package torrent
+import (
+ "errors"
+ "fmt"
+ "io"
+ "net"
+ "strings"
+ "time"
+
+ "github.com/RoaringBitmap/roaring"
+ "github.com/anacrolix/chansync"
+ . "github.com/anacrolix/generics"
+ "github.com/anacrolix/log"
+ "github.com/anacrolix/missinggo/iter"
+ "github.com/anacrolix/missinggo/v2/bitmap"
+ "github.com/anacrolix/multiless"
+
+ "github.com/anacrolix/torrent/internal/alloclim"
+ "github.com/anacrolix/torrent/mse"
+ pp "github.com/anacrolix/torrent/peer_protocol"
+ request_strategy "github.com/anacrolix/torrent/request-strategy"
+ typedRoaring "github.com/anacrolix/torrent/typed-roaring"
+)
+
+type (
+ Peer struct {
+ // First to ensure 64-bit alignment for atomics. See #262.
+ _stats ConnStats
+
+ t *Torrent
+
+ peerImpl
+ callbacks *Callbacks
+
+ outgoing bool
+ Network string
+ RemoteAddr PeerRemoteAddr
+ // The local address as observed by the remote peer. WebRTC seems to get this right without needing hints from the
+ // config.
+ localPublicAddr peerLocalPublicAddr
+ bannableAddr Option[bannableAddr]
+ // True if the connection is operating over MSE obfuscation.
+ headerEncrypted bool
+ cryptoMethod mse.CryptoMethod
+ Discovery PeerSource
+ trusted bool
+ closed chansync.SetOnce
+ // Set true after we've added our ConnStats generated during handshake to
+ // other ConnStat instances as determined when the *Torrent became known.
+ reconciledHandshakeStats bool
+
+ lastMessageReceived time.Time
+ completedHandshake time.Time
+ lastUsefulChunkReceived time.Time
+ lastChunkSent time.Time
+
+ // Stuff controlled by the local peer.
+ needRequestUpdate string
+ requestState request_strategy.PeerRequestState
+ updateRequestsTimer *time.Timer
+ lastRequestUpdate time.Time
+ peakRequests maxRequests
+ lastBecameInterested time.Time
+ priorInterest time.Duration
+
+ lastStartedExpectingToReceiveChunks time.Time
+ cumulativeExpectedToReceiveChunks time.Duration
+ _chunksReceivedWhileExpecting int64
+
+ choking bool
+ piecesReceivedSinceLastRequestUpdate maxRequests
+ maxPiecesReceivedBetweenRequestUpdates maxRequests
+ // Chunks that we might reasonably expect to receive from the peer. Due to latency, buffering,
+ // and implementation differences, we may receive chunks that are no longer in the set of
+ // requests actually want. This could use a roaring.BSI if the memory use becomes noticeable.
+ validReceiveChunks map[RequestIndex]int
+ // Indexed by metadata piece, set to true if posted and pending a
+ // response.
+ metadataRequests []bool
+ sentHaves bitmap.Bitmap
+
+ // Stuff controlled by the remote peer.
+ peerInterested bool
+ peerChoking bool
+ peerRequests map[Request]*peerRequestState
+ PeerPrefersEncryption bool // as indicated by 'e' field in extension handshake
+ // The highest possible number of pieces the torrent could have based on
+ // communication with the peer. Generally only useful until we have the
+ // torrent info.
+ peerMinPieces pieceIndex
+ // Pieces we've accepted chunks for from the peer.
+ peerTouchedPieces map[pieceIndex]struct{}
+ peerAllowedFast typedRoaring.Bitmap[pieceIndex]
+
+ PeerMaxRequests maxRequests // Maximum pending requests the peer allows.
+
+ logger log.Logger
+ }
+
+ PeerSource string
+
+ peerRequestState struct {
+ data []byte
+ allocReservation *alloclim.Reservation
+ }
+
+ PeerRemoteAddr interface {
+ String() string
+ }
+
+ peerRequests = orderedBitmap[RequestIndex]
+)
+
+const (
+ PeerSourceUtHolepunch = "C"
+ PeerSourceTracker = "Tr"
+ PeerSourceIncoming = "I"
+ PeerSourceDhtGetPeers = "Hg" // Peers we found by searching a DHT.
