forked from jackpal/Taipei-Torrent
/
metainfo.go
227 lines (200 loc) · 4.62 KB
/
metainfo.go
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package main
import (
"bytes"
"crypto/sha1"
"errors"
"io"
"io/ioutil"
"log"
"os"
"strings"
"time"
bencode "code.google.com/p/bencode-go"
"github.com/nictuku/dht"
)
type FileDict struct {
Length int64
Path []string
Md5sum string
}
type InfoDict struct {
PieceLength int64 "piece length"
Pieces string
Private int64
Name string
// Single File Mode
Length int64
Md5sum string
// Multiple File mode
Files []FileDict
}
type MetaInfo struct {
Info InfoDict
InfoHash string
Announce string
AnnounceList [][]string "announce-list"
CreationDate string "creation date"
Comment string
CreatedBy string "created by"
Encoding string
}
func getString(m map[string]interface{}, k string) string {
if v, ok := m[k]; ok {
if s, ok := v.(string); ok {
return s
}
}
return ""
}
// Parse a list of list of strings structure, filtering out anything that's
// not a string, and filtering out empty lists. May return nil.
func getSliceSliceString(m map[string]interface{}, k string) (aas [][]string) {
if a, ok := m[k]; ok {
if b, ok := a.([]interface{}); ok {
for _, c := range b {
if d, ok := c.([]interface{}); ok {
var sliceOfStrings []string
for _, e := range d {
if f, ok := e.(string); ok {
sliceOfStrings = append(sliceOfStrings, f)
}
}
if len(sliceOfStrings) > 0 {
aas = append(aas, sliceOfStrings)
}
}
}
}
}
return
}
func getMetaInfo(torrent string) (metaInfo *MetaInfo, err error) {
var input io.ReadCloser
if strings.HasPrefix(torrent, "http:") {
r, err := proxyHttpGet(torrent)
if err != nil {
return nil, err
}
input = r.Body
} else if strings.HasPrefix(torrent, "magnet:") {
magnet, err := parseMagnet(torrent)
if err != nil {
log.Println("Couldn't parse magnet: ", err)
return nil, err
}
ih, err := dht.DecodeInfoHash(magnet.InfoHashes[0])
if err != nil {
return nil, err
}
metaInfo = &MetaInfo{InfoHash: string(ih)}
return metaInfo, err
} else {
if input, err = os.Open(torrent); err != nil {
return
}
}
// We need to calcuate the sha1 of the Info map, including every value in the
// map. The easiest way to do this is to read the data using the Decode
// API, and then pick through it manually.
var m interface{}
m, err = bencode.Decode(input)
input.Close()
if err != nil {
err = errors.New("Couldn't parse torrent file phase 1: " + err.Error())
return
}
topMap, ok := m.(map[string]interface{})
if !ok {
err = errors.New("Couldn't parse torrent file phase 2.")
return
}
infoMap, ok := topMap["info"]
if !ok {
err = errors.New("Couldn't parse torrent file. info")
return
}
var b bytes.Buffer
if err = bencode.Marshal(&b, infoMap); err != nil {
return
}
hash := sha1.New()
hash.Write(b.Bytes())
var m2 MetaInfo
err = bencode.Unmarshal(&b, &m2.Info)
if err != nil {
return
}
m2.InfoHash = string(hash.Sum(nil))
m2.Announce = getString(topMap, "announce")
m2.AnnounceList = getSliceSliceString(topMap, "announce-list")
m2.CreationDate = getString(topMap, "creation date")
m2.Comment = getString(topMap, "comment")
m2.CreatedBy = getString(topMap, "created by")
m2.Encoding = getString(topMap, "encoding")
metaInfo = &m2
return
}
type TrackerResponse struct {
FailureReason string "failure reason"
WarningMessage string "warning message"
Interval time.Duration
MinInterval time.Duration "min interval"
TrackerId string "tracker id"
Complete int
Incomplete int
Peers string
Peers6 string
}
type SessionInfo struct {
PeerId string
Port int
Uploaded int64
Downloaded int64
Left int64
UseDHT bool
FromMagnet bool
HaveTorrent bool
OurExtensions map[int]string
ME *MetaDataExchange
}
type MetaDataExchange struct {
Transferring bool
Pieces [][]byte
}
func getTrackerInfo(url string) (tr *TrackerResponse, err error) {
r, err := proxyHttpGet(url)
if err != nil {
return
}
defer r.Body.Close()
if r.StatusCode >= 400 {
data, _ := ioutil.ReadAll(r.Body)
reason := "Bad Request " + string(data)
log.Println(reason)
err = errors.New(reason)
return
}
var tr2 TrackerResponse
err = bencode.Unmarshal(r.Body, &tr2)
r.Body.Close()
if err != nil {
return
}
tr = &tr2
return
}
func saveMetaInfo(metadata string) (err error) {
var info InfoDict
err = bencode.Unmarshal(bytes.NewReader([]byte(metadata)), &info)
if err != nil {
return
}
f, err := os.Create(info.Name + ".torrent")
if err != nil {
log.Println("Error when opening file for creation: ", err)
return
}
defer f.Close()
_, err = f.WriteString(metadata)
return
}