Determine peer max requests based on receive speed

diff --git a/peerconn.go b/peerconn.go
index 71ac5f3d252a230d4b7bbed38ae9033e41d30e52..f3680e1832472b6e893c2784a4ddcc621bc42dd1 100644 (file)
--- a/peerconn.go
+++ b/peerconn.go
@@ -47,6 +47,10 @@ type PeerRemoteAddr interface {
        String() string
 }
 
+// Since we have to store all the requests in memory, we can't reasonably exceed what would be
+// indexable with the memory space available.
+type maxRequests = int
+
 type Peer struct {
        // First to ensure 64-bit alignment for atomics. See #262.
        _stats ConnStats
@@ -83,9 +87,10 @@ type Peer struct {
        cumulativeExpectedToReceiveChunks   time.Duration
        _chunksReceivedWhileExpecting       int64
 
-       choking          bool
-       requests         map[Request]struct{}
-       requestsLowWater int
+       choking                                bool
+       requests                               map[Request]struct{}
+       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.
@@ -114,7 +119,7 @@ type Peer struct {
        peerTouchedPieces map[pieceIndex]struct{}
        peerAllowedFast   bitmap.Bitmap
 
-       PeerMaxRequests  int // Maximum pending requests the peer allows.
+       PeerMaxRequests  maxRequests // Maximum pending requests the peer allows.
        PeerExtensionIDs map[pp.ExtensionName]pp.ExtensionNumber
        PeerClientName   string
 
@@ -470,8 +475,8 @@ func (cn *PeerConn) requestedMetadataPiece(index int) bool {
 }
 
 // The actual value to use as the maximum outbound requests.
-func (cn *Peer) nominalMaxRequests() (ret int) {
-       return int(clamp(1, int64(cn.PeerMaxRequests), 64))
+func (cn *Peer) nominalMaxRequests() (ret maxRequests) {
+       return int(clamp(1, 2*int64(cn.maxPiecesReceivedBetweenRequestUpdates), int64(cn.PeerMaxRequests)))
 }
 
 func (cn *Peer) totalExpectingTime() (ret time.Duration) {
@@ -1358,6 +1363,7 @@ func (c *Peer) receiveChunk(msg *pp.Message) error {
        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 deletedRequest {
+               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 {

diff --git a/request-strategy.go b/request-strategy.go
index 7c7660bc4cc83d705a8c38541c5ad835fff2a0d7..f0470007ccf91d58567c2b54b62f3862b0a96751 100644 (file)
--- a/request-strategy.go
+++ b/request-strategy.go
@@ -53,6 +53,10 @@ func (cl *Client) doRequests() {
                        if p.closed.IsSet() {
                                return
                        }
+                       if p.piecesReceivedSinceLastRequestUpdate > p.maxPiecesReceivedBetweenRequestUpdates {
+                               p.maxPiecesReceivedBetweenRequestUpdates = p.piecesReceivedSinceLastRequestUpdate
+                       }
+                       p.piecesReceivedSinceLastRequestUpdate = 0
                        rst.Peers = append(rst.Peers, request_strategy.Peer{
                                HasPiece:    p.peerHasPiece,
                                MaxRequests: p.nominalMaxRequests(),