From 2fee24995aa5cd47f16ff79908f6146a11e9e13f Mon Sep 17 00:00:00 2001
From: nadoo <287492+nadoo@users.noreply.github.com>
Date: Fri, 7 Aug 2020 12:07:30 +0800
Subject: [PATCH] pool: use binary search to find proper index

---
 common/pool/buffer.go | 24 ++++++++++++------------
 go.mod                |  4 ++--
 go.sum                |  8 ++++----
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/common/pool/buffer.go b/common/pool/buffer.go
index d83d5f6..0235fa0 100644
--- a/common/pool/buffer.go
+++ b/common/pool/buffer.go
@@ -1,14 +1,17 @@
 package pool
 
 import (
+	"sort"
 	"sync"
 )
 
-const num = 17 // number of pools, pool size range: 1<<0 ~ 1<<16 bytes. (1Byte~64KBytes)
+// number of pools.
+// pool sizes: 1<<0 ~ 1<<16 bytes, (1Byte~64KBytes).
+const num = 17
 
 var (
-	pools [num]sync.Pool
 	sizes [num]int
+	pools [num]sync.Pool
 )
 
 func init() {
@@ -23,21 +26,18 @@ func init() {
 
 // GetBuffer gets a buffer from pool.
 func GetBuffer(size int) []byte {
-	for i := 0; i < num; i++ {
-		if size <= sizes[i] {
-			return pools[i].Get().([]byte)[:size]
-		}
+	i := sort.Search(num, func(i int) bool { return sizes[i] >= size })
+	if i < num {
+		return pools[i].Get().([]byte)[:size]
 	}
 	return make([]byte, size)
 }
 
 // PutBuffer puts a buffer into pool.
 func PutBuffer(buf []byte) {
-	c := cap(buf)
-	for i := 0; i < num; i++ {
-		if c == sizes[i] {
-			pools[i].Put(buf)
-			return
-		}
+	size := cap(buf)
+	i := sort.Search(num, func(i int) bool { return sizes[i] >= size })
+	if i < num && sizes[i] == size {
+		pools[i].Put(buf)
 	}
 }
diff --git a/go.mod b/go.mod
index 6db1c26..9287328 100644
--- a/go.mod
+++ b/go.mod
@@ -15,8 +15,8 @@ require (
 	github.com/xtaci/kcp-go/v5 v5.5.14
 	golang.org/x/crypto v0.0.0-20200728195943-123391ffb6de
 	golang.org/x/net v0.0.0-20200707034311-ab3426394381 // indirect
-	golang.org/x/sys v0.0.0-20200806060901-a37d78b92225 // indirect
-	golang.org/x/tools v0.0.0-20200806022845-90696ccdc692 // indirect
+	golang.org/x/sys v0.0.0-20200806125547-5acd03effb82 // indirect
+	golang.org/x/tools v0.0.0-20200806234136-990129eca547 // indirect
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 )
diff --git a/go.sum b/go.sum
index e331984..b7e2914 100644
--- a/go.sum
+++ b/go.sum
@@ -111,14 +111,14 @@ golang.org/x/sys v0.0.0-20191020212454-3e7259c5e7c2/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20191228213918-04cbcbbfeed8/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200501145240-bc7a7d42d5c3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200806060901-a37d78b92225 h1:a5kp7Ohh+lqGCGHUBQdPwGHTJXKNhVVWp34F+ncDC9M=
-golang.org/x/sys v0.0.0-20200806060901-a37d78b92225/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200806125547-5acd03effb82 h1:6cBnXxYO+CiRVrChvCosSv7magqTPbyAgz1M8iOv5wM=
+golang.org/x/sys v0.0.0-20200806125547-5acd03effb82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c h1:iHhCR0b26amDCiiO+kBguKZom9aMF+NrFxh9zeKR/XU=
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
-golang.org/x/tools v0.0.0-20200806022845-90696ccdc692 h1:fsn47thVa7Ar/TMyXYlZgOoT7M4+kRpb+KpSAqRQx1w=
-golang.org/x/tools v0.0.0-20200806022845-90696ccdc692/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
+golang.org/x/tools v0.0.0-20200806234136-990129eca547 h1:HjPd370wmFEFsBBdDEikoje9tDY3OHE7UB2erLJBmss=
+golang.org/x/tools v0.0.0-20200806234136-990129eca547/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=