+ PeerSourceDhtAnnouncePeer = "Ha" // Peers that were announced to us by a DHT.
+ PeerSourcePex = "X"
+ // The peer was given directly, such as through a magnet link.
+ PeerSourceDirect = "M"
+)
+
+// Returns the Torrent a Peer belongs to. Shouldn't change for the lifetime of the Peer. May be nil
+// if we are the receiving end of a connection and the handshake hasn't been received or accepted
+// yet.
+func (p *Peer) Torrent() *Torrent {
+ return p.t
+}
+
+func (p *Peer) initRequestState() {
+ p.requestState.Requests = &peerRequests{}
+}
+
+func (cn *Peer) updateExpectingChunks() {
+ if cn.expectingChunks() {
+ if cn.lastStartedExpectingToReceiveChunks.IsZero() {
+ cn.lastStartedExpectingToReceiveChunks = time.Now()
+ }
+ } else {
+ if !cn.lastStartedExpectingToReceiveChunks.IsZero() {
+ cn.cumulativeExpectedToReceiveChunks += time.Since(cn.lastStartedExpectingToReceiveChunks)
+ cn.lastStartedExpectingToReceiveChunks = time.Time{}
+ }
+ }
+}
+
+func (cn *Peer) expectingChunks() bool {
+ if cn.requestState.Requests.IsEmpty() {
+ return false
+ }
+ if !cn.requestState.Interested {
+ return false
+ }
+ if !cn.peerChoking {
+ return true
+ }
+ haveAllowedFastRequests := false
+ cn.peerAllowedFast.Iterate(func(i pieceIndex) bool {
+ haveAllowedFastRequests = roaringBitmapRangeCardinality[RequestIndex](
+ cn.requestState.Requests,
+ cn.t.pieceRequestIndexOffset(i),
+ cn.t.pieceRequestIndexOffset(i+1),
+ ) == 0
+ return !haveAllowedFastRequests
+ })
+ return haveAllowedFastRequests
+}
+
+func (cn *Peer) remoteChokingPiece(piece pieceIndex) bool {
+ return cn.peerChoking && !cn.peerAllowedFast.Contains(piece)
+}
+
+func (cn *Peer) cumInterest() time.Duration {
+ ret := cn.priorInterest
+ if cn.requestState.Interested {
+ ret += time.Since(cn.lastBecameInterested)
+ }
+ return ret
+}
+
+func (cn *Peer) locker() *lockWithDeferreds {
+ return cn.t.cl.locker()
+}
+
+func (cn *PeerConn) supportsExtension(ext pp.ExtensionName) bool {
+ _, ok := cn.PeerExtensionIDs[ext]
+ return ok
+}
+
+// The best guess at number of pieces in the torrent for this peer.
+func (cn *Peer) bestPeerNumPieces() pieceIndex {
+ if cn.t.haveInfo() {
+ return cn.t.numPieces()
+ }
+ return cn.peerMinPieces
+}
+
+func (cn *Peer) completedString() string {
+ have := pieceIndex(cn.peerPieces().GetCardinality())
+ if all, _ := cn.peerHasAllPieces(); all {
+ have = cn.bestPeerNumPieces()
+ }
+ return fmt.Sprintf("%d/%d", have, cn.bestPeerNumPieces())
+}
+
+func eventAgeString(t time.Time) string {
+ if t.IsZero() {
+ return "never"
+ }
+ return fmt.Sprintf("%.2fs ago", time.Since(t).Seconds())
+}
+
+// Inspired by https://github.com/transmission/transmission/wiki/Peer-Status-Text.
