Correctly manage partial writes

mtglib/internal/faketls/record/pools.go

@@ -1,12 +1,22 @@
 package record
 
-import "sync"
+import (
+	"bytes"
+	"sync"
+)
 
-var recordPool = sync.Pool{
-	New: func() interface{} {
-		return &Record{}
-	},
-}
+var (
+	recordPool = sync.Pool{
+		New: func() interface{} {
+			return &Record{}
+		},
+	}
+	bytesBufferPool = sync.Pool{
+		New: func() interface{} {
+			return &bytes.Buffer{}
+		},
+	}
+)
 
 func AcquireRecord() *Record {
 	return recordPool.Get().(*Record)
@@ -16,3 +26,12 @@ func ReleaseRecord(r *Record) {
 	r.Reset()
 	recordPool.Put(r)
 }
+
+func acquireBytesBuffer() *bytes.Buffer {
+	return bytesBufferPool.Get().(*bytes.Buffer)
+}
+
+func releaseBytesBuffer(buf *bytes.Buffer) {
+	buf.Reset()
+	bytesBufferPool.Put(buf)
+}