStreamsNotImplemented
+	}
+
+	numbers := make([]*int64, numFiles)
+	for i := 0; i < numFiles; i++ {
+		if defined[i] {
+			num, err := ReadUint64(r)
+			if err != nil {
+				return nil, err
+			}
+
+			val := int64(num)
+			numbers[i] = &val
+		} else {
+			numbers[i] = nil
+		}
+	}
+
+	return numbers, err
+}
+
+// ReadDateTimeVector reads a vector of datetime values.
+func ReadDateTimeVector(r io.Reader, numFiles int) ([]time.Time, error) {
+	timestamps, err := ReadNumberVector(r, numFiles)
+	if err != nil {
+		return nil, err
+	}
+
+	times := make([]time.Time, len(timestamps))
+	for i := range times {
+		if timestamps[i] != nil {
+			nsec := *timestamps[i]
+			nsec -= 116444736000000000
+			nsec *= 100
+
+			times[i] = time.Unix(0, nsec)
+		}
+	}
+
+	return times, nil
+}
+
+// ReadAttributeVector reads a vector of uint32s.
+func ReadAttributeVector(r io.Reader, numFiles int) ([]uint32, error) {
+	defined, _, err := ReadOptionalBoolVector(r, numFiles)
+	if err != nil {
+		return nil, err
+	}
+
+	external, err := ReadByte(r)
+	if err != nil {
+		return nil, err
+	}
+	if external != 0 {
+		return nil, ErrAdditionalStreamsNotImplemented
+	}
+
+	attributes := make([]uint32, numFiles)
+	for i := range attributes {
+		if defined[i] {
+			val, err := ReadUint32(r)
+			if err != nil {
+				return nil, err
+			}
+
+			attributes[i] = val
+		}
+	}
+
+	return attributes, nil
+}

vendor/github.com/saracen/go7z/headers/streams_info.go

@@ -0,0 +1,143 @@
+package headers
+
+import (
+	"io"
+)
+
+// StreamsInfo is a top-level structure of the 7z format.
+type StreamsInfo struct {
+	PackInfo       *PackInfo
+	UnpackInfo     *UnpackInfo
+	SubStreamsInfo *SubStreamsInfo
+}
+
+// ReadStreamsInfo reads the streams info structure.
+func ReadStreamsInfo(r io.Reader) (*StreamsInfo, error) {
+	streamsInfo := &StreamsInfo{}
+
+	for {
+		id, err := ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+
+		switch id {
+		case k7zPackInfo:
+			if streamsInfo.PackInfo, err = ReadPackInfo(r); err != nil {
+				return nil, err
+			}
+
+		case k7zUnpackInfo:
+			if streamsInfo.UnpackInfo, err = ReadUnpackInfo(r); err != nil {
+				return nil, err
+			}
+
+		case k7zSubStreamsInfo:
+			if streamsInfo.UnpackInfo == nil {
+				return nil, ErrUnexpectedPropertyID
+			}
+
+			if streamsInfo.SubStreamsInfo, err = ReadSubStreamsInfo(r, streamsInfo.UnpackInfo); err != nil {
+				return nil, err
+			}
+
+		case k7zEnd:
+			if streamsInfo.PackInfo == nil || streamsInfo.UnpackInfo == nil {
+				return nil, ErrUnexpectedPropertyID
+			}
+
+			return streamsInfo, nil
+
+		default:
+			return nil, ErrUnexpectedPropertyID
+		}
+	}
+}
+
+// SubStreamsInfo is a structure found within the StreamsInfo structure.
+type SubStreamsInfo struct {
+	NumUnpackStreamsInFolders []int
+	UnpackSizes               []uint64
+	Digests                   []uint32
+}
+
+// ReadSubStreamsInfo reads the substreams info structure.
+func ReadSubStreamsInfo(r io.Reader, unpackInfo *UnpackInfo) (*SubStreamsInfo, error) {
+	id, err := ReadByte(r)
+	if err != nil {
+		return nil, err
+	}
+
+	subStreamInfo := &SubStreamsInfo{}
+	subStreamInfo.NumUnpackStreamsInFolders = make([]int, len(unpackInfo.Folders))
+	for i := range subStreamInfo.NumUnpackStreamsInFolders {
+		subStreamInfo.NumUnpackStreamsInFolders[i] = 1
+	}
+
+	if id == k7zNumUnpackStream {
+		for i := range subStreamInfo.NumUnpackStreamsInFolders {
+			if subStreamInfo.NumUnpackStreamsInFolders[i], err = ReadNumberInt(r); err != nil {
+				return nil, err
+			}
+		}
+
+		id, err = ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	for i := range unpackInfo.Folders {
+		if subStreamInfo.NumUnpackStreamsInFolders[i] == 0 {
+			continue
+		}
+
+		var sum uint64
+		if id == k7zSize {
+			for j := 1; j < subStreamInfo.NumUnpackStreamsInFolders[i]; j++ {
+				size, err := ReadNumber(r)
+				if err != nil {
+					return nil, err
+				}
+
+				sum += size
+				subStreamInfo.UnpackSizes = append(subStreamInfo.UnpackSizes, size)
+			}
+		}
+
+		subStreamInfo.UnpackSizes = append(subStreamInfo.UnpackSizes, unpackInfo.Folders[i].UnpackSize()-uint64(sum))
+	}
+
+	if id == k7zSize {
+		id, err = ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	numDigests := 0
+	for i := range unpackInfo.Folders {
+		numSubStreams := subStreamInfo.NumUnpackStreamsInFolders[i]
+		if numSubStreams > 1 || unpackInfo.Folders[i].UnpackCRC == 0 {
+			numDigests += int(numSubStreams)
+		}
+	}
+
+	if id == k7zCRC {
+		subStreamInfo.Digests, err = ReadDigests(r, numDigests)
+		if err != nil {
+			return nil, err
+		}
+
+		id, err = ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if id != k7zEnd {
+		return nil, ErrUnexpectedPropertyID
+	}
+
+	return subStreamInfo, nil
+}

vendor/github.com/saracen/go7z/headers/unpack_info.go

@@ -0,0 +1,89 @@
+package headers
+
+import (
+	"errors"
+	"io"
+)
+
+const MaxFolderCount = 1 << 30
+
+// ErrInvalidCountExceeded is returned when the folder count is
+// < 0 || > MaxFolderCount
+var ErrInvalidCountExceeded = errors.New("invalid folder count")
+
+// UnpackInfo is a structure containing folders.
+type UnpackInfo struct {
+	Folders []*Folder
+}
+
+// ReadUnpackInfo reads unpack info structures.
+func ReadUnpackInfo(r io.Reader) (*UnpackInfo, error) {
+	err := ReadByteExpect(r, k7zFolder)
+	if err != nil {
+		return nil, err
+	}
+
+	numFolders, err := ReadNumberInt(r)
+	if err != nil {
+		return nil, err
+	}
+	if numFolders > MaxFolderCount {
+		return nil, ErrInvalidCountExceeded
+	}
+
+	unpackInfo := &UnpackInfo{}
+	external, err := ReadByte(r)
+	if err != nil {
+		return nil, err
+	}
+
+	switch external {
+	case 0:
+		unpackInfo.Folders = make([]*Folder, numFolders)
+		for i := range unpackInfo.Folders {
+			if unpackInfo.Folders[i], err = ReadFolder(r); err != nil {
+				return nil, err
+			}
+		}
+
+	default:
+		return nil, ErrAdditionalStreamsNotImplemented
+	}
+
+	if err = ReadByteExpect(r, k7zCodersUnpackSize); err != nil {
+		return nil, err
+	}
+	for _, folder := range unpackInfo.Folders {
+		folder.UnpackSizes = make([]uint64, folder.NumOutStreamsTotal())
+		for i := range folder.UnpackSizes {
+			if folder.UnpackSizes[i], err = ReadNumber(r); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	id, err := ReadByte(r)
+	if err != nil {
+		return nil, err
+	}
+	if id == k7zCRC {
+		crcs, err := ReadDigests(r, len(unpackInfo.Folders))
+		if err != nil {
+			return nil, err
+		}
+		for i := range unpackInfo.Folders {
+			unpackInfo.Folders[i].UnpackCRC = crcs[i]
+		}
+
+		id, err = ReadByte(r)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if id != k7zEnd {
+		return nil, ErrUnexpectedPropertyID
+	}
+
+	return unpackInfo, nil
+}

vendor/github.com/saracen/go7z/reader.go

@@ -0,0 +1,377 @@
+package go7z
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"hash/crc32"
+	"io"
+	"os"
+	"sync"
+
+	"github.com/saracen/go7z/headers"
+	"github.com/saracen/solidblock"
+)
+
+var (
+	// ErrNotSupported is returned when an unrecognized archive format is
+	// encountered.
+	ErrNotSupported = errors.New("not supported")
+
+	// ErrDecompressorNotFound is returned when a requested decompressor has not
+	// been registered.
+	ErrDecompressorNotFound = errors.New("decompressor not found")
+)
+
+// Reader is a 7z archive reader.
+type Reader struct {
+	r   *io.SectionReader
+	err error
+
+	header *headers.Header
+
+	folderIndex int
+	fileIndex   int
+	emptyStream bool
+
+	folders []*folderReader
+
+	Options ReaderOptions
+}
+
+// ReaderOptions are optional options to configure a 7z archive reader.
+type ReaderOptions struct {
+	password string
+	cb       func() string
+}
+
+// SetPassword sets the password used for extraction.
+func (o *ReaderOptions) SetPassword(password string) {
+	o.password = password
+}
+
+// SetPasswordCallback sets the callback thats used if a password is required,
+// but wasn't supplied with SetPassword()
+func (o *ReaderOptions) SetPasswordCallback(cb func() string) {
+	o.cb = cb
+}
+
+// Password returns the set password. This will call the password callback
+// supplied to SetPasswordCallback() if no password is set.
+func (o *ReaderOptions) Password() string {
+	if o.password != "" {
+		return o.password
+	}
+	if o.cb != nil {
+		o.password = o.cb()
+	}
+	return o.password
+}
+
+// ReadCloser provides an io.ReadCloser for the archive when opened with
+// OpenReader.
+type ReadCloser struct {
+	f *os.File
+	Reader
+}
+
+// Close closes the 7z file, rendering it unusable for I/O.
+func (rc *ReadCloser) Close() error {
+	return rc.f.Close()
+}
+
+// OpenReader will open the 7z file specified by name and return a ReadCloser.
+func OpenReader(name string) (*ReadCloser, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+
+	fi, err := f.Stat()
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+
+	r := new(ReadCloser)
+	if err := r.init(f, fi.Size(), false); err != nil {
+		f.Close()
+		return nil, err
+	}
+	r.f = f
+
+	return r, nil
+}
+
+// NewReader returns a new Reader reading from r, which is assumed to
+// have the given size in bytes.
+func NewReader(r io.ReaderAt, size int64) (*Reader, error) {
+	szr := new(Reader)
+	if err := szr.init(r, size, false); err != nil {
+		return nil, err
+	}
+	return szr, nil
+}
+
+func (sz *Reader) init(r io.ReaderAt, size int64, ignoreChecksumError bool) error {
+	sz.r = io.NewSectionReader(r, 0, size)
+	signatureHeader, err := headers.ReadSignatureHeader(sz.r)
+	if err != nil {
+		if !(ignoreChecksumError && err == headers.ErrChecksumMismatch) {
+			return err
+		}
+	}
+	if _, err := sz.r.Seek(signatureHeader.StartHeader.NextHeaderOffset, io.SeekCurrent); err != nil {
+		return err
+	}
+
+	if signatureHeader.StartHeader.NextHeaderSize > size-headers.SignatureHeaderSize {
+		return io.ErrUnexpectedEOF
+	}
+
+	crc := crc32.NewIEEE()
+	tee := io.TeeReader(bufio.NewReader(io.LimitReader(sz.r, signatureHeader.StartHeader.NextHeaderSize)), crc)
+
+	header, encoded, err := headers.ReadPackedStreamsForHeaders(&io.LimitedReader{tee, signatureHeader.StartHeader.NextHeaderSize})
+	if err != nil {
+		return err
+	}
+	if crc.Sum32() != signatureHeader.StartHeader.NextHeaderCRC {
+		if !ignoreChecksumError {
+			return headers.ErrChecksumMismatch
+		}
+	}
+
+	if encoded != nil {
+		folders, err := sz.extract(encoded)
+		if err != nil {
+			return err
+		}
+		if len(folders) != 1 {
+			return ErrNotSupported
+		}
+		if err = folders[0].Next(); err != nil {
+			return err
+		}
+
+		header, _, err = headers.ReadPackedStreamsForHeaders(&io.LimitedReader{folders[0].sb, folders[0].sb.Size()})
+		if err != nil {
+			return err
+		}
+
+		if err = folders[0].Next(); err != io.EOF {
+			return ErrNotSupported
+		}
+	}
+
+	if header == nil {
+		return ErrNotSupported
+	}
+	sz.header = header
+	sz.folders, err = sz.extract(sz.header.MainStreamsInfo)
+
+	return err
+}
+
+// Next advances to the next entry in the 7z archive.
+//
+// io.EOF is returned at the end of the input.
+func (sz *Reader) Next() (*headers.FileInfo, error) {
+	if sz.err != nil {
+		return nil, sz.err
+	}
+	hdr, err := sz.next()
+	sz.err = err
+	return hdr, err
+}
+
+func (sz *Reader) nextFileInfo() *headers.FileInfo {
+	var fileInfo *headers.FileInfo
+	if sz.fileIndex < len(sz.header.FilesInfo) {
+		fileInfo = sz.header.FilesInfo[sz.fileIndex]
+		sz.fileIndex++
+		return fileInfo
+	}
+
+	return nil
+}
+
+func (sz *Reader) extract(streamsInfo *headers.StreamsInfo) ([]*folderReader, error) {
+	var sizes []uint64
+	var crcs []uint32
+	if streamsInfo.SubStreamsInfo != nil {
+		sizes = streamsInfo.SubStreamsInfo.UnpackSizes
+		crcs = streamsInfo.SubStreamsInfo.Digests
+	}
+
+	offset := int64(headers.SignatureHeaderSize)
+	offset += int64(streamsInfo.PackInfo.PackPos)
+	packedIndicesOffset := 0
+
+	var folders []*folderReader
+	for i, folder := range streamsInfo.UnpackInfo.Folders {
+		if len(folder.PackedIndices) == 0 {
+			folder.PackedIndices = []int{0}
+		}
+
+		fr := &folderReader{}
+		fr.inputs = make(map[int]io.Reader)
+		fr.binder = solidblock.Binder{}
+
+		// setup codecs
+		for j := range folder.CoderInfo {
+			coderInfo := folder.CoderInfo[j]
+			size := folder.UnpackSizes[j]
+
+			d := decompressor(coderInfo.CodecID)
+			if d == nil {
+				return folders, ErrDecompressorNotFound
+			}
+
+			fn := func(in []io.Reader) ([]io.Reader, error) {
+				r, err := d(in, coderInfo.Properties, size, &sz.Options)
+
+				return []io.Reader{r}, err
+			}
+
+			fr.binder.AddCodec(fn, coderInfo.NumInStreams, coderInfo.NumOutStreams)
+		}
+
+		// setup initial inputs
+		for index, input := range folder.PackedIndices {
+			if packedIndicesOffset+index >= len(streamsInfo.PackInfo.PackSizes) {
+				return nil, fmt.Errorf("folder references invalid packinfo")
+			}
+
+			size := int64(streamsInfo.PackInfo.PackSizes[packedIndicesOffset+index])
+			fr.inputs[input] = io.NewSectionReader(sz.r, offset, size)
+			offset += size
+		}
+		packedIndicesOffset += len(folder.PackedIndices)
+
+		// setup pairs
+		for _, bindPairsInfo := range folder.BindPairsInfo {
+			fr.binder.Pair(bindPairsInfo.InIndex, bindPairsInfo.OutIndex)
+		}
+
+		if streamsInfo.SubStreamsInfo != nil {
+			numUnpackStreamsInFolders := streamsInfo.SubStreamsInfo.NumUnpackStreamsInFolders
+			if i >= len(numUnpackStreamsInFolders) {
+				return nil, fmt.Errorf("folder references invalid unpack stream")
+			}
+
+			off := numUnpackStreamsInFolders[i]
+			if off > len(sizes) || off > len(crcs) {
+				return nil, fmt.Errorf("folder references invalid unpack size or digest")
+			}
+
+			fr.sizes = sizes[:off]
+			fr.crcs = crcs[:off]
+			sizes = sizes[len(fr.sizes):]
+			crcs = crcs[len(fr.crcs):]
+		} else {
+			fr.sizes = []uint64{folder.UnpackSize()}
+			fr.crcs = []uint32{folder.UnpackCRC}
+		}
+
+		folders = append(folders, fr)
+	}
+
+	return folders, nil
+}
+
+type folderReader struct {
+	binder solidblock.Binder
+	sizes  []uint64
+	crcs   []uint32
+
+	inputs map[int]io.Reader
+
+	bufs []*bufio.Reader
+
+	sb *solidblock.Solidblock
+}
+
+var bufioReaderPool = sync.Pool{
+	New: func() interface{} {
+		return bufio.NewReaderSize(nil, 32*1024)
+	},
+}
+
+func (fr *folderReader) Next() error {
+	if fr.sb == nil {
+
+		fr.bufs = make([]*bufio.Reader, 0, len(fr.inputs))
+		for in, r := range fr.inputs {
+			br := bufioReaderPool.Get().(*bufio.Reader)
+			br.Reset(r)
+			fr.bufs = append(fr.bufs, br)
+
+			fr.binder.Reader(br, in)
+		}
+
+		outputs, err := fr.binder.Outputs()
+		if err != nil {
+			return err
+		}
+		if len(outputs) != 1 {
+			return ErrNotSupported
+		}
+		if outputs[0] == nil {
+			return ErrNotSupported
+		}
+
+		fr.sb = solidblock.New(outputs[0], fr.sizes, fr.crcs)
+	}
+
+	return fr.sb.Next()
+}
+
+func (fr *folderReader) Close() error {
+	for _, buf := range fr.bufs {
+		bufioReaderPool.Put(buf)
+	}
+	fr.bufs = nil
+	return nil
+}
+
+func (sz *Reader) next() (*headers.FileInfo, error) {
+	fileInfo := sz.nextFileInfo()
+	if fileInfo == nil {
+		return nil, io.EOF
+	}
+
+	sz.emptyStream = fileInfo.IsEmptyStream
+	if sz.emptyStream {
+		return fileInfo, nil
+	}
+
+	if sz.folders[sz.folderIndex].Next() == io.EOF {
+		sz.folders[sz.folderIndex].Close()
+		sz.folderIndex++
+		if sz.folderIndex >= len(sz.folders) {
+			return nil, io.EOF
+		}
+		sz.folders[sz.folderIndex].Next()
+	}
+
+	return fileInfo, nil
+}
+
+// Read reads from the current file in the 7z archive.
+// It returns (0, io.EOF) when it reaches the end of that file,
+// until Next is called to advance to the next file.
+func (sz *Reader) Read(p []byte) (int, error) {
+	if sz.err != nil {
+		return 0, sz.err
+	}
+	if sz.emptyStream {
+		return 0, io.EOF
+	}
+
+	n, err := sz.folders[sz.folderIndex].sb.Read(p)
+	if err != nil && err != io.EOF {
+		sz.err = err
+	}
+	return n, err
+}

vendor/github.com/saracen/go7z/register.go

@@ -0,0 +1,129 @@
+package go7z
+
+import (
+	"bytes"
+	"compress/bzip2"
+	"compress/flate"
+	"encoding/binary"
+	"io"
+	"sync"
+
+	"github.com/saracen/go7z/filters"
+	"github.com/ulikunitz/xz/lzma"
+)
+
+// Decompressor is a handler function called when a registered decompressor is
+// initialized.
+type Decompressor func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error)
+
+var (
+	decompressors sync.Map // map[uint32]Decompressor
+)
+
+func init() {
+	// copy
+	RegisterDecompressor(0x00, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 1 {
+			return nil, ErrNotSupported
+		}
+		return r[0], nil
+	}))
+
+	// delta
+	RegisterDecompressor(0x03, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 1 || len(options) == 0 || len(options) > 1 {
+			return nil, ErrNotSupported
+		}
+
+		return filters.NewDeltaDecoder(r[0], uint(options[0])+1, int64(unpackSize))
+	}))
+
+	// lzma
+	RegisterDecompressor(0x030101, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 1 {
+			return nil, ErrNotSupported
+		}
+
+		// We can't set options in the lzma decoder library, so instead we add
+		// a fake header
+		header := bytes.NewBuffer(options)
+		binary.Write(header, binary.LittleEndian, unpackSize)
+
+		return lzma.NewReader(io.MultiReader(header, r[0]))
+	}))
+
+	// lzma2
+	RegisterDecompressor(0x21, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 1 {
+			return nil, ErrNotSupported
+		}
+
+		config := lzma.Reader2Config{}
+		if len(options) > 0 {
+			config.DictCap = int(2 | (options[0] & 1))
+			config.DictCap <<= (options[0] >> 1) + 11
+		}
+
+		return config.NewReader2(r[0])
+	}))
+
+	// bcj2
+	RegisterDecompressor(0x303011b, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 4 {
+			return nil, ErrNotSupported
+		}
+		return filters.NewBCJ2Decoder(r[0], r[1], r[2], r[3], int64(unpackSize))
+	}))
+
+	// deflate
+	RegisterDecompressor(0x40108, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 1 {
+			return nil, ErrNotSupported
+		}
+		return flate.NewReader(r[0]), nil
+	}))
+
+	// bzip2
+	RegisterDecompressor(0x40202, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 1 {
+			return nil, ErrNotSupported
+		}
+
+		return bzip2.NewReader(r[0]), nil
+	}))
+
+	// AES
+	RegisterDecompressor(0x6f10701, Decompressor(func(r []io.Reader, options []byte, unpackSize uint64, ro *ReaderOptions) (io.Reader, error) {
+		if len(r) != 1 {
+			return nil, ErrNotSupported
+		}
+		if len(options) < 2 {
+			return nil, ErrNotSupported
+		}
+
+		saltSize := ((options[0] >> 7) & 1) + (options[1] >> 4)
+		ivSize := ((options[0] >> 6) & 1) + (options[1] & 0x0F)
+		power := int(options[0]) & 0x3f
+
+		options = options[2:]
+		salt := options[:saltSize]
+		iv := options[saltSize : saltSize+ivSize]
+
+		return filters.NewAESDecrypter(r[0], power, salt, iv, ro.Password())
+	}))
+}
+
+// RegisterDecompressor registers a decompressor.
+func RegisterDecompressor(method uint32, dcomp Decompressor) {
+	if _, dup := decompressors.LoadOrStore(method, dcomp); dup {
+		panic("decompressor already registered")
+	}
+}
+
+func decompressor(method uint32) Decompressor {
+	di, ok := decompressors.Load(method)
+	if !ok {
+		return nil
+	}
+	return di.(Decompressor)
+}

vendor/github.com/saracen/solidblock/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Arran Walker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/saracen/solidblock/README.md

@@ -0,0 +1,159 @@
+# Solidblock
+
+Solidblock is a Go library providing `io.Reader`s for solid compression and
+codec binding/chaining.
+
+## Solid Compression Reader
+
+Wrapped around a compressed solid block of concatenated files, it provides
+sequential access to the files:
+```
+// file contents
+files := [][]byte{
+    []byte("file 1\n"),
+    []byte("file 2\n"),
+}
+
+// file metadata
+var metadata struct {
+    sizes []uint64
+    crcs  []uint32
+}
+metadata.sizes = []uint64{
+    uint64(len(files[0])),
+    uint64(len(files[1])),
+}
+metadata.crcs = []uint32{
+    crc32.ChecksumIEEE(files[0]),
+    crc32.ChecksumIEEE(files[1]),
+}
+
+// Concatenate files to compressed block
+block := new(bytes.Buffer)
+w := gzip.NewWriter(block)
+w.Write(files[0])
+w.Write(files[1])
+w.Close()
+
+// Open gzip reader to compressed block
+r, err := gzip.NewReader(block)
+if err != nil {
+    panic(err)
+}
+
+// Create a new solidblock reader
+s := solidblock.New(r, metadata.sizes, metadata.crcs)
+
+for {
+    err := s.Next()
+    if err == io.EOF {
+        break
+    }
+    if err != nil {
+        panic(err)
+    }
+
+    io.Copy(os.Stdout, s)
+}
+```
+
+## Codec Binding
+
+To improve compression, some codecs (such as BCJ2), split data up into multiple
+streams that compress better individually. `solidblock.Binder` provides a simple
+way to pair together the inputs and outputs of various codecs/readers.
+
+For example:
+
+```
+func BCJ2Decoder(inputs []io.Reader) ([]io.Reader, error) {
+    // 1. take 4 input readers
+    // 2. do magic
+    // 3. return 1 reader
+}
+
+func GzipDecoder(inputs []io.Reader) ([]io.Reader, error) {
+    if len(inputs) != 1 {
+        panic("unsupported input configuration")
+    }
+    r, err := gzip.NewReader(inputs[0])
+    return []io.Reader{r}, nil
+}
+
+file, err := os.Open("file")
+if err != nil {
+    panic(err)
+}
+
+// Assume file has 4 concatenated streams. 3 of the streams are from a BCJ2 
+// encoder, compressed to gzip streams. 1 is the 4th stream of the BCJ2 encoder,
+// but left uncompressed.
+streams := make([]io.Reader, 4)
+streams[0] = io.NewSectionReader(file, 0, 100)
+streams[1] = io.NewSectionReader(file, 101, 200)
+streams[2] = io.NewSectionReader(file, 201, 300)
+streams[3] = io.NewSectionReader(file, 301, 400)
+
+// Create a new binder
+binder := solidblock.NewBinder()
+
+// Create gzip decompressors for the 4 initial input streams.
+gzip0InputIDs, gzip0OutputIDs := binder.AddCodec(GzipDecoder, 1, 1)
+gzip1InputIDs, gzip1OutputIDs := binder.AddCodec(GzipDecoder, 1, 1)
+gzip2InputIDs, gzip2OutputIDs := binder.AddCodec(GzipDecoder, 1, 1)
+
+// Create BCJ2 decoder for the 4 gzip decoded streams.
+bcj2InputIDs, bcj2outputIDs := binder.AddCodec(BCJ2Decoder, 4, 1)
+
+// Connect initial streams to gzip decoders
+binder.Reader(streams[0], gzip0InputIDs[0])
+binder.Reader(streams[1], gzip1InputIDs[0])
+binder.Reader(streams[2], gzip2InputIDs[0])
+
+// Connect 4th initial stream straight to 4th input of BCJ2 decoder.
+binder.Reader(streams[3], bcj2InputIDs[3])
+
+// Pair the 3 gzip output streams to the 1st, 2nd, 3rd input of BCJ2 decoder.
+binder.Pair(gzip0OutputIDs[0], bcj2InputIDs[0])
+binder.Pair(gzip1OutputIDs[0], bcj2InputIDs[1])
+binder.Pair(gzip2OutputIDs[0], bcj2InputIDs[2])
+
+// Create single output to read from
+outputs, err := binder.Outputs()
+if err != nil {
+    panic(err)
+}
+if len(outputs) != 1 {
+    panic("output should only contain one stream")
+}
+
+io.Copy(os.Stdout, outputs[0])
+```
+
+A picture says 60 lines of code...
+```      
+                                        +------------+
+   concatenated file                    |bcj2 decoder+--->io.Reader
++--------------------+                  +-+--+--+--+-+
+|                    |                    ^  ^  ^  ^
+|  +--------------+  |   +------------+   |  |  |  |
+|  |gzipped stream+------>gzip decoder+---+  |  |  |
+|  +--------------+  |   +------------+      |  |  |
+|                    |                       |  |  |
+|  +--------------+  |   +------------+      |  |  |
+|  |gzipped stream+------>gzip decoder+------+  |  |
+|  +--------------+  |   +------------+         |  |
+|                    |                          |  |
+|  +--------------+  |   +------------+         |  |
+|  |gzipped stream+------>gzip decoder+---------+  |
+|  +--------------+  |   +------------+            |
+|                    |                             |
+|  +--------------+  |                             |
+|  | uncompressed +--------------------------------+
+|  |    stream    |  |
+|  +--------------+  |
+|                    |
++--------------------+
+
+```
+

vendor/github.com/saracen/solidblock/binder.go

@@ -0,0 +1,123 @@
+package solidblock
+
+import (
+	"errors"
+	"fmt"
+	"io"
+)
+
+var (
+	// ErrInputIsUnbound is returned when an input hasn't been binded to either
+	// a reader/paired without an output.
+	ErrInputIsUnbound = errors.New("input is unbound")
+
+	// ErrUnexpectedOutputCount is returned when the amount of io.Readers
+	// returned from a codec handler doesn't match the amount specified when
+	// adding the codec.
+	ErrUnexpectedOutputCount = errors.New("unexpected output count")
+)
+
+type reader struct {
+	Name string
+	R    io.Reader
+}
+
+type codec struct {
+	fn func([]io.Reader) ([]io.Reader, error)
+
+	inIndexes  []int
+	outIndexes []int
+}
+
+// Binder holds information regarding codecs, their inputs/outputs and how they
+// join together.
+type Binder struct {
+	numInStreams  int
+	numOutStreams int
+
+	in  []*reader
+	out []*reader
+
+	codecs []*codec
+}
+
+// NewBinder returns a new binder.
+func NewBinder() *Binder {
+	return &Binder{}
+}
+
+// AddCodec adds a handler function for processing information from input(s) and
+// producing output(s).
+func (b *Binder) AddCodec(fn func([]io.Reader) ([]io.Reader, error), inputs, outputs int) (in, out []int) {
+	c := &codec{fn: fn}
+	b.in = append(b.in, make([]*reader, inputs)...)
+	b.out = append(b.out, make([]*reader, outputs)...)
+
+	for i := 0; i < inputs; i++ {
+		c.inIndexes = append(c.inIndexes, b.numInStreams+i)
+	}
+	for i := 0; i < outputs; i++ {
+		c.outIndexes = append(c.outIndexes, b.numOutStreams+i)
+	}
+
+	b.numInStreams += inputs
+	b.numOutStreams += outputs
+
+	b.codecs = append(b.codecs, c)
+
+	return c.inIndexes, c.outIndexes
+}
+
+// Reader binds a reader to an in stream.
+func (b *Binder) Reader(r io.Reader, in int) {
+	if in < 0 || in >= len(b.in) {
+		return
+	}
+	b.in[in] = &reader{fmt.Sprintf("In: %v", in), r}
+}
+
+// Pair pairs two streams, binding an in stream to an out stream.
+func (b *Binder) Pair(in int, out int) {
+	if in < 0 || in >= len(b.in) || out < 0 || out >= len(b.out) {
+		return
+	}
+
+	if b.out[out] == nil {
+		b.out[out] = &reader{fmt.Sprintf("Bind %v:%v", in, out), nil}
+	}
+
+	b.in[in] = b.out[out]
+}
+
+// Outputs returns any unbound output readers to ready from.
+func (b *Binder) Outputs() ([]io.Reader, error) {
+	var unbound []io.Reader
+
+	for i := range b.codecs {
+		var ins []io.Reader
+		for _, num := range b.codecs[i].inIndexes {
+			if b.in[num] == nil || b.in[num].R == nil {
+				return unbound, ErrInputIsUnbound
+			}
+			ins = append(ins, b.in[num].R)
+		}
+
+		outs, err := b.codecs[i].fn(ins)
+		if err != nil {
+			return nil, err
+		}
+
+		if len(outs) != len(b.codecs[i].outIndexes) {
+			return unbound, ErrUnexpectedOutputCount
+		}
+		for j, num := range b.codecs[i].outIndexes {
+			if b.out[num] == nil {
+				b.out[num] = &reader{fmt.Sprintf("Out %v", outs), nil}
+				unbound = append(unbound, outs[j])
+			}
+			b.out[num].R = outs[j]
+		}
+	}
+
+	return unbound, nil
+}

vendor/github.com/saracen/solidblock/solidblock.go

@@ -0,0 +1,100 @@
+package solidblock
+
+import (
+	"errors"
+	"hash"
+	"hash/crc32"
+	"io"
+	"io/ioutil"
+)
+
+var (
+	// ErrChecksumMismatch is returned when a file's crc check fails.
+	ErrChecksumMismatch = errors.New("checksum mismatch")
+)
+
+// Solidblock provides sequential access to files that have been concatenated
+// into a single compressed data block.
+type Solidblock struct {
+	sizes []uint64
+	crcs  []uint32
+
+	base io.Reader
+	file io.Reader
+	crc  hash.Hash32
+
+	target int
+	index  int
+}
+
+// New returns a new solidblock reader.
+func New(r io.Reader, sizes []uint64, crcs []uint32) *Solidblock {
+	if len(sizes) != len(crcs) {
+		panic("crcs slice needs to be the same length as sizes slice")
+	}
+
+	return &Solidblock{
+		sizes:  sizes,
+		crcs:   crcs,
+		target: -1,
+		base:   r,
+	}
+}
+
+// Next advances to the next file entry in solid block.
+//
+// Calling Next without reading the current file is supported. Only when Read
+// is called will decompression occur for current file. Any skipped files will
+// still need to be decompressed, but their contents is discarded.
+//
+// io.EOF is returned at the end of the input.
+func (fr *Solidblock) Next() error {
+	if fr.target < len(fr.sizes)-1 {
+		fr.target++
+		return nil
+	}
+	return io.EOF
+}
+
+// Read reads from the current file in solid block.
+// It returns (0, io.EOF) when it reaches the end of that file,
+// until Next is called to advance to the next file.
+func (fr *Solidblock) Read(p []byte) (int, error) {
+	if fr.file != nil && fr.index != fr.target {
+		// drain current fileReader
+		_, err := io.Copy(ioutil.Discard, fr.file)
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	if fr.file == nil || fr.index != fr.target {
+		// discard until we're at the position we want to be at
+		for i := fr.index + 1; i < fr.target; i++ {
+			_, err := io.CopyN(ioutil.Discard, fr.base, int64(fr.sizes[i]))
+			if err != nil {
+				return 0, err
+			}
+		}
+
+		fr.crc = crc32.NewIEEE()
+		fr.file = io.TeeReader(io.LimitReader(fr.base, int64(fr.sizes[fr.target])), fr.crc)
+		fr.index = fr.target
+	}
+
+	n, err := fr.file.Read(p)
+	if err == io.EOF {
+		if fr.crc.Sum32() != fr.crcs[fr.index] {
+			return n, ErrChecksumMismatch
+		}
+	}
+
+	return n, err
+}
+
+func (fr *Solidblock) Size() int64 {
+	if fr.target < 0 {
+		return 0
+	}
+	return int64(fr.sizes[fr.target])
+}

vendor/github.com/ulikunitz/xz/LICENSE

@@ -0,0 +1,26 @@
+Copyright (c) 2014-2021  Ulrich Kunitz
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* My name, Ulrich Kunitz, may not be used to endorse or promote products
+  derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/ulikunitz/xz/internal/hash/cyclic_poly.go