+func (cn *Peer) statusFlags() (ret string) {
+ c := func(b byte) {
+ ret += string([]byte{b})
+ }
+ if cn.requestState.Interested {
+ c('i')
+ }
+ if cn.choking {
+ c('c')
+ }
+ c('-')
+ ret += cn.connectionFlags()
+ c('-')
+ if cn.peerInterested {
+ c('i')
+ }
+ if cn.peerChoking {
+ c('c')
+ }
+ return
+}
+
+func (cn *Peer) downloadRate() float64 {
+ num := cn._stats.BytesReadUsefulData.Int64()
+ if num == 0 {
+ return 0
+ }
+ return float64(num) / cn.totalExpectingTime().Seconds()
+}
+
+func (cn *Peer) DownloadRate() float64 {
+ cn.locker().RLock()
+ defer cn.locker().RUnlock()
+
+ return cn.downloadRate()
+}
+
+func (cn *Peer) iterContiguousPieceRequests(f func(piece pieceIndex, count int)) {
+ var last Option[pieceIndex]
+ var count int
+ next := func(item Option[pieceIndex]) {
+ if item == last {
+ count++
+ } else {
+ if count != 0 {
+ f(last.Value, count)
+ }
+ last = item
+ count = 1
+ }
+ }
+ cn.requestState.Requests.Iterate(func(requestIndex request_strategy.RequestIndex) bool {
+ next(Some(cn.t.pieceIndexOfRequestIndex(requestIndex)))
+ return true
+ })
+ next(None[pieceIndex]())
+}
+
+func (cn *Peer) writeStatus(w io.Writer) {
+ // \t isn't preserved in <pre> blocks?
+ if cn.closed.IsSet() {
+ fmt.Fprint(w, "CLOSED: ")
+ }
+ fmt.Fprintln(w, strings.Join(cn.peerImplStatusLines(), "\n"))
+ prio, err := cn.peerPriority()
+ prioStr := fmt.Sprintf("%08x", prio)
+ if err != nil {
+ prioStr += ": " + err.Error()
+ }
+ fmt.Fprintf(w, "bep40-prio: %v\n", prioStr)
+ fmt.Fprintf(w, "last msg: %s, connected: %s, last helpful: %s, itime: %s, etime: %s\n",
+ eventAgeString(cn.lastMessageReceived),
+ eventAgeString(cn.completedHandshake),
+ eventAgeString(cn.lastHelpful()),
+ cn.cumInterest(),
+ cn.totalExpectingTime(),
+ )
+ fmt.Fprintf(w,
+ "%s completed, %d pieces touched, good chunks: %v/%v:%v reqq: %d+%v/(%d/%d):%d/%d, flags: %s, dr: %.1f KiB/s\n",
+ cn.completedString(),
+ len(cn.peerTouchedPieces),
+ &cn._stats.ChunksReadUseful,
+ &cn._stats.ChunksRead,
+ &cn._stats.ChunksWritten,
+ cn.requestState.Requests.GetCardinality(),
+ cn.requestState.Cancelled.GetCardinality(),
+ cn.nominalMaxRequests(),
+ cn.PeerMaxRequests,
+ len(cn.peerRequests),
+ localClientReqq,
+ cn.statusFlags(),
+ cn.downloadRate()/(1<<10),
+ )
+ fmt.Fprintf(w, "requested pieces:")
+ cn.iterContiguousPieceRequests(func(piece pieceIndex, count int) {
+ fmt.Fprintf(w, " %v(%v)", piece, count)
+ })
+ fmt.Fprintf(w, "\n")
+}
+
+func (p *Peer) close() {
+ if !p.closed.Set() {
+ return
+ }
+ if p.updateRequestsTimer != nil {
+ p.updateRequestsTimer.Stop()
+ }
+ for _, prs := range p.peerRequests {
+ prs.allocReservation.Drop()
+ }
+ p.peerImpl.onClose()
+ if p.t != nil {
+ p.t.decPeerPieceAvailability(p)
+ }
+ for _, f := range p.callbacks.PeerClosed {
+ f(p)
+ }
+}
+
+// Peer definitely has a piece, for purposes of requesting. So it's not sufficient that we think
+// they do (known=true).
