Unify open() and openSSL() (#165)

* Unify open() and openSSL()

* Fix test

client_test.go

@@ -61,7 +61,7 @@ func logoutAndClose(conn *connection, sessionID int64) {
 func TestConnection(t *testing.T) {
 	hostAdress := HostAddress{Host: address, Port: port}
 	conn := newConnection(hostAdress)
-	err := conn.open(hostAdress, testPoolConfig.TimeOut)
+	err := conn.open(hostAdress, testPoolConfig.TimeOut, nil)
 	if err != nil {
 		t.Fatalf("fail to open connection, address: %s, port: %d, %s", address, port, err.Error())
 	}
@@ -186,7 +186,7 @@ func TestAuthentication(t *testing.T) {
 	hostAdress := HostAddress{Host: address, Port: port}
 
 	conn := newConnection(hostAdress)
-	err := conn.open(hostAdress, testPoolConfig.TimeOut)
+	err := conn.open(hostAdress, testPoolConfig.TimeOut, nil)
 	if err != nil {
 		t.Fatalf("fail to open connection, address: %s, port: %d, %s", address, port, err.Error())
 	}

connection.go

@@ -23,6 +23,7 @@ type connection struct {
 	severAddress HostAddress
 	timeout      time.Duration
 	returnedAt   time.Time // the connection was created or returned.
+	sslConfig    *tls.Config
 	graph        *graph.GraphServiceClient
 }
 
@@ -31,15 +32,14 @@ func newConnection(severAddress HostAddress) *connection {
 		severAddress: severAddress,
 		timeout:      0 * time.Millisecond,
 		returnedAt:   time.Now(),
+		sslConfig:    nil,
 		graph:        nil,
 	}
 }
 
-func (cn *connection) open(hostAddress HostAddress, timeout time.Duration) error {
-	return cn.openSSL(hostAddress, timeout, nil)
-}
-
-func (cn *connection) openSSL(hostAddress HostAddress, timeout time.Duration, sslConfig *tls.Config) error {
+// open opens a transport for the connection
+// if sslConfig is not nil, an SSL transport will be created
+func (cn *connection) open(hostAddress HostAddress, timeout time.Duration, sslConfig *tls.Config) error {
 	ip := hostAddress.Host
 	port := hostAddress.Port
 	newAdd := fmt.Sprintf("%s:%d", ip, port)
@@ -79,7 +79,7 @@ func (cn *connection) verifyClientVersion() error {
 		return fmt.Errorf("failed to verify client version: %s", err.Error())
 	}
 	if resp.GetErrorCode() != nebula.ErrorCode_SUCCEEDED {
-		return fmt.Errorf("incompatible version between client and server: %s.", string(resp.GetErrorMsg()))
+		return fmt.Errorf("incompatible version between client and server: %s", string(resp.GetErrorMsg()))
 	}
 	return nil
 }
@@ -90,7 +90,7 @@ func (cn *connection) verifyClientVersion() error {
 // When the timeout occurs, the connection will be reopened to avoid the impact of the message.
 func (cn *connection) reopen() error {
 	cn.close()
-	return cn.open(cn.severAddress, cn.timeout)
+	return cn.open(cn.severAddress, cn.timeout, cn.sslConfig)
 }
 
 // Authenticate

connection_pool.go

@@ -79,7 +79,7 @@ func (pool *ConnectionPool) initPool() error {
 		newConn := newConnection(pool.addresses[i%len(pool.addresses)])
 
 		// Open connection to host
-		if err := newConn.openSSL(newConn.severAddress, pool.conf.TimeOut, pool.sslConfig); err != nil {
+		if err := newConn.open(newConn.severAddress, pool.conf.TimeOut, pool.sslConfig); err != nil {
 			// If initialization failed, clean idle queue
 			idleLen := pool.idleConnectionQueue.Len()
 			for i := 0; i < idleLen; i++ {
@@ -181,14 +181,8 @@ func (pool *ConnectionPool) release(conn *connection) {
 func (pool *ConnectionPool) Ping(host HostAddress, timeout time.Duration) error {
 	newConn := newConnection(host)
 	// Open connection to host
-	if pool.sslConfig == nil {
-		if err := newConn.open(newConn.severAddress, timeout); err != nil {
-			return err
-		}
-	} else {
-		if err := newConn.openSSL(newConn.severAddress, timeout, pool.sslConfig); err != nil {
-			return err
-		}
+	if err := newConn.open(newConn.severAddress, timeout, pool.sslConfig); err != nil {
+		return err
 	}
 	newConn.close()
 	return nil
@@ -240,14 +234,8 @@ func (pool *ConnectionPool) newConnToHost() (*connection, error) {
 	host := pool.getHost()
 	newConn := newConnection(host)
 	// Open connection to host
-	if pool.sslConfig == nil {
-		if err := newConn.open(newConn.severAddress, pool.conf.TimeOut); err != nil {
-			return nil, err
-		}
-	} else {
-		if err := newConn.openSSL(newConn.severAddress, pool.conf.TimeOut, pool.sslConfig); err != nil {
-			return nil, err
-		}
+	if err := newConn.open(newConn.severAddress, pool.conf.TimeOut, pool.sslConfig); err != nil {
+		return nil, err
 	}
 	// Add connection to active queue
 	pool.activeConnectionQueue.PushBack(newConn)