@@ -0,0 +1,181 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hash
+
+// CyclicPoly provides a cyclic polynomial rolling hash.
+type CyclicPoly struct {
+	h uint64
+	p []uint64
+	i int
+}
+
+// ror rotates the unsigned 64-bit integer to right. The argument s must be
+// less than 64.
+func ror(x uint64, s uint) uint64 {
+	return (x >> s) | (x << (64 - s))
+}
+
+// NewCyclicPoly creates a new instance of the CyclicPoly structure. The
+// argument n gives the number of bytes for which a hash will be executed.
+// This number must be positive; the method panics if this isn't the case.
+func NewCyclicPoly(n int) *CyclicPoly {
+	if n < 1 {
+		panic("argument n must be positive")
+	}
+	return &CyclicPoly{p: make([]uint64, 0, n)}
+}
+
+// Len returns the length of the byte sequence for which a hash is generated.
+func (r *CyclicPoly) Len() int {
+	return cap(r.p)
+}
+
+// RollByte hashes the next byte and returns a hash value. The complete becomes
+// available after at least Len() bytes have been hashed.
+func (r *CyclicPoly) RollByte(x byte) uint64 {
+	y := hash[x]
+	if len(r.p) < cap(r.p) {
+		r.h = ror(r.h, 1) ^ y
+		r.p = append(r.p, y)
+	} else {
+		r.h ^= ror(r.p[r.i], uint(cap(r.p)-1))
+		r.h = ror(r.h, 1) ^ y
+		r.p[r.i] = y
+		r.i = (r.i + 1) % cap(r.p)
+	}
+	return r.h
+}
+
+// Stores the hash for the individual bytes.
+var hash = [256]uint64{
+	0x2e4fc3f904065142, 0xc790984cfbc99527,
+	0x879f95eb8c62f187, 0x3b61be86b5021ef2,
+	0x65a896a04196f0a5, 0xc5b307b80470b59e,
+	0xd3bff376a70df14b, 0xc332f04f0b3f1701,
+	0x753b5f0e9abf3e0d, 0xb41538fdfe66ef53,
+	0x1906a10c2c1c0208, 0xfb0c712a03421c0d,
+	0x38be311a65c9552b, 0xfee7ee4ca6445c7e,
+	0x71aadeded184f21e, 0xd73426fccda23b2d,
+	0x29773fb5fb9600b5, 0xce410261cd32981a,
+	0xfe2848b3c62dbc2d, 0x459eaaff6e43e11c,
+	0xc13e35fc9c73a887, 0xf30ed5c201e76dbc,
+	0xa5f10b3910482cea, 0x2945d59be02dfaad,
+	0x06ee334ff70571b5, 0xbabf9d8070f44380,
+	0xee3e2e9912ffd27c, 0x2a7118d1ea6b8ea7,
+	0x26183cb9f7b1664c, 0xea71dac7da068f21,
+	0xea92eca5bd1d0bb7, 0x415595862defcd75,
+	0x248a386023c60648, 0x9cf021ab284b3c8a,
+	0xfc9372df02870f6c, 0x2b92d693eeb3b3fc,
+	0x73e799d139dc6975, 0x7b15ae312486363c,
+	0xb70e5454a2239c80, 0x208e3fb31d3b2263,
+	0x01f563cabb930f44, 0x2ac4533d2a3240d8,
+	0x84231ed1064f6f7c, 0xa9f020977c2a6d19,
+	0x213c227271c20122, 0x09fe8a9a0a03d07a,
+	0x4236dc75bcaf910c, 0x460a8b2bead8f17e,
+	0xd9b27be1aa07055f, 0xd202d5dc4b11c33e,
+	0x70adb010543bea12, 0xcdae938f7ea6f579,
+	0x3f3d870208672f4d, 0x8e6ccbce9d349536,
+	0xe4c0871a389095ae, 0xf5f2a49152bca080,
+	0x9a43f9b97269934e, 0xc17b3753cb6f475c,
+	0xd56d941e8e206bd4, 0xac0a4f3e525eda00,
+	0xa06d5a011912a550, 0x5537ed19537ad1df,
+	0xa32fe713d611449d, 0x2a1d05b47c3b579f,
+	0x991d02dbd30a2a52, 0x39e91e7e28f93eb0,
+	0x40d06adb3e92c9ac, 0x9b9d3afde1c77c97,
+	0x9a3f3f41c02c616f, 0x22ecd4ba00f60c44,
+	0x0b63d5d801708420, 0x8f227ca8f37ffaec,
+	0x0256278670887c24, 0x107e14877dbf540b,
+	0x32c19f2786ac1c05, 0x1df5b12bb4bc9c61,
+	0xc0cac129d0d4c4e2, 0x9fdb52ee9800b001,
+	0x31f601d5d31c48c4, 0x72ff3c0928bcaec7,
+	0xd99264421147eb03, 0x535a2d6d38aefcfe,
+	0x6ba8b4454a916237, 0xfa39366eaae4719c,
+	0x10f00fd7bbb24b6f, 0x5bd23185c76c84d4,
+	0xb22c3d7e1b00d33f, 0x3efc20aa6bc830a8,
+	0xd61c2503fe639144, 0x30ce625441eb92d3,
+	0xe5d34cf359e93100, 0xa8e5aa13f2b9f7a5,
+	0x5c2b8d851ca254a6, 0x68fb6c5e8b0d5fdf,
+	0xc7ea4872c96b83ae, 0x6dd5d376f4392382,
+	0x1be88681aaa9792f, 0xfef465ee1b6c10d9,
+	0x1f98b65ed43fcb2e, 0x4d1ca11eb6e9a9c9,
+	0x7808e902b3857d0b, 0x171c9c4ea4607972,
+	0x58d66274850146df, 0x42b311c10d3981d1,
+	0x647fa8c621c41a4c, 0xf472771c66ddfedc,
+	0x338d27e3f847b46b, 0x6402ce3da97545ce,
+	0x5162db616fc38638, 0x9c83be97bc22a50e,
+	0x2d3d7478a78d5e72, 0xe621a9b938fd5397,
+	0x9454614eb0f81c45, 0x395fb6e742ed39b6,
+	0x77dd9179d06037bf, 0xc478d0fee4d2656d,
+	0x35d9d6cb772007af, 0x83a56e92c883f0f6,
+	0x27937453250c00a1, 0x27bd6ebc3a46a97d,
+	0x9f543bf784342d51, 0xd158f38c48b0ed52,
+	0x8dd8537c045f66b4, 0x846a57230226f6d5,
+	0x6b13939e0c4e7cdf, 0xfca25425d8176758,
+	0x92e5fc6cd52788e6, 0x9992e13d7a739170,
+	0x518246f7a199e8ea, 0xf104c2a71b9979c7,
+	0x86b3ffaabea4768f, 0x6388061cf3e351ad,
+	0x09d9b5295de5bbb5, 0x38bf1638c2599e92,
+	0x1d759846499e148d, 0x4c0ff015e5f96ef4,
+	0xa41a94cfa270f565, 0x42d76f9cb2326c0b,
+	0x0cf385dd3c9c23ba, 0x0508a6c7508d6e7a,
+	0x337523aabbe6cf8d, 0x646bb14001d42b12,
+	0xc178729d138adc74, 0xf900ef4491f24086,
+	0xee1a90d334bb5ac4, 0x9755c92247301a50,
+	0xb999bf7c4ff1b610, 0x6aeeb2f3b21e8fc9,
+	0x0fa8084cf91ac6ff, 0x10d226cf136e6189,
+	0xd302057a07d4fb21, 0x5f03800e20a0fcc3,
+	0x80118d4ae46bd210, 0x58ab61a522843733,
+	0x51edd575c5432a4b, 0x94ee6ff67f9197f7,
+	0x765669e0e5e8157b, 0xa5347830737132f0,
+	0x3ba485a69f01510c, 0x0b247d7b957a01c3,
+	0x1b3d63449fd807dc, 0x0fdc4721c30ad743,
+	0x8b535ed3829b2b14, 0xee41d0cad65d232c,
+	0xe6a99ed97a6a982f, 0x65ac6194c202003d,
+	0x692accf3a70573eb, 0xcc3c02c3e200d5af,
+	0x0d419e8b325914a3, 0x320f160f42c25e40,
+	0x00710d647a51fe7a, 0x3c947692330aed60,
+	0x9288aa280d355a7a, 0xa1806a9b791d1696,
+	0x5d60e38496763da1, 0x6c69e22e613fd0f4,
+	0x977fc2a5aadffb17, 0xfb7bd063fc5a94ba,
+	0x460c17992cbaece1, 0xf7822c5444d3297f,
+	0x344a9790c69b74aa, 0xb80a42e6cae09dce,
+	0x1b1361eaf2b1e757, 0xd84c1e758e236f01,
+	0x88e0b7be347627cc, 0x45246009b7a99490,
+	0x8011c6dd3fe50472, 0xc341d682bffb99d7,
+	0x2511be93808e2d15, 0xd5bc13d7fd739840,
+	0x2a3cd030679ae1ec, 0x8ad9898a4b9ee157,
+	0x3245fef0a8eaf521, 0x3d6d8dbbb427d2b0,
+	0x1ed146d8968b3981, 0x0c6a28bf7d45f3fc,
+	0x4a1fd3dbcee3c561, 0x4210ff6a476bf67e,
+	0xa559cce0d9199aac, 0xde39d47ef3723380,
+	0xe5b69d848ce42e35, 0xefa24296f8e79f52,
+	0x70190b59db9a5afc, 0x26f166cdb211e7bf,
+	0x4deaf2df3c6b8ef5, 0xf171dbdd670f1017,
+	0xb9059b05e9420d90, 0x2f0da855c9388754,
+	0x611d5e9ab77949cc, 0x2912038ac01163f4,
+	0x0231df50402b2fba, 0x45660fc4f3245f58,
+	0xb91cc97c7c8dac50, 0xb72d2aafe4953427,
+	0xfa6463f87e813d6b, 0x4515f7ee95d5c6a2,
+	0x1310e1c1a48d21c3, 0xad48a7810cdd8544,
+	0x4d5bdfefd5c9e631, 0xa43ed43f1fdcb7de,
+	0xe70cfc8fe1ee9626, 0xef4711b0d8dda442,
+	0xb80dd9bd4dab6c93, 0xa23be08d31ba4d93,
+	0x9b37db9d0335a39c, 0x494b6f870f5cfebc,
+	0x6d1b3c1149dda943, 0x372c943a518c1093,
+	0xad27af45e77c09c4, 0x3b6f92b646044604,
+	0xac2917909f5fcf4f, 0x2069a60e977e5557,
+	0x353a469e71014de5, 0x24be356281f55c15,
+	0x2b6d710ba8e9adea, 0x404ad1751c749c29,
+	0xed7311bf23d7f185, 0xba4f6976b4acc43e,
+	0x32d7198d2bc39000, 0xee667019014d6e01,
+	0x494ef3e128d14c83, 0x1f95a152baecd6be,
+	0x201648dff1f483a5, 0x68c28550c8384af6,
+	0x5fc834a6824a7f48, 0x7cd06cb7365eaf28,
+	0xd82bbd95e9b30909, 0x234f0d1694c53f6d,
+	0xd2fb7f4a96d83f4a, 0xff0d5da83acac05e,
+	0xf8f6b97f5585080a, 0x74236084be57b95b,
+	0xa25e40c03bbc36ad, 0x6b6e5c14ce88465b,
+	0x4378ffe93e1528c5, 0x94ca92a17118e2d2,
+}

vendor/github.com/ulikunitz/xz/internal/hash/doc.go

@@ -0,0 +1,14 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package hash provides rolling hashes.
+
+Rolling hashes have to be used for maintaining the positions of n-byte
+sequences in the dictionary buffer.
+
+The package provides currently the Rabin-Karp rolling hash and a Cyclic
+Polynomial hash. Both support the Hashes method to be used with an interface.
+*/
+package hash

vendor/github.com/ulikunitz/xz/internal/hash/rabin_karp.go

@@ -0,0 +1,66 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hash
+
+// A is the default constant for Robin-Karp rolling hash. This is a random
+// prime.
+const A = 0x97b548add41d5da1
+
+// RabinKarp supports the computation of a rolling hash.
+type RabinKarp struct {
+	A uint64
+	// a^n
+	aOldest uint64
+	h       uint64
+	p       []byte
+	i       int
+}
+
+// NewRabinKarp creates a new RabinKarp value. The argument n defines the
+// length of the byte sequence to be hashed. The default constant will will be
+// used.
+func NewRabinKarp(n int) *RabinKarp {
+	return NewRabinKarpConst(n, A)
+}
+
+// NewRabinKarpConst creates a new RabinKarp value. The argument n defines the
+// length of the byte sequence to be hashed. The argument a provides the
+// constant used to compute the hash.
+func NewRabinKarpConst(n int, a uint64) *RabinKarp {
+	if n <= 0 {
+		panic("number of bytes n must be positive")
+	}
+	aOldest := uint64(1)
+	// There are faster methods. For the small n required by the LZMA
+	// compressor O(n) is sufficient.
+	for i := 0; i < n; i++ {
+		aOldest *= a
+	}
+	return &RabinKarp{
+		A: a, aOldest: aOldest,
+		p: make([]byte, 0, n),
+	}
+}
+
+// Len returns the length of the byte sequence.
+func (r *RabinKarp) Len() int {
+	return cap(r.p)
+}
+
+// RollByte computes the hash after x has been added.
+func (r *RabinKarp) RollByte(x byte) uint64 {
+	if len(r.p) < cap(r.p) {
+		r.h += uint64(x)
+		r.h *= r.A
+		r.p = append(r.p, x)
+	} else {
+		r.h -= uint64(r.p[r.i]) * r.aOldest
+		r.h += uint64(x)
+		r.h *= r.A
+		r.p[r.i] = x
+		r.i = (r.i + 1) % cap(r.p)
+	}
+	return r.h
+}

vendor/github.com/ulikunitz/xz/internal/hash/roller.go

@@ -0,0 +1,29 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hash
+
+// Roller provides an interface for rolling hashes. The hash value will become
+// valid after hash has been called Len times.
+type Roller interface {
+	Len() int
+	RollByte(x byte) uint64
+}
+
+// Hashes computes all hash values for the array p. Note that the state of the
+// roller is changed.
+func Hashes(r Roller, p []byte) []uint64 {
+	n := r.Len()
+	if len(p) < n {
+		return nil
+	}
+	h := make([]uint64, len(p)-n+1)
+	for i := 0; i < n-1; i++ {
+		r.RollByte(p[i])
+	}
+	for i := range h {
+		h[i] = r.RollByte(p[i+n-1])
+	}
+	return h
+}

vendor/github.com/ulikunitz/xz/internal/xlog/xlog.go

@@ -0,0 +1,457 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package xlog provides a simple logging package that allows to disable
+// certain message categories. It defines a type, Logger, with multiple
+// methods for formatting output. The package has also a predefined
+// 'standard' Logger accessible through helper function Print[f|ln],
+// Fatal[f|ln], Panic[f|ln], Warn[f|ln], Print[f|ln] and Debug[f|ln]
+// that are easier to use then creating a Logger manually. That logger
+// writes to standard error and prints the date and time of each logged
+// message, which can be configured using the function SetFlags.
+//
+// The Fatal functions call os.Exit(1) after the message is output
+// unless not suppressed by the flags. The Panic functions call panic
+// after the writing the log message unless suppressed.
+package xlog
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+	"sync"
+	"time"
+)
+
+// The flags define what information is prefixed to each log entry
+// generated by the Logger. The Lno* versions allow the suppression of
+// specific output. The bits are or'ed together to control what will be
+// printed. There is no control over the order of the items printed and
+// the format. The full format is:
+//
+//   2009-01-23 01:23:23.123123 /a/b/c/d.go:23: message
+//
+const (
+	Ldate         = 1 << iota // the date: 2009-01-23
+	Ltime                     // the time: 01:23:23
+	Lmicroseconds             // microsecond resolution: 01:23:23.123123
+	Llongfile                 // full file name and line number: /a/b/c/d.go:23
+	Lshortfile                // final file name element and line number: d.go:23
+	Lnopanic                  // suppresses output from Panic[f|ln] but not the panic call
+	Lnofatal                  // suppresses output from Fatal[f|ln] but not the exit
+	Lnowarn                   // suppresses output from Warn[f|ln]
+	Lnoprint                  // suppresses output from Print[f|ln]
+	Lnodebug                  // suppresses output from Debug[f|ln]
+	// initial values for the standard logger
+	Lstdflags = Ldate | Ltime | Lnodebug
+)
+
+// A Logger represents an active logging object that generates lines of
+// output to an io.Writer. Each logging operation if not suppressed
+// makes a single call to the Writer's Write method. A Logger can be
+// used simultaneously from multiple goroutines; it guarantees to
+// serialize access to the Writer.
+type Logger struct {
+	mu sync.Mutex // ensures atomic writes; and protects the following
+	// fields
+	prefix string    // prefix to write at beginning of each line
+	flag   int       // properties
+	out    io.Writer // destination for output
+	buf    []byte    // for accumulating text to write
+}
+
+// New creates a new Logger. The out argument sets the destination to
+// which the log output will be written. The prefix appears at the
+// beginning of each log line. The flag argument defines the logging
+// properties.
+func New(out io.Writer, prefix string, flag int) *Logger {
+	return &Logger{out: out, prefix: prefix, flag: flag}
+}
+
+// std is the standard logger used by the package scope functions.
+var std = New(os.Stderr, "", Lstdflags)
+
+// itoa converts the integer to ASCII. A negative widths will avoid
+// zero-padding. The function supports only non-negative integers.
+func itoa(buf *[]byte, i int, wid int) {
+	var u = uint(i)
+	if u == 0 && wid <= 1 {
+		*buf = append(*buf, '0')
+		return
+	}
+	var b [32]byte
+	bp := len(b)
+	for ; u > 0 || wid > 0; u /= 10 {
+		bp--
+		wid--
+		b[bp] = byte(u%10) + '0'
+	}
+	*buf = append(*buf, b[bp:]...)
+}
+
+// formatHeader puts the header into the buf field of the buffer.
+func (l *Logger) formatHeader(t time.Time, file string, line int) {
+	l.buf = append(l.buf, l.prefix...)
+	if l.flag&(Ldate|Ltime|Lmicroseconds) != 0 {
+		if l.flag&Ldate != 0 {
+			year, month, day := t.Date()
+			itoa(&l.buf, year, 4)
+			l.buf = append(l.buf, '-')
+			itoa(&l.buf, int(month), 2)
+			l.buf = append(l.buf, '-')
+			itoa(&l.buf, day, 2)
+			l.buf = append(l.buf, ' ')
+		}
+		if l.flag&(Ltime|Lmicroseconds) != 0 {
+			hour, min, sec := t.Clock()
+			itoa(&l.buf, hour, 2)
+			l.buf = append(l.buf, ':')
+			itoa(&l.buf, min, 2)
+			l.buf = append(l.buf, ':')
+			itoa(&l.buf, sec, 2)
+			if l.flag&Lmicroseconds != 0 {
+				l.buf = append(l.buf, '.')
+				itoa(&l.buf, t.Nanosecond()/1e3, 6)
+			}
+			l.buf = append(l.buf, ' ')
+		}
+	}
+	if l.flag&(Lshortfile|Llongfile) != 0 {
+		if l.flag&Lshortfile != 0 {
+			short := file
+			for i := len(file) - 1; i > 0; i-- {
+				if file[i] == '/' {
+					short = file[i+1:]
+					break
+				}
+			}
+			file = short
+		}
+		l.buf = append(l.buf, file...)
+		l.buf = append(l.buf, ':')
+		itoa(&l.buf, line, -1)
+		l.buf = append(l.buf, ": "...)
+	}
+}
+
+func (l *Logger) output(calldepth int, now time.Time, s string) error {
+	var file string
+	var line int
+	if l.flag&(Lshortfile|Llongfile) != 0 {
+		l.mu.Unlock()
+		var ok bool
+		_, file, line, ok = runtime.Caller(calldepth)
+		if !ok {
+			file = "???"
+			line = 0
+		}
+		l.mu.Lock()
+	}
+	l.buf = l.buf[:0]
+	l.formatHeader(now, file, line)
+	l.buf = append(l.buf, s...)
+	if len(s) == 0 || s[len(s)-1] != '\n' {
+		l.buf = append(l.buf, '\n')
+	}
+	_, err := l.out.Write(l.buf)
+	return err
+}
+
+// Output writes the string s with the header controlled by the flags to
+// the l.out writer. A newline will be appended if s doesn't end in a
+// newline. Calldepth is used to recover the PC, although all current
+// calls of Output use the call depth 2. Access to the function is serialized.
+func (l *Logger) Output(calldepth, noflag int, v ...interface{}) error {
+	now := time.Now()
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.flag&noflag != 0 {
+		return nil
+	}
+	s := fmt.Sprint(v...)
+	return l.output(calldepth+1, now, s)
+}
+
+// Outputf works like output but formats the output like Printf.
+func (l *Logger) Outputf(calldepth int, noflag int, format string, v ...interface{}) error {
+	now := time.Now()
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.flag&noflag != 0 {
+		return nil
+	}
+	s := fmt.Sprintf(format, v...)
+	return l.output(calldepth+1, now, s)
+}
+
+// Outputln works like output but formats the output like Println.
+func (l *Logger) Outputln(calldepth int, noflag int, v ...interface{}) error {
+	now := time.Now()
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.flag&noflag != 0 {
+		return nil
+	}
+	s := fmt.Sprintln(v...)
+	return l.output(calldepth+1, now, s)
+}
+
+// Panic prints the message like Print and calls panic. The printing
+// might be suppressed by the flag Lnopanic.
+func (l *Logger) Panic(v ...interface{}) {
+	l.Output(2, Lnopanic, v...)
+	s := fmt.Sprint(v...)
+	panic(s)
+}
+
+// Panic prints the message like Print and calls panic. The printing
+// might be suppressed by the flag Lnopanic.
+func Panic(v ...interface{}) {
+	std.Output(2, Lnopanic, v...)
+	s := fmt.Sprint(v...)
+	panic(s)
+}
+
+// Panicf prints the message like Printf and calls panic. The printing
+// might be suppressed by the flag Lnopanic.
+func (l *Logger) Panicf(format string, v ...interface{}) {
+	l.Outputf(2, Lnopanic, format, v...)
+	s := fmt.Sprintf(format, v...)
+	panic(s)
+}
+
+// Panicf prints the message like Printf and calls panic. The printing
+// might be suppressed by the flag Lnopanic.
+func Panicf(format string, v ...interface{}) {
+	std.Outputf(2, Lnopanic, format, v...)
+	s := fmt.Sprintf(format, v...)
+	panic(s)
+}
+
+// Panicln prints the message like Println and calls panic. The printing
+// might be suppressed by the flag Lnopanic.
+func (l *Logger) Panicln(v ...interface{}) {
+	l.Outputln(2, Lnopanic, v...)
+	s := fmt.Sprintln(v...)
+	panic(s)
+}
+
+// Panicln prints the message like Println and calls panic. The printing
+// might be suppressed by the flag Lnopanic.
+func Panicln(v ...interface{}) {
+	std.Outputln(2, Lnopanic, v...)
+	s := fmt.Sprintln(v...)
+	panic(s)
+}
+
+// Fatal prints the message like Print and calls os.Exit(1). The
+// printing might be suppressed by the flag Lnofatal.
+func (l *Logger) Fatal(v ...interface{}) {
+	l.Output(2, Lnofatal, v...)
+	os.Exit(1)
+}
+
+// Fatal prints the message like Print and calls os.Exit(1). The
+// printing might be suppressed by the flag Lnofatal.
+func Fatal(v ...interface{}) {
+	std.Output(2, Lnofatal, v...)
+	os.Exit(1)
+}
+
+// Fatalf prints the message like Printf and calls os.Exit(1). The
+// printing might be suppressed by the flag Lnofatal.
+func (l *Logger) Fatalf(format string, v ...interface{}) {
+	l.Outputf(2, Lnofatal, format, v...)
+	os.Exit(1)
+}
+
+// Fatalf prints the message like Printf and calls os.Exit(1). The
+// printing might be suppressed by the flag Lnofatal.
+func Fatalf(format string, v ...interface{}) {
+	std.Outputf(2, Lnofatal, format, v...)
+	os.Exit(1)
+}
+
+// Fatalln prints the message like Println and calls os.Exit(1). The
+// printing might be suppressed by the flag Lnofatal.
+func (l *Logger) Fatalln(format string, v ...interface{}) {
+	l.Outputln(2, Lnofatal, v...)
+	os.Exit(1)
+}
+
+// Fatalln prints the message like Println and calls os.Exit(1). The
+// printing might be suppressed by the flag Lnofatal.
+func Fatalln(format string, v ...interface{}) {
+	std.Outputln(2, Lnofatal, v...)
+	os.Exit(1)
+}
+
+// Warn prints the message like Print. The printing might be suppressed
+// by the flag Lnowarn.
+func (l *Logger) Warn(v ...interface{}) {
+	l.Output(2, Lnowarn, v...)
+}
+
+// Warn prints the message like Print. The printing might be suppressed
+// by the flag Lnowarn.
+func Warn(v ...interface{}) {
+	std.Output(2, Lnowarn, v...)
+}
+
+// Warnf prints the message like Printf. The printing might be suppressed
+// by the flag Lnowarn.
+func (l *Logger) Warnf(format string, v ...interface{}) {
+	l.Outputf(2, Lnowarn, format, v...)
+}
+
+// Warnf prints the message like Printf. The printing might be suppressed
+// by the flag Lnowarn.
+func Warnf(format string, v ...interface{}) {
+	std.Outputf(2, Lnowarn, format, v...)
+}
+
+// Warnln prints the message like Println. The printing might be suppressed
+// by the flag Lnowarn.
+func (l *Logger) Warnln(v ...interface{}) {
+	l.Outputln(2, Lnowarn, v...)
+}
+
+// Warnln prints the message like Println. The printing might be suppressed
+// by the flag Lnowarn.
+func Warnln(v ...interface{}) {
+	std.Outputln(2, Lnowarn, v...)
+}
+
+// Print prints the message like fmt.Print. The printing might be suppressed
+// by the flag Lnoprint.
+func (l *Logger) Print(v ...interface{}) {
+	l.Output(2, Lnoprint, v...)
+}
+
+// Print prints the message like fmt.Print. The printing might be suppressed
+// by the flag Lnoprint.
+func Print(v ...interface{}) {
+	std.Output(2, Lnoprint, v...)
+}
+
+// Printf prints the message like fmt.Printf. The printing might be suppressed
+// by the flag Lnoprint.
+func (l *Logger) Printf(format string, v ...interface{}) {
+	l.Outputf(2, Lnoprint, format, v...)
+}
+
+// Printf prints the message like fmt.Printf. The printing might be suppressed
+// by the flag Lnoprint.
+func Printf(format string, v ...interface{}) {
+	std.Outputf(2, Lnoprint, format, v...)
+}
+
+// Println prints the message like fmt.Println. The printing might be
+// suppressed by the flag Lnoprint.
+func (l *Logger) Println(v ...interface{}) {
+	l.Outputln(2, Lnoprint, v...)
+}
+
+// Println prints the message like fmt.Println. The printing might be
+// suppressed by the flag Lnoprint.
+func Println(v ...interface{}) {
+	std.Outputln(2, Lnoprint, v...)
+}
+
+// Debug prints the message like Print. The printing might be suppressed
+// by the flag Lnodebug.
+func (l *Logger) Debug(v ...interface{}) {
+	l.Output(2, Lnodebug, v...)
+}
+
+// Debug prints the message like Print. The printing might be suppressed
+// by the flag Lnodebug.
+func Debug(v ...interface{}) {
+	std.Output(2, Lnodebug, v...)
+}
+
+// Debugf prints the message like Printf. The printing might be suppressed
+// by the flag Lnodebug.
+func (l *Logger) Debugf(format string, v ...interface{}) {
+	l.Outputf(2, Lnodebug, format, v...)
+}
+
+// Debugf prints the message like Printf. The printing might be suppressed
+// by the flag Lnodebug.
+func Debugf(format string, v ...interface{}) {
+	std.Outputf(2, Lnodebug, format, v...)
+}
+
+// Debugln prints the message like Println. The printing might be suppressed
+// by the flag Lnodebug.
+func (l *Logger) Debugln(v ...interface{}) {
+	l.Outputln(2, Lnodebug, v...)
+}
+
+// Debugln prints the message like Println. The printing might be suppressed
+// by the flag Lnodebug.
+func Debugln(v ...interface{}) {
+	std.Outputln(2, Lnodebug, v...)
+}
+
+// Flags returns the current flags used by the logger.
+func (l *Logger) Flags() int {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	return l.flag
+}
+
+// Flags returns the current flags used by the standard logger.
+func Flags() int {
+	return std.Flags()
+}
+
+// SetFlags sets the flags of the logger.
+func (l *Logger) SetFlags(flag int) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.flag = flag
+}
+
+// SetFlags sets the flags for the standard logger.
+func SetFlags(flag int) {
+	std.SetFlags(flag)
+}
+
+// Prefix returns the prefix used by the logger.
+func (l *Logger) Prefix() string {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	return l.prefix
+}
+
+// Prefix returns the prefix used by the standard logger of the package.
+func Prefix() string {
+	return std.Prefix()
+}
+
+// SetPrefix sets the prefix for the logger.
+func (l *Logger) SetPrefix(prefix string) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.prefix = prefix
+}
+
+// SetPrefix sets the prefix of the standard logger of the package.
+func SetPrefix(prefix string) {
+	std.SetPrefix(prefix)
+}
+
+// SetOutput sets the output of the logger.
+func (l *Logger) SetOutput(w io.Writer) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.out = w
+}
+
+// SetOutput sets the output for the standard logger of the package.
+func SetOutput(w io.Writer) {
+	std.SetOutput(w)
+}

