package torrent import ( "fmt" "sync" "github.com/anacrolix/chansync" "github.com/anacrolix/missinggo/v2/bitmap" "github.com/anacrolix/torrent/metainfo" pp "github.com/anacrolix/torrent/peer_protocol" "github.com/anacrolix/torrent/storage" ) type Piece struct { // The completed piece SHA1 hash, from the metainfo "pieces" field. hash *metainfo.Hash t *Torrent index pieceIndex files []*File // Chunks we've written to since the last check. The chunk offset and // length can be determined by the request chunkSize in use. _dirtyChunks bitmap.Bitmap readerCond chansync.BroadcastCond numVerifies int64 hashing bool marking bool storageCompletionOk bool publicPieceState PieceState priority piecePriority availability int64 // This can be locked when the Client lock is taken, but probably not vice versa. pendingWritesMutex sync.Mutex pendingWrites int noPendingWrites sync.Cond // Connections that have written data to this piece since its last check. // This can include connections that have closed. dirtiers map[*Peer]struct{} } func (p *Piece) String() string { return fmt.Sprintf("%s/%d", p.t.infoHash.HexString(), p.index) } func (p *Piece) Info() metainfo.Piece { return p.t.info.Piece(int(p.index)) } func (p *Piece) Storage() storage.Piece { return p.t.storage.Piece(p.Info()) } func (p *Piece) pendingChunkIndex(chunkIndex int) bool { return !p._dirtyChunks.Contains(bitmap.BitIndex(chunkIndex)) } func (p *Piece) pendingChunk(cs ChunkSpec, chunkSize pp.Integer) bool { return p.pendingChunkIndex(chunkIndex(cs, chunkSize)) } func (p *Piece) hasDirtyChunks() bool { return p._dirtyChunks.Len() != 0 } func (p *Piece) numDirtyChunks() pp.Integer { return pp.Integer(p._dirtyChunks.Len()) } func (p *Piece) unpendChunkIndex(i int) { p._dirtyChunks.Add(bitmap.BitIndex(i)) p.readerCond.Broadcast() } func (p *Piece) pendChunkIndex(i int) { p._dirtyChunks.Remove(bitmap.BitIndex(i)) } func (p *Piece) numChunks() pp.Integer { return p.t.pieceNumChunks(p.index) } func (p *Piece) incrementPendingWrites() { p.pendingWritesMutex.Lock() p.pendingWrites++ p.pendingWritesMutex.Unlock() } func (p *Piece) decrementPendingWrites() { p.pendingWritesMutex.Lock() if p.pendingWrites == 0 { panic("assertion") } p.pendingWrites-- if p.pendingWrites == 0 { p.noPendingWrites.Broadcast() } p.pendingWritesMutex.Unlock() } func (p *Piece) waitNoPendingWrites() { p.pendingWritesMutex.Lock() for p.pendingWrites != 0 { p.noPendingWrites.Wait() } p.pendingWritesMutex.Unlock() } func (p *Piece) chunkIndexDirty(chunk pp.Integer) bool { return p._dirtyChunks.Contains(bitmap.BitIndex(chunk)) } func (p *Piece) chunkIndexSpec(chunk pp.Integer) ChunkSpec { return chunkIndexSpec(chunk, p.length(), p.chunkSize()) } func (p *Piece) numDirtyBytes() (ret pp.Integer) { // defer func() { // if ret > p.length() { // panic("too many dirty bytes") // } // }() numRegularDirtyChunks := p.numDirtyChunks() if p.chunkIndexDirty(p.numChunks() - 1) { numRegularDirtyChunks-- ret += p.chunkIndexSpec(p.lastChunkIndex()).Length } ret += pp.Integer(numRegularDirtyChunks) * p.chunkSize() return } func (p *Piece) length() pp.Integer { return p.t.pieceLength(p.index) } func (p *Piece) chunkSize() pp.Integer { return p.t.chunkSize } func (p *Piece) lastChunkIndex() pp.Integer { return p.numChunks() - 1 } func (p *Piece) bytesLeft() (ret pp.Integer) { if p.t.pieceComplete(p.index) { return 0 } return p.length() - p.numDirtyBytes() } // Forces the piece data to be rehashed. func (p *Piece) VerifyData() { p.t.cl.lock() defer p.t.cl.unlock() target := p.numVerifies + 1 if p.hashing { target++ } //log.Printf("target: %d", target) p.t.queuePieceCheck(p.index) for { //log.Printf("got %d verifies", p.numVerifies) if p.numVerifies >= target { break } p.t.cl.event.Wait() } // log.Print("done") } func (p *Piece) queuedForHash() bool { return p.t.piecesQueuedForHash.Get(bitmap.BitIndex(p.index)) } func (p *Piece) torrentBeginOffset() int64 { return int64(p.index) * p.t.info.PieceLength } func (p *Piece) torrentEndOffset() int64 { return p.torrentBeginOffset() + int64(p.length()) } func (p *Piece) SetPriority(prio piecePriority) { p.t.cl.lock() defer p.t.cl.unlock() p.priority = prio p.t.updatePiecePriority(p.index) } func (p *Piece) purePriority() (ret piecePriority) { for _, f := range p.files { ret.Raise(f.prio) } if p.t.readerNowPieces().Contains(bitmap.BitIndex(p.index)) { ret.Raise(PiecePriorityNow) } // if t._readerNowPieces.Contains(piece - 1) { // return PiecePriorityNext // } if p.t.readerReadaheadPieces().Contains(bitmap.BitIndex(p.index)) { ret.Raise(PiecePriorityReadahead) } ret.Raise(p.priority) return } func (p *Piece) uncachedPriority() (ret piecePriority) { if p.t.pieceComplete(p.index) || p.t.pieceQueuedForHash(p.index) || p.t.hashingPiece(p.index) { return PiecePriorityNone } return p.purePriority() } // Tells the Client to refetch the completion status from storage, updating priority etc. if // necessary. Might be useful if you know the state of the piece data has changed externally. func (p *Piece) UpdateCompletion() { p.t.cl.lock() defer p.t.cl.unlock() p.t.updatePieceCompletion(p.index) } func (p *Piece) completion() (ret storage.Completion) { ret.Complete = p.t.pieceComplete(p.index) ret.Ok = p.storageCompletionOk return } func (p *Piece) allChunksDirty() bool { return p._dirtyChunks.Len() == bitmap.BitRange(p.numChunks()) } func (p *Piece) State() PieceState { return p.t.PieceState(p.index) } func (p *Piece) iterUndirtiedChunks(f func(cs ChunkSpec) bool) bool { for i := pp.Integer(0); i < p.numChunks(); i++ { if p.chunkIndexDirty(i) { continue } if !f(p.chunkIndexSpec(i)) { return false } } return true }