requesting.go

   1 package torrent
   2
   3 import (
   4         "container/heap"
   5         "context"
   6         "encoding/gob"
   7         "reflect"
   8         "runtime/pprof"
   9         "time"
  10         "unsafe"
  11
  12         "github.com/RoaringBitmap/roaring"
  13         "github.com/anacrolix/log"
  14         "github.com/anacrolix/missinggo/v2/bitmap"
  15         "github.com/anacrolix/multiless"
  16
  17         request_strategy "github.com/anacrolix/torrent/request-strategy"
  18 )
  19
  20 func (cl *Client) tickleRequester() {
  21         cl.updateRequests.Broadcast()
  22 }
  23
  24 func (cl *Client) getRequestStrategyInput() request_strategy.Input {
  25         ts := make([]request_strategy.Torrent, 0, len(cl.torrents))
  26         for _, t := range cl.torrents {
  27                 if !t.haveInfo() {
  28                         // This would be removed if metadata is handled here. We have to guard against not
  29                         // knowing the piece size. If we have no info, we have no pieces too, so the end result
  30                         // is the same.
  31                         continue
  32                 }
  33                 rst := request_strategy.Torrent{
  34                         InfoHash:       t.infoHash,
  35                         ChunksPerPiece: (t.usualPieceSize() + int(t.chunkSize) - 1) / int(t.chunkSize),
  36                 }
  37                 if t.storage != nil {
  38                         rst.Capacity = t.storage.Capacity
  39                 }
  40                 rst.Pieces = make([]request_strategy.Piece, 0, len(t.pieces))
  41                 for i := range t.pieces {
  42                         p := &t.pieces[i]
  43                         rst.Pieces = append(rst.Pieces, request_strategy.Piece{
  44                                 Request:           !t.ignorePieceForRequests(i),
  45                                 Priority:          p.purePriority(),
  46                                 Partial:           t.piecePartiallyDownloaded(i),
  47                                 Availability:      p.availability,
  48                                 Length:            int64(p.length()),
  49                                 NumPendingChunks:  int(t.pieceNumPendingChunks(i)),
  50                                 IterPendingChunks: p.undirtiedChunksIter(),
  51                         })
  52                 }
  53                 t.iterPeers(func(p *Peer) {
  54                         if p.closed.IsSet() {
  55                                 return
  56                         }
  57                         if p.piecesReceivedSinceLastRequestUpdate > p.maxPiecesReceivedBetweenRequestUpdates {
  58                                 p.maxPiecesReceivedBetweenRequestUpdates = p.piecesReceivedSinceLastRequestUpdate
  59                         }
  60                         p.piecesReceivedSinceLastRequestUpdate = 0
  61                         rst.Peers = append(rst.Peers, request_strategy.Peer{
  62                                 Pieces:           *p.newPeerPieces(),
  63                                 MaxRequests:      p.nominalMaxRequests(),
  64                                 ExistingRequests: p.actualRequestState.Requests,
  65                                 Choking:          p.peerChoking,
  66                                 PieceAllowedFast: p.peerAllowedFast,
  67                                 DownloadRate:     p.downloadRate(),
  68                                 Age:              time.Since(p.completedHandshake),
  69                                 Id: peerId{
  70                                         Peer: p,
  71                                         ptr:  uintptr(unsafe.Pointer(p)),
  72                                 },
  73                         })
  74                 })
  75                 ts = append(ts, rst)
  76         }
  77         return request_strategy.Input{
  78                 Torrents:           ts,
  79                 MaxUnverifiedBytes: cl.config.MaxUnverifiedBytes,
  80         }
  81 }
  82
  83 func init() {
  84         gob.Register(peerId{})
  85 }
  86
  87 type peerId struct {
  88         *Peer
  89         ptr uintptr
  90 }
  91
  92 func (p peerId) Uintptr() uintptr {
  93         return p.ptr
  94 }
  95
  96 func (p peerId) GobEncode() (b []byte, _ error) {
  97         *(*reflect.SliceHeader)(unsafe.Pointer(&b)) = reflect.SliceHeader{
  98                 Data: uintptr(unsafe.Pointer(&p.ptr)),
  99                 Len:  int(unsafe.Sizeof(p.ptr)),
 100                 Cap:  int(unsafe.Sizeof(p.ptr)),
 101         }
 102         return
 103 }
 104
 105 func (p *peerId) GobDecode(b []byte) error {
 106         if uintptr(len(b)) != unsafe.Sizeof(p.ptr) {
 107                 panic(len(b))
 108         }
 109         ptr := unsafe.Pointer(&b[0])
 110         p.ptr = *(*uintptr)(ptr)
 111         log.Printf("%p", ptr)
 112         dst := reflect.SliceHeader{
 113                 Data: uintptr(unsafe.Pointer(&p.Peer)),
 114                 Len:  int(unsafe.Sizeof(p.Peer)),
 115                 Cap:  int(unsafe.Sizeof(p.Peer)),
 116         }
 117         copy(*(*[]byte)(unsafe.Pointer(&dst)), b)
 118         return nil
 119 }
 120
 121 type RequestIndex = request_strategy.RequestIndex
 122 type chunkIndexType = request_strategy.ChunkIndex
 123
 124 type peerRequests struct {
 125         requestIndexes       []RequestIndex
 126         peer                 *Peer
 127         torrentStrategyInput request_strategy.Torrent
 128 }
 129
 130 func (p peerRequests) Len() int {
 131         return len(p.requestIndexes)
 132 }
 133
 134 func (p peerRequests) Less(i, j int) bool {
 135         leftRequest := p.requestIndexes[i]
 136         rightRequest := p.requestIndexes[j]
 137         t := p.peer.t
