10 "github.com/anacrolix/missinggo"
11 "github.com/edsrzf/mmap-go"
13 "github.com/anacrolix/torrent/metainfo"
14 "github.com/anacrolix/torrent/mmap_span"
17 type mmapClientImpl struct {
22 func NewMMap(baseDir string) ClientImplCloser {
23 return NewMMapWithCompletion(baseDir, pieceCompletionForDir(baseDir))
26 func NewMMapWithCompletion(baseDir string, completion PieceCompletion) *mmapClientImpl {
27 return &mmapClientImpl{
33 func (s *mmapClientImpl) OpenTorrent(info *metainfo.Info, infoHash metainfo.Hash) (_ TorrentImpl, err error) {
34 span, err := mMapTorrent(info, s.baseDir)
35 t := &mmapTorrentStorage{
40 return TorrentImpl{Piece: t.Piece, Close: t.Close}, err
43 func (s *mmapClientImpl) Close() error {
47 type mmapTorrentStorage struct {
48 infoHash metainfo.Hash
49 span *mmap_span.MMapSpan
50 pc PieceCompletionGetSetter
53 func (ts *mmapTorrentStorage) Piece(p metainfo.Piece) PieceImpl {
54 return mmapStoragePiece{
58 ReaderAt: io.NewSectionReader(ts.span, p.Offset(), p.Length()),
59 WriterAt: missinggo.NewSectionWriter(ts.span, p.Offset(), p.Length()),
63 func (ts *mmapTorrentStorage) Close() error {
64 errs := ts.span.Close()
71 type mmapStoragePiece struct {
72 pc PieceCompletionGetSetter
79 func (me mmapStoragePiece) pieceKey() metainfo.PieceKey {
80 return metainfo.PieceKey{me.ih, me.p.Index()}
83 func (sp mmapStoragePiece) Completion() Completion {
84 c, err := sp.pc.Get(sp.pieceKey())
91 func (sp mmapStoragePiece) MarkComplete() error {
92 sp.pc.Set(sp.pieceKey(), true)
96 func (sp mmapStoragePiece) MarkNotComplete() error {
97 sp.pc.Set(sp.pieceKey(), false)
101 func mMapTorrent(md *metainfo.Info, location string) (mms *mmap_span.MMapSpan, err error) {
102 mms = &mmap_span.MMapSpan{}
108 for _, miFile := range md.UpvertedFiles() {
110 safeName, err = ToSafeFilePath(append([]string{md.Name}, miFile.Path...)...)
114 fileName := filepath.Join(location, safeName)
116 mm, err = mmapFile(fileName, miFile.Length)
118 err = fmt.Errorf("file %q: %s", miFile.DisplayPath(md), err)
129 func mmapFile(name string, size int64) (ret mmap.MMap, err error) {
130 dir := filepath.Dir(name)
131 err = os.MkdirAll(dir, 0777)
133 err = fmt.Errorf("making directory %q: %s", dir, err)
137 file, err = os.OpenFile(name, os.O_CREATE|os.O_RDWR, 0666)
143 fi, err = file.Stat()
147 if fi.Size() < size {
148 // I think this is necessary on HFS+. Maybe Linux will SIGBUS too if
149 // you overmap a file but I'm not sure.
150 err = file.Truncate(size)
156 // Can't mmap() regions with length 0.
160 if int64(intLen) != size {
161 err = errors.New("size too large for system")
164 ret, err = mmap.MapRegion(file, intLen, mmap.RDWR, 0, 0)
166 err = fmt.Errorf("error mapping region: %s", err)
169 if int64(len(ret)) != size {