package metainfo
import (
- "crypto/sha1"
- "errors"
- "fmt"
+ "bufio"
"io"
- "log"
+ "net/url"
"os"
- "path/filepath"
- "strings"
"time"
"github.com/anacrolix/torrent/bencode"
)
-// Information specific to a single file inside the MetaInfo structure.
-type FileInfo struct {
- Length int64 `bencode:"length"`
- Path []string `bencode:"path"`
+type MetaInfo struct {
+ InfoBytes bencode.Bytes `bencode:"info,omitempty"` // BEP 3
+ Announce string `bencode:"announce,omitempty"` // BEP 3
+ AnnounceList AnnounceList `bencode:"announce-list,omitempty"` // BEP 12
+ Nodes []Node `bencode:"nodes,omitempty,ignore_unmarshal_type_error"` // BEP 5
+ // Where's this specified? Mentioned at
+ // https://wiki.theory.org/index.php/BitTorrentSpecification: (optional) the creation time of
+ // the torrent, in standard UNIX epoch format (integer, seconds since 1-Jan-1970 00:00:00 UTC)
+ CreationDate int64 `bencode:"creation date,omitempty,ignore_unmarshal_type_error"`
+ Comment string `bencode:"comment,omitempty"`
+ CreatedBy string `bencode:"created by,omitempty"`
+ Encoding string `bencode:"encoding,omitempty"`
+ UrlList UrlList `bencode:"url-list,omitempty"` // BEP 19 WebSeeds
}
// Load a MetaInfo from an io.Reader. Returns a non-nil error in case of
return nil, err
}
defer f.Close()
- return Load(f)
-}
-
-// The info dictionary.
-type Info struct {
- PieceLength int64 `bencode:"piece length"`
- Pieces []byte `bencode:"pieces"`
- Name string `bencode:"name"`
- Length int64 `bencode:"length,omitempty"`
- Private bool `bencode:"private,omitempty"`
- Files []FileInfo `bencode:"files,omitempty"`
+ var buf bufio.Reader
+ buf.Reset(f)
+ return Load(&buf)
}
-func (info *Info) BuildFromFilePath(root string) (err error) {
- info.Name = filepath.Base(root)
- info.Files = nil
- err = filepath.Walk(root, func(path string, fi os.FileInfo, err error) error {
- log.Println(path, root, err)
- if fi.IsDir() {
- // Directories are implicit in torrent files.
- return nil
- } else if path == root {
- // The root is a file.
- info.Length = fi.Size()
- return nil
- }
- relPath, err := filepath.Rel(root, path)
- log.Println(relPath, err)
- if err != nil {
- return fmt.Errorf("error getting relative path: %s", err)
- }
- info.Files = append(info.Files, FileInfo{
- Path: strings.Split(relPath, string(filepath.Separator)),
- Length: fi.Size(),
- })
- return nil
- })
- if err != nil {
- return
- }
- err = info.GeneratePieces(func(fi FileInfo) (io.ReadCloser, error) {
- return os.Open(filepath.Join(root, strings.Join(fi.Path, string(filepath.Separator))))
- })
- if err != nil {
- err = fmt.Errorf("error generating pieces: %s", err)
- }
+func (mi MetaInfo) UnmarshalInfo() (info Info, err error) {
+ err = bencode.Unmarshal(mi.InfoBytes, &info)
return
}
-func (info *Info) writeFiles(w io.Writer, open func(fi FileInfo) (io.ReadCloser, error)) error {
- for _, fi := range info.UpvertedFiles() {
- r, err := open(fi)
- if err != nil {
- return fmt.Errorf("error opening %v: %s", fi, err)
- }
- wn, err := io.CopyN(w, r, fi.Length)
- r.Close()
- if wn != fi.Length || err != nil {
- return fmt.Errorf("error hashing %v: %s", fi, err)
- }
- }
- return nil
-}
-
-// Set info.Pieces by hashing info.Files.
-func (info *Info) GeneratePieces(open func(fi FileInfo) (io.ReadCloser, error)) error {
- if info.PieceLength == 0 {
- return errors.New("piece length must be non-zero")
- }
- pr, pw := io.Pipe()
- go func() {
- err := info.writeFiles(pw, open)
- pw.CloseWithError(err)
- }()
- defer pr.Close()
- var pieces []byte
- for {
- hasher := sha1.New()
- wn, err := io.CopyN(hasher, pr, info.PieceLength)
- if err == io.EOF {
- err = nil
- }
- if err != nil {
- return err
- }
- if wn == 0 {
- break
- }
- pieces = hasher.Sum(pieces)
- if wn < info.PieceLength {
- break
- }
- }
- info.Pieces = pieces
- return nil
-}
-
-func (me *Info) TotalLength() (ret int64) {
- if me.IsDir() {
- for _, fi := range me.Files {
- ret += fi.Length
- }
- } else {
- ret = me.Length
- }
- return
+func (mi MetaInfo) HashInfoBytes() (infoHash Hash) {
+ return HashBytes(mi.InfoBytes)
}
-func (me *Info) NumPieces() int {
- if len(me.Pieces)%20 != 0 {
- panic(len(me.Pieces))
- }
- return len(me.Pieces) / 20
+// Encode to bencoded form.