vendor/github.com/ulikunitz/xz/lzma/bintree.go

@@ -0,0 +1,522 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"unicode"
+)
+
+// node represents a node in the binary tree.
+type node struct {
+	// x is the search value
+	x uint32
+	// p parent node
+	p uint32
+	// l left child
+	l uint32
+	// r right child
+	r uint32
+}
+
+// wordLen is the number of bytes represented by the v field of a node.
+const wordLen = 4
+
+// binTree supports the identification of the next operation based on a
+// binary tree.
+//
+// Nodes will be identified by their index into the ring buffer.
+type binTree struct {
+	dict *encoderDict
+	// ring buffer of nodes
+	node []node
+	// absolute offset of the entry for the next node. Position 4
+	// byte larger.
+	hoff int64
+	// front position in the node ring buffer
+	front uint32
+	// index of the root node
+	root uint32
+	// current x value
+	x uint32
+	// preallocated array
+	data []byte
+}
+
+// null represents the nonexistent index. We can't use zero because it
+// would always exist or we would need to decrease the index for each
+// reference.
+const null uint32 = 1<<32 - 1
+
+// newBinTree initializes the binTree structure. The capacity defines
+// the size of the buffer and defines the maximum distance for which
+// matches will be found.
+func newBinTree(capacity int) (t *binTree, err error) {
+	if capacity < 1 {
+		return nil, errors.New(
+			"newBinTree: capacity must be larger than zero")
+	}
+	if int64(capacity) >= int64(null) {
+		return nil, errors.New(
+			"newBinTree: capacity must less 2^{32}-1")
+	}
+	t = &binTree{
+		node: make([]node, capacity),
+		hoff: -int64(wordLen),
+		root: null,
+		data: make([]byte, maxMatchLen),
+	}
+	return t, nil
+}
+
+func (t *binTree) SetDict(d *encoderDict) { t.dict = d }
+
+// WriteByte writes a single byte into the binary tree.
+func (t *binTree) WriteByte(c byte) error {
+	t.x = (t.x << 8) | uint32(c)
+	t.hoff++
+	if t.hoff < 0 {
+		return nil
+	}
+	v := t.front
+	if int64(v) < t.hoff {
+		// We are overwriting old nodes stored in the tree.
+		t.remove(v)
+	}
+	t.node[v].x = t.x
+	t.add(v)
+	t.front++
+	if int64(t.front) >= int64(len(t.node)) {
+		t.front = 0
+	}
+	return nil
+}
+
+// Writes writes a sequence of bytes into the binTree structure.
+func (t *binTree) Write(p []byte) (n int, err error) {
+	for _, c := range p {
+		t.WriteByte(c)
+	}
+	return len(p), nil
+}
+
+// add puts the node v into the tree. The node must not be part of the
+// tree before.
+func (t *binTree) add(v uint32) {
+	vn := &t.node[v]
+	// Set left and right to null indices.
+	vn.l, vn.r = null, null
+	// If the binary tree is empty make v the root.
+	if t.root == null {
+		t.root = v
+		vn.p = null
+		return
+	}
+	x := vn.x
+	p := t.root
+	// Search for the right leave link and add the new node.
+	for {
+		pn := &t.node[p]
+		if x <= pn.x {
+			if pn.l == null {
+				pn.l = v
+				vn.p = p
+				return
+			}
+			p = pn.l
+		} else {
+			if pn.r == null {
+				pn.r = v
+				vn.p = p
+				return
+			}
+			p = pn.r
+		}
+	}
+}
+
+// parent returns the parent node index of v and the pointer to v value
+// in the parent.
+func (t *binTree) parent(v uint32) (p uint32, ptr *uint32) {
+	if t.root == v {
+		return null, &t.root
+	}
+	p = t.node[v].p
+	if t.node[p].l == v {
+		ptr = &t.node[p].l
+	} else {
+		ptr = &t.node[p].r
+	}
+	return
+}
+
+// Remove node v.
+func (t *binTree) remove(v uint32) {
+	vn := &t.node[v]
+	p, ptr := t.parent(v)
+	l, r := vn.l, vn.r
+	if l == null {
+		// Move the right child up.
+		*ptr = r
+		if r != null {
+			t.node[r].p = p
+		}
+		return
+	}
+	if r == null {
+		// Move the left child up.
+		*ptr = l
+		t.node[l].p = p
+		return
+	}
+
+	// Search the in-order predecessor u.
+	un := &t.node[l]
+	ur := un.r
+	if ur == null {
+		// In order predecessor is l. Move it up.
+		un.r = r
+		t.node[r].p = l
+		un.p = p
+		*ptr = l
+		return
+	}
+	var u uint32
+	for {
+		// Look for the max value in the tree where l is root.
+		u = ur
+		ur = t.node[u].r
+		if ur == null {
+			break
+		}
+	}
+	// replace u with ul
+	un = &t.node[u]
+	ul := un.l
+	up := un.p
+	t.node[up].r = ul
+	if ul != null {
+		t.node[ul].p = up
+	}
+
+	// replace v by u
+	un.l, un.r = l, r
+	t.node[l].p = u
+	t.node[r].p = u
+	*ptr = u
+	un.p = p
+}
+
+// search looks for the node that have the value x or for the nodes that
+// brace it. The node highest in the tree with the value x will be
+// returned. All other nodes with the same value live in left subtree of
+// the returned node.
+func (t *binTree) search(v uint32, x uint32) (a, b uint32) {
+	a, b = null, null
+	if v == null {
+		return
+	}
+	for {
+		vn := &t.node[v]
+		if x <= vn.x {
+			if x == vn.x {
+				return v, v
+			}
+			b = v
+			if vn.l == null {
+				return
+			}
+			v = vn.l
+		} else {
+			a = v
+			if vn.r == null {
+				return
+			}
+			v = vn.r
+		}
+	}
+}
+
+// max returns the node with maximum value in the subtree with v as
+// root.
+func (t *binTree) max(v uint32) uint32 {
+	if v == null {
+		return null
+	}
+	for {
+		r := t.node[v].r
+		if r == null {
+			return v
+		}
+		v = r
+	}
+}
+
+// min returns the node with the minimum value in the subtree with v as
+// root.
+func (t *binTree) min(v uint32) uint32 {
+	if v == null {
+		return null
+	}
+	for {
+		l := t.node[v].l
+		if l == null {
+			return v
+		}
+		v = l
+	}
+}
+
+// pred returns the in-order predecessor of node v.
+func (t *binTree) pred(v uint32) uint32 {
+	if v == null {
+		return null
+	}
+	u := t.max(t.node[v].l)
+	if u != null {
+		return u
+	}
+	for {
+		p := t.node[v].p
+		if p == null {
+			return null
+		}
+		if t.node[p].r == v {
+			return p
+		}
+		v = p
+	}
+}
+
+// succ returns the in-order successor of node v.
+func (t *binTree) succ(v uint32) uint32 {
+	if v == null {
+		return null
+	}
+	u := t.min(t.node[v].r)
+	if u != null {
+		return u
+	}
+	for {
+		p := t.node[v].p
+		if p == null {
+			return null
+		}
+		if t.node[p].l == v {
+			return p
+		}
+		v = p
+	}
+}
+
+// xval converts the first four bytes of a into an 32-bit unsigned
+// integer in big-endian order.
+func xval(a []byte) uint32 {
+	var x uint32
+	switch len(a) {
+	default:
+		x |= uint32(a[3])
+		fallthrough
+	case 3:
+		x |= uint32(a[2]) << 8
+		fallthrough
+	case 2:
+		x |= uint32(a[1]) << 16
+		fallthrough
+	case 1:
+		x |= uint32(a[0]) << 24
+	case 0:
+	}
+	return x
+}
+
+// dumpX converts value x into a four-letter string.
+func dumpX(x uint32) string {
+	a := make([]byte, 4)
+	for i := 0; i < 4; i++ {
+		c := byte(x >> uint((3-i)*8))
+		if unicode.IsGraphic(rune(c)) {
+			a[i] = c
+		} else {
+			a[i] = '.'
+		}
+	}
+	return string(a)
+}
+
+/*
+// dumpNode writes a representation of the node v into the io.Writer.
+func (t *binTree) dumpNode(w io.Writer, v uint32, indent int) {
+	if v == null {
+		return
+	}
+
+	vn := &t.node[v]
+
+	t.dumpNode(w, vn.r, indent+2)
+
+	for i := 0; i < indent; i++ {
+		fmt.Fprint(w, " ")
+	}
+	if vn.p == null {
+		fmt.Fprintf(w, "node %d %q parent null\n", v, dumpX(vn.x))
+	} else {
+		fmt.Fprintf(w, "node %d %q parent %d\n", v, dumpX(vn.x), vn.p)
+	}
+
+	t.dumpNode(w, vn.l, indent+2)
+}
+
+// dump prints a representation of the binary tree into the writer.
+func (t *binTree) dump(w io.Writer) error {
+	bw := bufio.NewWriter(w)
+	t.dumpNode(bw, t.root, 0)
+	return bw.Flush()
+}
+*/
+
+func (t *binTree) distance(v uint32) int {
+	dist := int(t.front) - int(v)
+	if dist <= 0 {
+		dist += len(t.node)
+	}
+	return dist
+}
+
+type matchParams struct {
+	rep [4]uint32
+	// length when match will be accepted
+	nAccept int
+	// nodes to check
+	check int
+	// finish if length get shorter
+	stopShorter bool
+}
+
+func (t *binTree) match(m match, distIter func() (int, bool), p matchParams,
+) (r match, checked int, accepted bool) {
+	buf := &t.dict.buf
+	for {
+		if checked >= p.check {
+			return m, checked, true
+		}
+		dist, ok := distIter()
+		if !ok {
+			return m, checked, false
+		}
+		checked++
+		if m.n > 0 {
+			i := buf.rear - dist + m.n - 1
+			if i < 0 {
+				i += len(buf.data)
+			} else if i >= len(buf.data) {
+				i -= len(buf.data)
+			}
+			if buf.data[i] != t.data[m.n-1] {
+				if p.stopShorter {
+					return m, checked, false
+				}
+				continue
+			}
+		}
+		n := buf.matchLen(dist, t.data)
+		switch n {
+		case 0:
+			if p.stopShorter {
+				return m, checked, false
+			}
+			continue
+		case 1:
+			if uint32(dist-minDistance) != p.rep[0] {
+				continue
+			}
+		}
+		if n < m.n || (n == m.n && int64(dist) >= m.distance) {
+			continue
+		}
+		m = match{int64(dist), n}
+		if n >= p.nAccept {
+			return m, checked, true
+		}
+	}
+}
+
+func (t *binTree) NextOp(rep [4]uint32) operation {
+	// retrieve maxMatchLen data
+	n, _ := t.dict.buf.Peek(t.data[:maxMatchLen])
+	if n == 0 {
+		panic("no data in buffer")
+	}
+	t.data = t.data[:n]
+
+	var (
+		m                  match
+		x, u, v            uint32
+		iterPred, iterSucc func() (int, bool)
+	)
+	p := matchParams{
+		rep:     rep,
+		nAccept: maxMatchLen,
+		check:   32,
+	}
+	i := 4
+	iterSmall := func() (dist int, ok bool) {
+		i--
+		if i <= 0 {
+			return 0, false
+		}
+		return i, true
+	}
+	m, checked, accepted := t.match(m, iterSmall, p)
+	if accepted {
+		goto end
+	}
+	p.check -= checked
+	x = xval(t.data)
+	u, v = t.search(t.root, x)
+	if u == v && len(t.data) == 4 {
+		iter := func() (dist int, ok bool) {
+			if u == null {
+				return 0, false
+			}
+			dist = t.distance(u)
+			u, v = t.search(t.node[u].l, x)
+			if u != v {
+				u = null
+			}
+			return dist, true
+		}
+		m, _, _ = t.match(m, iter, p)
+		goto end
+	}
+	p.stopShorter = true
+	iterSucc = func() (dist int, ok bool) {
+		if v == null {
+			return 0, false
+		}
+		dist = t.distance(v)
+		v = t.succ(v)
+		return dist, true
+	}
+	m, checked, accepted = t.match(m, iterSucc, p)
+	if accepted {
+		goto end
+	}
+	p.check -= checked
+	iterPred = func() (dist int, ok bool) {
+		if u == null {
+			return 0, false
+		}
+		dist = t.distance(u)
+		u = t.pred(u)
+		return dist, true
+	}
+	m, _, _ = t.match(m, iterPred, p)
+end:
+	if m.n == 0 {
+		return lit{t.data[0]}
+	}
+	return m
+}

vendor/github.com/ulikunitz/xz/lzma/bitops.go

@@ -0,0 +1,47 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+/* Naming conventions follows the CodeReviewComments in the Go Wiki. */
+
+// ntz32Const is used by the functions NTZ and NLZ.
+const ntz32Const = 0x04d7651f
+
+// ntz32Table is a helper table for de Bruijn algorithm by Danny Dubé.
+// See Henry S. Warren, Jr. "Hacker's Delight" section 5-1 figure 5-26.
+var ntz32Table = [32]int8{
+	0, 1, 2, 24, 3, 19, 6, 25,
+	22, 4, 20, 10, 16, 7, 12, 26,
+	31, 23, 18, 5, 21, 9, 15, 11,
+	30, 17, 8, 14, 29, 13, 28, 27,
+}
+
+/*
+// ntz32 computes the number of trailing zeros for an unsigned 32-bit integer.
+func ntz32(x uint32) int {
+	if x == 0 {
+		return 32
+	}
+	x = (x & -x) * ntz32Const
+	return int(ntz32Table[x>>27])
+}
+*/
+
+// nlz32 computes the number of leading zeros for an unsigned 32-bit integer.
+func nlz32(x uint32) int {
+	// Smear left most bit to the right
+	x |= x >> 1
+	x |= x >> 2
+	x |= x >> 4
+	x |= x >> 8
+	x |= x >> 16
+	// Use ntz mechanism to calculate nlz.
+	x++
+	if x == 0 {
+		return 0
+	}
+	x *= ntz32Const
+	return 32 - int(ntz32Table[x>>27])
+}

vendor/github.com/ulikunitz/xz/lzma/breader.go

@@ -0,0 +1,39 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"io"
+)
+
+// breader provides the ReadByte function for a Reader. It doesn't read
+// more data from the reader than absolutely necessary.
+type breader struct {
+	io.Reader
+	// helper slice to save allocations
+	p []byte
+}
+
+// ByteReader converts an io.Reader into an io.ByteReader.
+func ByteReader(r io.Reader) io.ByteReader {
+	br, ok := r.(io.ByteReader)
+	if !ok {
+		return &breader{r, make([]byte, 1)}
+	}
+	return br
+}
+
+// ReadByte read byte function.
+func (r *breader) ReadByte() (c byte, err error) {
+	n, err := r.Reader.Read(r.p)
+	if n < 1 {
+		if err == nil {
+			err = errors.New("breader.ReadByte: no data")
+		}
+		return 0, err
+	}
+	return r.p[0], nil
+}

vendor/github.com/ulikunitz/xz/lzma/buffer.go

@@ -0,0 +1,171 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+)
+
+// buffer provides a circular buffer of bytes. If the front index equals
+// the rear index the buffer is empty. As a consequence front cannot be
+// equal rear for a full buffer. So a full buffer has a length that is
+// one byte less the the length of the data slice.
+type buffer struct {
+	data  []byte
+	front int
+	rear  int
+}
+
+// newBuffer creates a buffer with the given size.
+func newBuffer(size int) *buffer {
+	return &buffer{data: make([]byte, size+1)}
+}
+
+// Cap returns the capacity of the buffer.
+func (b *buffer) Cap() int {
+	return len(b.data) - 1
+}
+
+// Resets the buffer. The front and rear index are set to zero.
+func (b *buffer) Reset() {
+	b.front = 0
+	b.rear = 0
+}
+
+// Buffered returns the number of bytes buffered.
+func (b *buffer) Buffered() int {
+	delta := b.front - b.rear
+	if delta < 0 {
+		delta += len(b.data)
+	}
+	return delta
+}
+
+// Available returns the number of bytes available for writing.
+func (b *buffer) Available() int {
+	delta := b.rear - 1 - b.front
+	if delta < 0 {
+		delta += len(b.data)
+	}
+	return delta
+}
+
+// addIndex adds a non-negative integer to the index i and returns the
+// resulting index. The function takes care of wrapping the index as
+// well as potential overflow situations.
+func (b *buffer) addIndex(i int, n int) int {
+	// subtraction of len(b.data) prevents overflow
+	i += n - len(b.data)
+	if i < 0 {
+		i += len(b.data)
+	}
+	return i
+}
+
+// Read reads bytes from the buffer into p and returns the number of
+// bytes read. The function never returns an error but might return less
+// data than requested.
+func (b *buffer) Read(p []byte) (n int, err error) {
+	n, err = b.Peek(p)
+	b.rear = b.addIndex(b.rear, n)
+	return n, err
+}
+
+// Peek reads bytes from the buffer into p without changing the buffer.
+// Peek will never return an error but might return less data than
+// requested.
+func (b *buffer) Peek(p []byte) (n int, err error) {
+	m := b.Buffered()
+	n = len(p)
+	if m < n {
+		n = m
+		p = p[:n]
+	}
+	k := copy(p, b.data[b.rear:])
+	if k < n {
+		copy(p[k:], b.data)
+	}
+	return n, nil
+}
+
+// Discard skips the n next bytes to read from the buffer, returning the
+// bytes discarded.
+//
+// If Discards skips fewer than n bytes, it returns an error.
+func (b *buffer) Discard(n int) (discarded int, err error) {
+	if n < 0 {
+		return 0, errors.New("buffer.Discard: negative argument")
+	}
+	m := b.Buffered()
+	if m < n {
+		n = m
+		err = errors.New(
+			"buffer.Discard: discarded less bytes then requested")
+	}
+	b.rear = b.addIndex(b.rear, n)
+	return n, err
+}
+
+// ErrNoSpace indicates that there is insufficient space for the Write
+// operation.
+var ErrNoSpace = errors.New("insufficient space")
+
+// Write puts data into the  buffer. If less bytes are written than
+// requested ErrNoSpace is returned.
+func (b *buffer) Write(p []byte) (n int, err error) {
+	m := b.Available()
+	n = len(p)
+	if m < n {
+		n = m
+		p = p[:m]
+		err = ErrNoSpace
+	}
+	k := copy(b.data[b.front:], p)
+	if k < n {
+		copy(b.data, p[k:])
+	}
+	b.front = b.addIndex(b.front, n)
+	return n, err
+}
+
+// WriteByte writes a single byte into the buffer. The error ErrNoSpace
+// is returned if no single byte is available in the buffer for writing.
+func (b *buffer) WriteByte(c byte) error {
+	if b.Available() < 1 {
+		return ErrNoSpace
+	}
+	b.data[b.front] = c
+	b.front = b.addIndex(b.front, 1)
+	return nil
+}
+
+// prefixLen returns the length of the common prefix of a and b.
+func prefixLen(a, b []byte) int {
+	if len(a) > len(b) {
+		a, b = b, a
+	}
+	for i, c := range a {
+		if b[i] != c {
+			return i
+		}
+	}
+	return len(a)
+}
+
+// matchLen returns the length of the common prefix for the given
+// distance from the rear and the byte slice p.
+func (b *buffer) matchLen(distance int, p []byte) int {
+	var n int
+	i := b.rear - distance
+	if i < 0 {
+		if n = prefixLen(p, b.data[len(b.data)+i:]); n < -i {
+			return n
+		}
+		p = p[n:]
+		i = 0
+	}
+	n += prefixLen(p, b.data[i:])
+	return n
+}

vendor/github.com/ulikunitz/xz/lzma/bytewriter.go

@@ -0,0 +1,37 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"io"
+)
+
+// ErrLimit indicates that the limit of the LimitedByteWriter has been
+// reached.
+var ErrLimit = errors.New("limit reached")
+
+// LimitedByteWriter provides a byte writer that can be written until a
+// limit is reached. The field N provides the number of remaining
+// bytes.
+type LimitedByteWriter struct {
+	BW io.ByteWriter
+	N  int64
+}
+
+// WriteByte writes a single byte to the limited byte writer. It returns
+// ErrLimit if the limit has been reached. If the byte is successfully
+// written the field N of the LimitedByteWriter will be decremented by
+// one.
+func (l *LimitedByteWriter) WriteByte(c byte) error {
+	if l.N <= 0 {
+		return ErrLimit
+	}
+	if err := l.BW.WriteByte(c); err != nil {
+		return err
+	}
+	l.N--
+	return nil
+}

vendor/github.com/ulikunitz/xz/lzma/decoder.go

@@ -0,0 +1,277 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+	"io"
+)
+
+// decoder decodes a raw LZMA stream without any header.
+type decoder struct {
+	// dictionary; the rear pointer of the buffer will be used for
+	// reading the data.
+	Dict *decoderDict
+	// decoder state
+	State *state
+	// range decoder
+	rd *rangeDecoder
+	// start stores the head value of the dictionary for the LZMA
+	// stream
+	start int64
+	// size of uncompressed data
+	size int64
+	// end-of-stream encountered
+	eos bool
+	// EOS marker found
+	eosMarker bool
+}
+
+// newDecoder creates a new decoder instance. The parameter size provides
+// the expected byte size of the decompressed data. If the size is
+// unknown use a negative value. In that case the decoder will look for
+// a terminating end-of-stream marker.
+func newDecoder(br io.ByteReader, state *state, dict *decoderDict, size int64) (d *decoder, err error) {
+	rd, err := newRangeDecoder(br)
+	if err != nil {
+		return nil, err
+	}
+	d = &decoder{
+		State: state,
+		Dict:  dict,
+		rd:    rd,
+		size:  size,
+		start: dict.pos(),
+	}
+	return d, nil
+}
+
+// Reopen restarts the decoder with a new byte reader and a new size. Reopen
+// resets the Decompressed counter to zero.
+func (d *decoder) Reopen(br io.ByteReader, size int64) error {
+	var err error
+	if d.rd, err = newRangeDecoder(br); err != nil {
+		return err
+	}
+	d.start = d.Dict.pos()
+	d.size = size
+	d.eos = false
+	return nil
+}
+
+// decodeLiteral decodes a single literal from the LZMA stream.
+func (d *decoder) decodeLiteral() (op operation, err error) {
+	litState := d.State.litState(d.Dict.byteAt(1), d.Dict.head)
+	match := d.Dict.byteAt(int(d.State.rep[0]) + 1)
+	s, err := d.State.litCodec.Decode(d.rd, d.State.state, match, litState)
+	if err != nil {
+		return nil, err
+	}
+	return lit{s}, nil
+}
+
+// errEOS indicates that an EOS marker has been found.
+var errEOS = errors.New("EOS marker found")
+
+// readOp decodes the next operation from the compressed stream. It
+// returns the operation. If an explicit end of stream marker is
+// identified the eos error is returned.
+func (d *decoder) readOp() (op operation, err error) {
+	// Value of the end of stream (EOS) marker
+	const eosDist = 1<<32 - 1
+
+	state, state2, posState := d.State.states(d.Dict.head)
+
+	b, err := d.State.isMatch[state2].Decode(d.rd)
+	if err != nil {
+		return nil, err
+	}
+	if b == 0 {
+		// literal
+		op, err := d.decodeLiteral()
+		if err != nil {
+			return nil, err
+		}
+		d.State.updateStateLiteral()
+		return op, nil
+	}
+	b, err = d.State.isRep[state].Decode(d.rd)
+	if err != nil {
+		return nil, err
+	}
+	if b == 0 {
+		// simple match
+		d.State.rep[3], d.State.rep[2], d.State.rep[1] =
+			d.State.rep[2], d.State.rep[1], d.State.rep[0]
+
+		d.State.updateStateMatch()
+		// The length decoder returns the length offset.
+		n, err := d.State.lenCodec.Decode(d.rd, posState)
+		if err != nil {
+			return nil, err
+		}
+		// The dist decoder returns the distance offset. The actual
+		// distance is 1 higher.
+		d.State.rep[0], err = d.State.distCodec.Decode(d.rd, n)
+		if err != nil {
+			return nil, err
+		}
+		if d.State.rep[0] == eosDist {
+			d.eosMarker = true
+			return nil, errEOS
+		}
+		op = match{n: int(n) + minMatchLen,
+			distance: int64(d.State.rep[0]) + minDistance}
+		return op, nil
+	}
+	b, err = d.State.isRepG0[state].Decode(d.rd)
+	if err != nil {
+		return nil, err
+	}
+	dist := d.State.rep[0]
+	if b == 0 {
+		// rep match 0
+		b, err = d.State.isRepG0Long[state2].Decode(d.rd)
+		if err != nil {
+			return nil, err
+		}
+		if b == 0 {
+			d.State.updateStateShortRep()
+			op = match{n: 1, distance: int64(dist) + minDistance}
+			return op, nil
+		}
+	} else {
+		b, err = d.State.isRepG1[state].Decode(d.rd)
+		if err != nil {
+			return nil, err
+		}
+		if b == 0 {
+			dist = d.State.rep[1]
+		} else {
+			b, err = d.State.isRepG2[state].Decode(d.rd)
+			if err != nil {
+				return nil, err
+			}
+			if b == 0 {
+				dist = d.State.rep[2]
+			} else {
+				dist = d.State.rep[3]
+				d.State.rep[3] = d.State.rep[2]
+			}
+			d.State.rep[2] = d.State.rep[1]
+		}
+		d.State.rep[1] = d.State.rep[0]
+		d.State.rep[0] = dist
+	}
+	n, err := d.State.repLenCodec.Decode(d.rd, posState)
+	if err != nil {
+		return nil, err
+	}
+	d.State.updateStateRep()
+	op = match{n: int(n) + minMatchLen, distance: int64(dist) + minDistance}
+	return op, nil
+}
+
+// apply takes the operation and transforms the decoder dictionary accordingly.
+func (d *decoder) apply(op operation) error {
+	var err error
+	switch x := op.(type) {
+	case match:
+		err = d.Dict.writeMatch(x.distance, x.n)
+	case lit:
+		err = d.Dict.WriteByte(x.b)
+	default:
+		panic("op is neither a match nor a literal")
+	}
+	return err
+}
+
+// decompress fills the dictionary unless no space for new data is
+// available. If the end of the LZMA stream has been reached io.EOF will
+// be returned.
+func (d *decoder) decompress() error {
+	if d.eos {
+		return io.EOF
+	}
+	for d.Dict.Available() >= maxMatchLen {
+		op, err := d.readOp()
+		switch err {
+		case nil:
+			// break
+		case errEOS:
+			d.eos = true
+			if !d.rd.possiblyAtEnd() {
+				return errDataAfterEOS
+			}
+			if d.size >= 0 && d.size != d.Decompressed() {
+				return errSize
+			}
+			return io.EOF
+		case io.EOF:
+			d.eos = true
+			return io.ErrUnexpectedEOF
+		default:
+			return err
+		}
+		if err = d.apply(op); err != nil {
+			return err
+		}
+		if d.size >= 0 && d.Decompressed() >= d.size {
+			d.eos = true
+			if d.Decompressed() > d.size {
+				return errSize
+			}
+			if !d.rd.possiblyAtEnd() {
+				switch _, err = d.readOp(); err {
+				case nil:
+					return errSize
+				case io.EOF:
+					return io.ErrUnexpectedEOF
+				case errEOS:
+					break
+				default:
+					return err
+				}
+			}
+			return io.EOF
+		}
+	}
+	return nil
+}
+
+// Errors that may be returned while decoding data.
+var (
+	errDataAfterEOS = errors.New("lzma: data after end of stream marker")
+	errSize         = errors.New("lzma: wrong uncompressed data size")
+)
+
+// Read reads data from the buffer. If no more data is available io.EOF is
+// returned.
+func (d *decoder) Read(p []byte) (n int, err error) {
+	var k int
+	for {
+		// Read of decoder dict never returns an error.
+		k, err = d.Dict.Read(p[n:])
+		if err != nil {
+			panic(fmt.Errorf("dictionary read error %s", err))
+		}
+		if k == 0 && d.eos {
+			return n, io.EOF
+		}
+		n += k
+		if n >= len(p) {
+			return n, nil
+		}
+		if err = d.decompress(); err != nil && err != io.EOF {
+			return n, err
+		}
+	}
+}
+
+// Decompressed returns the number of bytes decompressed by the decoder.
+func (d *decoder) Decompressed() int64 {
+	return d.Dict.pos() - d.start
+}

