package torrent import ( "fmt" "sync" "github.com/anacrolix/missinggo/bitmap" "github.com/anacrolix/torrent/metainfo" pp "github.com/anacrolix/torrent/peer_protocol" "github.com/anacrolix/torrent/storage" ) // Describes the importance of obtaining a particular piece. type piecePriority byte func (pp *piecePriority) Raise(maybe piecePriority) bool { if maybe > *pp { *pp = maybe return true } return false } // Priority for use in PriorityBitmap func (me piecePriority) BitmapPriority() int { return -int(me) } const ( PiecePriorityNone piecePriority = iota // Not wanted. Must be the zero value. PiecePriorityNormal // Wanted. PiecePriorityHigh // Wanted a lot. PiecePriorityReadahead // May be required soon. // Succeeds a piece where a read occurred. Currently the same as Now, // apparently due to issues with caching. PiecePriorityNext PiecePriorityNow // A Reader is reading in this piece. Highest urgency. ) 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 hashing bool numVerifies int64 storageCompletionOk bool publicPieceState PieceState priority piecePriority 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[*connection]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(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(i) p.t.tickleReaders() } func (p *Piece) pendChunkIndex(i int) { p.dirtyChunks.Remove(i) } func (p *Piece) numChunks() pp.Integer { return p.t.pieceNumChunks(p.index) } func (p *Piece) undirtiedChunkIndices() (ret bitmap.Bitmap) { ret = p.dirtyChunks.Copy() ret.FlipRange(0, bitmap.BitIndex(p.numChunks())) return } 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 p.numVerifies < target { // log.Printf("got %d verifies", p.numVerifies) 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) uncachedPriority() (ret piecePriority) { if p.t.pieceComplete(p.index) || p.t.pieceQueuedForHash(p.index) || p.t.hashingPiece(p.index) { return PiecePriorityNone } for _, f := range p.files { ret.Raise(f.prio) } if p.t.readerNowPieces.Contains(int(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) completion() (ret storage.Completion) { ret.Complete = p.t.pieceComplete(p.index) ret.Ok = p.storageCompletionOk return }