+func (mi MetaInfo) Write(w io.Writer) error {
+ return bencode.NewEncoder(w).Encode(mi)
}
-type Piece struct {
- Info *Info
- i int
+// Set good default values in preparation for creating a new MetaInfo file.
+func (mi *MetaInfo) SetDefaults() {
+ mi.CreatedBy = "github.com/anacrolix/torrent"
+ mi.CreationDate = time.Now().Unix()
}
-func (me Piece) Length() int64 {
- if me.i == me.Info.NumPieces()-1 {
- return me.Info.TotalLength() - int64(me.i)*me.Info.PieceLength
+// Creates a Magnet from a MetaInfo. Optional infohash and parsed info can be provided.
+func (mi MetaInfo) Magnet(infoHash *Hash, info *Info) (m Magnet) {
+ m.Trackers = append(m.Trackers, mi.UpvertedAnnounceList().DistinctValues()...)
+ if info != nil {
+ m.DisplayName = info.BestName()
}
- return me.Info.PieceLength
-}
-
-func (me Piece) Offset() int64 {
- return int64(me.i) * me.Info.PieceLength
-}
-
-func (me Piece) Hash() []byte {
- return me.Info.Pieces[me.i*20 : (me.i+1)*20]
-}
-
-func (me *Info) Piece(i int) Piece {
- return Piece{me, i}
-}
-
-func (i *Info) IsDir() bool {
- return len(i.Files) != 0
-}
-
-// The files field, converted up from the old single-file in the parent info
-// dict if necessary. This is a helper to avoid having to conditionally handle
-// single and multi-file torrent infos.
-func (i *Info) UpvertedFiles() []FileInfo {
- if len(i.Files) == 0 {
- return []FileInfo{{
- Length: i.Length,
- // Callers should determine that Info.Name is the basename, and
- // thus a regular file.
- Path: nil,
- }}
+ if infoHash != nil {
+ m.InfoHash = *infoHash
+ } else {
+ m.InfoHash = mi.HashInfoBytes()
}
- return i.Files
-}
-
-// The info dictionary with its hash and raw bytes exposed, as these are
-// important to Bittorrent.
-type InfoEx struct {
- Info
- Hash []byte
- Bytes []byte
+ m.Params = make(url.Values)
+ m.Params["ws"] = mi.UrlList
+ return
}
-var (
- _ bencode.Marshaler = InfoEx{}
- _ bencode.Unmarshaler = &InfoEx{}
-)
-
-func (this *InfoEx) UnmarshalBencode(data []byte) error {
- this.Bytes = make([]byte, 0, len(data))
- this.Bytes = append(this.Bytes, data...)
- h := sha1.New()
- _, err := h.Write(this.Bytes)
- if err != nil {
- panic(err)
+// Returns the announce list converted from the old single announce field if
+// necessary.
+func (mi *MetaInfo) UpvertedAnnounceList() AnnounceList {
+ if mi.AnnounceList.OverridesAnnounce(mi.Announce) {
+ return mi.AnnounceList
}
- this.Hash = h.Sum(nil)
- return bencode.Unmarshal(data, &this.Info)
-}
-
-func (this InfoEx) MarshalBencode() ([]byte, error) {
- if this.Bytes != nil {
- return this.Bytes, nil
+ if mi.Announce != "" {
+ return [][]string{{mi.Announce}}
}
- return bencode.Marshal(&this.Info)
-}
-
-type MetaInfo struct {
- Info InfoEx `bencode:"info"`
- Announce string `bencode:"announce,omitempty"`
- AnnounceList [][]string `bencode:"announce-list,omitempty"`
- Nodes []string `bencode:"nodes,omitempty"`
- CreationDate int64 `bencode:"creation date,omitempty"`
- Comment string `bencode:"comment,omitempty"`
- CreatedBy string `bencode:"created by,omitempty"`
- Encoding string `bencode:"encoding,omitempty"`
- URLList interface{} `bencode:"url-list,omitempty"`
-}
-
-// Encode to bencoded form.
-func (mi *MetaInfo) Write(w io.Writer) error {
- return bencode.NewEncoder(w).Encode(mi)
-}
-
-// Set good default values in preparation for creating a new MetaInfo file.
-func (mi *MetaInfo) SetDefaults() {
- mi.Comment = "yoloham"
- mi.CreatedBy = "github.com/anacrolix/torrent"
- mi.CreationDate = time.Now().Unix()
- mi.Info.PieceLength = 256 * 1024
+ return nil
}