piece.go

   1 package torrent
   2
   3 import (
   4         "fmt"
   5         "sync"
   6
   7         "github.com/anacrolix/chansync"
   8         "github.com/anacrolix/missinggo/v2/bitmap"
   9
  10         "github.com/anacrolix/torrent/metainfo"
  11         pp "github.com/anacrolix/torrent/peer_protocol"
  12         "github.com/anacrolix/torrent/storage"
  13 )
  14
  15 type Piece struct {
  16         // The completed piece SHA1 hash, from the metainfo "pieces" field.
  17         hash  *metainfo.Hash
  18         t     *Torrent
  19         index pieceIndex
  20         files []*File
  21
  22         readerCond chansync.BroadcastCond
  23
  24         numVerifies         int64
  25         hashing             bool
  26         marking             bool
  27         storageCompletionOk bool
  28
  29         publicPieceState PieceState
  30         priority         piecePriority
  31         availability     int64
  32
  33         // This can be locked when the Client lock is taken, but probably not vice versa.
  34         pendingWritesMutex sync.Mutex
  35         pendingWrites      int
  36         noPendingWrites    sync.Cond
  37
  38         // Connections that have written data to this piece since its last check.
  39         // This can include connections that have closed.
  40         dirtiers map[*Peer]struct{}
  41 }
  42
  43 func (p *Piece) String() string {
  44         return fmt.Sprintf("%s/%d", p.t.infoHash.HexString(), p.index)
  45 }
  46
  47 func (p *Piece) Info() metainfo.Piece {
  48         return p.t.info.Piece(int(p.index))
  49 }
  50
  51 func (p *Piece) Storage() storage.Piece {
  52         return p.t.storage.Piece(p.Info())
  53 }
  54
  55 func (p *Piece) pendingChunkIndex(chunkIndex chunkIndexType) bool {
  56         return !p.chunkIndexDirty(chunkIndex)
  57 }
  58
  59 func (p *Piece) pendingChunk(cs ChunkSpec, chunkSize pp.Integer) bool {
  60         return p.pendingChunkIndex(chunkIndexFromChunkSpec(cs, chunkSize))
  61 }
  62
  63 func (p *Piece) hasDirtyChunks() bool {
  64         return p.numDirtyChunks() != 0
  65 }
  66
  67 func (p *Piece) numDirtyChunks() chunkIndexType {
  68         return chunkIndexType(roaringBitmapRangeCardinality(
  69                 &p.t.dirtyChunks,
  70                 p.requestIndexOffset(),
  71                 p.t.pieceRequestIndexOffset(p.index+1)))
  72 }
  73
  74 func (p *Piece) unpendChunkIndex(i chunkIndexType) {
  75         p.t.dirtyChunks.Add(p.requestIndexOffset() + i)
  76         p.readerCond.Broadcast()
  77 }
  78
  79 func (p *Piece) pendChunkIndex(i RequestIndex) {
  80         p.t.dirtyChunks.Remove(p.requestIndexOffset() + i)
  81 }
  82
  83 func (p *Piece) numChunks() chunkIndexType {
  84         return p.t.pieceNumChunks(p.index)
  85 }
  86
  87 func (p *Piece) incrementPendingWrites() {
  88         p.pendingWritesMutex.Lock()
  89         p.pendingWrites++
  90         p.pendingWritesMutex.Unlock()
  91 }
  92
  93 func (p *Piece) decrementPendingWrites() {
  94         p.pendingWritesMutex.Lock()
  95         if p.pendingWrites == 0 {
  96                 panic("assertion")
  97         }
  98         p.pendingWrites--
  99         if p.pendingWrites == 0 {
 100                 p.noPendingWrites.Broadcast()
 101         }
 102         p.pendingWritesMutex.Unlock()
 103 }
 104
 105 func (p *Piece) waitNoPendingWrites() {
 106         p.pendingWritesMutex.Lock()
 107         for p.pendingWrites != 0 {
 108                 p.noPendingWrites.Wait()
 109         }
 110         p.pendingWritesMutex.Unlock()
 111 }
 112
 113 func (p *Piece) chunkIndexDirty(chunk chunkIndexType) bool {
 114         return p.t.dirtyChunks.Contains(p.requestIndexOffset() + chunk)
 115 }
 116
 117 func (p *Piece) chunkIndexSpec(chunk chunkIndexType) ChunkSpec {
 118         return chunkIndexSpec(pp.Integer(chunk), p.length(), p.chunkSize())
 119 }
 120
 121 func (p *Piece) numDirtyBytes() (ret pp.Integer) {
 122         // defer func() {
 123         //      if ret > p.length() {
 124         //              panic("too many dirty bytes")
 125         //      }
 126         // }()
 127         numRegularDirtyChunks := p.numDirtyChunks()
 128         if p.chunkIndexDirty(p.numChunks() - 1) {
 129                 numRegularDirtyChunks--
 130                 ret += p.chunkIndexSpec(p.lastChunkIndex()).Length
 131         }
 132         ret += pp.Integer(numRegularDirtyChunks) * p.chunkSize()
 133         return
 134 }
 135
 136 func (p *Piece) length() pp.Integer {
 137         return p.t.pieceLength(p.index)
 138 }
 139
 140 func (p *Piece) chunkSize() pp.Integer {
 141         return p.t.chunkSize
 142 }
 143
 144 func (p *Piece) lastChunkIndex() chunkIndexType {
 145         return p.numChunks() - 1
 146 }
 147
 148 func (p *Piece) bytesLeft() (ret pp.Integer) {
 149         if p.t.pieceComplete(p.index) {
 150                 return 0
 151         }
 152         return p.length() - p.numDirtyBytes()
 153 }
 154
 155 // Forces the piece data to be rehashed.