vendor/github.com/ulikunitz/xz/lzma/decoderdict.go

@@ -0,0 +1,128 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+)
+
+// decoderDict provides the dictionary for the decoder. The whole
+// dictionary is used as reader buffer.
+type decoderDict struct {
+	buf  buffer
+	head int64
+}
+
+// newDecoderDict creates a new decoder dictionary. The whole dictionary
+// will be used as reader buffer.
+func newDecoderDict(dictCap int) (d *decoderDict, err error) {
+	// lower limit supports easy test cases
+	if !(1 <= dictCap && int64(dictCap) <= MaxDictCap) {
+		return nil, errors.New("lzma: dictCap out of range")
+	}
+	d = &decoderDict{buf: *newBuffer(dictCap)}
+	return d, nil
+}
+
+// Reset clears the dictionary. The read buffer is not changed, so the
+// buffered data can still be read.
+func (d *decoderDict) Reset() {
+	d.head = 0
+}
+
+// WriteByte writes a single byte into the dictionary. It is used to
+// write literals into the dictionary.
+func (d *decoderDict) WriteByte(c byte) error {
+	if err := d.buf.WriteByte(c); err != nil {
+		return err
+	}
+	d.head++
+	return nil
+}
+
+// pos returns the position of the dictionary head.
+func (d *decoderDict) pos() int64 { return d.head }
+
+// dictLen returns the actual length of the dictionary.
+func (d *decoderDict) dictLen() int {
+	capacity := d.buf.Cap()
+	if d.head >= int64(capacity) {
+		return capacity
+	}
+	return int(d.head)
+}
+
+// byteAt returns a byte stored in the dictionary. If the distance is
+// non-positive or exceeds the current length of the dictionary the zero
+// byte is returned.
+func (d *decoderDict) byteAt(dist int) byte {
+	if !(0 < dist && dist <= d.dictLen()) {
+		return 0
+	}
+	i := d.buf.front - dist
+	if i < 0 {
+		i += len(d.buf.data)
+	}
+	return d.buf.data[i]
+}
+
+// writeMatch writes the match at the top of the dictionary. The given
+// distance must point in the current dictionary and the length must not
+// exceed the maximum length 273 supported in LZMA.
+//
+// The error value ErrNoSpace indicates that no space is available in
+// the dictionary for writing. You need to read from the dictionary
+// first.
+func (d *decoderDict) writeMatch(dist int64, length int) error {
+	if !(0 < dist && dist <= int64(d.dictLen())) {
+		return errors.New("writeMatch: distance out of range")
+	}
+	if !(0 < length && length <= maxMatchLen) {
+		return errors.New("writeMatch: length out of range")
+	}
+	if length > d.buf.Available() {
+		return ErrNoSpace
+	}
+	d.head += int64(length)
+
+	i := d.buf.front - int(dist)
+	if i < 0 {
+		i += len(d.buf.data)
+	}
+	for length > 0 {
+		var p []byte
+		if i >= d.buf.front {
+			p = d.buf.data[i:]
+			i = 0
+		} else {
+			p = d.buf.data[i:d.buf.front]
+			i = d.buf.front
+		}
+		if len(p) > length {
+			p = p[:length]
+		}
+		if _, err := d.buf.Write(p); err != nil {
+			panic(fmt.Errorf("d.buf.Write returned error %s", err))
+		}
+		length -= len(p)
+	}
+	return nil
+}
+
+// Write writes the given bytes into the dictionary and advances the
+// head.
+func (d *decoderDict) Write(p []byte) (n int, err error) {
+	n, err = d.buf.Write(p)
+	d.head += int64(n)
+	return n, err
+}
+
+// Available returns the number of available bytes for writing into the
+// decoder dictionary.
+func (d *decoderDict) Available() int { return d.buf.Available() }
+
+// Read reads data from the buffer contained in the decoder dictionary.
+func (d *decoderDict) Read(p []byte) (n int, err error) { return d.buf.Read(p) }

vendor/github.com/ulikunitz/xz/lzma/directcodec.go

@@ -0,0 +1,38 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+// directCodec allows the encoding and decoding of values with a fixed number
+// of bits. The number of bits must be in the range [1,32].
+type directCodec byte
+
+// Bits returns the number of bits supported by this codec.
+func (dc directCodec) Bits() int {
+	return int(dc)
+}
+
+// Encode uses the range encoder to encode a value with the fixed number of
+// bits. The most-significant bit is encoded first.
+func (dc directCodec) Encode(e *rangeEncoder, v uint32) error {
+	for i := int(dc) - 1; i >= 0; i-- {
+		if err := e.DirectEncodeBit(v >> uint(i)); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Decode uses the range decoder to decode a value with the given number of
+// given bits. The most-significant bit is decoded first.
+func (dc directCodec) Decode(d *rangeDecoder) (v uint32, err error) {
+	for i := int(dc) - 1; i >= 0; i-- {
+		x, err := d.DirectDecodeBit()
+		if err != nil {
+			return 0, err
+		}
+		v = (v << 1) | x
+	}
+	return v, nil
+}

vendor/github.com/ulikunitz/xz/lzma/distcodec.go

@@ -0,0 +1,140 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+// Constants used by the distance codec.
+const (
+	// minimum supported distance
+	minDistance = 1
+	// maximum supported distance, value is used for the eos marker.
+	maxDistance = 1 << 32
+	// number of the supported len states
+	lenStates = 4
+	// start for the position models
+	startPosModel = 4
+	// first index with align bits support
+	endPosModel = 14
+	// bits for the position slots
+	posSlotBits = 6
+	// number of align bits
+	alignBits = 4
+)
+
+// distCodec provides encoding and decoding of distance values.
+type distCodec struct {
+	posSlotCodecs [lenStates]treeCodec
+	posModel      [endPosModel - startPosModel]treeReverseCodec
+	alignCodec    treeReverseCodec
+}
+
+// deepcopy initializes dc as deep copy of the source.
+func (dc *distCodec) deepcopy(src *distCodec) {
+	if dc == src {
+		return
+	}
+	for i := range dc.posSlotCodecs {
+		dc.posSlotCodecs[i].deepcopy(&src.posSlotCodecs[i])
+	}
+	for i := range dc.posModel {
+		dc.posModel[i].deepcopy(&src.posModel[i])
+	}
+	dc.alignCodec.deepcopy(&src.alignCodec)
+}
+
+// newDistCodec creates a new distance codec.
+func (dc *distCodec) init() {
+	for i := range dc.posSlotCodecs {
+		dc.posSlotCodecs[i] = makeTreeCodec(posSlotBits)
+	}
+	for i := range dc.posModel {
+		posSlot := startPosModel + i
+		bits := (posSlot >> 1) - 1
+		dc.posModel[i] = makeTreeReverseCodec(bits)
+	}
+	dc.alignCodec = makeTreeReverseCodec(alignBits)
+}
+
+// lenState converts the value l to a supported lenState value.
+func lenState(l uint32) uint32 {
+	if l >= lenStates {
+		l = lenStates - 1
+	}
+	return l
+}
+
+// Encode encodes the distance using the parameter l. Dist can have values from
+// the full range of uint32 values. To get the distance offset the actual match
+// distance has to be decreased by 1. A distance offset of 0xffffffff (eos)
+// indicates the end of the stream.
+func (dc *distCodec) Encode(e *rangeEncoder, dist uint32, l uint32) (err error) {
+	// Compute the posSlot using nlz32
+	var posSlot uint32
+	var bits uint32
+	if dist < startPosModel {
+		posSlot = dist
+	} else {
+		bits = uint32(30 - nlz32(dist))
+		posSlot = startPosModel - 2 + (bits << 1)
+		posSlot += (dist >> uint(bits)) & 1
+	}
+
+	if err = dc.posSlotCodecs[lenState(l)].Encode(e, posSlot); err != nil {
+		return
+	}
+
+	switch {
+	case posSlot < startPosModel:
+		return nil
+	case posSlot < endPosModel:
+		tc := &dc.posModel[posSlot-startPosModel]
+		return tc.Encode(dist, e)
+	}
+	dic := directCodec(bits - alignBits)
+	if err = dic.Encode(e, dist>>alignBits); err != nil {
+		return
+	}
+	return dc.alignCodec.Encode(dist, e)
+}
+
+// Decode decodes the distance offset using the parameter l. The dist value
+// 0xffffffff (eos) indicates the end of the stream. Add one to the distance
+// offset to get the actual match distance.
+func (dc *distCodec) Decode(d *rangeDecoder, l uint32) (dist uint32, err error) {
+	posSlot, err := dc.posSlotCodecs[lenState(l)].Decode(d)
+	if err != nil {
+		return
+	}
+
+	// posSlot equals distance
+	if posSlot < startPosModel {
+		return posSlot, nil
+	}
+
+	// posSlot uses the individual models
+	bits := (posSlot >> 1) - 1
+	dist = (2 | (posSlot & 1)) << bits
+	var u uint32
+	if posSlot < endPosModel {
+		tc := &dc.posModel[posSlot-startPosModel]
+		if u, err = tc.Decode(d); err != nil {
+			return 0, err
+		}
+		dist += u
+		return dist, nil
+	}
+
+	// posSlots use direct encoding and a single model for the four align
+	// bits.
+	dic := directCodec(bits - alignBits)
+	if u, err = dic.Decode(d); err != nil {
+		return 0, err
+	}
+	dist += u << alignBits
+	if u, err = dc.alignCodec.Decode(d); err != nil {
+		return 0, err
+	}
+	dist += u
+	return dist, nil
+}

vendor/github.com/ulikunitz/xz/lzma/encoder.go

@@ -0,0 +1,268 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"fmt"
+	"io"
+)
+
+// opLenMargin provides the upper limit of the number of bytes required
+// to encode a single operation.
+const opLenMargin = 16
+
+// compressFlags control the compression process.
+type compressFlags uint32
+
+// Values for compressFlags.
+const (
+	// all data should be compressed, even if compression is not
+	// optimal.
+	all compressFlags = 1 << iota
+)
+
+// encoderFlags provide the flags for an encoder.
+type encoderFlags uint32
+
+// Flags for the encoder.
+const (
+	// eosMarker requests an EOS marker to be written.
+	eosMarker encoderFlags = 1 << iota
+)
+
+// Encoder compresses data buffered in the encoder dictionary and writes
+// it into a byte writer.
+type encoder struct {
+	dict  *encoderDict
+	state *state
+	re    *rangeEncoder
+	start int64
+	// generate eos marker
+	marker bool
+	limit  bool
+	margin int
+}
+
+// newEncoder creates a new encoder. If the byte writer must be
+// limited use LimitedByteWriter provided by this package. The flags
+// argument supports the eosMarker flag, controlling whether a
+// terminating end-of-stream marker must be written.
+func newEncoder(bw io.ByteWriter, state *state, dict *encoderDict,
+	flags encoderFlags) (e *encoder, err error) {
+
+	re, err := newRangeEncoder(bw)
+	if err != nil {
+		return nil, err
+	}
+	e = &encoder{
+		dict:   dict,
+		state:  state,
+		re:     re,
+		marker: flags&eosMarker != 0,
+		start:  dict.Pos(),
+		margin: opLenMargin,
+	}
+	if e.marker {
+		e.margin += 5
+	}
+	return e, nil
+}
+
+// Write writes the bytes from p into the dictionary. If not enough
+// space is available the data in the dictionary buffer will be
+// compressed to make additional space available. If the limit of the
+// underlying writer has been reached ErrLimit will be returned.
+func (e *encoder) Write(p []byte) (n int, err error) {
+	for {
+		k, err := e.dict.Write(p[n:])
+		n += k
+		if err == ErrNoSpace {
+			if err = e.compress(0); err != nil {
+				return n, err
+			}
+			continue
+		}
+		return n, err
+	}
+}
+
+// Reopen reopens the encoder with a new byte writer.
+func (e *encoder) Reopen(bw io.ByteWriter) error {
+	var err error
+	if e.re, err = newRangeEncoder(bw); err != nil {
+		return err
+	}
+	e.start = e.dict.Pos()
+	e.limit = false
+	return nil
+}
+
+// writeLiteral writes a literal into the LZMA stream
+func (e *encoder) writeLiteral(l lit) error {
+	var err error
+	state, state2, _ := e.state.states(e.dict.Pos())
+	if err = e.state.isMatch[state2].Encode(e.re, 0); err != nil {
+		return err
+	}
+	litState := e.state.litState(e.dict.ByteAt(1), e.dict.Pos())
+	match := e.dict.ByteAt(int(e.state.rep[0]) + 1)
+	err = e.state.litCodec.Encode(e.re, l.b, state, match, litState)
+	if err != nil {
+		return err
+	}
+	e.state.updateStateLiteral()
+	return nil
+}
+
+// iverson implements the Iverson operator as proposed by Donald Knuth in his
+// book Concrete Mathematics.
+func iverson(ok bool) uint32 {
+	if ok {
+		return 1
+	}
+	return 0
+}
+
+// writeMatch writes a repetition operation into the operation stream
+func (e *encoder) writeMatch(m match) error {
+	var err error
+	if !(minDistance <= m.distance && m.distance <= maxDistance) {
+		panic(fmt.Errorf("match distance %d out of range", m.distance))
+	}
+	dist := uint32(m.distance - minDistance)
+	if !(minMatchLen <= m.n && m.n <= maxMatchLen) &&
+		!(dist == e.state.rep[0] && m.n == 1) {
+		panic(fmt.Errorf(
+			"match length %d out of range; dist %d rep[0] %d",
+			m.n, dist, e.state.rep[0]))
+	}
+	state, state2, posState := e.state.states(e.dict.Pos())
+	if err = e.state.isMatch[state2].Encode(e.re, 1); err != nil {
+		return err
+	}
+	g := 0
+	for ; g < 4; g++ {
+		if e.state.rep[g] == dist {
+			break
+		}
+	}
+	b := iverson(g < 4)
+	if err = e.state.isRep[state].Encode(e.re, b); err != nil {
+		return err
+	}
+	n := uint32(m.n - minMatchLen)
+	if b == 0 {
+		// simple match
+		e.state.rep[3], e.state.rep[2], e.state.rep[1], e.state.rep[0] =
+			e.state.rep[2], e.state.rep[1], e.state.rep[0], dist
+		e.state.updateStateMatch()
+		if err = e.state.lenCodec.Encode(e.re, n, posState); err != nil {
+			return err
+		}
+		return e.state.distCodec.Encode(e.re, dist, n)
+	}
+	b = iverson(g != 0)
+	if err = e.state.isRepG0[state].Encode(e.re, b); err != nil {
+		return err
+	}
+	if b == 0 {
+		// g == 0
+		b = iverson(m.n != 1)
+		if err = e.state.isRepG0Long[state2].Encode(e.re, b); err != nil {
+			return err
+		}
+		if b == 0 {
+			e.state.updateStateShortRep()
+			return nil
+		}
+	} else {
+		// g in {1,2,3}
+		b = iverson(g != 1)
+		if err = e.state.isRepG1[state].Encode(e.re, b); err != nil {
+			return err
+		}
+		if b == 1 {
+			// g in {2,3}
+			b = iverson(g != 2)
+			err = e.state.isRepG2[state].Encode(e.re, b)
+			if err != nil {
+				return err
+			}
+			if b == 1 {
+				e.state.rep[3] = e.state.rep[2]
+			}
+			e.state.rep[2] = e.state.rep[1]
+		}
+		e.state.rep[1] = e.state.rep[0]
+		e.state.rep[0] = dist
+	}
+	e.state.updateStateRep()
+	return e.state.repLenCodec.Encode(e.re, n, posState)
+}
+
+// writeOp writes a single operation to the range encoder. The function
+// checks whether there is enough space available to close the LZMA
+// stream.
+func (e *encoder) writeOp(op operation) error {
+	if e.re.Available() < int64(e.margin) {
+		return ErrLimit
+	}
+	switch x := op.(type) {
+	case lit:
+		return e.writeLiteral(x)
+	case match:
+		return e.writeMatch(x)
+	default:
+		panic("unexpected operation")
+	}
+}
+
+// compress compressed data from the dictionary buffer. If the flag all
+// is set, all data in the dictionary buffer will be compressed. The
+// function returns ErrLimit if the underlying writer has reached its
+// limit.
+func (e *encoder) compress(flags compressFlags) error {
+	n := 0
+	if flags&all == 0 {
+		n = maxMatchLen - 1
+	}
+	d := e.dict
+	m := d.m
+	for d.Buffered() > n {
+		op := m.NextOp(e.state.rep)
+		if err := e.writeOp(op); err != nil {
+			return err
+		}
+		d.Discard(op.Len())
+	}
+	return nil
+}
+
+// eosMatch is a pseudo operation that indicates the end of the stream.
+var eosMatch = match{distance: maxDistance, n: minMatchLen}
+
+// Close terminates the LZMA stream. If requested the end-of-stream
+// marker will be written. If the byte writer limit has been or will be
+// reached during compression of the remaining data in the buffer the
+// LZMA stream will be closed and data will remain in the buffer.
+func (e *encoder) Close() error {
+	err := e.compress(all)
+	if err != nil && err != ErrLimit {
+		return err
+	}
+	if e.marker {
+		if err := e.writeMatch(eosMatch); err != nil {
+			return err
+		}
+	}
+	err = e.re.Close()
+	return err
+}
+
+// Compressed returns the number bytes of the input data that been
+// compressed.
+func (e *encoder) Compressed() int64 {
+	return e.dict.Pos() - e.start
+}

vendor/github.com/ulikunitz/xz/lzma/encoderdict.go

@@ -0,0 +1,149 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+	"io"
+)
+
+// matcher is an interface that supports the identification of the next
+// operation.
+type matcher interface {
+	io.Writer
+	SetDict(d *encoderDict)
+	NextOp(rep [4]uint32) operation
+}
+
+// encoderDict provides the dictionary of the encoder. It includes an
+// additional buffer atop of the actual dictionary.
+type encoderDict struct {
+	buf      buffer
+	m        matcher
+	head     int64
+	capacity int
+	// preallocated array
+	data [maxMatchLen]byte
+}
+
+// newEncoderDict creates the encoder dictionary. The argument bufSize
+// defines the size of the additional buffer.
+func newEncoderDict(dictCap, bufSize int, m matcher) (d *encoderDict, err error) {
+	if !(1 <= dictCap && int64(dictCap) <= MaxDictCap) {
+		return nil, errors.New(
+			"lzma: dictionary capacity out of range")
+	}
+	if bufSize < 1 {
+		return nil, errors.New(
+			"lzma: buffer size must be larger than zero")
+	}
+	d = &encoderDict{
+		buf:      *newBuffer(dictCap + bufSize),
+		capacity: dictCap,
+		m:        m,
+	}
+	m.SetDict(d)
+	return d, nil
+}
+
+// Discard discards n bytes. Note that n must not be larger than
+// MaxMatchLen.
+func (d *encoderDict) Discard(n int) {
+	p := d.data[:n]
+	k, _ := d.buf.Read(p)
+	if k < n {
+		panic(fmt.Errorf("lzma: can't discard %d bytes", n))
+	}
+	d.head += int64(n)
+	d.m.Write(p)
+}
+
+// Len returns the data available in the encoder dictionary.
+func (d *encoderDict) Len() int {
+	n := d.buf.Available()
+	if int64(n) > d.head {
+		return int(d.head)
+	}
+	return n
+}
+
+// DictLen returns the actual length of data in the dictionary.
+func (d *encoderDict) DictLen() int {
+	if d.head < int64(d.capacity) {
+		return int(d.head)
+	}
+	return d.capacity
+}
+
+// Available returns the number of bytes that can be written by a
+// following Write call.
+func (d *encoderDict) Available() int {
+	return d.buf.Available() - d.DictLen()
+}
+
+// Write writes data into the dictionary buffer. Note that the position
+// of the dictionary head will not be moved. If there is not enough
+// space in the buffer ErrNoSpace will be returned.
+func (d *encoderDict) Write(p []byte) (n int, err error) {
+	m := d.Available()
+	if len(p) > m {
+		p = p[:m]
+		err = ErrNoSpace
+	}
+	var e error
+	if n, e = d.buf.Write(p); e != nil {
+		err = e
+	}
+	return n, err
+}
+
+// Pos returns the position of the head.
+func (d *encoderDict) Pos() int64 { return d.head }
+
+// ByteAt returns the byte at the given distance.
+func (d *encoderDict) ByteAt(distance int) byte {
+	if !(0 < distance && distance <= d.Len()) {
+		return 0
+	}
+	i := d.buf.rear - distance
+	if i < 0 {
+		i += len(d.buf.data)
+	}
+	return d.buf.data[i]
+}
+
+// CopyN copies the last n bytes from the dictionary into the provided
+// writer. This is used for copying uncompressed data into an
+// uncompressed segment.
+func (d *encoderDict) CopyN(w io.Writer, n int) (written int, err error) {
+	if n <= 0 {
+		return 0, nil
+	}
+	m := d.Len()
+	if n > m {
+		n = m
+		err = ErrNoSpace
+	}
+	i := d.buf.rear - n
+	var e error
+	if i < 0 {
+		i += len(d.buf.data)
+		if written, e = w.Write(d.buf.data[i:]); e != nil {
+			return written, e
+		}
+		i = 0
+	}
+	var k int
+	k, e = w.Write(d.buf.data[i:d.buf.rear])
+	written += k
+	if e != nil {
+		err = e
+	}
+	return written, err
+}
+
+// Buffered returns the number of bytes in the buffer.
+func (d *encoderDict) Buffered() int { return d.buf.Buffered() }

vendor/github.com/ulikunitz/xz/lzma/hashtable.go

@@ -0,0 +1,309 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/ulikunitz/xz/internal/hash"
+)
+
+/* For compression we need to find byte sequences that match the byte
+ * sequence at the dictionary head. A hash table is a simple method to
+ * provide this capability.
+ */
+
+// maxMatches limits the number of matches requested from the Matches
+// function. This controls the speed of the overall encoding.
+const maxMatches = 16
+
+// shortDists defines the number of short distances supported by the
+// implementation.
+const shortDists = 8
+
+// The minimum is somehow arbitrary but the maximum is limited by the
+// memory requirements of the hash table.
+const (
+	minTableExponent = 9
+	maxTableExponent = 20
+)
+
+// newRoller contains the function used to create an instance of the
+// hash.Roller.
+var newRoller = func(n int) hash.Roller { return hash.NewCyclicPoly(n) }
+
+// hashTable stores the hash table including the rolling hash method.
+//
+// We implement chained hashing into a circular buffer. Each entry in
+// the circular buffer stores the delta distance to the next position with a
+// word that has the same hash value.
+type hashTable struct {
+	dict *encoderDict
+	// actual hash table
+	t []int64
+	// circular list data with the offset to the next word
+	data  []uint32
+	front int
+	// mask for computing the index for the hash table
+	mask uint64
+	// hash offset; initial value is -int64(wordLen)
+	hoff int64
+	// length of the hashed word
+	wordLen int
+	// hash roller for computing the hash values for the Write
+	// method
+	wr hash.Roller
+	// hash roller for computing arbitrary hashes
+	hr hash.Roller
+	// preallocated slices
+	p         [maxMatches]int64
+	distances [maxMatches + shortDists]int
+}
+
+// hashTableExponent derives the hash table exponent from the dictionary
+// capacity.
+func hashTableExponent(n uint32) int {
+	e := 30 - nlz32(n)
+	switch {
+	case e < minTableExponent:
+		e = minTableExponent
+	case e > maxTableExponent:
+		e = maxTableExponent
+	}
+	return e
+}
+
+// newHashTable creates a new hash table for words of length wordLen
+func newHashTable(capacity int, wordLen int) (t *hashTable, err error) {
+	if !(0 < capacity) {
+		return nil, errors.New(
+			"newHashTable: capacity must not be negative")
+	}
+	exp := hashTableExponent(uint32(capacity))
+	if !(1 <= wordLen && wordLen <= 4) {
+		return nil, errors.New("newHashTable: " +
+			"argument wordLen out of range")
+	}
+	n := 1 << uint(exp)
+	if n <= 0 {
+		panic("newHashTable: exponent is too large")
+	}
+	t = &hashTable{
+		t:       make([]int64, n),
+		data:    make([]uint32, capacity),
+		mask:    (uint64(1) << uint(exp)) - 1,
+		hoff:    -int64(wordLen),
+		wordLen: wordLen,
+		wr:      newRoller(wordLen),
+		hr:      newRoller(wordLen),
+	}
+	return t, nil
+}
+
+func (t *hashTable) SetDict(d *encoderDict) { t.dict = d }
+
+// buffered returns the number of bytes that are currently hashed.
+func (t *hashTable) buffered() int {
+	n := t.hoff + 1
+	switch {
+	case n <= 0:
+		return 0
+	case n >= int64(len(t.data)):
+		return len(t.data)
+	}
+	return int(n)
+}
+
+// addIndex adds n to an index ensuring that is stays inside the
+// circular buffer for the hash chain.
+func (t *hashTable) addIndex(i, n int) int {
+	i += n - len(t.data)
+	if i < 0 {
+		i += len(t.data)
+	}
+	return i
+}
+
+// putDelta puts the delta instance at the current front of the circular
+// chain buffer.
+func (t *hashTable) putDelta(delta uint32) {
+	t.data[t.front] = delta
+	t.front = t.addIndex(t.front, 1)
+}
+
+// putEntry puts a new entry into the hash table. If there is already a
+// value stored it is moved into the circular chain buffer.
+func (t *hashTable) putEntry(h uint64, pos int64) {
+	if pos < 0 {
+		return
+	}
+	i := h & t.mask
+	old := t.t[i] - 1
+	t.t[i] = pos + 1
+	var delta int64
+	if old >= 0 {
+		delta = pos - old
+		if delta > 1<<32-1 || delta > int64(t.buffered()) {
+			delta = 0
+		}
+	}
+	t.putDelta(uint32(delta))
+}
+
+// WriteByte converts a single byte into a hash and puts them into the hash
+// table.
+func (t *hashTable) WriteByte(b byte) error {
+	h := t.wr.RollByte(b)
+	t.hoff++
+	t.putEntry(h, t.hoff)
+	return nil
+}
+
+// Write converts the bytes provided into hash tables and stores the
+// abbreviated offsets into the hash table. The method will never return an
+// error.
+func (t *hashTable) Write(p []byte) (n int, err error) {
+	for _, b := range p {
+		// WriteByte doesn't generate an error.
+		t.WriteByte(b)
+	}
+	return len(p), nil
+}
+
+// getMatches the matches for a specific hash. The functions returns the
+// number of positions found.
+//
+// TODO: Make a getDistances because that we are actually interested in.
+func (t *hashTable) getMatches(h uint64, positions []int64) (n int) {
+	if t.hoff < 0 || len(positions) == 0 {
+		return 0
+	}
+	buffered := t.buffered()
+	tailPos := t.hoff + 1 - int64(buffered)
+	rear := t.front - buffered
+	if rear >= 0 {
+		rear -= len(t.data)
+	}
+	// get the slot for the hash
+	pos := t.t[h&t.mask] - 1
+	delta := pos - tailPos
+	for {
+		if delta < 0 {
+			return n
+		}
+		positions[n] = tailPos + delta
+		n++
+		if n >= len(positions) {
+			return n
+		}
+		i := rear + int(delta)
+		if i < 0 {
+			i += len(t.data)
+		}
+		u := t.data[i]
+		if u == 0 {
+			return n
+		}
+		delta -= int64(u)
+	}
+}
+
+// hash computes the rolling hash for the word stored in p. For correct
+// results its length must be equal to t.wordLen.
+func (t *hashTable) hash(p []byte) uint64 {
+	var h uint64
+	for _, b := range p {
+		h = t.hr.RollByte(b)
+	}
+	return h
+}
+
+// Matches fills the positions slice with potential matches. The
+// functions returns the number of positions filled into positions. The
+// byte slice p must have word length of the hash table.
+func (t *hashTable) Matches(p []byte, positions []int64) int {
+	if len(p) != t.wordLen {
+		panic(fmt.Errorf(
+			"byte slice must have length %d", t.wordLen))
+	}
+	h := t.hash(p)
+	return t.getMatches(h, positions)
+}
+
+// NextOp identifies the next operation using the hash table.
+//
+// TODO: Use all repetitions to find matches.
+func (t *hashTable) NextOp(rep [4]uint32) operation {
+	// get positions
+	data := t.dict.data[:maxMatchLen]
+	n, _ := t.dict.buf.Peek(data)
+	data = data[:n]
+	var p []int64
+	if n < t.wordLen {
+		p = t.p[:0]
+	} else {
+		p = t.p[:maxMatches]
+		n = t.Matches(data[:t.wordLen], p)
+		p = p[:n]
+	}
+
+	// convert positions in potential distances
+	head := t.dict.head
+	dists := append(t.distances[:0], 1, 2, 3, 4, 5, 6, 7, 8)
+	for _, pos := range p {
+		dis := int(head - pos)
+		if dis > shortDists {
+			dists = append(dists, dis)
+		}
+	}
+
+	// check distances
+	var m match
+	dictLen := t.dict.DictLen()
+	for _, dist := range dists {
+		if dist > dictLen {
+			continue
+		}
+
+		// Here comes a trick. We are only interested in matches
+		// that are longer than the matches we have been found
+		// before. So before we test the whole byte sequence at
+		// the given distance, we test the first byte that would
+		// make the match longer. If it doesn't match the byte
+		// to match, we don't to care any longer.
+		i := t.dict.buf.rear - dist + m.n
+		if i < 0 {
+			i += len(t.dict.buf.data)
+		}
+		if t.dict.buf.data[i] != data[m.n] {
+			// We can't get a longer match. Jump to the next
+			// distance.
+			continue
+		}
+
+		n := t.dict.buf.matchLen(dist, data)
+		switch n {
+		case 0:
+			continue
+		case 1:
+			if uint32(dist-minDistance) != rep[0] {
+				continue
+			}
+		}
+		if n > m.n {
+			m = match{int64(dist), n}
+			if n == len(data) {
+				// No better match will be found.
+				break
+			}
+		}
+	}
+
+	if m.n == 0 {
+		return lit{data[0]}
+	}
+	return m
+}

