Add persistent fabric session client

agents/rap-node-agent/internal/mesh/client.go

@@ -20,10 +20,17 @@ type Client struct {
 }
 
 type FabricSessionDialOptions struct {
-	Token   string
-	Header  http.Header
-	Dialer  *websocket.Dialer
-	Timeout time.Duration
+	Token      string
+	Header     http.Header
+	Dialer     *websocket.Dialer
+	Timeout    time.Duration
+	MaxPayload int
+}
+
+type FabricSessionClient struct {
+	conn       *websocket.Conn
+	timeout    time.Duration
+	maxPayload int
 }
 
 func NewClient(baseURL string) Client {
@@ -142,35 +149,89 @@ func (c Client) DialFabricSession(ctx context.Context, opts FabricSessionDialOpt
 	return dialer.DialContext(ctx, target, header)
 }
 
-func (c Client) SendFabricSessionFrame(ctx context.Context, opts FabricSessionDialOptions, frame fabricproto.Frame) (fabricproto.Frame, error) {
+func (c Client) OpenFabricSession(ctx context.Context, opts FabricSessionDialOptions) (*FabricSessionClient, *http.Response, error) {
 	conn, resp, err := c.DialFabricSession(ctx, opts)
 	if err != nil {
 		if resp != nil {
-			return fabricproto.Frame{}, fmt.Errorf("fabric session websocket rejected with status %d: %w", resp.StatusCode, err)
+			return nil, resp, fmt.Errorf("fabric session websocket rejected with status %d: %w", resp.StatusCode, err)
 		}
-		return fabricproto.Frame{}, err
+		return nil, resp, err
 	}
-	defer conn.Close()
-	payload, err := fabricproto.MarshalFrame(frame)
+	maxPayload := opts.MaxPayload
+	if maxPayload <= 0 {
+		maxPayload = fabricproto.DefaultMaxPayload
+	}
+	return &FabricSessionClient{
+		conn:       conn,
+		timeout:    opts.Timeout,
+		maxPayload: maxPayload,
+	}, resp, nil
+}
+
+func (c Client) SendFabricSessionFrame(ctx context.Context, opts FabricSessionDialOptions, frame fabricproto.Frame) (fabricproto.Frame, error) {
+	session, _, err := c.OpenFabricSession(ctx, opts)
 	if err != nil {
 		return fabricproto.Frame{}, err
 	}
-	if err := conn.WriteMessage(websocket.BinaryMessage, payload); err != nil {
-		return fabricproto.Frame{}, err
+	defer session.Close()
+	return session.RoundTrip(ctx, frame)
+}
+
+func (c *FabricSessionClient) Close() error {
+	if c == nil || c.conn == nil {
+		return nil
 	}
-	if deadline, ok := ctx.Deadline(); ok {
-		_ = conn.SetReadDeadline(deadline)
-	} else if opts.Timeout > 0 {
-		_ = conn.SetReadDeadline(time.Now().Add(opts.Timeout))
+	return c.conn.Close()
+}
+
+func (c *FabricSessionClient) WriteFrame(ctx context.Context, frame fabricproto.Frame) error {
+	if c == nil || c.conn == nil {
+		return fmt.Errorf("fabric session client is closed")
 	}
-	messageType, responsePayload, err := conn.ReadMessage()
+	payload, err := fabricproto.MarshalFrame(frame)
+	if err != nil {
+		return err
+	}
+	c.applyWriteDeadline(ctx)
+	return c.conn.WriteMessage(websocket.BinaryMessage, payload)
+}
+
+func (c *FabricSessionClient) ReadFrame(ctx context.Context) (fabricproto.Frame, error) {
+	if c == nil || c.conn == nil {
+		return fabricproto.Frame{}, fmt.Errorf("fabric session client is closed")
+	}
+	c.applyReadDeadline(ctx)
+	messageType, responsePayload, err := c.conn.ReadMessage()
 	if err != nil {
 		return fabricproto.Frame{}, err
 	}
 	if messageType != websocket.BinaryMessage {
 		return fabricproto.Frame{}, fmt.Errorf("fabric session websocket returned non-binary message type %d", messageType)
 	}
-	return fabricproto.UnmarshalFrame(responsePayload, fabricproto.DefaultMaxPayload)
+	return fabricproto.UnmarshalFrame(responsePayload, c.maxPayload)
+}
+
+func (c *FabricSessionClient) RoundTrip(ctx context.Context, frame fabricproto.Frame) (fabricproto.Frame, error) {
+	if err := c.WriteFrame(ctx, frame); err != nil {
+		return fabricproto.Frame{}, err
+	}
+	return c.ReadFrame(ctx)
+}
+
+func (c *FabricSessionClient) applyReadDeadline(ctx context.Context) {
+	if deadline, ok := ctx.Deadline(); ok {
+		_ = c.conn.SetReadDeadline(deadline)
+	} else if c.timeout > 0 {
+		_ = c.conn.SetReadDeadline(time.Now().Add(c.timeout))
+	}
+}
+
+func (c *FabricSessionClient) applyWriteDeadline(ctx context.Context) {
+	if deadline, ok := ctx.Deadline(); ok {
+		_ = c.conn.SetWriteDeadline(deadline)
+	} else if c.timeout > 0 {
+		_ = c.conn.SetWriteDeadline(time.Now().Add(c.timeout))
+	}
 }
 
 func (c Client) fabricSessionWebSocketURL() (string, error) {