+func (cn *Peer) peerHasPiece(piece pieceIndex) bool {
+ if all, known := cn.peerHasAllPieces(); all && known {
+ return true
+ }
+ return cn.peerPieces().ContainsInt(piece)
+}
+
+// 64KiB, but temporarily less to work around an issue with WebRTC. TODO: Update when
+// https://github.com/pion/datachannel/issues/59 is fixed.
+const (
+ writeBufferHighWaterLen = 1 << 15
+ writeBufferLowWaterLen = writeBufferHighWaterLen / 2
+)
+
+var (
+ interestedMsgLen = len(pp.Message{Type: pp.Interested}.MustMarshalBinary())
+ requestMsgLen = len(pp.Message{Type: pp.Request}.MustMarshalBinary())
+ // This is the maximum request count that could fit in the write buffer if it's at or below the
+ // low water mark when we run maybeUpdateActualRequestState.
+ maxLocalToRemoteRequests = (writeBufferHighWaterLen - writeBufferLowWaterLen - interestedMsgLen) / requestMsgLen
+)
+
+// The actual value to use as the maximum outbound requests.
+func (cn *Peer) nominalMaxRequests() maxRequests {
+ return maxInt(1, minInt(cn.PeerMaxRequests, cn.peakRequests*2, maxLocalToRemoteRequests))
+}
+
+func (cn *Peer) totalExpectingTime() (ret time.Duration) {
+ ret = cn.cumulativeExpectedToReceiveChunks
+ if !cn.lastStartedExpectingToReceiveChunks.IsZero() {
+ ret += time.Since(cn.lastStartedExpectingToReceiveChunks)
+ }
+ return
+}
+
+func (cn *Peer) setInterested(interested bool) bool {
+ if cn.requestState.Interested == interested {
+ return true
+ }
+ cn.requestState.Interested = interested
+ if interested {
+ cn.lastBecameInterested = time.Now()
+ } else if !cn.lastBecameInterested.IsZero() {
+ cn.priorInterest += time.Since(cn.lastBecameInterested)
+ }
+ cn.updateExpectingChunks()
+ // log.Printf("%p: setting interest: %v", cn, interested)
+ return cn.writeInterested(interested)
+}
+
+// The function takes a message to be sent, and returns true if more messages
+// are okay.
+type messageWriter func(pp.Message) bool
+
+// This function seems to only used by Peer.request. It's all logic checks, so maybe we can no-op it
+// when we want to go fast.
+func (cn *Peer) shouldRequest(r RequestIndex) error {
+ err := cn.t.checkValidReceiveChunk(cn.t.requestIndexToRequest(r))
+ if err != nil {
+ return err
+ }
+ pi := cn.t.pieceIndexOfRequestIndex(r)
+ if cn.requestState.Cancelled.Contains(r) {
+ return errors.New("request is cancelled and waiting acknowledgement")
+ }
+ if !cn.peerHasPiece(pi) {
+ return errors.New("requesting piece peer doesn't have")
+ }
+ if !cn.t.peerIsActive(cn) {
+ panic("requesting but not in active conns")
+ }
+ if cn.closed.IsSet() {
+ panic("requesting when connection is closed")
+ }
+ if cn.t.hashingPiece(pi) {
+ panic("piece is being hashed")
+ }
+ if cn.t.pieceQueuedForHash(pi) {
+ panic("piece is queued for hash")
+ }
+ if cn.peerChoking && !cn.peerAllowedFast.Contains(pi) {
+ // This could occur if we made a request with the fast extension, and then got choked and
+ // haven't had the request rejected yet.