 156 func (p *Piece) VerifyData() {
 157         p.t.cl.lock()
 158         defer p.t.cl.unlock()
 159         target := p.numVerifies + 1
 160         if p.hashing {
 161                 target++
 162         }
 163         //log.Printf("target: %d", target)
 164         p.t.queuePieceCheck(p.index)
 165         for {
 166                 //log.Printf("got %d verifies", p.numVerifies)
 167                 if p.numVerifies >= target {
 168                         break
 169                 }
 170                 p.t.cl.event.Wait()
 171         }
 172         // log.Print("done")
 173 }
 174
 175 func (p *Piece) queuedForHash() bool {
 176         return p.t.piecesQueuedForHash.Get(bitmap.BitIndex(p.index))
 177 }
 178
 179 func (p *Piece) torrentBeginOffset() int64 {
 180         return int64(p.index) * p.t.info.PieceLength
 181 }
 182
 183 func (p *Piece) torrentEndOffset() int64 {
 184         return p.torrentBeginOffset() + int64(p.length())
 185 }
 186
 187 func (p *Piece) SetPriority(prio piecePriority) {
 188         p.t.cl.lock()
 189         defer p.t.cl.unlock()
 190         p.priority = prio
 191         p.t.updatePiecePriority(p.index)
 192 }
 193
 194 func (p *Piece) purePriority() (ret piecePriority) {
 195         for _, f := range p.files {
 196                 ret.Raise(f.prio)
 197         }
 198         if p.t.readerNowPieces().Contains(bitmap.BitIndex(p.index)) {
 199                 ret.Raise(PiecePriorityNow)
 200         }
 201         // if t._readerNowPieces.Contains(piece - 1) {
 202         //      return PiecePriorityNext
 203         // }
 204         if p.t.readerReadaheadPieces().Contains(bitmap.BitIndex(p.index)) {
 205                 ret.Raise(PiecePriorityReadahead)
 206         }
 207         ret.Raise(p.priority)
 208         return
 209 }
 210
 211 func (p *Piece) uncachedPriority() (ret piecePriority) {
 212         if p.t.pieceComplete(p.index) || p.t.pieceQueuedForHash(p.index) || p.t.hashingPiece(p.index) {
 213                 return PiecePriorityNone
 214         }
 215         return p.purePriority()
 216 }
 217
 218 // Tells the Client to refetch the completion status from storage, updating priority etc. if
 219 // necessary. Might be useful if you know the state of the piece data has changed externally.
 220 func (p *Piece) UpdateCompletion() {
 221         p.t.cl.lock()
 222         defer p.t.cl.unlock()
 223         p.t.updatePieceCompletion(p.index)
 224 }
 225
 226 func (p *Piece) completion() (ret storage.Completion) {
 227         ret.Complete = p.t.pieceComplete(p.index)
 228         ret.Ok = p.storageCompletionOk
 229         return
 230 }
 231
 232 func (p *Piece) allChunksDirty() bool {
 233         return p.numDirtyChunks() == p.numChunks()
 234 }
 235
 236 func (p *Piece) State() PieceState {
 237         return p.t.PieceState(p.index)
 238 }
 239
 240 func (p *Piece) iterUndirtiedChunks(f func(cs chunkIndexType)) {
 241         for i := chunkIndexType(0); i < p.numChunks(); i++ {
 242                 if p.chunkIndexDirty(i) {
 243                         continue
 244                 }
 245                 f(i)
 246         }
 247 }
 248
 249 func (p *Piece) requestIndexOffset() RequestIndex {
 250         return p.t.pieceRequestIndexOffset(p.index)
 251 }