transport: limit writer buffer size (#251)

Signed-off-by: Miguel Ángel Ortuño <ortuman@gmail.com>

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * [ENHANCEMENT] Re-enable TLS 1.3 channel binding during auth using [RFC 9266](https://www.rfc-editor.org/rfc/rfc9266).
 * [ENHANCEMENT] hook: include propagated context into execution parameter. [249](https://github.com/ortuman/jackal/pull/249)
+* [ENHANCEMENT] transport: limit writer buffer size [#251](https://github.com/ortuman/jackal/pull/251)
 
 ## 0.61.0 (2022/06/06)
 

pkg/transport/socket.go

@@ -30,13 +30,17 @@ import (
 	"golang.org/x/time/rate"
 )
 
-const readBufferSize = 4096
+const (
+	readBufferSize = 4096
+
+	maxWriteBufferSize = 256 * 1024
+)
 
 var errNoWriteFlush = errors.New("transport: flushing buffer before writing")
 
 var bufWriterPool = sync.Pool{
 	New: func() interface{} {
-		return bufio.NewWriter(nil)
+		return bufio.NewWriterSize(nil, maxWriteBufferSize)
 	},
 }
 
@@ -213,6 +217,8 @@ func (s *socketTransport) releaseBuffWriter() {
 	if s.bw == nil {
 		return
 	}
-	bufWriterPool.Put(s.bw)
+	if s.bw.Size() <= maxWriteBufferSize {
+		bufWriterPool.Put(s.bw)
+	}
 	s.bw = nil
 }