+ if !cn.requestState.Requests.Contains(r) {
+ panic("peer choking and piece not allowed fast")
+ }
+ }
+ return nil
+}
+
+func (cn *Peer) mustRequest(r RequestIndex) bool {
+ more, err := cn.request(r)
+ if err != nil {
+ panic(err)
+ }
+ return more
+}
+
+func (cn *Peer) request(r RequestIndex) (more bool, err error) {
+ if err := cn.shouldRequest(r); err != nil {
+ panic(err)
+ }
+ if cn.requestState.Requests.Contains(r) {
+ return true, nil
+ }
+ if maxRequests(cn.requestState.Requests.GetCardinality()) >= cn.nominalMaxRequests() {
+ return true, errors.New("too many outstanding requests")
+ }
+ cn.requestState.Requests.Add(r)
+ if cn.validReceiveChunks == nil {
+ cn.validReceiveChunks = make(map[RequestIndex]int)
+ }
+ cn.validReceiveChunks[r]++
+ cn.t.requestState[r] = requestState{
+ peer: cn,
+ when: time.Now(),
+ }
+ cn.updateExpectingChunks()
+ ppReq := cn.t.requestIndexToRequest(r)
+ for _, f := range cn.callbacks.SentRequest {
+ f(PeerRequestEvent{cn, ppReq})
+ }
+ return cn.peerImpl._request(ppReq), nil
+}
+
+func (me *Peer) cancel(r RequestIndex) {
+ if !me.deleteRequest(r) {
+ panic("request not existing should have been guarded")
+ }
+ if me._cancel(r) {
+ if !me.requestState.Cancelled.CheckedAdd(r) {
+ panic("request already cancelled")
+ }
+ }
+ me.decPeakRequests()
+ if me.isLowOnRequests() {
+ me.updateRequests("Peer.cancel")
+ }
+}
+
+// Sets a reason to update requests, and if there wasn't already one, handle it.
+func (cn *Peer) updateRequests(reason string) {
+ if cn.needRequestUpdate != "" {
+ return
+ }
+ if reason != peerUpdateRequestsTimerReason && !cn.isLowOnRequests() {
+ return
+ }
+ cn.needRequestUpdate = reason
+ cn.handleUpdateRequests()
+}
+
+// Emits the indices in the Bitmaps bms in order, never repeating any index.
+// skip is mutated during execution, and its initial values will never be
+// emitted.
+func iterBitmapsDistinct(skip *bitmap.Bitmap, bms ...bitmap.Bitmap) iter.Func {
+ return func(cb iter.Callback) {
+ for _, bm := range bms {
+ if !iter.All(
+ func(_i interface{}) bool {
+ i := _i.(int)
+ if skip.Contains(bitmap.BitIndex(i)) {
+ return true
+ }
+ skip.Add(bitmap.BitIndex(i))
+ return cb(i)
+ },
+ bm.Iter,
+ ) {
+ return
+ }
+ }
+ }
+}
+
+// After handshake, we know what Torrent and Client stats to include for a
+// connection.
+func (cn *Peer) postHandshakeStats(f func(*ConnStats)) {
+ t := cn.t
+ f(&t.stats)
+ f(&t.cl.connStats)
+}
+
+// All ConnStats that include this connection. Some objects are not known
+// until the handshake is complete, after which it's expected to reconcile the
+// differences.
+func (cn *Peer) allStats(f func(*ConnStats)) {
+ f(&cn._stats)
+ if cn.reconciledHandshakeStats {
+ cn.postHandshakeStats(f)
+ }
+}
+
+func (cn *Peer) readBytes(n int64) {
+ cn.allStats(add(n, func(cs *ConnStats) *Count { return &cs.BytesRead }))
+}
+
+func (c *Peer) lastHelpful() (ret time.Time) {
+ ret = c.lastUsefulChunkReceived
+ if c.t.seeding() && c.lastChunkSent.After(ret) {
+ ret = c.lastChunkSent
+ }
+ return
+}
+
+// Returns whether any part of the chunk would lie outside a piece of the given length.