vendor/github.com/ulikunitz/xz/lzma/header.go

@@ -0,0 +1,167 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+)
+
+// uint32LE reads an uint32 integer from a byte slice
+func uint32LE(b []byte) uint32 {
+	x := uint32(b[3]) << 24
+	x |= uint32(b[2]) << 16
+	x |= uint32(b[1]) << 8
+	x |= uint32(b[0])
+	return x
+}
+
+// uint64LE converts the uint64 value stored as little endian to an uint64
+// value.
+func uint64LE(b []byte) uint64 {
+	x := uint64(b[7]) << 56
+	x |= uint64(b[6]) << 48
+	x |= uint64(b[5]) << 40
+	x |= uint64(b[4]) << 32
+	x |= uint64(b[3]) << 24
+	x |= uint64(b[2]) << 16
+	x |= uint64(b[1]) << 8
+	x |= uint64(b[0])
+	return x
+}
+
+// putUint32LE puts an uint32 integer into a byte slice that must have at least
+// a length of 4 bytes.
+func putUint32LE(b []byte, x uint32) {
+	b[0] = byte(x)
+	b[1] = byte(x >> 8)
+	b[2] = byte(x >> 16)
+	b[3] = byte(x >> 24)
+}
+
+// putUint64LE puts the uint64 value into the byte slice as little endian
+// value. The byte slice b must have at least place for 8 bytes.
+func putUint64LE(b []byte, x uint64) {
+	b[0] = byte(x)
+	b[1] = byte(x >> 8)
+	b[2] = byte(x >> 16)
+	b[3] = byte(x >> 24)
+	b[4] = byte(x >> 32)
+	b[5] = byte(x >> 40)
+	b[6] = byte(x >> 48)
+	b[7] = byte(x >> 56)
+}
+
+// noHeaderSize defines the value of the length field in the LZMA header.
+const noHeaderSize uint64 = 1<<64 - 1
+
+// HeaderLen provides the length of the LZMA file header.
+const HeaderLen = 13
+
+// header represents the header of an LZMA file.
+type header struct {
+	properties Properties
+	dictCap    int
+	// uncompressed size; negative value if no size is given
+	size int64
+}
+
+// marshalBinary marshals the header.
+func (h *header) marshalBinary() (data []byte, err error) {
+	if err = h.properties.verify(); err != nil {
+		return nil, err
+	}
+	if !(0 <= h.dictCap && int64(h.dictCap) <= MaxDictCap) {
+		return nil, fmt.Errorf("lzma: DictCap %d out of range",
+			h.dictCap)
+	}
+
+	data = make([]byte, 13)
+
+	// property byte
+	data[0] = h.properties.Code()
+
+	// dictionary capacity
+	putUint32LE(data[1:5], uint32(h.dictCap))
+
+	// uncompressed size
+	var s uint64
+	if h.size > 0 {
+		s = uint64(h.size)
+	} else {
+		s = noHeaderSize
+	}
+	putUint64LE(data[5:], s)
+
+	return data, nil
+}
+
+// unmarshalBinary unmarshals the header.
+func (h *header) unmarshalBinary(data []byte) error {
+	if len(data) != HeaderLen {
+		return errors.New("lzma.unmarshalBinary: data has wrong length")
+	}
+
+	// properties
+	var err error
+	if h.properties, err = PropertiesForCode(data[0]); err != nil {
+		return err
+	}
+
+	// dictionary capacity
+	h.dictCap = int(uint32LE(data[1:]))
+	if h.dictCap < 0 {
+		return errors.New(
+			"LZMA header: dictionary capacity exceeds maximum " +
+				"integer")
+	}
+
+	// uncompressed size
+	s := uint64LE(data[5:])
+	if s == noHeaderSize {
+		h.size = -1
+	} else {
+		h.size = int64(s)
+		if h.size < 0 {
+			return errors.New(
+				"LZMA header: uncompressed size " +
+					"out of int64 range")
+		}
+	}
+
+	return nil
+}
+
+// validDictCap checks whether the dictionary capacity is correct. This
+// is used to weed out wrong file headers.
+func validDictCap(dictcap int) bool {
+	if int64(dictcap) == MaxDictCap {
+		return true
+	}
+	for n := uint(10); n < 32; n++ {
+		if dictcap == 1<<n {
+			return true
+		}
+		if dictcap == 1<<n+1<<(n-1) {
+			return true
+		}
+	}
+	return false
+}
+
+// ValidHeader checks for a valid LZMA file header. It allows only
+// dictionary sizes of 2^n or 2^n+2^(n-1) with n >= 10 or 2^32-1. If
+// there is an explicit size it must not exceed 256 GiB. The length of
+// the data argument must be HeaderLen.
+func ValidHeader(data []byte) bool {
+	var h header
+	if err := h.unmarshalBinary(data); err != nil {
+		return false
+	}
+	if !validDictCap(h.dictCap) {
+		return false
+	}
+	return h.size < 0 || h.size <= 1<<38
+}

vendor/github.com/ulikunitz/xz/lzma/header2.go

@@ -0,0 +1,398 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+	"io"
+)
+
+const (
+	// maximum size of compressed data in a chunk
+	maxCompressed = 1 << 16
+	// maximum size of uncompressed data in a chunk
+	maxUncompressed = 1 << 21
+)
+
+// chunkType represents the type of an LZMA2 chunk. Note that this
+// value is an internal representation and no actual encoding of a LZMA2
+// chunk header.
+type chunkType byte
+
+// Possible values for the chunk type.
+const (
+	// end of stream
+	cEOS chunkType = iota
+	// uncompressed; reset dictionary
+	cUD
+	// uncompressed; no reset of dictionary
+	cU
+	// LZMA compressed; no reset
+	cL
+	// LZMA compressed; reset state
+	cLR
+	// LZMA compressed; reset state; new property value
+	cLRN
+	// LZMA compressed; reset state; new property value; reset dictionary
+	cLRND
+)
+
+// chunkTypeStrings provide a string representation for the chunk types.
+var chunkTypeStrings = [...]string{
+	cEOS:  "EOS",
+	cU:    "U",
+	cUD:   "UD",
+	cL:    "L",
+	cLR:   "LR",
+	cLRN:  "LRN",
+	cLRND: "LRND",
+}
+
+// String returns a string representation of the chunk type.
+func (c chunkType) String() string {
+	if !(cEOS <= c && c <= cLRND) {
+		return "unknown"
+	}
+	return chunkTypeStrings[c]
+}
+
+// Actual encodings for the chunk types in the value. Note that the high
+// uncompressed size bits are stored in the header byte additionally.
+const (
+	hEOS  = 0
+	hUD   = 1
+	hU    = 2
+	hL    = 1 << 7
+	hLR   = 1<<7 | 1<<5
+	hLRN  = 1<<7 | 1<<6
+	hLRND = 1<<7 | 1<<6 | 1<<5
+)
+
+// errHeaderByte indicates an unsupported value for the chunk header
+// byte. These bytes starts the variable-length chunk header.
+var errHeaderByte = errors.New("lzma: unsupported chunk header byte")
+
+// headerChunkType converts the header byte into a chunk type. It
+// ignores the uncompressed size bits in the chunk header byte.
+func headerChunkType(h byte) (c chunkType, err error) {
+	if h&hL == 0 {
+		// no compression
+		switch h {
+		case hEOS:
+			c = cEOS
+		case hUD:
+			c = cUD
+		case hU:
+			c = cU
+		default:
+			return 0, errHeaderByte
+		}
+		return
+	}
+	switch h & hLRND {
+	case hL:
+		c = cL
+	case hLR:
+		c = cLR
+	case hLRN:
+		c = cLRN
+	case hLRND:
+		c = cLRND
+	default:
+		return 0, errHeaderByte
+	}
+	return
+}
+
+// uncompressedHeaderLen provides the length of an uncompressed header
+const uncompressedHeaderLen = 3
+
+// headerLen returns the length of the LZMA2 header for a given chunk
+// type.
+func headerLen(c chunkType) int {
+	switch c {
+	case cEOS:
+		return 1
+	case cU, cUD:
+		return uncompressedHeaderLen
+	case cL, cLR:
+		return 5
+	case cLRN, cLRND:
+		return 6
+	}
+	panic(fmt.Errorf("unsupported chunk type %d", c))
+}
+
+// chunkHeader represents the contents of a chunk header.
+type chunkHeader struct {
+	ctype        chunkType
+	uncompressed uint32
+	compressed   uint16
+	props        Properties
+}
+
+// String returns a string representation of the chunk header.
+func (h *chunkHeader) String() string {
+	return fmt.Sprintf("%s %d %d %s", h.ctype, h.uncompressed,
+		h.compressed, &h.props)
+}
+
+// UnmarshalBinary reads the content of the chunk header from the data
+// slice. The slice must have the correct length.
+func (h *chunkHeader) UnmarshalBinary(data []byte) error {
+	if len(data) == 0 {
+		return errors.New("no data")
+	}
+	c, err := headerChunkType(data[0])
+	if err != nil {
+		return err
+	}
+
+	n := headerLen(c)
+	if len(data) < n {
+		return errors.New("incomplete data")
+	}
+	if len(data) > n {
+		return errors.New("invalid data length")
+	}
+
+	*h = chunkHeader{ctype: c}
+	if c == cEOS {
+		return nil
+	}
+
+	h.uncompressed = uint32(uint16BE(data[1:3]))
+	if c <= cU {
+		return nil
+	}
+	h.uncompressed |= uint32(data[0]&^hLRND) << 16
+
+	h.compressed = uint16BE(data[3:5])
+	if c <= cLR {
+		return nil
+	}
+
+	h.props, err = PropertiesForCode(data[5])
+	return err
+}
+
+// MarshalBinary encodes the chunk header value. The function checks
+// whether the content of the chunk header is correct.
+func (h *chunkHeader) MarshalBinary() (data []byte, err error) {
+	if h.ctype > cLRND {
+		return nil, errors.New("invalid chunk type")
+	}
+	if err = h.props.verify(); err != nil {
+		return nil, err
+	}
+
+	data = make([]byte, headerLen(h.ctype))
+
+	switch h.ctype {
+	case cEOS:
+		return data, nil
+	case cUD:
+		data[0] = hUD
+	case cU:
+		data[0] = hU
+	case cL:
+		data[0] = hL
+	case cLR:
+		data[0] = hLR
+	case cLRN:
+		data[0] = hLRN
+	case cLRND:
+		data[0] = hLRND
+	}
+
+	putUint16BE(data[1:3], uint16(h.uncompressed))
+	if h.ctype <= cU {
+		return data, nil
+	}
+	data[0] |= byte(h.uncompressed>>16) &^ hLRND
+
+	putUint16BE(data[3:5], h.compressed)
+	if h.ctype <= cLR {
+		return data, nil
+	}
+
+	data[5] = h.props.Code()
+	return data, nil
+}
+
+// readChunkHeader reads the chunk header from the IO reader.
+func readChunkHeader(r io.Reader) (h *chunkHeader, err error) {
+	p := make([]byte, 1, 6)
+	if _, err = io.ReadFull(r, p); err != nil {
+		return
+	}
+	c, err := headerChunkType(p[0])
+	if err != nil {
+		return
+	}
+	p = p[:headerLen(c)]
+	if _, err = io.ReadFull(r, p[1:]); err != nil {
+		return
+	}
+	h = new(chunkHeader)
+	if err = h.UnmarshalBinary(p); err != nil {
+		return nil, err
+	}
+	return h, nil
+}
+
+// uint16BE converts a big-endian uint16 representation to an uint16
+// value.
+func uint16BE(p []byte) uint16 {
+	return uint16(p[0])<<8 | uint16(p[1])
+}
+
+// putUint16BE puts the big-endian uint16 presentation into the given
+// slice.
+func putUint16BE(p []byte, x uint16) {
+	p[0] = byte(x >> 8)
+	p[1] = byte(x)
+}
+
+// chunkState is used to manage the state of the chunks
+type chunkState byte
+
+// start and stop define the initial and terminating state of the chunk
+// state
+const (
+	start chunkState = 'S'
+	stop  chunkState = 'T'
+)
+
+// errors for the chunk state handling
+var (
+	errChunkType = errors.New("lzma: unexpected chunk type")
+	errState     = errors.New("lzma: wrong chunk state")
+)
+
+// next transitions state based on chunk type input
+func (c *chunkState) next(ctype chunkType) error {
+	switch *c {
+	// start state
+	case 'S':
+		switch ctype {
+		case cEOS:
+			*c = 'T'
+		case cUD:
+			*c = 'R'
+		case cLRND:
+			*c = 'L'
+		default:
+			return errChunkType
+		}
+	// normal LZMA mode
+	case 'L':
+		switch ctype {
+		case cEOS:
+			*c = 'T'
+		case cUD:
+			*c = 'R'
+		case cU:
+			*c = 'U'
+		case cL, cLR, cLRN, cLRND:
+			break
+		default:
+			return errChunkType
+		}
+	// reset required
+	case 'R':
+		switch ctype {
+		case cEOS:
+			*c = 'T'
+		case cUD, cU:
+			break
+		case cLRN, cLRND:
+			*c = 'L'
+		default:
+			return errChunkType
+		}
+	// uncompressed
+	case 'U':
+		switch ctype {
+		case cEOS:
+			*c = 'T'
+		case cUD:
+			*c = 'R'
+		case cU:
+			break
+		case cL, cLR, cLRN, cLRND:
+			*c = 'L'
+		default:
+			return errChunkType
+		}
+	// terminal state
+	case 'T':
+		return errChunkType
+	default:
+		return errState
+	}
+	return nil
+}
+
+// defaultChunkType returns the default chunk type for each chunk state.
+func (c chunkState) defaultChunkType() chunkType {
+	switch c {
+	case 'S':
+		return cLRND
+	case 'L', 'U':
+		return cL
+	case 'R':
+		return cLRN
+	default:
+		// no error
+		return cEOS
+	}
+}
+
+// maxDictCap defines the maximum dictionary capacity supported by the
+// LZMA2 dictionary capacity encoding.
+const maxDictCap = 1<<32 - 1
+
+// maxDictCapCode defines the maximum dictionary capacity code.
+const maxDictCapCode = 40
+
+// The function decodes the dictionary capacity byte, but doesn't change
+// for the correct range of the given byte.
+func decodeDictCap(c byte) int64 {
+	return (2 | int64(c)&1) << (11 + (c>>1)&0x1f)
+}
+
+// DecodeDictCap decodes the encoded dictionary capacity. The function
+// returns an error if the code is out of range.
+func DecodeDictCap(c byte) (n int64, err error) {
+	if c >= maxDictCapCode {
+		if c == maxDictCapCode {
+			return maxDictCap, nil
+		}
+		return 0, errors.New("lzma: invalid dictionary size code")
+	}
+	return decodeDictCap(c), nil
+}
+
+// EncodeDictCap encodes a dictionary capacity. The function returns the
+// code for the capacity that is greater or equal n. If n exceeds the
+// maximum support dictionary capacity, the maximum value is returned.
+func EncodeDictCap(n int64) byte {
+	a, b := byte(0), byte(40)
+	for a < b {
+		c := a + (b-a)>>1
+		m := decodeDictCap(c)
+		if n <= m {
+			if n == m {
+				return c
+			}
+			b = c
+		} else {
+			a = c + 1
+		}
+	}
+	return a
+}

vendor/github.com/ulikunitz/xz/lzma/lengthcodec.go

@@ -0,0 +1,116 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import "errors"
+
+// maxPosBits defines the number of bits of the position value that are used to
+// to compute the posState value. The value is used to select the tree codec
+// for length encoding and decoding.
+const maxPosBits = 4
+
+// minMatchLen and maxMatchLen give the minimum and maximum values for
+// encoding and decoding length values. minMatchLen is also used as base
+// for the encoded length values.
+const (
+	minMatchLen = 2
+	maxMatchLen = minMatchLen + 16 + 256 - 1
+)
+
+// lengthCodec support the encoding of the length value.
+type lengthCodec struct {
+	choice [2]prob
+	low    [1 << maxPosBits]treeCodec
+	mid    [1 << maxPosBits]treeCodec
+	high   treeCodec
+}
+
+// deepcopy initializes the lc value as deep copy of the source value.
+func (lc *lengthCodec) deepcopy(src *lengthCodec) {
+	if lc == src {
+		return
+	}
+	lc.choice = src.choice
+	for i := range lc.low {
+		lc.low[i].deepcopy(&src.low[i])
+	}
+	for i := range lc.mid {
+		lc.mid[i].deepcopy(&src.mid[i])
+	}
+	lc.high.deepcopy(&src.high)
+}
+
+// init initializes a new length codec.
+func (lc *lengthCodec) init() {
+	for i := range lc.choice {
+		lc.choice[i] = probInit
+	}
+	for i := range lc.low {
+		lc.low[i] = makeTreeCodec(3)
+	}
+	for i := range lc.mid {
+		lc.mid[i] = makeTreeCodec(3)
+	}
+	lc.high = makeTreeCodec(8)
+}
+
+// Encode encodes the length offset. The length offset l can be compute by
+// subtracting minMatchLen (2) from the actual length.
+//
+//   l = length - minMatchLen
+//
+func (lc *lengthCodec) Encode(e *rangeEncoder, l uint32, posState uint32,
+) (err error) {
+	if l > maxMatchLen-minMatchLen {
+		return errors.New("lengthCodec.Encode: l out of range")
+	}
+	if l < 8 {
+		if err = lc.choice[0].Encode(e, 0); err != nil {
+			return
+		}
+		return lc.low[posState].Encode(e, l)
+	}
+	if err = lc.choice[0].Encode(e, 1); err != nil {
+		return
+	}
+	if l < 16 {
+		if err = lc.choice[1].Encode(e, 0); err != nil {
+			return
+		}
+		return lc.mid[posState].Encode(e, l-8)
+	}
+	if err = lc.choice[1].Encode(e, 1); err != nil {
+		return
+	}
+	if err = lc.high.Encode(e, l-16); err != nil {
+		return
+	}
+	return nil
+}
+
+// Decode reads the length offset. Add minMatchLen to compute the actual length
+// to the length offset l.
+func (lc *lengthCodec) Decode(d *rangeDecoder, posState uint32,
+) (l uint32, err error) {
+	var b uint32
+	if b, err = lc.choice[0].Decode(d); err != nil {
+		return
+	}
+	if b == 0 {
+		l, err = lc.low[posState].Decode(d)
+		return
+	}
+	if b, err = lc.choice[1].Decode(d); err != nil {
+		return
+	}
+	if b == 0 {
+		l, err = lc.mid[posState].Decode(d)
+		l += 8
+		return
+	}
+	l, err = lc.high.Decode(d)
+	l += 16
+	return
+}

vendor/github.com/ulikunitz/xz/lzma/literalcodec.go

@@ -0,0 +1,125 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+// literalCodec supports the encoding of literal. It provides 768 probability
+// values per literal state. The upper 512 probabilities are used with the
+// context of a match bit.
+type literalCodec struct {
+	probs []prob
+}
+
+// deepcopy initializes literal codec c as a deep copy of the source.
+func (c *literalCodec) deepcopy(src *literalCodec) {
+	if c == src {
+		return
+	}
+	c.probs = make([]prob, len(src.probs))
+	copy(c.probs, src.probs)
+}
+
+// init initializes the literal codec.
+func (c *literalCodec) init(lc, lp int) {
+	switch {
+	case !(minLC <= lc && lc <= maxLC):
+		panic("lc out of range")
+	case !(minLP <= lp && lp <= maxLP):
+		panic("lp out of range")
+	}
+	c.probs = make([]prob, 0x300<<uint(lc+lp))
+	for i := range c.probs {
+		c.probs[i] = probInit
+	}
+}
+
+// Encode encodes the byte s using a range encoder as well as the current LZMA
+// encoder state, a match byte and the literal state.
+func (c *literalCodec) Encode(e *rangeEncoder, s byte,
+	state uint32, match byte, litState uint32,
+) (err error) {
+	k := litState * 0x300
+	probs := c.probs[k : k+0x300]
+	symbol := uint32(1)
+	r := uint32(s)
+	if state >= 7 {
+		m := uint32(match)
+		for {
+			matchBit := (m >> 7) & 1
+			m <<= 1
+			bit := (r >> 7) & 1
+			r <<= 1
+			i := ((1 + matchBit) << 8) | symbol
+			if err = probs[i].Encode(e, bit); err != nil {
+				return
+			}
+			symbol = (symbol << 1) | bit
+			if matchBit != bit {
+				break
+			}
+			if symbol >= 0x100 {
+				break
+			}
+		}
+	}
+	for symbol < 0x100 {
+		bit := (r >> 7) & 1
+		r <<= 1
+		if err = probs[symbol].Encode(e, bit); err != nil {
+			return
+		}
+		symbol = (symbol << 1) | bit
+	}
+	return nil
+}
+
+// Decode decodes a literal byte using the range decoder as well as the LZMA
+// state, a match byte, and the literal state.
+func (c *literalCodec) Decode(d *rangeDecoder,
+	state uint32, match byte, litState uint32,
+) (s byte, err error) {
+	k := litState * 0x300
+	probs := c.probs[k : k+0x300]
+	symbol := uint32(1)
+	if state >= 7 {
+		m := uint32(match)
+		for {
+			matchBit := (m >> 7) & 1
+			m <<= 1
+			i := ((1 + matchBit) << 8) | symbol
+			bit, err := d.DecodeBit(&probs[i])
+			if err != nil {
+				return 0, err
+			}
+			symbol = (symbol << 1) | bit
+			if matchBit != bit {
+				break
+			}
+			if symbol >= 0x100 {
+				break
+			}
+		}
+	}
+	for symbol < 0x100 {
+		bit, err := d.DecodeBit(&probs[symbol])
+		if err != nil {
+			return 0, err
+		}
+		symbol = (symbol << 1) | bit
+	}
+	s = byte(symbol - 0x100)
+	return s, nil
+}
+
+// minLC and maxLC define the range for LC values.
+const (
+	minLC = 0
+	maxLC = 8
+)
+
+// minLC and maxLC define the range for LP values.
+const (
+	minLP = 0
+	maxLP = 4
+)

vendor/github.com/ulikunitz/xz/lzma/matchalgorithm.go

@@ -0,0 +1,52 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import "errors"
+
+// MatchAlgorithm identifies an algorithm to find matches in the
+// dictionary.
+type MatchAlgorithm byte
+
+// Supported matcher algorithms.
+const (
+	HashTable4 MatchAlgorithm = iota
+	BinaryTree
+)
+
+// maStrings are used by the String method.
+var maStrings = map[MatchAlgorithm]string{
+	HashTable4: "HashTable4",
+	BinaryTree: "BinaryTree",
+}
+
+// String returns a string representation of the Matcher.
+func (a MatchAlgorithm) String() string {
+	if s, ok := maStrings[a]; ok {
+		return s
+	}
+	return "unknown"
+}
+
+var errUnsupportedMatchAlgorithm = errors.New(
+	"lzma: unsupported match algorithm value")
+
+// verify checks whether the matcher value is supported.
+func (a MatchAlgorithm) verify() error {
+	if _, ok := maStrings[a]; !ok {
+		return errUnsupportedMatchAlgorithm
+	}
+	return nil
+}
+
+func (a MatchAlgorithm) new(dictCap int) (m matcher, err error) {
+	switch a {
+	case HashTable4:
+		return newHashTable(dictCap, 4)
+	case BinaryTree:
+		return newBinTree(dictCap)
+	}
+	return nil, errUnsupportedMatchAlgorithm
+}

vendor/github.com/ulikunitz/xz/lzma/operation.go

@@ -0,0 +1,55 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"fmt"
+	"unicode"
+)
+
+// operation represents an operation on the dictionary during encoding or
+// decoding.
+type operation interface {
+	Len() int
+}
+
+// rep represents a repetition at the given distance and the given length
+type match struct {
+	// supports all possible distance values, including the eos marker
+	distance int64
+	// length
+	n int
+}
+
+// Len returns the number of bytes matched.
+func (m match) Len() int {
+	return m.n
+}
+
+// String returns a string representation for the repetition.
+func (m match) String() string {
+	return fmt.Sprintf("M{%d,%d}", m.distance, m.n)
+}
+
+// lit represents a single byte literal.
+type lit struct {
+	b byte
+}
+
+// Len returns 1 for the single byte literal.
+func (l lit) Len() int {
+	return 1
+}
+
+// String returns a string representation for the literal.
+func (l lit) String() string {
+	var c byte
+	if unicode.IsPrint(rune(l.b)) {
+		c = l.b
+	} else {
+		c = '.'
+	}
+	return fmt.Sprintf("L{%c/%02x}", c, l.b)
+}

vendor/github.com/ulikunitz/xz/lzma/prob.go

@@ -0,0 +1,53 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+// movebits defines the number of bits used for the updates of probability
+// values.
+const movebits = 5
+
+// probbits defines the number of bits of a probability value.
+const probbits = 11
+
+// probInit defines 0.5 as initial value for prob values.
+const probInit prob = 1 << (probbits - 1)
+
+// Type prob represents probabilities. The type can also be used to encode and
+// decode single bits.
+type prob uint16
+
+// Dec decreases the probability. The decrease is proportional to the
+// probability value.
+func (p *prob) dec() {
+	*p -= *p >> movebits
+}
+
+// Inc increases the probability. The Increase is proportional to the
+// difference of 1 and the probability value.
+func (p *prob) inc() {
+	*p += ((1 << probbits) - *p) >> movebits
+}
+
+// Computes the new bound for a given range using the probability value.
+func (p prob) bound(r uint32) uint32 {
+	return (r >> probbits) * uint32(p)
+}
+
+// Bits returns 1. One is the number of bits that can be encoded or decoded
+// with a single prob value.
+func (p prob) Bits() int {
+	return 1
+}
+
+// Encode encodes the least-significant bit of v. Note that the p value will be
+// changed.
+func (p *prob) Encode(e *rangeEncoder, v uint32) error {
+	return e.EncodeBit(v, p)
+}
+
+// Decode decodes a single bit. Note that the p value will change.
+func (p *prob) Decode(d *rangeDecoder) (v uint32, err error) {
+	return d.DecodeBit(p)
+}

vendor/github.com/ulikunitz/xz/lzma/properties.go

@@ -0,0 +1,69 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+)
+
+// maximum and minimum values for the LZMA properties.
+const (
+	minPB = 0
+	maxPB = 4
+)
+
+// maxPropertyCode is the possible maximum of a properties code byte.
+const maxPropertyCode = (maxPB+1)*(maxLP+1)*(maxLC+1) - 1
+
+// Properties contains the parameters LC, LP and PB. The parameter LC
+// defines the number of literal context bits; parameter LP the number
+// of literal position bits and PB the number of position bits.
+type Properties struct {
+	LC int
+	LP int
+	PB int
+}
+
+// String returns the properties in a string representation.
+func (p *Properties) String() string {
+	return fmt.Sprintf("LC %d LP %d PB %d", p.LC, p.LP, p.PB)
+}
+
+// PropertiesForCode converts a properties code byte into a Properties value.
+func PropertiesForCode(code byte) (p Properties, err error) {
+	if code > maxPropertyCode {
+		return p, errors.New("lzma: invalid properties code")
+	}
+	p.LC = int(code % 9)
+	code /= 9
+	p.LP = int(code % 5)
+	code /= 5
+	p.PB = int(code % 5)
+	return p, err
+}
+
+// verify checks the properties for correctness.
+func (p *Properties) verify() error {
+	if p == nil {
+		return errors.New("lzma: properties are nil")
+	}
+	if !(minLC <= p.LC && p.LC <= maxLC) {
+		return errors.New("lzma: lc out of range")
+	}
+	if !(minLP <= p.LP && p.LP <= maxLP) {
+		return errors.New("lzma: lp out of range")
+	}
+	if !(minPB <= p.PB && p.PB <= maxPB) {
+		return errors.New("lzma: pb out of range")
+	}
+	return nil
+}
+
+// Code converts the properties to a byte. The function assumes that
+// the properties components are all in range.
+func (p Properties) Code() byte {
+	return byte((p.PB*5+p.LP)*9 + p.LC)
+}

