control/controlbase: use less memory when idle (remove txState.buf)
Uses 4KB less per Conn.
Updates
@@ -63,7 +63,6 @@ type txState struct {
sync.Mutex
cipher cipher.AEAD
nonce nonce
- buf [maxMessageSize]byte
err error // records the first partial write error for all future calls
}
@@ -134,19 +133,19 @@ func (c *Conn) decryptLocked(msg []byte) (err error) {
return err
}
-// encryptLocked encrypts plaintext into c.tx.buf (including the
+// encryptLocked encrypts plaintext into buf (including the
// packet header) and returns a slice of the ciphertext, or an error
// if the cipher is exhausted (i.e. can no longer be used safely).
-func (c *Conn) encryptLocked(plaintext []byte) ([]byte, error) {
+func (c *Conn) encryptLocked(plaintext []byte, buf *maxMsgBuffer) ([]byte, error) {
if !c.tx.nonce.Valid() {
// Received 2^64-1 messages on this cipher state. Connection
// is no longer usable.
return nil, errCipherExhausted{}
}
- c.tx.buf[0] = msgTypeRecord
- binary.BigEndian.PutUint16(c.tx.buf[1:headerLen], uint16(len(plaintext)+chp.Overhead))
- ret := c.tx.cipher.Seal(c.tx.buf[:headerLen], c.tx.nonce[:], plaintext, nil)
+ buf[0] = msgTypeRecord
+ binary.BigEndian.PutUint16(buf[1:headerLen], uint16(len(plaintext)+chp.Overhead))
+ ret := c.tx.cipher.Seal(buf[:headerLen], c.tx.nonce[:], plaintext, nil)
c.tx.nonce.Increment()
return ret, nil
@@ -257,6 +256,9 @@ func (c *Conn) Write(bs []byte) (n int, err error) {
return 0, net.ErrClosed
}
+ buf := bufPool.Get().(*maxMsgBuffer)
+ defer bufPool.Put(buf)
+
var sent int
for len(bs) > 0 {
toSend := bs
@@ -265,7 +267,7 @@ func (c *Conn) Write(bs []byte) (n int, err error) {
}
bs = bs[len(toSend):]
- ciphertext, err := c.encryptLocked(toSend)
+ ciphertext, err := c.encryptLocked(toSend, buf)
if err != nil {
return sent, err
}
@@ -355,3 +357,12 @@ func (n *nonce) Increment() {
}
binary.BigEndian.PutUint64(n[4:], 1+binary.BigEndian.Uint64(n[4:]))
}
+
+type maxMsgBuffer [maxMessageSize]byte
+
+// bufPool holds the temporary buffers for Conn.Read & Write.
+var bufPool = &sync.Pool{
+ New: func() interface{} {
+ return new(maxMsgBuffer)
+ },
+}