+func chunkOverflowsPiece(cs ChunkSpec, pieceLength pp.Integer) bool {
+ switch {
+ default:
+ return false
+ case cs.Begin+cs.Length > pieceLength:
+ // Check for integer overflow
+ case cs.Begin > pp.IntegerMax-cs.Length:
+ }
+ return true
+}
+
+func runSafeExtraneous(f func()) {
+ if true {
+ go f()
+ } else {
+ f()
+ }
+}
+
+// Returns true if it was valid to reject the request.
+func (c *Peer) remoteRejectedRequest(r RequestIndex) bool {
+ if c.deleteRequest(r) {
+ c.decPeakRequests()
+ } else if !c.requestState.Cancelled.CheckedRemove(r) {
+ return false
+ }
+ if c.isLowOnRequests() {
+ c.updateRequests("Peer.remoteRejectedRequest")
+ }
+ c.decExpectedChunkReceive(r)
+ return true
+}
+
+func (c *Peer) decExpectedChunkReceive(r RequestIndex) {
+ count := c.validReceiveChunks[r]
+ if count == 1 {
+ delete(c.validReceiveChunks, r)
+ } else if count > 1 {
+ c.validReceiveChunks[r] = count - 1
+ } else {
+ panic(r)
+ }
+}
+
+func (c *Peer) doChunkReadStats(size int64) {
+ c.allStats(func(cs *ConnStats) { cs.receivedChunk(size) })
+}
+
+// Handle a received chunk from a peer.
+func (c *Peer) receiveChunk(msg *pp.Message) error {
+ chunksReceived.Add("total", 1)
+
+ ppReq := newRequestFromMessage(msg)
+ t := c.t
+ err := t.checkValidReceiveChunk(ppReq)
+ if err != nil {
+ err = log.WithLevel(log.Warning, err)
+ return err
+ }
+ req := c.t.requestIndexFromRequest(ppReq)
+
+ if c.bannableAddr.Ok {
+ t.smartBanCache.RecordBlock(c.bannableAddr.Value, req, msg.Piece)
+ }
+
+ if c.peerChoking {
+ chunksReceived.Add("while choked", 1)
+ }
+
+ if c.validReceiveChunks[req] <= 0 {
+ chunksReceived.Add("unexpected", 1)
+ return errors.New("received unexpected chunk")
+ }
+ c.decExpectedChunkReceive(req)
+
+ if c.peerChoking && c.peerAllowedFast.Contains(pieceIndex(ppReq.Index)) {
+ chunksReceived.Add("due to allowed fast", 1)
+ }
+
+ // The request needs to be deleted immediately to prevent cancels occurring asynchronously when
+ // have actually already received the piece, while we have the Client unlocked to write the data
+ // out.
+ intended := false
+ {
+ if c.requestState.Requests.Contains(req) {
+ for _, f := range c.callbacks.ReceivedRequested {
+ f(PeerMessageEvent{c, msg})
+ }
+ }
+ // Request has been satisfied.
+ if c.deleteRequest(req) || c.requestState.Cancelled.CheckedRemove(req) {
+ intended = true
+ if !c.peerChoking {
+ c._chunksReceivedWhileExpecting++
+ }
+ if c.isLowOnRequests() {
+ c.updateRequests("Peer.receiveChunk deleted request")
+ }
+ } else {
+ chunksReceived.Add("unintended", 1)
+ }
+ }
+
+ cl := t.cl
+
+ // Do we actually want this chunk?
+ if t.haveChunk(ppReq) {
+ // panic(fmt.Sprintf("%+v", ppReq))
+ chunksReceived.Add("redundant", 1)
+ c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.ChunksReadWasted }))
+ return nil
+ }
+
+ piece := &t.pieces[ppReq.Index]
+
+ c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.ChunksReadUseful }))
+ c.allStats(add(int64(len(msg.Piece)), func(cs *ConnStats) *Count { return &cs.BytesReadUsefulData }))
+ if intended {
+ c.piecesReceivedSinceLastRequestUpdate++
+ c.allStats(add(int64(len(msg.Piece)), func(cs *ConnStats) *Count { return &cs.BytesReadUsefulIntendedData }))
+ }
+ for _, f := range c.t.cl.config.Callbacks.ReceivedUsefulData {
+ f(ReceivedUsefulDataEvent{c, msg})
+ }
+ c.lastUsefulChunkReceived = time.Now()
+
+ // Need to record that it hasn't been written yet, before we attempt to do
+ // anything with it.
