13 "github.com/anacrolix/missinggo/v2"
14 "github.com/edsrzf/mmap-go"
16 "github.com/anacrolix/torrent/metainfo"
17 "github.com/anacrolix/torrent/mmap_span"
20 type mmapClientImpl struct {
25 func NewMMap(baseDir string) ClientImplCloser {
26 return NewMMapWithCompletion(baseDir, pieceCompletionForDir(baseDir))
29 func NewMMapWithCompletion(baseDir string, completion PieceCompletion) *mmapClientImpl {
30 return &mmapClientImpl{
36 func (s *mmapClientImpl) OpenTorrent(info *metainfo.Info, infoHash metainfo.Hash) (_ TorrentImpl, err error) {
37 span, err := mMapTorrent(info, s.baseDir)
38 t := &mmapTorrentStorage{
43 return TorrentImpl{Piece: t.Piece, Close: t.Close}, err
46 func (s *mmapClientImpl) Close() error {
50 type mmapTorrentStorage struct {
51 infoHash metainfo.Hash
52 span *mmap_span.MMapSpan
53 pc PieceCompletionGetSetter
56 func (ts *mmapTorrentStorage) Piece(p metainfo.Piece) PieceImpl {
57 return mmapStoragePiece{
61 ReaderAt: io.NewSectionReader(ts.span, p.Offset(), p.Length()),
62 WriterAt: missinggo.NewSectionWriter(ts.span, p.Offset(), p.Length()),
66 func (ts *mmapTorrentStorage) Close() error {
67 errs := ts.span.Close()
74 type mmapStoragePiece struct {
75 pc PieceCompletionGetSetter
82 func (me mmapStoragePiece) pieceKey() metainfo.PieceKey {
83 return metainfo.PieceKey{me.ih, me.p.Index()}
86 func (sp mmapStoragePiece) Completion() Completion {
87 c, err := sp.pc.Get(sp.pieceKey())
94 func (sp mmapStoragePiece) MarkComplete() error {
95 sp.pc.Set(sp.pieceKey(), true)
99 func (sp mmapStoragePiece) MarkNotComplete() error {
100 sp.pc.Set(sp.pieceKey(), false)
104 func mMapTorrent(md *metainfo.Info, location string) (mms *mmap_span.MMapSpan, err error) {
105 mms = &mmap_span.MMapSpan{}
111 for _, miFile := range md.UpvertedFiles() {
113 safeName, err = ToSafeFilePath(append([]string{md.Name}, miFile.Path...)...)
117 fileName := filepath.Join(location, safeName)
119 mm, err = mmapFile(fileName, miFile.Length)
121 err = fmt.Errorf("file %q: %s", miFile.DisplayPath(md), err)
132 func mmapFile(name string, size int64) (ret mmap.MMap, err error) {
133 dir := filepath.Dir(name)
134 err = os.MkdirAll(dir, 0777)
136 err = fmt.Errorf("making directory %q: %s", dir, err)
140 file, err = os.OpenFile(name, os.O_CREATE|os.O_RDWR, 0666)
146 fi, err = file.Stat()
150 if fi.Size() < size {
151 // I think this is necessary on HFS+. Maybe Linux will SIGBUS too if
152 // you overmap a file but I'm not sure.
153 err = file.Truncate(size)
159 // Can't mmap() regions with length 0.
163 if int64(intLen) != size {
164 err = errors.New("size too large for system")
167 ret, err = mmap.MapRegion(file, intLen, mmap.RDWR, 0, 0)
169 err = fmt.Errorf("error mapping region: %s", err)
172 if int64(len(ret)) != size {