vendor/github.com/ulikunitz/xz/lzma/rangecodec.go

@@ -0,0 +1,222 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"io"
+)
+
+// rangeEncoder implements range encoding of single bits. The low value can
+// overflow therefore we need uint64. The cache value is used to handle
+// overflows.
+type rangeEncoder struct {
+	lbw      *LimitedByteWriter
+	nrange   uint32
+	low      uint64
+	cacheLen int64
+	cache    byte
+}
+
+// maxInt64 provides the  maximal value of the int64 type
+const maxInt64 = 1<<63 - 1
+
+// newRangeEncoder creates a new range encoder.
+func newRangeEncoder(bw io.ByteWriter) (re *rangeEncoder, err error) {
+	lbw, ok := bw.(*LimitedByteWriter)
+	if !ok {
+		lbw = &LimitedByteWriter{BW: bw, N: maxInt64}
+	}
+	return &rangeEncoder{
+		lbw:      lbw,
+		nrange:   0xffffffff,
+		cacheLen: 1}, nil
+}
+
+// Available returns the number of bytes that still can be written. The
+// method takes the bytes that will be currently written by Close into
+// account.
+func (e *rangeEncoder) Available() int64 {
+	return e.lbw.N - (e.cacheLen + 4)
+}
+
+// writeByte writes a single byte to the underlying writer. An error is
+// returned if the limit is reached. The written byte will be counted if
+// the underlying writer doesn't return an error.
+func (e *rangeEncoder) writeByte(c byte) error {
+	if e.Available() < 1 {
+		return ErrLimit
+	}
+	return e.lbw.WriteByte(c)
+}
+
+// DirectEncodeBit encodes the least-significant bit of b with probability 1/2.
+func (e *rangeEncoder) DirectEncodeBit(b uint32) error {
+	e.nrange >>= 1
+	e.low += uint64(e.nrange) & (0 - (uint64(b) & 1))
+
+	// normalize
+	const top = 1 << 24
+	if e.nrange >= top {
+		return nil
+	}
+	e.nrange <<= 8
+	return e.shiftLow()
+}
+
+// EncodeBit encodes the least significant bit of b. The p value will be
+// updated by the function depending on the bit encoded.
+func (e *rangeEncoder) EncodeBit(b uint32, p *prob) error {
+	bound := p.bound(e.nrange)
+	if b&1 == 0 {
+		e.nrange = bound
+		p.inc()
+	} else {
+		e.low += uint64(bound)
+		e.nrange -= bound
+		p.dec()
+	}
+
+	// normalize
+	const top = 1 << 24
+	if e.nrange >= top {
+		return nil
+	}
+	e.nrange <<= 8
+	return e.shiftLow()
+}
+
+// Close writes a complete copy of the low value.
+func (e *rangeEncoder) Close() error {
+	for i := 0; i < 5; i++ {
+		if err := e.shiftLow(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// shiftLow shifts the low value for 8 bit. The shifted byte is written into
+// the byte writer. The cache value is used to handle overflows.
+func (e *rangeEncoder) shiftLow() error {
+	if uint32(e.low) < 0xff000000 || (e.low>>32) != 0 {
+		tmp := e.cache
+		for {
+			err := e.writeByte(tmp + byte(e.low>>32))
+			if err != nil {
+				return err
+			}
+			tmp = 0xff
+			e.cacheLen--
+			if e.cacheLen <= 0 {
+				if e.cacheLen < 0 {
+					panic("negative cacheLen")
+				}
+				break
+			}
+		}
+		e.cache = byte(uint32(e.low) >> 24)
+	}
+	e.cacheLen++
+	e.low = uint64(uint32(e.low) << 8)
+	return nil
+}
+
+// rangeDecoder decodes single bits of the range encoding stream.
+type rangeDecoder struct {
+	br     io.ByteReader
+	nrange uint32
+	code   uint32
+}
+
+// newRangeDecoder initializes a range decoder. It reads five bytes from the
+// reader and therefore may return an error.
+func newRangeDecoder(br io.ByteReader) (d *rangeDecoder, err error) {
+	d = &rangeDecoder{br: br, nrange: 0xffffffff}
+
+	b, err := d.br.ReadByte()
+	if err != nil {
+		return nil, err
+	}
+	if b != 0 {
+		return nil, errors.New("newRangeDecoder: first byte not zero")
+	}
+
+	for i := 0; i < 4; i++ {
+		if err = d.updateCode(); err != nil {
+			return nil, err
+		}
+	}
+
+	if d.code >= d.nrange {
+		return nil, errors.New("newRangeDecoder: d.code >= d.nrange")
+	}
+
+	return d, nil
+}
+
+// possiblyAtEnd checks whether the decoder may be at the end of the stream.
+func (d *rangeDecoder) possiblyAtEnd() bool {
+	return d.code == 0
+}
+
+// DirectDecodeBit decodes a bit with probability 1/2. The return value b will
+// contain the bit at the least-significant position. All other bits will be
+// zero.
+func (d *rangeDecoder) DirectDecodeBit() (b uint32, err error) {
+	d.nrange >>= 1
+	d.code -= d.nrange
+	t := 0 - (d.code >> 31)
+	d.code += d.nrange & t
+	b = (t + 1) & 1
+
+	// d.code will stay less then d.nrange
+
+	// normalize
+	// assume d.code < d.nrange
+	const top = 1 << 24
+	if d.nrange >= top {
+		return b, nil
+	}
+	d.nrange <<= 8
+	// d.code < d.nrange will be maintained
+	return b, d.updateCode()
+}
+
+// decodeBit decodes a single bit. The bit will be returned at the
+// least-significant position. All other bits will be zero. The probability
+// value will be updated.
+func (d *rangeDecoder) DecodeBit(p *prob) (b uint32, err error) {
+	bound := p.bound(d.nrange)
+	if d.code < bound {
+		d.nrange = bound
+		p.inc()
+		b = 0
+	} else {
+		d.code -= bound
+		d.nrange -= bound
+		p.dec()
+		b = 1
+	}
+	// normalize
+	// assume d.code < d.nrange
+	const top = 1 << 24
+	if d.nrange >= top {
+		return b, nil
+	}
+	d.nrange <<= 8
+	// d.code < d.nrange will be maintained
+	return b, d.updateCode()
+}
+
+// updateCode reads a new byte into the code.
+func (d *rangeDecoder) updateCode() error {
+	b, err := d.br.ReadByte()
+	if err != nil {
+		return err
+	}
+	d.code = (d.code << 8) | uint32(b)
+	return nil
+}

vendor/github.com/ulikunitz/xz/lzma/reader.go

@@ -0,0 +1,100 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package lzma supports the decoding and encoding of LZMA streams.
+// Reader and Writer support the classic LZMA format. Reader2 and
+// Writer2 support the decoding and encoding of LZMA2 streams.
+//
+// The package is written completely in Go and doesn't rely on any external
+// library.
+package lzma
+
+import (
+	"errors"
+	"io"
+)
+
+// ReaderConfig stores the parameters for the reader of the classic LZMA
+// format.
+type ReaderConfig struct {
+	DictCap int
+}
+
+// fill converts the zero values of the configuration to the default values.
+func (c *ReaderConfig) fill() {
+	if c.DictCap == 0 {
+		c.DictCap = 8 * 1024 * 1024
+	}
+}
+
+// Verify checks the reader configuration for errors. Zero values will
+// be replaced by default values.
+func (c *ReaderConfig) Verify() error {
+	c.fill()
+	if !(MinDictCap <= c.DictCap && int64(c.DictCap) <= MaxDictCap) {
+		return errors.New("lzma: dictionary capacity is out of range")
+	}
+	return nil
+}
+
+// Reader provides a reader for LZMA files or streams.
+type Reader struct {
+	lzma io.Reader
+	h    header
+	d    *decoder
+}
+
+// NewReader creates a new reader for an LZMA stream using the classic
+// format. NewReader reads and checks the header of the LZMA stream.
+func NewReader(lzma io.Reader) (r *Reader, err error) {
+	return ReaderConfig{}.NewReader(lzma)
+}
+
+// NewReader creates a new reader for an LZMA stream in the classic
+// format. The function reads and verifies the the header of the LZMA
+// stream.
+func (c ReaderConfig) NewReader(lzma io.Reader) (r *Reader, err error) {
+	if err = c.Verify(); err != nil {
+		return nil, err
+	}
+	data := make([]byte, HeaderLen)
+	if _, err := io.ReadFull(lzma, data); err != nil {
+		if err == io.EOF {
+			return nil, errors.New("lzma: unexpected EOF")
+		}
+		return nil, err
+	}
+	r = &Reader{lzma: lzma}
+	if err = r.h.unmarshalBinary(data); err != nil {
+		return nil, err
+	}
+	if r.h.dictCap < MinDictCap {
+		return nil, errors.New("lzma: dictionary capacity too small")
+	}
+	dictCap := r.h.dictCap
+	if c.DictCap > dictCap {
+		dictCap = c.DictCap
+	}
+
+	state := newState(r.h.properties)
+	dict, err := newDecoderDict(dictCap)
+	if err != nil {
+		return nil, err
+	}
+	r.d, err = newDecoder(ByteReader(lzma), state, dict, r.h.size)
+	if err != nil {
+		return nil, err
+	}
+	return r, nil
+}
+
+// EOSMarker indicates that an EOS marker has been encountered.
+func (r *Reader) EOSMarker() bool {
+	return r.d.eosMarker
+}
+
+// Read returns uncompressed data.
+func (r *Reader) Read(p []byte) (n int, err error) {
+	return r.d.Read(p)
+}

vendor/github.com/ulikunitz/xz/lzma/reader2.go

@@ -0,0 +1,231 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"io"
+
+	"github.com/ulikunitz/xz/internal/xlog"
+)
+
+// Reader2Config stores the parameters for the LZMA2 reader.
+// format.
+type Reader2Config struct {
+	DictCap int
+}
+
+// fill converts the zero values of the configuration to the default values.
+func (c *Reader2Config) fill() {
+	if c.DictCap == 0 {
+		c.DictCap = 8 * 1024 * 1024
+	}
+}
+
+// Verify checks the reader configuration for errors. Zero configuration values
+// will be replaced by default values.
+func (c *Reader2Config) Verify() error {
+	c.fill()
+	if !(MinDictCap <= c.DictCap && int64(c.DictCap) <= MaxDictCap) {
+		return errors.New("lzma: dictionary capacity is out of range")
+	}
+	return nil
+}
+
+// Reader2 supports the reading of LZMA2 chunk sequences. Note that the
+// first chunk should have a dictionary reset and the first compressed
+// chunk a properties reset. The chunk sequence may not be terminated by
+// an end-of-stream chunk.
+type Reader2 struct {
+	r   io.Reader
+	err error
+
+	dict        *decoderDict
+	ur          *uncompressedReader
+	decoder     *decoder
+	chunkReader io.Reader
+
+	cstate chunkState
+}
+
+// NewReader2 creates a reader for an LZMA2 chunk sequence.
+func NewReader2(lzma2 io.Reader) (r *Reader2, err error) {
+	return Reader2Config{}.NewReader2(lzma2)
+}
+
+// NewReader2 creates an LZMA2 reader using the given configuration.
+func (c Reader2Config) NewReader2(lzma2 io.Reader) (r *Reader2, err error) {
+	if err = c.Verify(); err != nil {
+		return nil, err
+	}
+	r = &Reader2{r: lzma2, cstate: start}
+	r.dict, err = newDecoderDict(c.DictCap)
+	if err != nil {
+		return nil, err
+	}
+	if err = r.startChunk(); err != nil {
+		r.err = err
+	}
+	return r, nil
+}
+
+// uncompressed tests whether the chunk type specifies an uncompressed
+// chunk.
+func uncompressed(ctype chunkType) bool {
+	return ctype == cU || ctype == cUD
+}
+
+// startChunk parses a new chunk.
+func (r *Reader2) startChunk() error {
+	r.chunkReader = nil
+	header, err := readChunkHeader(r.r)
+	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return err
+	}
+	xlog.Debugf("chunk header %v", header)
+	if err = r.cstate.next(header.ctype); err != nil {
+		return err
+	}
+	if r.cstate == stop {
+		return io.EOF
+	}
+	if header.ctype == cUD || header.ctype == cLRND {
+		r.dict.Reset()
+	}
+	size := int64(header.uncompressed) + 1
+	if uncompressed(header.ctype) {
+		if r.ur != nil {
+			r.ur.Reopen(r.r, size)
+		} else {
+			r.ur = newUncompressedReader(r.r, r.dict, size)
+		}
+		r.chunkReader = r.ur
+		return nil
+	}
+	br := ByteReader(io.LimitReader(r.r, int64(header.compressed)+1))
+	if r.decoder == nil {
+		state := newState(header.props)
+		r.decoder, err = newDecoder(br, state, r.dict, size)
+		if err != nil {
+			return err
+		}
+		r.chunkReader = r.decoder
+		return nil
+	}
+	switch header.ctype {
+	case cLR:
+		r.decoder.State.Reset()
+	case cLRN, cLRND:
+		r.decoder.State = newState(header.props)
+	}
+	err = r.decoder.Reopen(br, size)
+	if err != nil {
+		return err
+	}
+	r.chunkReader = r.decoder
+	return nil
+}
+
+// Read reads data from the LZMA2 chunk sequence.
+func (r *Reader2) Read(p []byte) (n int, err error) {
+	if r.err != nil {
+		return 0, r.err
+	}
+	for n < len(p) {
+		var k int
+		k, err = r.chunkReader.Read(p[n:])
+		n += k
+		if err != nil {
+			if err == io.EOF {
+				err = r.startChunk()
+				if err == nil {
+					continue
+				}
+			}
+			r.err = err
+			return n, err
+		}
+		if k == 0 {
+			r.err = errors.New("lzma: Reader2 doesn't get data")
+			return n, r.err
+		}
+	}
+	return n, nil
+}
+
+// EOS returns whether the LZMA2 stream has been terminated by an
+// end-of-stream chunk.
+func (r *Reader2) EOS() bool {
+	return r.cstate == stop
+}
+
+// uncompressedReader is used to read uncompressed chunks.
+type uncompressedReader struct {
+	lr   io.LimitedReader
+	Dict *decoderDict
+	eof  bool
+	err  error
+}
+
+// newUncompressedReader initializes a new uncompressedReader.
+func newUncompressedReader(r io.Reader, dict *decoderDict, size int64) *uncompressedReader {
+	ur := &uncompressedReader{
+		lr:   io.LimitedReader{R: r, N: size},
+		Dict: dict,
+	}
+	return ur
+}
+
+// Reopen reinitializes an uncompressed reader.
+func (ur *uncompressedReader) Reopen(r io.Reader, size int64) {
+	ur.err = nil
+	ur.eof = false
+	ur.lr = io.LimitedReader{R: r, N: size}
+}
+
+// fill reads uncompressed data into the dictionary.
+func (ur *uncompressedReader) fill() error {
+	if !ur.eof {
+		n, err := io.CopyN(ur.Dict, &ur.lr, int64(ur.Dict.Available()))
+		if err != io.EOF {
+			return err
+		}
+		ur.eof = true
+		if n > 0 {
+			return nil
+		}
+	}
+	if ur.lr.N != 0 {
+		return io.ErrUnexpectedEOF
+	}
+	return io.EOF
+}
+
+// Read reads uncompressed data from the limited reader.
+func (ur *uncompressedReader) Read(p []byte) (n int, err error) {
+	if ur.err != nil {
+		return 0, ur.err
+	}
+	for {
+		var k int
+		k, err = ur.Dict.Read(p[n:])
+		n += k
+		if n >= len(p) {
+			return n, nil
+		}
+		if err != nil {
+			break
+		}
+		err = ur.fill()
+		if err != nil {
+			break
+		}
+	}
+	ur.err = err
+	return n, err
+}

vendor/github.com/ulikunitz/xz/lzma/state.go

@@ -0,0 +1,145 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+// states defines the overall state count
+const states = 12
+
+// State maintains the full state of the operation encoding or decoding
+// process.
+type state struct {
+	rep         [4]uint32
+	isMatch     [states << maxPosBits]prob
+	isRepG0Long [states << maxPosBits]prob
+	isRep       [states]prob
+	isRepG0     [states]prob
+	isRepG1     [states]prob
+	isRepG2     [states]prob
+	litCodec    literalCodec
+	lenCodec    lengthCodec
+	repLenCodec lengthCodec
+	distCodec   distCodec
+	state       uint32
+	posBitMask  uint32
+	Properties  Properties
+}
+
+// initProbSlice initializes a slice of probabilities.
+func initProbSlice(p []prob) {
+	for i := range p {
+		p[i] = probInit
+	}
+}
+
+// Reset sets all state information to the original values.
+func (s *state) Reset() {
+	p := s.Properties
+	*s = state{
+		Properties: p,
+		// dict:       s.dict,
+		posBitMask: (uint32(1) << uint(p.PB)) - 1,
+	}
+	initProbSlice(s.isMatch[:])
+	initProbSlice(s.isRep[:])
+	initProbSlice(s.isRepG0[:])
+	initProbSlice(s.isRepG1[:])
+	initProbSlice(s.isRepG2[:])
+	initProbSlice(s.isRepG0Long[:])
+	s.litCodec.init(p.LC, p.LP)
+	s.lenCodec.init()
+	s.repLenCodec.init()
+	s.distCodec.init()
+}
+
+// newState creates a new state from the give Properties.
+func newState(p Properties) *state {
+	s := &state{Properties: p}
+	s.Reset()
+	return s
+}
+
+// deepcopy initializes s as a deep copy of the source.
+func (s *state) deepcopy(src *state) {
+	if s == src {
+		return
+	}
+	s.rep = src.rep
+	s.isMatch = src.isMatch
+	s.isRepG0Long = src.isRepG0Long
+	s.isRep = src.isRep
+	s.isRepG0 = src.isRepG0
+	s.isRepG1 = src.isRepG1
+	s.isRepG2 = src.isRepG2
+	s.litCodec.deepcopy(&src.litCodec)
+	s.lenCodec.deepcopy(&src.lenCodec)
+	s.repLenCodec.deepcopy(&src.repLenCodec)
+	s.distCodec.deepcopy(&src.distCodec)
+	s.state = src.state
+	s.posBitMask = src.posBitMask
+	s.Properties = src.Properties
+}
+
+// cloneState creates a new clone of the give state.
+func cloneState(src *state) *state {
+	s := new(state)
+	s.deepcopy(src)
+	return s
+}
+
+// updateStateLiteral updates the state for a literal.
+func (s *state) updateStateLiteral() {
+	switch {
+	case s.state < 4:
+		s.state = 0
+		return
+	case s.state < 10:
+		s.state -= 3
+		return
+	}
+	s.state -= 6
+}
+
+// updateStateMatch updates the state for a match.
+func (s *state) updateStateMatch() {
+	if s.state < 7 {
+		s.state = 7
+	} else {
+		s.state = 10
+	}
+}
+
+// updateStateRep updates the state for a repetition.
+func (s *state) updateStateRep() {
+	if s.state < 7 {
+		s.state = 8
+	} else {
+		s.state = 11
+	}
+}
+
+// updateStateShortRep updates the state for a short repetition.
+func (s *state) updateStateShortRep() {
+	if s.state < 7 {
+		s.state = 9
+	} else {
+		s.state = 11
+	}
+}
+
+// states computes the states of the operation codec.
+func (s *state) states(dictHead int64) (state1, state2, posState uint32) {
+	state1 = s.state
+	posState = uint32(dictHead) & s.posBitMask
+	state2 = (s.state << maxPosBits) | posState
+	return
+}
+
+// litState computes the literal state.
+func (s *state) litState(prev byte, dictHead int64) uint32 {
+	lp, lc := uint(s.Properties.LP), uint(s.Properties.LC)
+	litState := ((uint32(dictHead) & ((1 << lp) - 1)) << lc) |
+		(uint32(prev) >> (8 - lc))
+	return litState
+}

vendor/github.com/ulikunitz/xz/lzma/treecodecs.go

@@ -0,0 +1,133 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+// treeCodec encodes or decodes values with a fixed bit size. It is using a
+// tree of probability value. The root of the tree is the most-significant bit.
+type treeCodec struct {
+	probTree
+}
+
+// makeTreeCodec makes a tree codec. The bits value must be inside the range
+// [1,32].
+func makeTreeCodec(bits int) treeCodec {
+	return treeCodec{makeProbTree(bits)}
+}
+
+// deepcopy initializes tc as a deep copy of the source.
+func (tc *treeCodec) deepcopy(src *treeCodec) {
+	tc.probTree.deepcopy(&src.probTree)
+}
+
+// Encode uses the range encoder to encode a fixed-bit-size value.
+func (tc *treeCodec) Encode(e *rangeEncoder, v uint32) (err error) {
+	m := uint32(1)
+	for i := int(tc.bits) - 1; i >= 0; i-- {
+		b := (v >> uint(i)) & 1
+		if err := e.EncodeBit(b, &tc.probs[m]); err != nil {
+			return err
+		}
+		m = (m << 1) | b
+	}
+	return nil
+}
+
+// Decodes uses the range decoder to decode a fixed-bit-size value. Errors may
+// be caused by the range decoder.
+func (tc *treeCodec) Decode(d *rangeDecoder) (v uint32, err error) {
+	m := uint32(1)
+	for j := 0; j < int(tc.bits); j++ {
+		b, err := d.DecodeBit(&tc.probs[m])
+		if err != nil {
+			return 0, err
+		}
+		m = (m << 1) | b
+	}
+	return m - (1 << uint(tc.bits)), nil
+}
+
+// treeReverseCodec is another tree codec, where the least-significant bit is
+// the start of the probability tree.
+type treeReverseCodec struct {
+	probTree
+}
+
+// deepcopy initializes the treeReverseCodec as a deep copy of the
+// source.
+func (tc *treeReverseCodec) deepcopy(src *treeReverseCodec) {
+	tc.probTree.deepcopy(&src.probTree)
+}
+
+// makeTreeReverseCodec creates treeReverseCodec value. The bits argument must
+// be in the range [1,32].
+func makeTreeReverseCodec(bits int) treeReverseCodec {
+	return treeReverseCodec{makeProbTree(bits)}
+}
+
+// Encode uses range encoder to encode a fixed-bit-size value. The range
+// encoder may cause errors.
+func (tc *treeReverseCodec) Encode(v uint32, e *rangeEncoder) (err error) {
+	m := uint32(1)
+	for i := uint(0); i < uint(tc.bits); i++ {
+		b := (v >> i) & 1
+		if err := e.EncodeBit(b, &tc.probs[m]); err != nil {
+			return err
+		}
+		m = (m << 1) | b
+	}
+	return nil
+}
+
+// Decodes uses the range decoder to decode a fixed-bit-size value. Errors
+// returned by the range decoder will be returned.
+func (tc *treeReverseCodec) Decode(d *rangeDecoder) (v uint32, err error) {
+	m := uint32(1)
+	for j := uint(0); j < uint(tc.bits); j++ {
+		b, err := d.DecodeBit(&tc.probs[m])
+		if err != nil {
+			return 0, err
+		}
+		m = (m << 1) | b
+		v |= b << j
+	}
+	return v, nil
+}
+
+// probTree stores enough probability values to be used by the treeEncode and
+// treeDecode methods of the range coder types.
+type probTree struct {
+	probs []prob
+	bits  byte
+}
+
+// deepcopy initializes the probTree value as a deep copy of the source.
+func (t *probTree) deepcopy(src *probTree) {
+	if t == src {
+		return
+	}
+	t.probs = make([]prob, len(src.probs))
+	copy(t.probs, src.probs)
+	t.bits = src.bits
+}
+
+// makeProbTree initializes a probTree structure.
+func makeProbTree(bits int) probTree {
+	if !(1 <= bits && bits <= 32) {
+		panic("bits outside of range [1,32]")
+	}
+	t := probTree{
+		bits:  byte(bits),
+		probs: make([]prob, 1<<uint(bits)),
+	}
+	for i := range t.probs {
+		t.probs[i] = probInit
+	}
+	return t
+}
+
+// Bits provides the number of bits for the values to de- or encode.
+func (t *probTree) Bits() int {
+	return int(t.bits)
+}

vendor/github.com/ulikunitz/xz/lzma/writer.go

@@ -0,0 +1,209 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"bufio"
+	"errors"
+	"io"
+)
+
+// MinDictCap and MaxDictCap provide the range of supported dictionary
+// capacities.
+const (
+	MinDictCap = 1 << 12
+	MaxDictCap = 1<<32 - 1
+)
+
+// WriterConfig defines the configuration parameter for a writer.
+type WriterConfig struct {
+	// Properties for the encoding. If the it is nil the value
+	// {LC: 3, LP: 0, PB: 2} will be chosen.
+	Properties *Properties
+	// The capacity of the dictionary. If DictCap is zero, the value
+	// 8 MiB will be chosen.
+	DictCap int
+	// Size of the lookahead buffer; value 0 indicates default size
+	// 4096
+	BufSize int
+	// Match algorithm
+	Matcher MatchAlgorithm
+	// SizeInHeader indicates that the header will contain an
+	// explicit size.
+	SizeInHeader bool
+	// Size of the data to be encoded. A positive value will imply
+	// than an explicit size will be set in the header.
+	Size int64
+	// EOSMarker requests whether the EOSMarker needs to be written.
+	// If no explicit size is been given the EOSMarker will be
+	// set automatically.
+	EOSMarker bool
+}
+
+// fill converts zero-value fields to their explicit default values.
+func (c *WriterConfig) fill() {
+	if c.Properties == nil {
+		c.Properties = &Properties{LC: 3, LP: 0, PB: 2}
+	}
+	if c.DictCap == 0 {
+		c.DictCap = 8 * 1024 * 1024
+	}
+	if c.BufSize == 0 {
+		c.BufSize = 4096
+	}
+	if c.Size > 0 {
+		c.SizeInHeader = true
+	}
+	if !c.SizeInHeader {
+		c.EOSMarker = true
+	}
+}
+
+// Verify checks WriterConfig for errors. Verify will replace zero
+// values with default values.
+func (c *WriterConfig) Verify() error {
+	c.fill()
+	var err error
+	if c == nil {
+		return errors.New("lzma: WriterConfig is nil")
+	}
+	if c.Properties == nil {
+		return errors.New("lzma: WriterConfig has no Properties set")
+	}
+	if err = c.Properties.verify(); err != nil {
+		return err
+	}
+	if !(MinDictCap <= c.DictCap && int64(c.DictCap) <= MaxDictCap) {
+		return errors.New("lzma: dictionary capacity is out of range")
+	}
+	if !(maxMatchLen <= c.BufSize) {
+		return errors.New("lzma: lookahead buffer size too small")
+	}
+	if c.SizeInHeader {
+		if c.Size < 0 {
+			return errors.New("lzma: negative size not supported")
+		}
+	} else if !c.EOSMarker {
+		return errors.New("lzma: EOS marker is required")
+	}
+	if err = c.Matcher.verify(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// header returns the header structure for this configuration.
+func (c *WriterConfig) header() header {
+	h := header{
+		properties: *c.Properties,
+		dictCap:    c.DictCap,
+		size:       -1,
+	}
+	if c.SizeInHeader {
+		h.size = c.Size
+	}
+	return h
+}
+
+// Writer writes an LZMA stream in the classic format.
+type Writer struct {
+	h   header
+	bw  io.ByteWriter
+	buf *bufio.Writer
+	e   *encoder
+}
+
+// NewWriter creates a new LZMA writer for the classic format. The
+// method will write the header to the underlying stream.
+func (c WriterConfig) NewWriter(lzma io.Writer) (w *Writer, err error) {
+	if err = c.Verify(); err != nil {
+		return nil, err
+	}
+	w = &Writer{h: c.header()}
+
+	var ok bool
+	w.bw, ok = lzma.(io.ByteWriter)
+	if !ok {
+		w.buf = bufio.NewWriter(lzma)
+		w.bw = w.buf
+	}
+	state := newState(w.h.properties)
+	m, err := c.Matcher.new(w.h.dictCap)
+	if err != nil {
+		return nil, err
+	}
+	dict, err := newEncoderDict(w.h.dictCap, c.BufSize, m)
+	if err != nil {
+		return nil, err
+	}
+	var flags encoderFlags
+	if c.EOSMarker {
+		flags = eosMarker
+	}
+	if w.e, err = newEncoder(w.bw, state, dict, flags); err != nil {
+		return nil, err
+	}
+
+	if err = w.writeHeader(); err != nil {
+		return nil, err
+	}
+	return w, nil
+}
+
+// NewWriter creates a new LZMA writer using the classic format. The
+// function writes the header to the underlying stream.
+func NewWriter(lzma io.Writer) (w *Writer, err error) {
+	return WriterConfig{}.NewWriter(lzma)
+}
+
+// writeHeader writes the LZMA header into the stream.
+func (w *Writer) writeHeader() error {
+	data, err := w.h.marshalBinary()
+	if err != nil {
+		return err
+	}
+	_, err = w.bw.(io.Writer).Write(data)
+	return err
+}
+
+// Write puts data into the Writer.
+func (w *Writer) Write(p []byte) (n int, err error) {
+	if w.h.size >= 0 {
+		m := w.h.size
+		m -= w.e.Compressed() + int64(w.e.dict.Buffered())
+		if m < 0 {
+			m = 0
+		}
+		if m < int64(len(p)) {
+			p = p[:m]
+			err = ErrNoSpace
+		}
+	}
+	var werr error
+	if n, werr = w.e.Write(p); werr != nil {
+		err = werr
+	}
+	return n, err
+}
+
+// Close closes the writer stream. It ensures that all data from the
+// buffer will be compressed and the LZMA stream will be finished.
+func (w *Writer) Close() error {
+	if w.h.size >= 0 {
+		n := w.e.Compressed() + int64(w.e.dict.Buffered())
+		if n != w.h.size {
+			return errSize
+		}
+	}
+	err := w.e.Close()
+	if w.buf != nil {
+		ferr := w.buf.Flush()
+		if err == nil {
+			err = ferr
+		}
+	}
+	return err
+}