+ piece.incrementPendingWrites()
+ // Record that we have the chunk, so we aren't trying to download it while
+ // waiting for it to be written to storage.
+ piece.unpendChunkIndex(chunkIndexFromChunkSpec(ppReq.ChunkSpec, t.chunkSize))
+
+ // Cancel pending requests for this chunk from *other* peers.
+ if p := t.requestingPeer(req); p != nil {
+ if p == c {
+ panic("should not be pending request from conn that just received it")
+ }
+ p.cancel(req)
+ }
+
+ err = func() error {
+ cl.unlock()
+ defer cl.lock()
+ concurrentChunkWrites.Add(1)
+ defer concurrentChunkWrites.Add(-1)
+ // Write the chunk out. Note that the upper bound on chunk writing concurrency will be the
+ // number of connections. We write inline with receiving the chunk (with this lock dance),
+ // because we want to handle errors synchronously and I haven't thought of a nice way to
+ // defer any concurrency to the storage and have that notify the client of errors. TODO: Do
+ // that instead.
+ return t.writeChunk(int(msg.Index), int64(msg.Begin), msg.Piece)
+ }()
+
+ piece.decrementPendingWrites()
+
+ if err != nil {
+ c.logger.WithDefaultLevel(log.Error).Printf("writing received chunk %v: %v", req, err)
+ t.pendRequest(req)
+ // Necessary to pass TestReceiveChunkStorageFailureSeederFastExtensionDisabled. I think a
+ // request update runs while we're writing the chunk that just failed. Then we never do a
+ // fresh update after pending the failed request.
+ c.updateRequests("Peer.receiveChunk error writing chunk")
+ t.onWriteChunkErr(err)
+ return nil
+ }
+
+ c.onDirtiedPiece(pieceIndex(ppReq.Index))
+
+ // We need to ensure the piece is only queued once, so only the last chunk writer gets this job.
+ if t.pieceAllDirty(pieceIndex(ppReq.Index)) && piece.pendingWrites == 0 {
+ t.queuePieceCheck(pieceIndex(ppReq.Index))
+ // We don't pend all chunks here anymore because we don't want code dependent on the dirty
+ // chunk status (such as the haveChunk call above) to have to check all the various other
+ // piece states like queued for hash, hashing etc. This does mean that we need to be sure
+ // that chunk pieces are pended at an appropriate time later however.
+ }
+
+ cl.event.Broadcast()
+ // We do this because we've written a chunk, and may change PieceState.Partial.
+ t.publishPieceChange(pieceIndex(ppReq.Index))
+
+ return nil
+}
+
+func (c *Peer) onDirtiedPiece(piece pieceIndex) {
+ if c.peerTouchedPieces == nil {
+ c.peerTouchedPieces = make(map[pieceIndex]struct{})
+ }
+ c.peerTouchedPieces[piece] = struct{}{}
+ ds := &c.t.pieces[piece].dirtiers
+ if *ds == nil {
+ *ds = make(map[*Peer]struct{})
+ }
+ (*ds)[c] = struct{}{}
+}
+
+func (cn *Peer) netGoodPiecesDirtied() int64 {
+ return cn._stats.PiecesDirtiedGood.Int64() - cn._stats.PiecesDirtiedBad.Int64()
+}
+
+func (c *Peer) peerHasWantedPieces() bool {
+ if all, _ := c.peerHasAllPieces(); all {
+ return !c.t.haveAllPieces() && !c.t._pendingPieces.IsEmpty()
+ }
+ if !c.t.haveInfo() {
+ return !c.peerPieces().IsEmpty()
+ }
+ return c.peerPieces().Intersects(&c.t._pendingPieces)
+}
+
+// Returns true if an outstanding request is removed. Cancelled requests should be handled
+// separately.
