piece.go

   1 package torrent
   2
   3 import (
   4         "encoding/gob"
   5         "fmt"
   6         "sync"
   7
   8         "github.com/RoaringBitmap/roaring"
   9         "github.com/anacrolix/chansync"
  10         "github.com/anacrolix/missinggo/v2/bitmap"
  11         request_strategy "github.com/anacrolix/torrent/request-strategy"
  12
  13         "github.com/anacrolix/torrent/metainfo"
  14         pp "github.com/anacrolix/torrent/peer_protocol"
  15         "github.com/anacrolix/torrent/storage"
  16 )
  17
  18 type Piece struct {
  19         // The completed piece SHA1 hash, from the metainfo "pieces" field.
  20         hash  *metainfo.Hash
  21         t     *Torrent
  22         index pieceIndex
  23         files []*File
  24
  25         readerCond chansync.BroadcastCond
  26
  27         numVerifies         int64
  28         hashing             bool
  29         marking             bool
  30         storageCompletionOk bool
  31
  32         publicPieceState PieceState
  33         priority         piecePriority
  34         availability     int64
  35
  36         // This can be locked when the Client lock is taken, but probably not vice versa.
  37         pendingWritesMutex sync.Mutex
  38         pendingWrites      int
  39         noPendingWrites    sync.Cond
  40
  41         // Connections that have written data to this piece since its last check.
  42         // This can include connections that have closed.
  43         dirtiers map[*Peer]struct{}
  44 }
  45
  46 func (p *Piece) String() string {
  47         return fmt.Sprintf("%s/%d", p.t.infoHash.HexString(), p.index)
  48 }
  49
  50 func (p *Piece) Info() metainfo.Piece {
  51         return p.t.info.Piece(int(p.index))
  52 }
  53
  54 func (p *Piece) Storage() storage.Piece {
  55         return p.t.storage.Piece(p.Info())
  56 }
  57
  58 func (p *Piece) pendingChunkIndex(chunkIndex chunkIndexType) bool {
  59         return !p.chunkIndexDirty(chunkIndex)
  60 }
  61
  62 func (p *Piece) pendingChunk(cs ChunkSpec, chunkSize pp.Integer) bool {
  63         return p.pendingChunkIndex(chunkIndexFromChunkSpec(cs, chunkSize))
  64 }
  65
  66 func (p *Piece) hasDirtyChunks() bool {
  67         return p.numDirtyChunks() != 0
  68 }
  69
  70 func (p *Piece) numDirtyChunks() chunkIndexType {
  71         return chunkIndexType(roaringBitmapRangeCardinality(
  72                 &p.t.dirtyChunks,
  73                 p.requestIndexOffset(),
  74                 p.t.pieceRequestIndexOffset(p.index+1)))
  75 }
  76
  77 func (p *Piece) unpendChunkIndex(i chunkIndexType) {
  78         p.t.dirtyChunks.Add(p.requestIndexOffset() + i)
  79         p.readerCond.Broadcast()
  80 }
  81
  82 func (p *Piece) pendChunkIndex(i RequestIndex) {
  83         p.t.dirtyChunks.Remove(p.requestIndexOffset() + i)
  84 }
  85
  86 func (p *Piece) numChunks() chunkIndexType {
  87         return p.t.pieceNumChunks(p.index)
  88 }
  89
  90 func (p *Piece) incrementPendingWrites() {
  91         p.pendingWritesMutex.Lock()
  92         p.pendingWrites++
  93         p.pendingWritesMutex.Unlock()
  94 }
  95
  96 func (p *Piece) decrementPendingWrites() {
  97         p.pendingWritesMutex.Lock()
  98         if p.pendingWrites == 0 {
  99                 panic("assertion")
 100         }
 101         p.pendingWrites--
 102         if p.pendingWrites == 0 {
 103                 p.noPendingWrites.Broadcast()
 104         }
 105         p.pendingWritesMutex.Unlock()
 106 }
 107
 108 func (p *Piece) waitNoPendingWrites() {
 109         p.pendingWritesMutex.Lock()
 110         for p.pendingWrites != 0 {
 111                 p.noPendingWrites.Wait()
 112         }
 113         p.pendingWritesMutex.Unlock()
 114 }
 115
 116 func (p *Piece) chunkIndexDirty(chunk chunkIndexType) bool {
 117         return p.t.dirtyChunks.Contains(p.requestIndexOffset() + chunk)
 118 }
 119
 120 func (p *Piece) chunkIndexSpec(chunk chunkIndexType) ChunkSpec {
 121         return chunkIndexSpec(pp.Integer(chunk), p.length(), p.chunkSize())
 122 }
 123
 124 func (p *Piece) numDirtyBytes() (ret pp.Integer) {
 125         // defer func() {
 126         //      if ret > p.length() {
 127         //              panic("too many dirty bytes")
 128         //      }
 129         // }()
 130         numRegularDirtyChunks := p.numDirtyChunks()
 131         if p.chunkIndexDirty(p.numChunks() - 1) {
 132                 numRegularDirtyChunks--
 133                 ret += p.chunkIndexSpec(p.lastChunkIndex()).Length
 134         }
 135         ret += pp.Integer(numRegularDirtyChunks) * p.chunkSize()
 136         return
 137 }
 138
 139 func (p *Piece) length() pp.Integer {
 140         return p.t.pieceLength(p.index)
 141 }
 142
 143 func (p *Piece) chunkSize() pp.Integer {
 144         return p.t.chunkSize
 145 }
 146
 147 func (p *Piece) lastChunkIndex() chunkIndexType {
 148         return p.numChunks() - 1
 149 }
 150
 151 func (p *Piece) bytesLeft() (ret pp.Integer) {
 152         if p.t.pieceComplete(p.index) {
 153                 return 0
 154         }
 155         return p.length() - p.numDirtyBytes()
 156 }
 157
 158 // Forces the piece data to be rehashed.
