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piece.go
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piece.go
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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 {
//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) 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
}