 138         leftPieceIndex := leftRequest / t.chunksPerRegularPiece()
 139         rightPieceIndex := rightRequest / t.chunksPerRegularPiece()
 140         leftCurrent := p.peer.actualRequestState.Requests.Contains(leftRequest)
 141         rightCurrent := p.peer.actualRequestState.Requests.Contains(rightRequest)
 142         pending := func(index RequestIndex, current bool) int {
 143                 ret := t.pendingRequests.Get(index)
 144                 if current {
 145                         ret--
 146                 }
 147                 return ret
 148         }
 149         ml := multiless.New()
 150         ml = ml.Int(
 151                 pending(leftRequest, leftCurrent),
 152                 pending(rightRequest, rightCurrent))
 153         ml = ml.Bool(rightCurrent, leftCurrent)
 154         ml = ml.Int(
 155                 int(p.torrentStrategyInput.Pieces[leftPieceIndex].Priority),
 156                 int(p.torrentStrategyInput.Pieces[rightPieceIndex].Priority))
 157         ml = ml.Int(
 158                 int(p.torrentStrategyInput.Pieces[leftPieceIndex].Availability),
 159                 int(p.torrentStrategyInput.Pieces[rightPieceIndex].Availability))
 160         ml = ml.Uint32(leftPieceIndex, rightPieceIndex)
 161         ml = ml.Uint32(leftRequest, rightRequest)
 162         return ml.MustLess()
 163 }
 164
 165 func (p peerRequests) Swap(i, j int) {
 166         p.requestIndexes[i], p.requestIndexes[j] = p.requestIndexes[j], p.requestIndexes[i]
 167 }
 168
 169 func (p *peerRequests) Push(x interface{}) {
 170         p.requestIndexes = append(p.requestIndexes, x.(RequestIndex))
 171 }
 172
 173 func (p *peerRequests) Pop() interface{} {
 174         last := len(p.requestIndexes) - 1
 175         x := p.requestIndexes[last]
 176         p.requestIndexes = p.requestIndexes[:last]
 177         return x
 178 }
 179
 180 func (p *Peer) getDesiredRequestState() (desired requestState) {
 181         input := p.t.cl.getRequestStrategyInput()
 182         requestHeap := peerRequests{
 183                 requestIndexes: nil,
 184                 peer:           p,
 185         }
 186         for _, t := range input.Torrents {
 187                 if t.InfoHash == p.t.infoHash {
 188                         requestHeap.torrentStrategyInput = t
 189                         break
 190                 }
 191         }
 192         request_strategy.GetRequestablePieces(
 193                 input,
 194                 func(t *request_strategy.Torrent, rsp *request_strategy.Piece, pieceIndex int) {
 195                         if t.InfoHash != p.t.infoHash {
 196                                 return
 197                         }
 198                         if !p.peerHasPiece(pieceIndex) {
 199                                 return
 200                         }
 201                         rsp.IterPendingChunks.Iter(func(ci request_strategy.ChunkIndex) {
 202                                 requestHeap.requestIndexes = append(
 203                                         requestHeap.requestIndexes,
 204                                         p.t.pieceRequestIndexOffset(pieceIndex)+ci)
 205                         })
 206                 },
 207         )
 208         heap.Init(&requestHeap)
 209         for requestHeap.Len() != 0 && desired.Requests.GetCardinality() < uint64(p.nominalMaxRequests()) {
 210                 requestIndex := heap.Pop(&requestHeap).(RequestIndex)
 211                 pieceIndex := requestIndex / p.t.chunksPerRegularPiece()
 212                 allowedFast := p.peerAllowedFast.Contains(pieceIndex)
 213                 if !allowedFast {
 214                         desired.Interested = true
 215                 }
 216                 if allowedFast || !p.peerChoking {
 217                         desired.Requests.Add(requestIndex)
 218                 }
 219         }
 220         return
 221 }
 222
 223 func (p *Peer) applyNextRequestState() bool {
 224         if p.needRequestUpdate == "" {
 225                 return true
 226         }
 227         var more bool
 228         pprof.Do(
 229                 context.Background(),
 230                 pprof.Labels("update request", p.needRequestUpdate),
 231                 func(_ context.Context) {
 232                         next := p.getDesiredRequestState()
 233                         more = p.applyRequestState(next)
 234                 },
 235         )
 236         return more
 237 }
 238
 239 func (p *Peer) applyRequestState(next requestState) bool {
 240         current := p.actualRequestState
 241         if !p.setInterested(next.Interested) {
 242                 return false
 243         }
 244         more := true
 245         cancel := roaring.AndNot(&current.Requests, &next.Requests)
 246         cancel.Iterate(func(req uint32) bool {
 247                 more = p.cancel(req)
 248                 return more
 249         })
 250         if !more {
 251                 return false
 252         }
 253         next.Requests.Iterate(func(req uint32) bool {
 254                 // This could happen if the peer chokes us between the next state being generated, and us
 255                 // trying to transmit the state.
 256                 if p.peerChoking && !p.peerAllowedFast.Contains(bitmap.BitIndex(req/p.t.chunksPerRegularPiece())) {
 257                         return true
 258                 }
 259                 var err error
 260                 more, err = p.request(req)
 261                 if err != nil {
 262                         panic(err)
 263                 } /* else {
 264                         log.Print(req)
 265                 } */
 266                 return more
 267         })
 268         if more {
 269                 p.needRequestUpdate = ""
 270         }
 271         return more
 272 }