vendor/github.com/ulikunitz/xz/lzma/writer2.go

@@ -0,0 +1,305 @@
+// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"bytes"
+	"errors"
+	"io"
+)
+
+// Writer2Config is used to create a Writer2 using parameters.
+type Writer2Config struct {
+	// The properties for the encoding. If the it is nil the value
+	// {LC: 3, LP: 0, PB: 2} will be chosen.
+	Properties *Properties
+	// The capacity of the dictionary. If DictCap is zero, the value
+	// 8 MiB will be chosen.
+	DictCap int
+	// Size of the lookahead buffer; value 0 indicates default size
+	// 4096
+	BufSize int
+	// Match algorithm
+	Matcher MatchAlgorithm
+}
+
+// fill replaces zero values with default values.
+func (c *Writer2Config) fill() {
+	if c.Properties == nil {
+		c.Properties = &Properties{LC: 3, LP: 0, PB: 2}
+	}
+	if c.DictCap == 0 {
+		c.DictCap = 8 * 1024 * 1024
+	}
+	if c.BufSize == 0 {
+		c.BufSize = 4096
+	}
+}
+
+// Verify checks the Writer2Config for correctness. Zero values will be
+// replaced by default values.
+func (c *Writer2Config) Verify() error {
+	c.fill()
+	var err error
+	if c == nil {
+		return errors.New("lzma: WriterConfig is nil")
+	}
+	if c.Properties == nil {
+		return errors.New("lzma: WriterConfig has no Properties set")
+	}
+	if err = c.Properties.verify(); err != nil {
+		return err
+	}
+	if !(MinDictCap <= c.DictCap && int64(c.DictCap) <= MaxDictCap) {
+		return errors.New("lzma: dictionary capacity is out of range")
+	}
+	if !(maxMatchLen <= c.BufSize) {
+		return errors.New("lzma: lookahead buffer size too small")
+	}
+	if c.Properties.LC+c.Properties.LP > 4 {
+		return errors.New("lzma: sum of lc and lp exceeds 4")
+	}
+	if err = c.Matcher.verify(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// Writer2 supports the creation of an LZMA2 stream. But note that
+// written data is buffered, so call Flush or Close to write data to the
+// underlying writer. The Close method writes the end-of-stream marker
+// to the stream. So you may be able to concatenate the output of two
+// writers as long the output of the first writer has only been flushed
+// but not closed.
+//
+// Any change to the fields Properties, DictCap must be done before the
+// first call to Write, Flush or Close.
+type Writer2 struct {
+	w io.Writer
+
+	start   *state
+	encoder *encoder
+
+	cstate chunkState
+	ctype  chunkType
+
+	buf bytes.Buffer
+	lbw LimitedByteWriter
+}
+
+// NewWriter2 creates an LZMA2 chunk sequence writer with the default
+// parameters and options.
+func NewWriter2(lzma2 io.Writer) (w *Writer2, err error) {
+	return Writer2Config{}.NewWriter2(lzma2)
+}
+
+// NewWriter2 creates a new LZMA2 writer using the given configuration.
+func (c Writer2Config) NewWriter2(lzma2 io.Writer) (w *Writer2, err error) {
+	if err = c.Verify(); err != nil {
+		return nil, err
+	}
+	w = &Writer2{
+		w:      lzma2,
+		start:  newState(*c.Properties),
+		cstate: start,
+		ctype:  start.defaultChunkType(),
+	}
+	w.buf.Grow(maxCompressed)
+	w.lbw = LimitedByteWriter{BW: &w.buf, N: maxCompressed}
+	m, err := c.Matcher.new(c.DictCap)
+	if err != nil {
+		return nil, err
+	}
+	d, err := newEncoderDict(c.DictCap, c.BufSize, m)
+	if err != nil {
+		return nil, err
+	}
+	w.encoder, err = newEncoder(&w.lbw, cloneState(w.start), d, 0)
+	if err != nil {
+		return nil, err
+	}
+	return w, nil
+}
+
+// written returns the number of bytes written to the current chunk
+func (w *Writer2) written() int {
+	if w.encoder == nil {
+		return 0
+	}
+	return int(w.encoder.Compressed()) + w.encoder.dict.Buffered()
+}
+
+// errClosed indicates that the writer is closed.
+var errClosed = errors.New("lzma: writer closed")
+
+// Writes data to LZMA2 stream. Note that written data will be buffered.
+// Use Flush or Close to ensure that data is written to the underlying
+// writer.
+func (w *Writer2) Write(p []byte) (n int, err error) {
+	if w.cstate == stop {
+		return 0, errClosed
+	}
+	for n < len(p) {
+		m := maxUncompressed - w.written()
+		if m <= 0 {
+			panic("lzma: maxUncompressed reached")
+		}
+		var q []byte
+		if n+m < len(p) {
+			q = p[n : n+m]
+		} else {
+			q = p[n:]
+		}
+		k, err := w.encoder.Write(q)
+		n += k
+		if err != nil && err != ErrLimit {
+			return n, err
+		}
+		if err == ErrLimit || k == m {
+			if err = w.flushChunk(); err != nil {
+				return n, err
+			}
+		}
+	}
+	return n, nil
+}
+
+// writeUncompressedChunk writes an uncompressed chunk to the LZMA2
+// stream.
+func (w *Writer2) writeUncompressedChunk() error {
+	u := w.encoder.Compressed()
+	if u <= 0 {
+		return errors.New("lzma: can't write empty uncompressed chunk")
+	}
+	if u > maxUncompressed {
+		panic("overrun of uncompressed data limit")
+	}
+	switch w.ctype {
+	case cLRND:
+		w.ctype = cUD
+	default:
+		w.ctype = cU
+	}
+	w.encoder.state = w.start
+
+	header := chunkHeader{
+		ctype:        w.ctype,
+		uncompressed: uint32(u - 1),
+	}
+	hdata, err := header.MarshalBinary()
+	if err != nil {
+		return err
+	}
+	if _, err = w.w.Write(hdata); err != nil {
+		return err
+	}
+	_, err = w.encoder.dict.CopyN(w.w, int(u))
+	return err
+}
+
+// writeCompressedChunk writes a compressed chunk to the underlying
+// writer.
+func (w *Writer2) writeCompressedChunk() error {
+	if w.ctype == cU || w.ctype == cUD {
+		panic("chunk type uncompressed")
+	}
+
+	u := w.encoder.Compressed()
+	if u <= 0 {
+		return errors.New("writeCompressedChunk: empty chunk")
+	}
+	if u > maxUncompressed {
+		panic("overrun of uncompressed data limit")
+	}
+	c := w.buf.Len()
+	if c <= 0 {
+		panic("no compressed data")
+	}
+	if c > maxCompressed {
+		panic("overrun of compressed data limit")
+	}
+	header := chunkHeader{
+		ctype:        w.ctype,
+		uncompressed: uint32(u - 1),
+		compressed:   uint16(c - 1),
+		props:        w.encoder.state.Properties,
+	}
+	hdata, err := header.MarshalBinary()
+	if err != nil {
+		return err
+	}
+	if _, err = w.w.Write(hdata); err != nil {
+		return err
+	}
+	_, err = io.Copy(w.w, &w.buf)
+	return err
+}
+
+// writes a single chunk to the underlying writer.
+func (w *Writer2) writeChunk() error {
+	u := int(uncompressedHeaderLen + w.encoder.Compressed())
+	c := headerLen(w.ctype) + w.buf.Len()
+	if u < c {
+		return w.writeUncompressedChunk()
+	}
+	return w.writeCompressedChunk()
+}
+
+// flushChunk terminates the current chunk. The encoder will be reset
+// to support the next chunk.
+func (w *Writer2) flushChunk() error {
+	if w.written() == 0 {
+		return nil
+	}
+	var err error
+	if err = w.encoder.Close(); err != nil {
+		return err
+	}
+	if err = w.writeChunk(); err != nil {
+		return err
+	}
+	w.buf.Reset()
+	w.lbw.N = maxCompressed
+	if err = w.encoder.Reopen(&w.lbw); err != nil {
+		return err
+	}
+	if err = w.cstate.next(w.ctype); err != nil {
+		return err
+	}
+	w.ctype = w.cstate.defaultChunkType()
+	w.start = cloneState(w.encoder.state)
+	return nil
+}
+
+// Flush writes all buffered data out to the underlying stream. This
+// could result in multiple chunks to be created.
+func (w *Writer2) Flush() error {
+	if w.cstate == stop {
+		return errClosed
+	}
+	for w.written() > 0 {
+		if err := w.flushChunk(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Close terminates the LZMA2 stream with an EOS chunk.
+func (w *Writer2) Close() error {
+	if w.cstate == stop {
+		return errClosed
+	}
+	if err := w.Flush(); err != nil {
+		return nil
+	}
+	// write zero byte EOS chunk
+	_, err := w.w.Write([]byte{0})
+	if err != nil {
+		return err
+	}
+	w.cstate = stop
+	return nil
+}

vendor/golang.org/x/text/AUTHORS

@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.

vendor/golang.org/x/text/CONTRIBUTORS

@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.

vendor/golang.org/x/text/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/golang.org/x/text/PATENTS

@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.

vendor/golang.org/x/text/encoding/encoding.go

@@ -0,0 +1,335 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package encoding defines an interface for character encodings, such as Shift
+// JIS and Windows 1252, that can convert to and from UTF-8.
+//
+// Encoding implementations are provided in other packages, such as
+// golang.org/x/text/encoding/charmap and
+// golang.org/x/text/encoding/japanese.
+package encoding // import "golang.org/x/text/encoding"
+
+import (
+	"errors"
+	"io"
+	"strconv"
+	"unicode/utf8"
+
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+// TODO:
+// - There seems to be some inconsistency in when decoders return errors
+//   and when not. Also documentation seems to suggest they shouldn't return
+//   errors at all (except for UTF-16).
+// - Encoders seem to rely on or at least benefit from the input being in NFC
+//   normal form. Perhaps add an example how users could prepare their output.
+
+// Encoding is a character set encoding that can be transformed to and from
+// UTF-8.
+type Encoding interface {
+	// NewDecoder returns a Decoder.
+	NewDecoder() *Decoder
+
+	// NewEncoder returns an Encoder.
+	NewEncoder() *Encoder
+}
+
+// A Decoder converts bytes to UTF-8. It implements transform.Transformer.
+//
+// Transforming source bytes that are not of that encoding will not result in an
+// error per se. Each byte that cannot be transcoded will be represented in the
+// output by the UTF-8 encoding of '\uFFFD', the replacement rune.
+type Decoder struct {
+	transform.Transformer
+
+	// This forces external creators of Decoders to use names in struct
+	// initializers, allowing for future extendibility without having to break
+	// code.
+	_ struct{}
+}
+
+// Bytes converts the given encoded bytes to UTF-8. It returns the converted
+// bytes or nil, err if any error occurred.
+func (d *Decoder) Bytes(b []byte) ([]byte, error) {
+	b, _, err := transform.Bytes(d, b)
+	if err != nil {
+		return nil, err
+	}
+	return b, nil
+}
+
+// String converts the given encoded string to UTF-8. It returns the converted
+// string or "", err if any error occurred.
+func (d *Decoder) String(s string) (string, error) {
+	s, _, err := transform.String(d, s)
+	if err != nil {
+		return "", err
+	}
+	return s, nil
+}
+
+// Reader wraps another Reader to decode its bytes.
+//
+// The Decoder may not be used for any other operation as long as the returned
+// Reader is in use.
+func (d *Decoder) Reader(r io.Reader) io.Reader {
+	return transform.NewReader(r, d)
+}
+
+// An Encoder converts bytes from UTF-8. It implements transform.Transformer.
+//
+// Each rune that cannot be transcoded will result in an error. In this case,
+// the transform will consume all source byte up to, not including the offending
+// rune. Transforming source bytes that are not valid UTF-8 will be replaced by
+// `\uFFFD`. To return early with an error instead, use transform.Chain to
+// preprocess the data with a UTF8Validator.
+type Encoder struct {
+	transform.Transformer
+
+	// This forces external creators of Encoders to use names in struct
+	// initializers, allowing for future extendibility without having to break
+	// code.
+	_ struct{}
+}
+
+// Bytes converts bytes from UTF-8. It returns the converted bytes or nil, err if
+// any error occurred.
+func (e *Encoder) Bytes(b []byte) ([]byte, error) {
+	b, _, err := transform.Bytes(e, b)
+	if err != nil {
+		return nil, err
+	}
+	return b, nil
+}
+
+// String converts a string from UTF-8. It returns the converted string or
+// "", err if any error occurred.
+func (e *Encoder) String(s string) (string, error) {
+	s, _, err := transform.String(e, s)
+	if err != nil {
+		return "", err
+	}
+	return s, nil
+}
+
+// Writer wraps another Writer to encode its UTF-8 output.
+//
+// The Encoder may not be used for any other operation as long as the returned
+// Writer is in use.
+func (e *Encoder) Writer(w io.Writer) io.Writer {
+	return transform.NewWriter(w, e)
+}
+
+// ASCIISub is the ASCII substitute character, as recommended by
+// https://unicode.org/reports/tr36/#Text_Comparison
+const ASCIISub = '\x1a'
+
+// Nop is the nop encoding. Its transformed bytes are the same as the source
+// bytes; it does not replace invalid UTF-8 sequences.
+var Nop Encoding = nop{}
+
+type nop struct{}
+
+func (nop) NewDecoder() *Decoder {
+	return &Decoder{Transformer: transform.Nop}
+}
+func (nop) NewEncoder() *Encoder {
+	return &Encoder{Transformer: transform.Nop}
+}
+
+// Replacement is the replacement encoding. Decoding from the replacement
+// encoding yields a single '\uFFFD' replacement rune. Encoding from UTF-8 to
+// the replacement encoding yields the same as the source bytes except that
+// invalid UTF-8 is converted to '\uFFFD'.
+//
+// It is defined at http://encoding.spec.whatwg.org/#replacement
+var Replacement Encoding = replacement{}
+
+type replacement struct{}
+
+func (replacement) NewDecoder() *Decoder {
+	return &Decoder{Transformer: replacementDecoder{}}
+}
+
+func (replacement) NewEncoder() *Encoder {
+	return &Encoder{Transformer: replacementEncoder{}}
+}
+
+func (replacement) ID() (mib identifier.MIB, other string) {
+	return identifier.Replacement, ""
+}
+
+type replacementDecoder struct{ transform.NopResetter }
+
+func (replacementDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	if len(dst) < 3 {
+		return 0, 0, transform.ErrShortDst
+	}
+	if atEOF {
+		const fffd = "\ufffd"
+		dst[0] = fffd[0]
+		dst[1] = fffd[1]
+		dst[2] = fffd[2]
+		nDst = 3
+	}
+	return nDst, len(src), nil
+}
+
+type replacementEncoder struct{ transform.NopResetter }
+
+func (replacementEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+
+	for ; nSrc < len(src); nSrc += size {
+		r = rune(src[nSrc])
+
+		// Decode a 1-byte rune.
+		if r < utf8.RuneSelf {
+			size = 1
+
+		} else {
+			// Decode a multi-byte rune.
+			r, size = utf8.DecodeRune(src[nSrc:])
+			if size == 1 {
+				// All valid runes of size 1 (those below utf8.RuneSelf) were
+				// handled above. We have invalid UTF-8 or we haven't seen the
+				// full character yet.
+				if !atEOF && !utf8.FullRune(src[nSrc:]) {
+					err = transform.ErrShortSrc
+					break
+				}
+				r = '\ufffd'
+			}
+		}
+
+		if nDst+utf8.RuneLen(r) > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		nDst += utf8.EncodeRune(dst[nDst:], r)
+	}
+	return nDst, nSrc, err
+}
+
+// HTMLEscapeUnsupported wraps encoders to replace source runes outside the
+// repertoire of the destination encoding with HTML escape sequences.
+//
+// This wrapper exists to comply to URL and HTML forms requiring a
+// non-terminating legacy encoder. The produced sequences may lead to data
+// loss as they are indistinguishable from legitimate input. To avoid this
+// issue, use UTF-8 encodings whenever possible.
+func HTMLEscapeUnsupported(e *Encoder) *Encoder {
+	return &Encoder{Transformer: &errorHandler{e, errorToHTML}}
+}
+
+// ReplaceUnsupported wraps encoders to replace source runes outside the
+// repertoire of the destination encoding with an encoding-specific
+// replacement.
+//
+// This wrapper is only provided for backwards compatibility and legacy
+// handling. Its use is strongly discouraged. Use UTF-8 whenever possible.
+func ReplaceUnsupported(e *Encoder) *Encoder {
+	return &Encoder{Transformer: &errorHandler{e, errorToReplacement}}
+}
+
+type errorHandler struct {
+	*Encoder
+	handler func(dst []byte, r rune, err repertoireError) (n int, ok bool)
+}
+
+// TODO: consider making this error public in some form.
+type repertoireError interface {
+	Replacement() byte
+}
+
+func (h errorHandler) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	nDst, nSrc, err = h.Transformer.Transform(dst, src, atEOF)
+	for err != nil {
+		rerr, ok := err.(repertoireError)
+		if !ok {
+			return nDst, nSrc, err
+		}
+		r, sz := utf8.DecodeRune(src[nSrc:])
+		n, ok := h.handler(dst[nDst:], r, rerr)
+		if !ok {
+			return nDst, nSrc, transform.ErrShortDst
+		}
+		err = nil
+		nDst += n
+		if nSrc += sz; nSrc < len(src) {
+			var dn, sn int
+			dn, sn, err = h.Transformer.Transform(dst[nDst:], src[nSrc:], atEOF)
+			nDst += dn
+			nSrc += sn
+		}
+	}
+	return nDst, nSrc, err
+}
+
+func errorToHTML(dst []byte, r rune, err repertoireError) (n int, ok bool) {
+	buf := [8]byte{}
+	b := strconv.AppendUint(buf[:0], uint64(r), 10)
+	if n = len(b) + len("&#;"); n >= len(dst) {
+		return 0, false
+	}
+	dst[0] = '&'
+	dst[1] = '#'
+	dst[copy(dst[2:], b)+2] = ';'
+	return n, true
+}
+
+func errorToReplacement(dst []byte, r rune, err repertoireError) (n int, ok bool) {
+	if len(dst) == 0 {
+		return 0, false
+	}
+	dst[0] = err.Replacement()
+	return 1, true
+}
+
+// ErrInvalidUTF8 means that a transformer encountered invalid UTF-8.
+var ErrInvalidUTF8 = errors.New("encoding: invalid UTF-8")
+
+// UTF8Validator is a transformer that returns ErrInvalidUTF8 on the first
+// input byte that is not valid UTF-8.
+var UTF8Validator transform.Transformer = utf8Validator{}
+
+type utf8Validator struct{ transform.NopResetter }
+
+func (utf8Validator) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	n := len(src)
+	if n > len(dst) {
+		n = len(dst)
+	}
+	for i := 0; i < n; {
+		if c := src[i]; c < utf8.RuneSelf {
+			dst[i] = c
+			i++
+			continue
+		}
+		_, size := utf8.DecodeRune(src[i:])
+		if size == 1 {
+			// All valid runes of size 1 (those below utf8.RuneSelf) were
+			// handled above. We have invalid UTF-8 or we haven't seen the
+			// full character yet.
+			err = ErrInvalidUTF8
+			if !atEOF && !utf8.FullRune(src[i:]) {
+				err = transform.ErrShortSrc
+			}
+			return i, i, err
+		}
+		if i+size > len(dst) {
+			return i, i, transform.ErrShortDst
+		}
+		for ; size > 0; size-- {
+			dst[i] = src[i]
+			i++
+		}
+	}
+	if len(src) > len(dst) {
+		err = transform.ErrShortDst
+	}
+	return n, n, err
+}

vendor/golang.org/x/text/encoding/internal/identifier/identifier.go

@@ -0,0 +1,81 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate go run gen.go
+
+// Package identifier defines the contract between implementations of Encoding
+// and Index by defining identifiers that uniquely identify standardized coded
+// character sets (CCS) and character encoding schemes (CES), which we will
+// together refer to as encodings, for which Encoding implementations provide
+// converters to and from UTF-8. This package is typically only of concern to
+// implementers of Indexes and Encodings.
+//
+// One part of the identifier is the MIB code, which is defined by IANA and
+// uniquely identifies a CCS or CES. Each code is associated with data that
+// references authorities, official documentation as well as aliases and MIME
+// names.
+//
+// Not all CESs are covered by the IANA registry. The "other" string that is
+// returned by ID can be used to identify other character sets or versions of
+// existing ones.
+//
+// It is recommended that each package that provides a set of Encodings provide
+// the All and Common variables to reference all supported encodings and
+// commonly used subset. This allows Index implementations to include all
+// available encodings without explicitly referencing or knowing about them.
+package identifier
+
+// Note: this package is internal, but could be made public if there is a need
+// for writing third-party Indexes and Encodings.
+
+// References:
+// - http://source.icu-project.org/repos/icu/icu/trunk/source/data/mappings/convrtrs.txt
+// - http://www.iana.org/assignments/character-sets/character-sets.xhtml
+// - http://www.iana.org/assignments/ianacharset-mib/ianacharset-mib
+// - http://www.ietf.org/rfc/rfc2978.txt
+// - https://www.unicode.org/reports/tr22/
+// - http://www.w3.org/TR/encoding/
+// - https://encoding.spec.whatwg.org/
+// - https://encoding.spec.whatwg.org/encodings.json
+// - https://tools.ietf.org/html/rfc6657#section-5
+
+// Interface can be implemented by Encodings to define the CCS or CES for which
+// it implements conversions.
+type Interface interface {
+	// ID returns an encoding identifier. Exactly one of the mib and other
+	// values should be non-zero.
+	//
+	// In the usual case it is only necessary to indicate the MIB code. The
+	// other string can be used to specify encodings for which there is no MIB,
+	// such as "x-mac-dingbat".
+	//
+	// The other string may only contain the characters a-z, A-Z, 0-9, - and _.
+	ID() (mib MIB, other string)
+
+	// NOTE: the restrictions on the encoding are to allow extending the syntax
+	// with additional information such as versions, vendors and other variants.
+}
+
+// A MIB identifies an encoding. It is derived from the IANA MIB codes and adds
+// some identifiers for some encodings that are not covered by the IANA
+// standard.
+//
+// See http://www.iana.org/assignments/ianacharset-mib.
+type MIB uint16
+
+// These additional MIB types are not defined in IANA. They are added because
+// they are common and defined within the text repo.
+const (
+	// Unofficial marks the start of encodings not registered by IANA.
+	Unofficial MIB = 10000 + iota
+
+	// Replacement is the WhatWG replacement encoding.
+	Replacement
+
+	// XUserDefined is the code for x-user-defined.
+	XUserDefined
+
+	// MacintoshCyrillic is the code for x-mac-cyrillic.
+	MacintoshCyrillic
+)

vendor/golang.org/x/text/encoding/internal/internal.go

@@ -0,0 +1,75 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package internal contains code that is shared among encoding implementations.
+package internal
+
+import (
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+// Encoding is an implementation of the Encoding interface that adds the String
+// and ID methods to an existing encoding.
+type Encoding struct {
+	encoding.Encoding
+	Name string
+	MIB  identifier.MIB
+}
+
+// _ verifies that Encoding implements identifier.Interface.
+var _ identifier.Interface = (*Encoding)(nil)
+
+func (e *Encoding) String() string {
+	return e.Name
+}
+
+func (e *Encoding) ID() (mib identifier.MIB, other string) {
+	return e.MIB, ""
+}
+
+// SimpleEncoding is an Encoding that combines two Transformers.
+type SimpleEncoding struct {
+	Decoder transform.Transformer
+	Encoder transform.Transformer
+}
+
+func (e *SimpleEncoding) NewDecoder() *encoding.Decoder {
+	return &encoding.Decoder{Transformer: e.Decoder}
+}
+
+func (e *SimpleEncoding) NewEncoder() *encoding.Encoder {
+	return &encoding.Encoder{Transformer: e.Encoder}
+}
+
+// FuncEncoding is an Encoding that combines two functions returning a new
+// Transformer.
+type FuncEncoding struct {
+	Decoder func() transform.Transformer
+	Encoder func() transform.Transformer
+}
+
+func (e FuncEncoding) NewDecoder() *encoding.Decoder {
+	return &encoding.Decoder{Transformer: e.Decoder()}
+}
+
+func (e FuncEncoding) NewEncoder() *encoding.Encoder {
+	return &encoding.Encoder{Transformer: e.Encoder()}
+}
+
+// A RepertoireError indicates a rune is not in the repertoire of a destination
+// encoding. It is associated with an encoding-specific suggested replacement
+// byte.
+type RepertoireError byte
+
+// Error implements the error interrface.
+func (r RepertoireError) Error() string {
+	return "encoding: rune not supported by encoding."
+}
+
+// Replacement returns the replacement string associated with this error.
+func (r RepertoireError) Replacement() byte { return byte(r) }
+
+var ErrASCIIReplacement = RepertoireError(encoding.ASCIISub)

vendor/golang.org/x/text/encoding/simplifiedchinese/all.go

@@ -0,0 +1,12 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package simplifiedchinese
+
+import (
+	"golang.org/x/text/encoding"
+)
+
+// All is a list of all defined encodings in this package.
+var All = []encoding.Encoding{GB18030, GBK, HZGB2312}

vendor/golang.org/x/text/encoding/simplifiedchinese/gbk.go

@@ -0,0 +1,269 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package simplifiedchinese
+
+import (
+	"unicode/utf8"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/internal"
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+var (
+	// GB18030 is the GB18030 encoding.
+	GB18030 encoding.Encoding = &gbk18030
+	// GBK is the GBK encoding. It encodes an extension of the GB2312 character set
+	// and is also known as Code Page 936.
+	GBK encoding.Encoding = &gbk
+)
+
+var gbk = internal.Encoding{
+	&internal.SimpleEncoding{
+		gbkDecoder{gb18030: false},
+		gbkEncoder{gb18030: false},
+	},
+	"GBK",
+	identifier.GBK,
+}
+
+var gbk18030 = internal.Encoding{
+	&internal.SimpleEncoding{
+		gbkDecoder{gb18030: true},
+		gbkEncoder{gb18030: true},
+	},
+	"GB18030",
+	identifier.GB18030,
+}
+
+type gbkDecoder struct {
+	transform.NopResetter
+	gb18030 bool
+}
+
+func (d gbkDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+loop:
+	for ; nSrc < len(src); nSrc += size {
+		switch c0 := src[nSrc]; {
+		case c0 < utf8.RuneSelf:
+			r, size = rune(c0), 1
+
+		// Microsoft's Code Page 936 extends GBK 1.0 to encode the euro sign U+20AC
+		// as 0x80. The HTML5 specification at http://encoding.spec.whatwg.org/#gbk
+		// says to treat "gbk" as Code Page 936.
+		case c0 == 0x80:
+			r, size = '€', 1
+
+		case c0 < 0xff:
+			if nSrc+1 >= len(src) {
+				if !atEOF {
+					err = transform.ErrShortSrc
+					break loop
+				}
+				r, size = utf8.RuneError, 1
+				goto write
+			}
+			c1 := src[nSrc+1]
+			switch {
+			case 0x40 <= c1 && c1 < 0x7f:
+				c1 -= 0x40
+			case 0x80 <= c1 && c1 < 0xff:
+				c1 -= 0x41
+			case d.gb18030 && 0x30 <= c1 && c1 < 0x40:
+				if nSrc+3 >= len(src) {
+					if !atEOF {
+						err = transform.ErrShortSrc
+						break loop
+					}
+					// The second byte here is always ASCII, so we can set size
+					// to 1 in all cases.
+					r, size = utf8.RuneError, 1
+					goto write
+				}
+				c2 := src[nSrc+2]
+				if c2 < 0x81 || 0xff <= c2 {
+					r, size = utf8.RuneError, 1
+					goto write
+				}
+				c3 := src[nSrc+3]
+				if c3 < 0x30 || 0x3a <= c3 {
+					r, size = utf8.RuneError, 1
+					goto write
+				}
+				size = 4
+				r = ((rune(c0-0x81)*10+rune(c1-0x30))*126+rune(c2-0x81))*10 + rune(c3-0x30)
+				if r < 39420 {
+					i, j := 0, len(gb18030)
+					for i < j {
+						h := i + (j-i)/2
+						if r >= rune(gb18030[h][0]) {
+							i = h + 1
+						} else {
+							j = h
+						}
+					}
+					dec := &gb18030[i-1]
+					r += rune(dec[1]) - rune(dec[0])
+					goto write
+				}
+				r -= 189000
+				if 0 <= r && r < 0x100000 {
+					r += 0x10000
+				} else {
+					r, size = utf8.RuneError, 1
+				}
+				goto write
+			default:
+				r, size = utf8.RuneError, 1
+				goto write
+			}
+			r, size = '\ufffd', 2
+			if i := int(c0-0x81)*190 + int(c1); i < len(decode) {
+				r = rune(decode[i])
+				if r == 0 {
+					r = '\ufffd'
+				}
+			}
+
+		default:
+			r, size = utf8.RuneError, 1
+		}
+
+	write:
+		if nDst+utf8.RuneLen(r) > len(dst) {
+			err = transform.ErrShortDst
+			break loop
+		}
+		nDst += utf8.EncodeRune(dst[nDst:], r)
+	}
+	return nDst, nSrc, err
+}
+
+type gbkEncoder struct {
+	transform.NopResetter
+	gb18030 bool
+}
+
+func (e gbkEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, r2, size := rune(0), rune(0), 0
+	for ; nSrc < len(src); nSrc += size {
+		r = rune(src[nSrc])
+
+		// Decode a 1-byte rune.
+		if r < utf8.RuneSelf {
+			size = 1
+
+		} else {
+			// Decode a multi-byte rune.
+			r, size = utf8.DecodeRune(src[nSrc:])
+			if size == 1 {
+				// All valid runes of size 1 (those below utf8.RuneSelf) were
+				// handled above. We have invalid UTF-8 or we haven't seen the
+				// full character yet.
+				if !atEOF && !utf8.FullRune(src[nSrc:]) {
+					err = transform.ErrShortSrc
+					break
+				}
+			}
+
+			// func init checks that the switch covers all tables.
+			switch {
+			case encode0Low <= r && r < encode0High:
+				if r2 = rune(encode0[r-encode0Low]); r2 != 0 {
+					goto write2
+				}
+			case encode1Low <= r && r < encode1High:
+				// Microsoft's Code Page 936 extends GBK 1.0 to encode the euro sign U+20AC
+				// as 0x80. The HTML5 specification at http://encoding.spec.whatwg.org/#gbk
+				// says to treat "gbk" as Code Page 936.
+				if r == '€' {
+					r = 0x80
+					goto write1
+				}
+				if r2 = rune(encode1[r-encode1Low]); r2 != 0 {
+					goto write2
+				}
+			case encode2Low <= r && r < encode2High:
+				if r2 = rune(encode2[r-encode2Low]); r2 != 0 {
+					goto write2
+				}
+			case encode3Low <= r && r < encode3High:
+				if r2 = rune(encode3[r-encode3Low]); r2 != 0 {
+					goto write2
+				}
+			case encode4Low <= r && r < encode4High:
+				if r2 = rune(encode4[r-encode4Low]); r2 != 0 {
+					goto write2
+				}
+			}
+
+			if e.gb18030 {
+				if r < 0x10000 {
+					i, j := 0, len(gb18030)
+					for i < j {
+						h := i + (j-i)/2
+						if r >= rune(gb18030[h][1]) {
+							i = h + 1
+						} else {
+							j = h
+						}
+					}
+					dec := &gb18030[i-1]
+					r += rune(dec[0]) - rune(dec[1])
+					goto write4
+				} else if r < 0x110000 {
+					r += 189000 - 0x10000
+					goto write4
+				}
+			}
+			err = internal.ErrASCIIReplacement
+			break
+		}
+
+	write1:
+		if nDst >= len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst] = uint8(r)
+		nDst++
+		continue
+
+	write2:
+		if nDst+2 > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst+0] = uint8(r2 >> 8)
+		dst[nDst+1] = uint8(r2)
+		nDst += 2
+		continue
+
+	write4:
+		if nDst+4 > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst+3] = uint8(r%10 + 0x30)
+		r /= 10
+		dst[nDst+2] = uint8(r%126 + 0x81)
+		r /= 126
+		dst[nDst+1] = uint8(r%10 + 0x30)
+		r /= 10
+		dst[nDst+0] = uint8(r + 0x81)
+		nDst += 4
+		continue
+	}
+	return nDst, nSrc, err
+}
+
+func init() {
+	// Check that the hard-coded encode switch covers all tables.
+	if numEncodeTables != 5 {
+		panic("bad numEncodeTables")
+	}
+}

