Reuse lengthFields

Author: shanson7

crc32_field.go

@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"fmt"
 	"hash/crc32"
+	"sync"
 )
 
 type crcPolynomial int8
@@ -13,6 +14,22 @@ const (
 	crcCastagnoli
 )
 
+var crc32FieldPool = sync.Pool{}
+
+func acquireCrc32Field(polynomial crcPolynomial) *crc32Field {
+	val := crc32FieldPool.Get()
+	if val != nil {
+		c := val.(*crc32Field)
+		c.polynomial = polynomial
+		return c
+	}
+	return newCRC32Field(polynomial)
+}
+
+func releaseCrc32Field(c *crc32Field) {
+	crc32FieldPool.Put(c)
+}
+
 var castagnoliTable = crc32.MakeTable(crc32.Castagnoli)
 
 // crc32Field implements the pushEncoder and pushDecoder interfaces for calculating CRC32s.

length_field.go

@@ -1,13 +1,30 @@
 package sarama
 
-import "encoding/binary"
+import (
+	"encoding/binary"
+	"sync"
+)
 
 // LengthField implements the PushEncoder and PushDecoder interfaces for calculating 4-byte lengths.
 type lengthField struct {
 	startOffset int
 	length      int32
 }
 
+var lengthFieldPool = sync.Pool{}
+
+func acquireLengthField() *lengthField {
+	val := lengthFieldPool.Get()
+	if val != nil {
+		return val.(*lengthField)
+	}
+	return &lengthField{}
+}
+
+func releaseLengthField(m *lengthField) {
+	lengthFieldPool.Put(m)
+}
+
 func (l *lengthField) decode(pd packetDecoder) error {
 	var err error
 	l.length, err = pd.getInt32()

message.go

@@ -103,7 +103,10 @@ func (m *Message) encode(pe packetEncoder) error {
 }
 
 func (m *Message) decode(pd packetDecoder) (err error) {
-	err = pd.push(newCRC32Field(crcIEEE))
+	crc32Decoder := acquireCrc32Field(crcIEEE)
+	defer releaseCrc32Field(crc32Decoder)
+
+	err = pd.push(crc32Decoder)
 	if err != nil {
 		return err
 	}

message_set.go

@@ -29,7 +29,10 @@ func (msb *MessageBlock) decode(pd packetDecoder) (err error) {
 		return err
 	}
 
-	if err = pd.push(&lengthField{}); err != nil {
+	lengthDecoder := acquireLengthField()
+	defer releaseLengthField(lengthDecoder)
+
+	if err = pd.push(lengthDecoder); err != nil {
 		return err
 	}
 

record_batch.go

@@ -116,7 +116,10 @@ func (b *RecordBatch) decode(pd packetDecoder) (err error) {
 		return err
 	}
 
-	if err = pd.push(&crc32Field{polynomial: crcCastagnoli}); err != nil {
+	crc32Decoder := acquireCrc32Field(crcCastagnoli)
+	defer releaseCrc32Field(crc32Decoder)
+
+	if err = pd.push(crc32Decoder); err != nil {
 		return err
 	}