fix(revert): align and reuse the Packet struct to reduce allocated memory

This reverts commit f4c3f8aa40.

Signed-off-by: leonrayang <chl696@sina.com>

metanode/packet.go

@@ -27,10 +27,6 @@ type Packet struct {
 	proto.Packet
 }
 
-func ClearPacket(p *Packet) {
-	proto.ClearPacket(&p.Packet)
-}
-
 // NewPacketToDeleteExtent returns a new packet to delete the extent.
 func NewPacketToDeleteExtent(dp *DataPartition, ext *proto.ExtentKey) (p *Packet, invalid bool) {
 	p = new(Packet)

metanode/packet_test.go

@@ -1,12 +0,0 @@
-package metanode
-
-import "testing"
-
-func TestClearPacket(t *testing.T) {
-	p := &Packet{}
-	p.Opcode = 3
-	ClearPacket(p)
-	if 0 != p.Opcode {
-		t.Fatalf("ClearPacket failed")
-	}
-}

metanode/server.go

@@ -81,14 +81,13 @@ func (m *MetaNode) serveConn(conn net.Conn, stopC chan uint8) {
 	c.SetKeepAlive(true)
 	c.SetNoDelay(true)
 	remoteAddr := conn.RemoteAddr().String()
-	p := &Packet{}
 	for {
 		select {
 		case <-stopC:
 			return
 		default:
 		}
-		ClearPacket(p)
+		p := &Packet{}
 		if err := p.ReadFromConnWithVer(conn, proto.NoReadDeadlineTime); err != nil {
 			if err != io.EOF {
 				log.LogError("serve MetaNode: ", err.Error())

proto/packet.go

@@ -342,6 +342,7 @@ type Packet struct {
 	ExtentType         uint8 // the highest bit be set while rsp to client if version not consistent then Verseq be valid
 	Opcode             uint8
 	ResultCode         uint8
+	RemainingFollowers uint8
 	CRC                uint32
 	Size               uint32
 	ArgLen             uint32
@@ -354,44 +355,16 @@ type Packet struct {
 	Data               []byte
 	StartT             int64
 	mesg               string
-	RemainingFollowers uint8
-
-	HasPrepare bool
-	noPrefix   bool
+	HasPrepare         bool
+	VerSeq             uint64 // only used in mod request to datanode
 
 	// protocol version of packet
 	// version-0: before v3.4
 	// version-1: from v3.4
 	ProtoVersion uint32
 
-	VerSeq uint64 // only used in mod request to datanode
-
-	VerList []*VolVersionInfo
-}
-
-func ClearPacket(p *Packet) {
-	p.Magic = 0
-	p.ExtentType = 0
-	p.Opcode = 0
-	p.ResultCode = 0
-	p.CRC = 0
-	p.Size = 0
-	p.ArgLen = 0
-	p.KernelOffset = 0
-	p.PartitionID = 0
-	p.ExtentID = 0
-	p.ExtentOffset = 0
-	p.ReqID = 0
-	p.Arg = nil
-	p.Data = nil
-	p.StartT = 0
-	p.mesg = ""
-	p.RemainingFollowers = 0
-	p.HasPrepare = false
-	p.VerSeq = 0
-	p.ProtoVersion = 0
-	p.VerList = nil
-	p.noPrefix = false
+	VerList  []*VolVersionInfo
+	noPrefix bool
 }
 
 func IsTinyExtentType(extentType uint8) bool {