vendor/golang.org/x/text/encoding/simplifiedchinese/hzgb2312.go

@@ -0,0 +1,245 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package simplifiedchinese
+
+import (
+	"unicode/utf8"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/internal"
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+// HZGB2312 is the HZ-GB2312 encoding.
+var HZGB2312 encoding.Encoding = &hzGB2312
+
+var hzGB2312 = internal.Encoding{
+	internal.FuncEncoding{hzGB2312NewDecoder, hzGB2312NewEncoder},
+	"HZ-GB2312",
+	identifier.HZGB2312,
+}
+
+func hzGB2312NewDecoder() transform.Transformer {
+	return new(hzGB2312Decoder)
+}
+
+func hzGB2312NewEncoder() transform.Transformer {
+	return new(hzGB2312Encoder)
+}
+
+const (
+	asciiState = iota
+	gbState
+)
+
+type hzGB2312Decoder int
+
+func (d *hzGB2312Decoder) Reset() {
+	*d = asciiState
+}
+
+func (d *hzGB2312Decoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+loop:
+	for ; nSrc < len(src); nSrc += size {
+		c0 := src[nSrc]
+		if c0 >= utf8.RuneSelf {
+			r, size = utf8.RuneError, 1
+			goto write
+		}
+
+		if c0 == '~' {
+			if nSrc+1 >= len(src) {
+				if !atEOF {
+					err = transform.ErrShortSrc
+					break loop
+				}
+				r, size = utf8.RuneError, 1
+				goto write
+			}
+			size = 2
+			switch src[nSrc+1] {
+			case '{':
+				*d = gbState
+				continue
+			case '}':
+				*d = asciiState
+				continue
+			case '~':
+				if nDst >= len(dst) {
+					err = transform.ErrShortDst
+					break loop
+				}
+				dst[nDst] = '~'
+				nDst++
+				continue
+			case '\n':
+				continue
+			default:
+				r = utf8.RuneError
+				goto write
+			}
+		}
+
+		if *d == asciiState {
+			r, size = rune(c0), 1
+		} else {
+			if nSrc+1 >= len(src) {
+				if !atEOF {
+					err = transform.ErrShortSrc
+					break loop
+				}
+				r, size = utf8.RuneError, 1
+				goto write
+			}
+			size = 2
+			c1 := src[nSrc+1]
+			if c0 < 0x21 || 0x7e <= c0 || c1 < 0x21 || 0x7f <= c1 {
+				// error
+			} else if i := int(c0-0x01)*190 + int(c1+0x3f); i < len(decode) {
+				r = rune(decode[i])
+				if r != 0 {
+					goto write
+				}
+			}
+			if c1 > utf8.RuneSelf {
+				// Be consistent and always treat non-ASCII as a single error.
+				size = 1
+			}
+			r = utf8.RuneError
+		}
+
+	write:
+		if nDst+utf8.RuneLen(r) > len(dst) {
+			err = transform.ErrShortDst
+			break loop
+		}
+		nDst += utf8.EncodeRune(dst[nDst:], r)
+	}
+	return nDst, nSrc, err
+}
+
+type hzGB2312Encoder int
+
+func (d *hzGB2312Encoder) Reset() {
+	*d = asciiState
+}
+
+func (e *hzGB2312Encoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+	for ; nSrc < len(src); nSrc += size {
+		r = rune(src[nSrc])
+
+		// Decode a 1-byte rune.
+		if r < utf8.RuneSelf {
+			size = 1
+			if r == '~' {
+				if nDst+2 > len(dst) {
+					err = transform.ErrShortDst
+					break
+				}
+				dst[nDst+0] = '~'
+				dst[nDst+1] = '~'
+				nDst += 2
+				continue
+			} else if *e != asciiState {
+				if nDst+3 > len(dst) {
+					err = transform.ErrShortDst
+					break
+				}
+				*e = asciiState
+				dst[nDst+0] = '~'
+				dst[nDst+1] = '}'
+				nDst += 2
+			} else if nDst >= len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+			dst[nDst] = uint8(r)
+			nDst += 1
+			continue
+
+		}
+
+		// Decode a multi-byte rune.
+		r, size = utf8.DecodeRune(src[nSrc:])
+		if size == 1 {
+			// All valid runes of size 1 (those below utf8.RuneSelf) were
+			// handled above. We have invalid UTF-8 or we haven't seen the
+			// full character yet.
+			if !atEOF && !utf8.FullRune(src[nSrc:]) {
+				err = transform.ErrShortSrc
+				break
+			}
+		}
+
+		// func init checks that the switch covers all tables.
+		switch {
+		case encode0Low <= r && r < encode0High:
+			if r = rune(encode0[r-encode0Low]); r != 0 {
+				goto writeGB
+			}
+		case encode1Low <= r && r < encode1High:
+			if r = rune(encode1[r-encode1Low]); r != 0 {
+				goto writeGB
+			}
+		case encode2Low <= r && r < encode2High:
+			if r = rune(encode2[r-encode2Low]); r != 0 {
+				goto writeGB
+			}
+		case encode3Low <= r && r < encode3High:
+			if r = rune(encode3[r-encode3Low]); r != 0 {
+				goto writeGB
+			}
+		case encode4Low <= r && r < encode4High:
+			if r = rune(encode4[r-encode4Low]); r != 0 {
+				goto writeGB
+			}
+		}
+
+	terminateInASCIIState:
+		// Switch back to ASCII state in case of error so that an ASCII
+		// replacement character can be written in the correct state.
+		if *e != asciiState {
+			if nDst+2 > len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+			dst[nDst+0] = '~'
+			dst[nDst+1] = '}'
+			nDst += 2
+		}
+		err = internal.ErrASCIIReplacement
+		break
+
+	writeGB:
+		c0 := uint8(r>>8) - 0x80
+		c1 := uint8(r) - 0x80
+		if c0 < 0x21 || 0x7e <= c0 || c1 < 0x21 || 0x7f <= c1 {
+			goto terminateInASCIIState
+		}
+		if *e == asciiState {
+			if nDst+4 > len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+			*e = gbState
+			dst[nDst+0] = '~'
+			dst[nDst+1] = '{'
+			nDst += 2
+		} else if nDst+2 > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst+0] = c0
+		dst[nDst+1] = c1
+		nDst += 2
+		continue
+	}
+	// TODO: should one always terminate in ASCII state to make it safe to
+	// concatenate two HZ-GB2312-encoded strings?
+	return nDst, nSrc, err
+}

vendor/golang.org/x/text/transform/transform.go

@@ -0,0 +1,709 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package transform provides reader and writer wrappers that transform the
+// bytes passing through as well as various transformations. Example
+// transformations provided by other packages include normalization and
+// conversion between character sets.
+package transform // import "golang.org/x/text/transform"
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"unicode/utf8"
+)
+
+var (
+	// ErrShortDst means that the destination buffer was too short to
+	// receive all of the transformed bytes.
+	ErrShortDst = errors.New("transform: short destination buffer")
+
+	// ErrShortSrc means that the source buffer has insufficient data to
+	// complete the transformation.
+	ErrShortSrc = errors.New("transform: short source buffer")
+
+	// ErrEndOfSpan means that the input and output (the transformed input)
+	// are not identical.
+	ErrEndOfSpan = errors.New("transform: input and output are not identical")
+
+	// errInconsistentByteCount means that Transform returned success (nil
+	// error) but also returned nSrc inconsistent with the src argument.
+	errInconsistentByteCount = errors.New("transform: inconsistent byte count returned")
+
+	// errShortInternal means that an internal buffer is not large enough
+	// to make progress and the Transform operation must be aborted.
+	errShortInternal = errors.New("transform: short internal buffer")
+)
+
+// Transformer transforms bytes.
+type Transformer interface {
+	// Transform writes to dst the transformed bytes read from src, and
+	// returns the number of dst bytes written and src bytes read. The
+	// atEOF argument tells whether src represents the last bytes of the
+	// input.
+	//
+	// Callers should always process the nDst bytes produced and account
+	// for the nSrc bytes consumed before considering the error err.
+	//
+	// A nil error means that all of the transformed bytes (whether freshly
+	// transformed from src or left over from previous Transform calls)
+	// were written to dst. A nil error can be returned regardless of
+	// whether atEOF is true. If err is nil then nSrc must equal len(src);
+	// the converse is not necessarily true.
+	//
+	// ErrShortDst means that dst was too short to receive all of the
+	// transformed bytes. ErrShortSrc means that src had insufficient data
+	// to complete the transformation. If both conditions apply, then
+	// either error may be returned. Other than the error conditions listed
+	// here, implementations are free to report other errors that arise.
+	Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)
+
+	// Reset resets the state and allows a Transformer to be reused.
+	Reset()
+}
+
+// SpanningTransformer extends the Transformer interface with a Span method
+// that determines how much of the input already conforms to the Transformer.
+type SpanningTransformer interface {
+	Transformer
+
+	// Span returns a position in src such that transforming src[:n] results in
+	// identical output src[:n] for these bytes. It does not necessarily return
+	// the largest such n. The atEOF argument tells whether src represents the
+	// last bytes of the input.
+	//
+	// Callers should always account for the n bytes consumed before
+	// considering the error err.
+	//
+	// A nil error means that all input bytes are known to be identical to the
+	// output produced by the Transformer. A nil error can be returned
+	// regardless of whether atEOF is true. If err is nil, then n must
+	// equal len(src); the converse is not necessarily true.
+	//
+	// ErrEndOfSpan means that the Transformer output may differ from the
+	// input after n bytes. Note that n may be len(src), meaning that the output
+	// would contain additional bytes after otherwise identical output.
+	// ErrShortSrc means that src had insufficient data to determine whether the
+	// remaining bytes would change. Other than the error conditions listed
+	// here, implementations are free to report other errors that arise.
+	//
+	// Calling Span can modify the Transformer state as a side effect. In
+	// effect, it does the transformation just as calling Transform would, only
+	// without copying to a destination buffer and only up to a point it can
+	// determine the input and output bytes are the same. This is obviously more
+	// limited than calling Transform, but can be more efficient in terms of
+	// copying and allocating buffers. Calls to Span and Transform may be
+	// interleaved.
+	Span(src []byte, atEOF bool) (n int, err error)
+}
+
+// NopResetter can be embedded by implementations of Transformer to add a nop
+// Reset method.
+type NopResetter struct{}
+
+// Reset implements the Reset method of the Transformer interface.
+func (NopResetter) Reset() {}
+
+// Reader wraps another io.Reader by transforming the bytes read.
+type Reader struct {
+	r   io.Reader
+	t   Transformer
+	err error
+
+	// dst[dst0:dst1] contains bytes that have been transformed by t but
+	// not yet copied out via Read.
+	dst        []byte
+	dst0, dst1 int
+
+	// src[src0:src1] contains bytes that have been read from r but not
+	// yet transformed through t.
+	src        []byte
+	src0, src1 int
+
+	// transformComplete is whether the transformation is complete,
+	// regardless of whether or not it was successful.
+	transformComplete bool
+}
+
+const defaultBufSize = 4096
+
+// NewReader returns a new Reader that wraps r by transforming the bytes read
+// via t. It calls Reset on t.
+func NewReader(r io.Reader, t Transformer) *Reader {
+	t.Reset()
+	return &Reader{
+		r:   r,
+		t:   t,
+		dst: make([]byte, defaultBufSize),
+		src: make([]byte, defaultBufSize),
+	}
+}
+
+// Read implements the io.Reader interface.
+func (r *Reader) Read(p []byte) (int, error) {
+	n, err := 0, error(nil)
+	for {
+		// Copy out any transformed bytes and return the final error if we are done.
+		if r.dst0 != r.dst1 {
+			n = copy(p, r.dst[r.dst0:r.dst1])
+			r.dst0 += n
+			if r.dst0 == r.dst1 && r.transformComplete {
+				return n, r.err
+			}
+			return n, nil
+		} else if r.transformComplete {
+			return 0, r.err
+		}
+
+		// Try to transform some source bytes, or to flush the transformer if we
+		// are out of source bytes. We do this even if r.r.Read returned an error.
+		// As the io.Reader documentation says, "process the n > 0 bytes returned
+		// before considering the error".
+		if r.src0 != r.src1 || r.err != nil {
+			r.dst0 = 0
+			r.dst1, n, err = r.t.Transform(r.dst, r.src[r.src0:r.src1], r.err == io.EOF)
+			r.src0 += n
+
+			switch {
+			case err == nil:
+				if r.src0 != r.src1 {
+					r.err = errInconsistentByteCount
+				}
+				// The Transform call was successful; we are complete if we
+				// cannot read more bytes into src.
+				r.transformComplete = r.err != nil
+				continue
+			case err == ErrShortDst && (r.dst1 != 0 || n != 0):
+				// Make room in dst by copying out, and try again.
+				continue
+			case err == ErrShortSrc && r.src1-r.src0 != len(r.src) && r.err == nil:
+				// Read more bytes into src via the code below, and try again.
+			default:
+				r.transformComplete = true
+				// The reader error (r.err) takes precedence over the
+				// transformer error (err) unless r.err is nil or io.EOF.
+				if r.err == nil || r.err == io.EOF {
+					r.err = err
+				}
+				continue
+			}
+		}
+
+		// Move any untransformed source bytes to the start of the buffer
+		// and read more bytes.
+		if r.src0 != 0 {
+			r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1])
+		}
+		n, r.err = r.r.Read(r.src[r.src1:])
+		r.src1 += n
+	}
+}
+
+// TODO: implement ReadByte (and ReadRune??).
+
+// Writer wraps another io.Writer by transforming the bytes read.
+// The user needs to call Close to flush unwritten bytes that may
+// be buffered.
+type Writer struct {
+	w   io.Writer
+	t   Transformer
+	dst []byte
+
+	// src[:n] contains bytes that have not yet passed through t.
+	src []byte
+	n   int
+}
+
+// NewWriter returns a new Writer that wraps w by transforming the bytes written
+// via t. It calls Reset on t.
+func NewWriter(w io.Writer, t Transformer) *Writer {
+	t.Reset()
+	return &Writer{
+		w:   w,
+		t:   t,
+		dst: make([]byte, defaultBufSize),
+		src: make([]byte, defaultBufSize),
+	}
+}
+
+// Write implements the io.Writer interface. If there are not enough
+// bytes available to complete a Transform, the bytes will be buffered
+// for the next write. Call Close to convert the remaining bytes.
+func (w *Writer) Write(data []byte) (n int, err error) {
+	src := data
+	if w.n > 0 {
+		// Append bytes from data to the last remainder.
+		// TODO: limit the amount copied on first try.
+		n = copy(w.src[w.n:], data)
+		w.n += n
+		src = w.src[:w.n]
+	}
+	for {
+		nDst, nSrc, err := w.t.Transform(w.dst, src, false)
+		if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
+			return n, werr
+		}
+		src = src[nSrc:]
+		if w.n == 0 {
+			n += nSrc
+		} else if len(src) <= n {
+			// Enough bytes from w.src have been consumed. We make src point
+			// to data instead to reduce the copying.
+			w.n = 0
+			n -= len(src)
+			src = data[n:]
+			if n < len(data) && (err == nil || err == ErrShortSrc) {
+				continue
+			}
+		}
+		switch err {
+		case ErrShortDst:
+			// This error is okay as long as we are making progress.
+			if nDst > 0 || nSrc > 0 {
+				continue
+			}
+		case ErrShortSrc:
+			if len(src) < len(w.src) {
+				m := copy(w.src, src)
+				// If w.n > 0, bytes from data were already copied to w.src and n
+				// was already set to the number of bytes consumed.
+				if w.n == 0 {
+					n += m
+				}
+				w.n = m
+				err = nil
+			} else if nDst > 0 || nSrc > 0 {
+				// Not enough buffer to store the remainder. Keep processing as
+				// long as there is progress. Without this case, transforms that
+				// require a lookahead larger than the buffer may result in an
+				// error. This is not something one may expect to be common in
+				// practice, but it may occur when buffers are set to small
+				// sizes during testing.
+				continue
+			}
+		case nil:
+			if w.n > 0 {
+				err = errInconsistentByteCount
+			}
+		}
+		return n, err
+	}
+}
+
+// Close implements the io.Closer interface.
+func (w *Writer) Close() error {
+	src := w.src[:w.n]
+	for {
+		nDst, nSrc, err := w.t.Transform(w.dst, src, true)
+		if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
+			return werr
+		}
+		if err != ErrShortDst {
+			return err
+		}
+		src = src[nSrc:]
+	}
+}
+
+type nop struct{ NopResetter }
+
+func (nop) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	n := copy(dst, src)
+	if n < len(src) {
+		err = ErrShortDst
+	}
+	return n, n, err
+}
+
+func (nop) Span(src []byte, atEOF bool) (n int, err error) {
+	return len(src), nil
+}
+
+type discard struct{ NopResetter }
+
+func (discard) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	return 0, len(src), nil
+}
+
+var (
+	// Discard is a Transformer for which all Transform calls succeed
+	// by consuming all bytes and writing nothing.
+	Discard Transformer = discard{}
+
+	// Nop is a SpanningTransformer that copies src to dst.
+	Nop SpanningTransformer = nop{}
+)
+
+// chain is a sequence of links. A chain with N Transformers has N+1 links and
+// N+1 buffers. Of those N+1 buffers, the first and last are the src and dst
+// buffers given to chain.Transform and the middle N-1 buffers are intermediate
+// buffers owned by the chain. The i'th link transforms bytes from the i'th
+// buffer chain.link[i].b at read offset chain.link[i].p to the i+1'th buffer
+// chain.link[i+1].b at write offset chain.link[i+1].n, for i in [0, N).
+type chain struct {
+	link []link
+	err  error
+	// errStart is the index at which the error occurred plus 1. Processing
+	// errStart at this level at the next call to Transform. As long as
+	// errStart > 0, chain will not consume any more source bytes.
+	errStart int
+}
+
+func (c *chain) fatalError(errIndex int, err error) {
+	if i := errIndex + 1; i > c.errStart {
+		c.errStart = i
+		c.err = err
+	}
+}
+
+type link struct {
+	t Transformer
+	// b[p:n] holds the bytes to be transformed by t.
+	b []byte
+	p int
+	n int
+}
+
+func (l *link) src() []byte {
+	return l.b[l.p:l.n]
+}
+
+func (l *link) dst() []byte {
+	return l.b[l.n:]
+}
+
+// Chain returns a Transformer that applies t in sequence.
+func Chain(t ...Transformer) Transformer {
+	if len(t) == 0 {
+		return nop{}
+	}
+	c := &chain{link: make([]link, len(t)+1)}
+	for i, tt := range t {
+		c.link[i].t = tt
+	}
+	// Allocate intermediate buffers.
+	b := make([][defaultBufSize]byte, len(t)-1)
+	for i := range b {
+		c.link[i+1].b = b[i][:]
+	}
+	return c
+}
+
+// Reset resets the state of Chain. It calls Reset on all the Transformers.
+func (c *chain) Reset() {
+	for i, l := range c.link {
+		if l.t != nil {
+			l.t.Reset()
+		}
+		c.link[i].p, c.link[i].n = 0, 0
+	}
+}
+
+// TODO: make chain use Span (is going to be fun to implement!)
+
+// Transform applies the transformers of c in sequence.
+func (c *chain) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	// Set up src and dst in the chain.
+	srcL := &c.link[0]
+	dstL := &c.link[len(c.link)-1]
+	srcL.b, srcL.p, srcL.n = src, 0, len(src)
+	dstL.b, dstL.n = dst, 0
+	var lastFull, needProgress bool // for detecting progress
+
+	// i is the index of the next Transformer to apply, for i in [low, high].
+	// low is the lowest index for which c.link[low] may still produce bytes.
+	// high is the highest index for which c.link[high] has a Transformer.
+	// The error returned by Transform determines whether to increase or
+	// decrease i. We try to completely fill a buffer before converting it.
+	for low, i, high := c.errStart, c.errStart, len(c.link)-2; low <= i && i <= high; {
+		in, out := &c.link[i], &c.link[i+1]
+		nDst, nSrc, err0 := in.t.Transform(out.dst(), in.src(), atEOF && low == i)
+		out.n += nDst
+		in.p += nSrc
+		if i > 0 && in.p == in.n {
+			in.p, in.n = 0, 0
+		}
+		needProgress, lastFull = lastFull, false
+		switch err0 {
+		case ErrShortDst:
+			// Process the destination buffer next. Return if we are already
+			// at the high index.
+			if i == high {
+				return dstL.n, srcL.p, ErrShortDst
+			}
+			if out.n != 0 {
+				i++
+				// If the Transformer at the next index is not able to process any
+				// source bytes there is nothing that can be done to make progress
+				// and the bytes will remain unprocessed. lastFull is used to
+				// detect this and break out of the loop with a fatal error.
+				lastFull = true
+				continue
+			}
+			// The destination buffer was too small, but is completely empty.
+			// Return a fatal error as this transformation can never complete.
+			c.fatalError(i, errShortInternal)
+		case ErrShortSrc:
+			if i == 0 {
+				// Save ErrShortSrc in err. All other errors take precedence.
+				err = ErrShortSrc
+				break
+			}
+			// Source bytes were depleted before filling up the destination buffer.
+			// Verify we made some progress, move the remaining bytes to the errStart
+			// and try to get more source bytes.
+			if needProgress && nSrc == 0 || in.n-in.p == len(in.b) {
+				// There were not enough source bytes to proceed while the source
+				// buffer cannot hold any more bytes. Return a fatal error as this
+				// transformation can never complete.
+				c.fatalError(i, errShortInternal)
+				break
+			}
+			// in.b is an internal buffer and we can make progress.
+			in.p, in.n = 0, copy(in.b, in.src())
+			fallthrough
+		case nil:
+			// if i == low, we have depleted the bytes at index i or any lower levels.
+			// In that case we increase low and i. In all other cases we decrease i to
+			// fetch more bytes before proceeding to the next index.
+			if i > low {
+				i--
+				continue
+			}
+		default:
+			c.fatalError(i, err0)
+		}
+		// Exhausted level low or fatal error: increase low and continue
+		// to process the bytes accepted so far.
+		i++
+		low = i
+	}
+
+	// If c.errStart > 0, this means we found a fatal error.  We will clear
+	// all upstream buffers. At this point, no more progress can be made
+	// downstream, as Transform would have bailed while handling ErrShortDst.
+	if c.errStart > 0 {
+		for i := 1; i < c.errStart; i++ {
+			c.link[i].p, c.link[i].n = 0, 0
+		}
+		err, c.errStart, c.err = c.err, 0, nil
+	}
+	return dstL.n, srcL.p, err
+}
+
+// Deprecated: Use runes.Remove instead.
+func RemoveFunc(f func(r rune) bool) Transformer {
+	return removeF(f)
+}
+
+type removeF func(r rune) bool
+
+func (removeF) Reset() {}
+
+// Transform implements the Transformer interface.
+func (t removeF) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	for r, sz := rune(0), 0; len(src) > 0; src = src[sz:] {
+
+		if r = rune(src[0]); r < utf8.RuneSelf {
+			sz = 1
+		} else {
+			r, sz = utf8.DecodeRune(src)
+
+			if sz == 1 {
+				// Invalid rune.
+				if !atEOF && !utf8.FullRune(src) {
+					err = ErrShortSrc
+					break
+				}
+				// We replace illegal bytes with RuneError. Not doing so might
+				// otherwise turn a sequence of invalid UTF-8 into valid UTF-8.
+				// The resulting byte sequence may subsequently contain runes
+				// for which t(r) is true that were passed unnoticed.
+				if !t(r) {
+					if nDst+3 > len(dst) {
+						err = ErrShortDst
+						break
+					}
+					nDst += copy(dst[nDst:], "\uFFFD")
+				}
+				nSrc++
+				continue
+			}
+		}
+
+		if !t(r) {
+			if nDst+sz > len(dst) {
+				err = ErrShortDst
+				break
+			}
+			nDst += copy(dst[nDst:], src[:sz])
+		}
+		nSrc += sz
+	}
+	return
+}
+
+// grow returns a new []byte that is longer than b, and copies the first n bytes
+// of b to the start of the new slice.
+func grow(b []byte, n int) []byte {
+	m := len(b)
+	if m <= 32 {
+		m = 64
+	} else if m <= 256 {
+		m *= 2
+	} else {
+		m += m >> 1
+	}
+	buf := make([]byte, m)
+	copy(buf, b[:n])
+	return buf
+}
+
+const initialBufSize = 128
+
+// String returns a string with the result of converting s[:n] using t, where
+// n <= len(s). If err == nil, n will be len(s). It calls Reset on t.
+func String(t Transformer, s string) (result string, n int, err error) {
+	t.Reset()
+	if s == "" {
+		// Fast path for the common case for empty input. Results in about a
+		// 86% reduction of running time for BenchmarkStringLowerEmpty.
+		if _, _, err := t.Transform(nil, nil, true); err == nil {
+			return "", 0, nil
+		}
+	}
+
+	// Allocate only once. Note that both dst and src escape when passed to
+	// Transform.
+	buf := [2 * initialBufSize]byte{}
+	dst := buf[:initialBufSize:initialBufSize]
+	src := buf[initialBufSize : 2*initialBufSize]
+
+	// The input string s is transformed in multiple chunks (starting with a
+	// chunk size of initialBufSize). nDst and nSrc are per-chunk (or
+	// per-Transform-call) indexes, pDst and pSrc are overall indexes.
+	nDst, nSrc := 0, 0
+	pDst, pSrc := 0, 0
+
+	// pPrefix is the length of a common prefix: the first pPrefix bytes of the
+	// result will equal the first pPrefix bytes of s. It is not guaranteed to
+	// be the largest such value, but if pPrefix, len(result) and len(s) are
+	// all equal after the final transform (i.e. calling Transform with atEOF
+	// being true returned nil error) then we don't need to allocate a new
+	// result string.
+	pPrefix := 0
+	for {
+		// Invariant: pDst == pPrefix && pSrc == pPrefix.
+
+		n := copy(src, s[pSrc:])
+		nDst, nSrc, err = t.Transform(dst, src[:n], pSrc+n == len(s))
+		pDst += nDst
+		pSrc += nSrc
+
+		// TODO:  let transformers implement an optional Spanner interface, akin
+		// to norm's QuickSpan. This would even allow us to avoid any allocation.
+		if !bytes.Equal(dst[:nDst], src[:nSrc]) {
+			break
+		}
+		pPrefix = pSrc
+		if err == ErrShortDst {
+			// A buffer can only be short if a transformer modifies its input.
+			break
+		} else if err == ErrShortSrc {
+			if nSrc == 0 {
+				// No progress was made.
+				break
+			}
+			// Equal so far and !atEOF, so continue checking.
+		} else if err != nil || pPrefix == len(s) {
+			return string(s[:pPrefix]), pPrefix, err
+		}
+	}
+	// Post-condition: pDst == pPrefix + nDst && pSrc == pPrefix + nSrc.
+
+	// We have transformed the first pSrc bytes of the input s to become pDst
+	// transformed bytes. Those transformed bytes are discontiguous: the first
+	// pPrefix of them equal s[:pPrefix] and the last nDst of them equal
+	// dst[:nDst]. We copy them around, into a new dst buffer if necessary, so
+	// that they become one contiguous slice: dst[:pDst].
+	if pPrefix != 0 {
+		newDst := dst
+		if pDst > len(newDst) {
+			newDst = make([]byte, len(s)+nDst-nSrc)
+		}
+		copy(newDst[pPrefix:pDst], dst[:nDst])
+		copy(newDst[:pPrefix], s[:pPrefix])
+		dst = newDst
+	}
+
+	// Prevent duplicate Transform calls with atEOF being true at the end of
+	// the input. Also return if we have an unrecoverable error.
+	if (err == nil && pSrc == len(s)) ||
+		(err != nil && err != ErrShortDst && err != ErrShortSrc) {
+		return string(dst[:pDst]), pSrc, err
+	}
+
+	// Transform the remaining input, growing dst and src buffers as necessary.
+	for {
+		n := copy(src, s[pSrc:])
+		atEOF := pSrc+n == len(s)
+		nDst, nSrc, err := t.Transform(dst[pDst:], src[:n], atEOF)
+		pDst += nDst
+		pSrc += nSrc
+
+		// If we got ErrShortDst or ErrShortSrc, do not grow as long as we can
+		// make progress. This may avoid excessive allocations.
+		if err == ErrShortDst {
+			if nDst == 0 {
+				dst = grow(dst, pDst)
+			}
+		} else if err == ErrShortSrc {
+			if atEOF {
+				return string(dst[:pDst]), pSrc, err
+			}
+			if nSrc == 0 {
+				src = grow(src, 0)
+			}
+		} else if err != nil || pSrc == len(s) {
+			return string(dst[:pDst]), pSrc, err
+		}
+	}
+}
+
+// Bytes returns a new byte slice with the result of converting b[:n] using t,
+// where n <= len(b). If err == nil, n will be len(b). It calls Reset on t.
+func Bytes(t Transformer, b []byte) (result []byte, n int, err error) {
+	return doAppend(t, 0, make([]byte, len(b)), b)
+}
+
+// Append appends the result of converting src[:n] using t to dst, where
+// n <= len(src), If err == nil, n will be len(src). It calls Reset on t.
+func Append(t Transformer, dst, src []byte) (result []byte, n int, err error) {
+	if len(dst) == cap(dst) {
+		n := len(src) + len(dst) // It is okay for this to be 0.
+		b := make([]byte, n)
+		dst = b[:copy(b, dst)]
+	}
+	return doAppend(t, len(dst), dst[:cap(dst)], src)
+}
+
+func doAppend(t Transformer, pDst int, dst, src []byte) (result []byte, n int, err error) {
+	t.Reset()
+	pSrc := 0
+	for {
+		nDst, nSrc, err := t.Transform(dst[pDst:], src[pSrc:], true)
+		pDst += nDst
+		pSrc += nSrc
+		if err != ErrShortDst {
+			return dst[:pDst], pSrc, err
+		}
+
+		// Grow the destination buffer, but do not grow as long as we can make
+		// progress. This may avoid excessive allocations.
+		if nDst == 0 {
+			dst = grow(dst, pDst)
+		}
+	}
+}

vendor/modules.txt

@@ -0,0 +1,25 @@
+# github.com/dtapps/gostring v1.0.0
+## explicit
+github.com/dtapps/gostring
+# github.com/saracen/go7z v0.0.0-20191010121135-9c09b6bd7fda
+## explicit
+github.com/saracen/go7z
+github.com/saracen/go7z/filters
+github.com/saracen/go7z/headers
+# github.com/saracen/go7z-fixtures v0.0.0-20190623165746-aa6b8fba1d2f
+## explicit
+# github.com/saracen/solidblock v0.0.0-20190426153529-45df20abab6f
+## explicit
+github.com/saracen/solidblock
+# github.com/ulikunitz/xz v0.5.10
+## explicit; go 1.12
+github.com/ulikunitz/xz/internal/hash
+github.com/ulikunitz/xz/internal/xlog
+github.com/ulikunitz/xz/lzma
+# golang.org/x/text v0.3.7
+## explicit; go 1.17
+golang.org/x/text/encoding
+golang.org/x/text/encoding/internal
+golang.org/x/text/encoding/internal/identifier
+golang.org/x/text/encoding/simplifiedchinese
+golang.org/x/text/transform