diff --git a/binary/pool.go b/binary/pool.go
index 3673b414..8d14a444 100644
--- a/binary/pool.go
+++ b/binary/pool.go
@@ -24,7 +24,7 @@ func SelectWriter() *Writer {
 // PutWriter 将 Writer 放回池中
 func PutWriter(w *Writer) {
 	// See https://golang.org/issue/23199
-	const maxSize = 1 << 16
+	const maxSize = 32 * 1024
 	if (*bytes.Buffer)(w).Cap() < maxSize { // 对于大Buffer直接丢弃
 		w.Reset()
 		bufferPool.Put(w)
diff --git a/client/client.go b/client/client.go
index 8aced500..f8ff2f81 100644
--- a/client/client.go
+++ b/client/client.go
@@ -49,7 +49,6 @@ type QQClient struct {
 	// protocol public field
 	SequenceId  atomic.Int32
 	SessionId   []byte
-	RandomKey   []byte
 	TCP         *network.TCPListener // todo: combine other protocol state into one struct
 	ConnectTime time.Time
 
@@ -269,7 +268,6 @@ func NewClientMd5(uin int64, passwordMd5 [16]byte) *QQClient {
 	}
 	cli.TCP.PlannedDisconnect(cli.plannedDisconnect)
 	cli.TCP.UnexpectedDisconnect(cli.unexpectedDisconnect)
-	rand.Read(cli.RandomKey)
 	return cli
 }
 
diff --git a/client/decoders.go b/client/decoders.go
index 2de61f18..aa646348 100644
--- a/client/decoders.go
+++ b/client/decoders.go
@@ -45,11 +45,11 @@ func decodeLoginResponse(c *QQClient, _ *network.IncomingPacketInfo, payload []b
 	}
 	if t == 0 { // login success
 		// if t150, ok := m[0x150]; ok {
-		// 	 c.t150 = t150
+		//  	c.t150 = t150
+		// }
+		// if t161, ok := m[0x161]; ok {
+		//  	c.decodeT161(t161)
 		// }
-		if t161, ok := m[0x161]; ok {
-			c.decodeT161(t161)
-		}
 		if m.Exists(0x403) {
 			c.sig.RandSeed = m[0x403]
 		}
diff --git a/client/events.go b/client/events.go
index ba7071c9..cdcc5bcf 100644
--- a/client/events.go
+++ b/client/events.go
@@ -20,7 +20,11 @@ type EventHandle[T any] struct {
 func (handle *EventHandle[T]) Subscribe(handler func(client *QQClient, event T)) {
 	eventMu.Lock()
 	defer eventMu.Unlock()
-	handle.handlers = append(handle.handlers, handler)
+	// shrink the slice
+	newHandlers := make([]func(client *QQClient, event T), len(handle.handlers)+1)
+	copy(newHandlers, handle.handlers)
+	newHandlers[len(handle.handlers)] = handler
+	handle.handlers = newHandlers
 }
 
 func (handle *EventHandle[T]) dispatch(client *QQClient, event T) {
diff --git a/client/tlv_decoders.go b/client/tlv_decoders.go
index ee8a37e3..030e7ee0 100644
--- a/client/tlv_decoders.go
+++ b/client/tlv_decoders.go
@@ -12,16 +12,16 @@ import (
 
 // --- tlv decoders for qq client ---
 
+/*
 func (c *QQClient) decodeT161(data []byte) {
-	/*
-		reader := binary.NewReader(data)
-		reader.ReadBytes(2)
-		t := reader.ReadTlvMap(2)
-		if t172, ok := t[0x172]; ok {
-			c.rollbackSig = t172
-		}
-	*/
+	reader := binary.NewReader(data)
+	reader.ReadBytes(2)
+	t := reader.ReadTlvMap(2)
+	if t172, ok := t[0x172]; ok {
+		c.rollbackSig = t172
+	}
 }
+*/
 
 func (c *QQClient) decodeT119(data, ek []byte) {
 	tea := binary.NewTeaCipher(ek)
@@ -63,32 +63,32 @@ func (c *QQClient) decodeT119(data, ek []byte) {
 		pt4TokenMap map[string][]byte
 	)
 
-	if _, ok := m[0x125]; ok {
-		// openId, openKey = readT125(t125)
-	}
-	if t186, ok := m[0x186]; ok {
-		c.decodeT186(t186)
-	}
 	if t11a, ok := m[0x11a]; ok {
 		nick, age, gender = readT11A(t11a)
 	}
-	if _, ok := m[0x199]; ok {
-		// openId, payToken = readT199(t199)
-	}
-	if _, ok := m[0x200]; ok {
-		// pf, pfkey = readT200(t200)
-	}
+	/*
+		if _, ok := m[0x125]; ok {
+			openId, openKey = readT125(t125)
+		}
+		if t186, ok := m[0x186]; ok {
+		 	c.decodeT186(t186)
+		}
+		if _, ok := m[0x199]; ok {
+			openId, payToken = readT199(t199)
+		}
+		if _, ok := m[0x200]; ok {
+			pf, pfkey = readT200(t200)
+		}
+		if _, ok := m[0x531]; ok {
+			a1, noPicSig = readT531(t531)
+		}
+		if _, ok := m[0x138]; ok {
+			readT138(t138) // chg time
+		}
+	*/
 	if t512, ok := m[0x512]; ok {
 		psKeyMap, pt4TokenMap = readT512(t512)
 	}
-	if _, ok := m[0x531]; ok {
-		// a1, noPicSig = readT531(t531)
-	}
-
-	if _, ok := m[0x138]; ok {
-		// readT138(t138) // chg time
-	}
-
 	c.oicq.WtSessionTicketKey = utils.Select(m[0x134], c.oicq.WtSessionTicketKey)
 
 	// we don't use `c.sigInfo = &auth.SigInfo{...}` here,
@@ -160,9 +160,11 @@ func (c *QQClient) decodeT113(data []byte) {
 	fmt.Println("got t113 uin:", uin)
 }
 
+/*
 func (c *QQClient) decodeT186(data []byte) {
 	// c.pwdFlag = data[1] == 1
 }
+*/
 
 // --- tlv readers ---