 159 func (p *Piece) VerifyData() {
 160         p.t.cl.lock()
 161         defer p.t.cl.unlock()
 162         target := p.numVerifies + 1
 163         if p.hashing {
 164                 target++
 165         }
 166         //log.Printf("target: %d", target)
 167         p.t.queuePieceCheck(p.index)
 168         for {
 169                 //log.Printf("got %d verifies", p.numVerifies)
 170                 if p.numVerifies >= target {
 171                         break
 172                 }
 173                 p.t.cl.event.Wait()
 174         }
 175         // log.Print("done")
 176 }
 177
 178 func (p *Piece) queuedForHash() bool {
 179         return p.t.piecesQueuedForHash.Get(bitmap.BitIndex(p.index))
 180 }
 181
 182 func (p *Piece) torrentBeginOffset() int64 {
 183         return int64(p.index) * p.t.info.PieceLength
 184 }
 185
 186 func (p *Piece) torrentEndOffset() int64 {
 187         return p.torrentBeginOffset() + int64(p.length())
 188 }
 189
 190 func (p *Piece) SetPriority(prio piecePriority) {
 191         p.t.cl.lock()
 192         defer p.t.cl.unlock()
 193         p.priority = prio
 194         p.t.updatePiecePriority(p.index)
 195 }
 196
 197 func (p *Piece) purePriority() (ret piecePriority) {
 198         for _, f := range p.files {
 199                 ret.Raise(f.prio)
 200         }
 201         if p.t.readerNowPieces().Contains(bitmap.BitIndex(p.index)) {
 202                 ret.Raise(PiecePriorityNow)
 203         }
 204         // if t._readerNowPieces.Contains(piece - 1) {
 205         //      return PiecePriorityNext
 206         // }
 207         if p.t.readerReadaheadPieces().Contains(bitmap.BitIndex(p.index)) {
 208                 ret.Raise(PiecePriorityReadahead)
 209         }
 210         ret.Raise(p.priority)
 211         return
 212 }
 213
 214 func (p *Piece) uncachedPriority() (ret piecePriority) {
 215         if p.hashing || p.marking || p.t.pieceComplete(p.index) || p.queuedForHash() {
 216                 return PiecePriorityNone
 217         }
 218         return p.purePriority()
 219 }
 220
 221 // Tells the Client to refetch the completion status from storage, updating priority etc. if
 222 // necessary. Might be useful if you know the state of the piece data has changed externally.
 223 func (p *Piece) UpdateCompletion() {
 224         p.t.cl.lock()
 225         defer p.t.cl.unlock()
 226         p.t.updatePieceCompletion(p.index)
 227 }
 228
 229 func (p *Piece) completion() (ret storage.Completion) {
 230         ret.Complete = p.t.pieceComplete(p.index)
 231         ret.Ok = p.storageCompletionOk
 232         return
 233 }
 234
 235 func (p *Piece) allChunksDirty() bool {
 236         return p.numDirtyChunks() == p.numChunks()
 237 }
 238
 239 func (p *Piece) State() PieceState {
 240         return p.t.PieceState(p.index)
 241 }
 242
 243 func init() {
 244         gob.Register(undirtiedChunksIter{})
 245 }
 246
 247 type undirtiedChunksIter struct {
 248         TorrentDirtyChunks *roaring.Bitmap
 249         StartRequestIndex  RequestIndex
 250         EndRequestIndex    RequestIndex
 251 }
 252
 253 func (me undirtiedChunksIter) Iter(f func(chunkIndexType)) {
 254         it := me.TorrentDirtyChunks.Iterator()
 255         startIndex := me.StartRequestIndex
 256         endIndex := me.EndRequestIndex
 257         it.AdvanceIfNeeded(startIndex)
 258         lastDirty := startIndex - 1
 259         for it.HasNext() {
 260                 next := it.Next()
 261                 if next >= endIndex {
 262                         break
 263                 }
 264                 for index := lastDirty + 1; index < next; index++ {
 265                         f(index - startIndex)
 266                 }
 267                 lastDirty = next
 268         }
 269         for index := lastDirty + 1; index < endIndex; index++ {
 270                 f(index - startIndex)
 271         }
 272         return
 273 }
 274
 275 func (p *Piece) undirtiedChunksIter() request_strategy.ChunksIter {
 276         // Use an iterator to jump between dirty bits.
 277         return undirtiedChunksIter{
 278                 TorrentDirtyChunks: &p.t.dirtyChunks,
 279                 StartRequestIndex:  p.requestIndexOffset(),
 280                 EndRequestIndex:    p.requestIndexOffset() + p.numChunks(),
 281         }
 282 }
 283
 284 func (p *Piece) iterUndirtiedChunks(f func(chunkIndexType)) {
 285         if true {
 286                 p.undirtiedChunksIter().Iter(f)
 287                 return
 288         }
 289         // The original implementation.
 290         for i := chunkIndexType(0); i < p.numChunks(); i++ {
 291                 if p.chunkIndexDirty(i) {
 292                         continue
 293                 }
 294                 f(i)
 295         }
 296 }
 297
 298 func (p *Piece) requestIndexOffset() RequestIndex {
 299         return p.t.pieceRequestIndexOffset(p.index)
 300 }