refactor: extract route funcs, unify newStream, fix query timeout leak

request.go

@@ -54,7 +54,8 @@ type request struct {
 	events chan ReqEvent
 	closed chan ReqClosed
 
-	once sync.Once
+	deregisterOnce sync.Once
+	closedOnce     sync.Once
 }
 
 // ----------------------------------------------------------------------------
@@ -106,29 +107,47 @@ func NewRequestManager(e *Envoy) *RequestManager {
 
 func (m *RequestManager) Stream(
 	filters [][]byte,
+) (string, <-chan ReqEvent, <-chan ReqClosed) {
+	id, events, closed := m.newStream(filters, false)
+	return id, events, closed
+}
+
+func (m *RequestManager) newStream(
+	filters [][]byte,
+	isQuery bool,
 ) (string, <-chan ReqEvent, <-chan ReqClosed) {
 	id := generateID()
 	buffer := make(chan ReqEvent, 64)
-	events := make(chan ReqEvent)
 	closed := make(chan ReqClosed, 1)
 
+	var events chan ReqEvent
+	if isQuery {
+		// Query reads directly from buffer. bufferedPipe drains asynchronously,
+		// so EOSE can close the pipe's output before all buffered EVENTs have
+		// passed through — causing Query's collect loop to exit short. Reading
+		// from the buffered channel directly avoids that race.
+		events = buffer
+	} else {
+		events = make(chan ReqEvent)
+		go func() {
+			bufferedPipe(buffer, events)
+			close(events)
+		}()
+	}
+
 	req := &request{
 		id:      id,
 		filters: filters,
 		buffer:  buffer,
 		events:  events,
 		closed:  closed,
-		isQuery: false,
+		isQuery: isQuery,
 	}
 
 	m.mu.Lock()
 	m.reqs[id] = req
-	go func() {
-		bufferedPipe(buffer, events)
-		close(events)
-	}()
 	if m.envoy.IsConnected() {
-		m.activateLock(req)
+		m.activate(req)
 	}
 	m.mu.Unlock()
 
@@ -138,27 +157,12 @@ func (m *RequestManager) Stream(
 func (m *RequestManager) Query(
 	filters [][]byte,
 	timeout time.Duration,
-) (events []ReqEvent, closed *ReqClosed) {
+) ([]ReqEvent, *ReqClosed) {
 	if !m.envoy.IsConnected() {
 		return nil, nil
 	}
 
-	id := generateID()
+	id, eventsCh, closedCh := m.newStream(filters, true)
-	eventsCh := make(chan ReqEvent)
-	closedCh := make(chan ReqClosed, 1)
-
-	req := &request{
-		id:      id,
-		filters: filters,
-		buffer:  eventsCh,
-		closed:  closedCh,
-		isQuery: true,
-	}
-
-	m.mu.Lock()
-	m.reqs[id] = req
-	m.activateLock(req)
-	m.mu.Unlock()
 
 	ctx, cancel := context.WithTimeout(m.ctx, timeout)
 	defer cancel()
@@ -177,6 +181,7 @@ func (m *RequestManager) Query(
 			}
 			return result, &cl
 		case <-ctx.Done():
+			m.Cancel(id)
 			return result, nil
 		}
 	}
@@ -196,7 +201,7 @@ func (m *RequestManager) Cancel(id string) error {
 		req.active = false
 	}
 
-	req.once.Do(func() {
+	req.deregisterOnce.Do(func() {
 		close(req.buffer)
 		close(req.closed)
 	})
@@ -216,7 +221,7 @@ func (m *RequestManager) Close() {
 		if req.active {
 			go m.envoy.Send(envelope.EncloseClose(id))
 		}
-		req.once.Do(func() {
+		req.deregisterOnce.Do(func() {
 			close(req.buffer)
 			close(req.closed)
 		})
@@ -224,14 +229,14 @@ func (m *RequestManager) Close() {
 	}
 }
 
-func (m *RequestManager) activateLock(req *request) {
+func (m *RequestManager) activate(req *request) {
 	req.active = true
 	go m.envoy.Send(envelope.EncloseReq(req.id, req.filters))
 }
 
-func (m *RequestManager) removeLock(req *request) {
+func (m *RequestManager) deregister(req *request) {
 	req.active = false
-	req.once.Do(func() {
+	req.deregisterOnce.Do(func() {
 		close(req.buffer)
 		close(req.closed)
 	})
@@ -254,7 +259,7 @@ func (m *RequestManager) handleEvents() {
 			case EventConnected:
 				for _, req := range m.reqs {
 					if !req.isQuery {
-						m.activateLock(req)
+						m.activate(req)
 					}
 				}
 			case EventDisconnected:
@@ -291,6 +296,19 @@ func (m *RequestManager) dispatchInbox(msg InboxMessage) {
 
 	switch string(label) {
 	case "EVENT":
+		m.routeEvent(msg)
+	case "EOSE":
+		m.routeEOSE(msg)
+	case "CLOSED":
+		m.routeClosed(msg)
+	}
+}
+
+// routeEvent, routeEOSE, and routeClosed use blocking sends into req.buffer.
+// This preserves every event without dropping: req.buffer feeds either an
+// unbounded bufferedPipe (streams) that absorbs a slow external reader, or
+// is read directly by Query's collect loop in the caller's goroutine.
+func (m *RequestManager) routeEvent(msg InboxMessage) {
 	subID, event, err := envelope.FindSubscriptionEvent(msg.Data)
 	if err != nil {
 		return
@@ -306,41 +324,42 @@ func (m *RequestManager) dispatchInbox(msg InboxMessage) {
 		ReceivedAt: msg.ReceivedAt,
 		Data:       event,
 	}
+}
 
-	case "EOSE":
+func (m *RequestManager) routeEOSE(msg InboxMessage) {
 	subID, err := envelope.FindEOSE(msg.Data)
 	if err != nil {
 		return
 	}
 	m.mu.Lock()
+	defer m.mu.Unlock()
 	req, ok := m.reqs[subID]
 	if !ok {
-			m.mu.Unlock()
 		return
 	}
 	if req.active && req.isQuery {
-			m.removeLock(req)
+		m.deregister(req)
 		go m.envoy.Send(envelope.EncloseClose(subID))
 	}
-		m.mu.Unlock()
+}
 
-	case "CLOSED":
+func (m *RequestManager) routeClosed(msg InboxMessage) {
 	subID, message, err := envelope.FindClosed(msg.Data)
 	if err != nil {
 		return
 	}
 	m.mu.Lock()
+	defer m.mu.Unlock()
 	req, ok := m.reqs[subID]
 	if !ok {
-			m.mu.Unlock()
 		return
 	}
+	req.closedOnce.Do(func() {
 		req.closed <- ReqClosed{
 			PeerID:     msg.ID,
 			ReceivedAt: msg.ReceivedAt,
 			Data:       message,
 		}
-		m.removeLock(req)
+	})
-		m.mu.Unlock()
+	m.deregister(req)
-	}
 }