From b99dd505b5745e51f5782a0318f8067e6235e930 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Tue, 30 Nov 2021 21:31:32 +1100
Subject: [PATCH] Avoid reflection sorting request pieces
---
request-strategy/order.go | 76 +++++++++++++++++++++++++++------------
1 file changed, 54 insertions(+), 22 deletions(-)
diff --git a/request-strategy/order.go b/request-strategy/order.go
index e6cf7dc0..91dfc74d 100644
--- a/request-strategy/order.go
+++ b/request-strategy/order.go
@@ -43,25 +43,37 @@ func equalFilterPieces(l, r []filterPiece) bool {
return true
}
-func sortFilterPieces(pieces []filterPiece, indices []int) {
- sort.Slice(indices, func(_i, _j int) bool {
- i := &pieces[indices[_i]]
- j := &pieces[indices[_j]]
- return multiless.New().Int(
- int(j.Priority), int(i.Priority),
- ).Bool(
- j.Partial, i.Partial,
- ).Int64(
- i.Availability, j.Availability,
- ).Int(
- i.index, j.index,
- ).Lazy(func() multiless.Computation {
- return multiless.New().Cmp(bytes.Compare(
- i.t.InfoHash[:],
- j.t.InfoHash[:],
- ))
- }).MustLess()
- })
+type pieceSorter struct {
+ swap func(i, j int)
+ get func(i int) *filterPiece
+ len int
+}
+
+func (me pieceSorter) Len() int {
+ return me.len
+}
+
+func (me pieceSorter) Swap(i, j int) {
+ me.swap(i, j)
+}
+
+func (me pieceSorter) Less(_i, _j int) bool {
+ i := me.get(_i)
+ j := me.get(_j)
+ return multiless.New().Int(
+ int(j.Priority), int(i.Priority),
+ ).Bool(
+ j.Partial, i.Partial,
+ ).Int64(
+ i.Availability, j.Availability,
+ ).Int(
+ i.index, j.index,
+ ).Lazy(func() multiless.Computation {
+ return multiless.New().Cmp(bytes.Compare(
+ i.t.InfoHash[:],
+ j.t.InfoHash[:],
+ ))
+ }).MustLess()
}
type requestsPeer struct {
@@ -124,6 +136,19 @@ func reorderedFilterPieces(pieces []filterPiece, indices []int) (ret []filterPie
var packageExpvarMap = expvar.NewMap("request-strategy")
func getSortedFilterPieces(unsorted []filterPiece) []filterPiece {
+ const cachePieceSorts = false
+ if !cachePieceSorts {
+ sort.Sort(pieceSorter{
+ len: len(unsorted),
+ swap: func(i, j int) {
+ unsorted[i], unsorted[j] = unsorted[j], unsorted[i]
+ },
+ get: func(i int) *filterPiece {
+ return &unsorted[i]
+ },
+ })
+ return unsorted
+ }
sortsMu.Lock()
defer sortsMu.Unlock()
for key, order := range sorts {
@@ -132,12 +157,19 @@ func getSortedFilterPieces(unsorted []filterPiece) []filterPiece {
return reorderedFilterPieces(unsorted, order)
}
}
- sorted := append(make([]filterPiece, 0, len(unsorted)), unsorted...)
- indices := make([]int, len(sorted))
+ indices := make([]int, len(unsorted))
for i := 0; i < len(indices); i++ {
indices[i] = i
}
- sortFilterPieces(sorted, indices)
+ sort.Sort(pieceSorter{
+ len: len(unsorted),
+ swap: func(i, j int) {
+ indices[i], indices[j] = indices[j], indices[i]
+ },
+ get: func(i int) *filterPiece {
+ return &unsorted[indices[i]]
+ },
+ })
packageExpvarMap.Add("added filter piece ordering", 1)
sorts[&unsorted] = indices
runtime.SetFinalizer(&pieceOrderingFinalizer{unsorted: &unsorted}, func(me *pieceOrderingFinalizer) {
--
2.51.0