Feature: socks5 udp associate

common/pool/pool.go

@@ -0,0 +1,15 @@
+package pool
+
+import (
+	"sync"
+)
+
+const (
+	// io.Copy default buffer size is 32 KiB
+	// but the maximum packet size of vmess/shadowsocks is about 16 KiB
+	// so define a buffer of 20 KiB to reduce the memory of each TCP relay
+	bufferSize = 20 * 1024
+)
+
+// BufPool provide buffer for relay
+var BufPool = sync.Pool{New: func() interface{} { return make([]byte, bufferSize) }}