+func (c *Peer) deleteRequest(r RequestIndex) bool {
+ if !c.requestState.Requests.CheckedRemove(r) {
+ return false
+ }
+ for _, f := range c.callbacks.DeletedRequest {
+ f(PeerRequestEvent{c, c.t.requestIndexToRequest(r)})
+ }
+ c.updateExpectingChunks()
+ if c.t.requestingPeer(r) != c {
+ panic("only one peer should have a given request at a time")
+ }
+ delete(c.t.requestState, r)
+ // c.t.iterPeers(func(p *Peer) {
+ // if p.isLowOnRequests() {
+ // p.updateRequests("Peer.deleteRequest")
+ // }
+ // })
+ return true
+}
+
+func (c *Peer) deleteAllRequests(reason string) {
+ if c.requestState.Requests.IsEmpty() {
+ return
+ }
+ c.requestState.Requests.IterateSnapshot(func(x RequestIndex) bool {
+ if !c.deleteRequest(x) {
+ panic("request should exist")
+ }
+ return true
+ })
+ c.assertNoRequests()
+ c.t.iterPeers(func(p *Peer) {
+ if p.isLowOnRequests() {
+ p.updateRequests(reason)
+ }
+ })
+ return
+}
+
+func (c *Peer) assertNoRequests() {
+ if !c.requestState.Requests.IsEmpty() {
+ panic(c.requestState.Requests.GetCardinality())
+ }
+}
+
+func (c *Peer) cancelAllRequests() {
+ c.requestState.Requests.IterateSnapshot(func(x RequestIndex) bool {
+ c.cancel(x)
+ return true
+ })
+ c.assertNoRequests()
+ return
+}
+
+func (c *Peer) peerPriority() (peerPriority, error) {
+ return bep40Priority(c.remoteIpPort(), c.localPublicAddr)
+}
+
+func (c *Peer) remoteIp() net.IP {
+ host, _, _ := net.SplitHostPort(c.RemoteAddr.String())
+ return net.ParseIP(host)
+}
+
+func (c *Peer) remoteIpPort() IpPort {
+ ipa, _ := tryIpPortFromNetAddr(c.RemoteAddr)
+ return IpPort{ipa.IP, uint16(ipa.Port)}
+}
+
+func (c *Peer) trust() connectionTrust {
+ return connectionTrust{c.trusted, c.netGoodPiecesDirtied()}
+}
+
+type connectionTrust struct {
+ Implicit bool
+ NetGoodPiecesDirted int64
+}
+
+func (l connectionTrust) Less(r connectionTrust) bool {
+ return multiless.New().Bool(l.Implicit, r.Implicit).Int64(l.NetGoodPiecesDirted, r.NetGoodPiecesDirted).Less()
+}
+
+// Returns a new Bitmap that includes bits for all pieces the peer could have based on their claims.
+func (cn *Peer) newPeerPieces() *roaring.Bitmap {
+ // TODO: Can we use copy on write?
+ ret := cn.peerPieces().Clone()
+ if all, _ := cn.peerHasAllPieces(); all {
+ if cn.t.haveInfo() {
+ ret.AddRange(0, bitmap.BitRange(cn.t.numPieces()))
+ } else {
+ ret.AddRange(0, bitmap.ToEnd)
+ }
+ }
+ return ret
+}
+
+func (cn *Peer) stats() *ConnStats {
+ return &cn._stats
+}
+
+func (p *Peer) TryAsPeerConn() (*PeerConn, bool) {
+ pc, ok := p.peerImpl.(*PeerConn)
+ return pc, ok
+}
+
+func (p *Peer) uncancelledRequests() uint64 {
+ return p.requestState.Requests.GetCardinality()
+}
+
+type peerLocalPublicAddr = IpPort
+
func (p *Peer) isLowOnRequests() bool {
return p.requestState.Requests.IsEmpty() && p.requestState.Cancelled.IsEmpty()
}