From e837483e393f90206e86f270510a1a4370015432 Mon Sep 17 00:00:00 2001
From: D3Hunter <jujj603@gmail.com>
Date: Thu, 21 Oct 2021 17:56:45 +0800
Subject: [PATCH 1/2] reuse byte buffer to avoid allocate/destroy buffers
 frequently

---
 replication/parser.go | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/replication/parser.go b/replication/parser.go
index 77eb7e9aa..a06a9d054 100644
--- a/replication/parser.go
+++ b/replication/parser.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"github.com/go-mysql-org/go-mysql/utils"
 	"hash/crc32"
 	"io"
 	"os"
@@ -110,8 +111,11 @@ func (p *BinlogParser) parseSingleEvent(r io.Reader, onEvent OnEventFunc) (bool,
 	var err error
 	var n int64
 
-	var buf bytes.Buffer
-	if n, err = io.CopyN(&buf, r, EventHeaderSize); err == io.EOF {
+	// Here we use `sync.Pool` to avoid allocate/destroy buffers frequently.
+	buf := utils.BytesBufferGet()
+	defer utils.BytesBufferPut(buf)
+
+	if n, err = io.CopyN(buf, r, EventHeaderSize); err == io.EOF {
 		return true, nil
 	} else if err != nil {
 		return false, errors.Errorf("get event header err %v, need %d but got %d", err, EventHeaderSize, n)
@@ -126,14 +130,15 @@ func (p *BinlogParser) parseSingleEvent(r io.Reader, onEvent OnEventFunc) (bool,
 	if h.EventSize < uint32(EventHeaderSize) {
 		return false, errors.Errorf("invalid event header, event size is %d, too small", h.EventSize)
 	}
-	if n, err = io.CopyN(&buf, r, int64(h.EventSize-EventHeaderSize)); err != nil {
+	if n, err = io.CopyN(buf, r, int64(h.EventSize-EventHeaderSize)); err != nil {
 		return false, errors.Errorf("get event err %v, need %d but got %d", err, h.EventSize, n)
 	}
 	if buf.Len() != int(h.EventSize) {
 		return false, errors.Errorf("invalid raw data size in event %s, need %d but got %d", h.EventType, h.EventSize, buf.Len())
 	}
 
-	rawData := buf.Bytes()
+	var rawData []byte
+	rawData = append(rawData, buf.Bytes()...)
 	bodyLen := int(h.EventSize) - EventHeaderSize
 	body := rawData[EventHeaderSize:]
 	if len(body) != bodyLen {

From d7f36836d6b7057d43fdf646cbd162148fb2f22f Mon Sep 17 00:00:00 2001
From: D3Hunter <jujj603@gmail.com>
Date: Thu, 11 Nov 2021 17:22:45 +0800
Subject: [PATCH 2/2] sort imports

---
 replication/parser.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/replication/parser.go b/replication/parser.go
index a06a9d054..bcbae5fbf 100644
--- a/replication/parser.go
+++ b/replication/parser.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
-	"github.com/go-mysql-org/go-mysql/utils"
 	"hash/crc32"
 	"io"
 	"os"
@@ -12,6 +11,8 @@ import (
 	"time"
 
 	"github.com/pingcap/errors"
+
+	"github.com/go-mysql-org/go-mysql/utils"
 )
 
 var (