fix: 完成 broker 复审 B-03 至 B-12

每连接异步下发与背压、写出后断开、校验当前连接与订阅、生命周期串行、登录条件更新、闲置按在线计、认证超时并发与 Shutdown 0x8B。
2026-09-30 16:21:05 +08:00
parent 0b9ce0359a
commit 91e887ba46
12 changed files with 1099 additions and 89 deletions
@@ -0,0 +1,192 @@
+package broker
+
+import (
+	"context"
+	"time"
+
+	"git.asio.asia/nixevol/NixMsg/internal/app/port"
+)
+
+type downItem struct {
+	payload    []byte
+	qos        byte
+	disconnect port.DisconnectReason // 非空表示该帧写出后断开（B-04）
+	sent       chan struct{}
+}
+
+func (st *connState) startDownLoop(b *Broker) {
+	st.mu.Lock()
+	if st.downCh != nil {
+		st.mu.Unlock()
+		return
+	}
+	st.downCh = make(chan downItem, downQueueMax)
+	st.downStop = make(chan struct{})
+	st.downDone = make(chan struct{})
+	st.mu.Unlock()
+	go st.downLoop(b)
+}
+
+func (st *connState) stopDownLoop() {
+	st.mu.Lock()
+	stop := st.downStop
+	done := st.downDone
+	ch := st.downCh
+	st.mu.Unlock()
+	if stop == nil {
+		return
+	}
+	select {
+	case <-stop:
+	default:
+		close(stop)
+	}
+	if done != nil {
+		select {
+		case <-done:
+		case <-time.After(2 * time.Second):
+		}
+	}
+	if ch != nil {
+		for {
+			select {
+			case item := <-ch:
+				st.downBytes.Add(-int64(len(item.payload)))
+			default:
+				return
+			}
+		}
+	}
+}
+
+func (st *connState) enqueueDown(item downItem) error {
+	st.mu.Lock()
+	ch := st.downCh
+	stop := st.downStop
+	closing := st.closing
+	st.mu.Unlock()
+	if ch == nil || stop == nil {
+		return ErrNoConnection
+	}
+	select {
+	case <-stop:
+		return ErrNoConnection
+	default:
+	}
+	if closing && item.disconnect == "" {
+		return ErrNoConnection
+	}
+	n := int64(len(item.payload))
+	for {
+		cur := st.downBytes.Load()
+		if cur+n > downQueueBytes {
+			return ErrBackpressure
+		}
+		if st.downBytes.CompareAndSwap(cur, cur+n) {
+			break
+		}
+	}
+	select {
+	case ch <- item:
+		return nil
+	default:
+		st.downBytes.Add(-n)
+		return ErrBackpressure
+	}
+}
+
+func (st *connState) downLoop(b *Broker) {
+	defer close(st.downDone)
+	for {
+		select {
+		case <-st.downStop:
+			return
+		case item, ok := <-st.downCh:
+			if !ok {
+				return
+			}
+			st.downBytes.Add(-int64(len(item.payload)))
+			st.sendOne(b, item)
+		}
+	}
+}
+
+func (st *connState) sendOne(b *Broker, item downItem) {
+	if b.closed.Load() {
+		st.signalSent(item)
+		return
+	}
+	large := len(item.payload) > largeFrameBytes
+	if large {
+		if err := b.acquireLarge(context.Background()); err != nil {
+			if b.onDrop != nil {
+				b.onDrop(context.Background(), st.endpointID, st.connID, item.payload)
+			}
+			st.signalSent(item)
+			return
+		}
+		st.mu.Lock()
+		st.largePending++
+		st.mu.Unlock()
+	}
+	topic := downTopic(st.endpointID)
+	before := st.sentPub.Load()
+	var err error
+	for {
+		if b.closed.Load() {
+			break
+		}
+		select {
+		case <-st.downStop:
+			err = ErrNoConnection
+		default:
+			err = b.server.Publish(topic, item.payload, false, item.qos)
+			if err == nil {
+				break
+			}
+			select {
+			case <-st.downStop:
+				err = ErrNoConnection
+			case <-time.After(2 * time.Millisecond):
+				continue
+			}
+		}
+		break
+	}
+	if large {
+		b.finishLargePublish(st)
+	}
+	if err != nil && b.onDrop != nil {
+		b.onDrop(context.Background(), st.endpointID, st.connID, item.payload)
+	}
+	st.signalSent(item)
+	if err == nil && item.disconnect != "" {
+		st.waitPacketWritten(before)
+		_ = b.Disconnect(context.Background(), st.endpointID, st.connID, item.disconnect)
+	}
+}
+
+func (st *connState) waitPacketWritten(before int64) {
+	deadline := time.Now().Add(2 * time.Second)
+	for time.Now().Before(deadline) {
+		if st.sentPub.Load() > before {
+			return
+		}
+		select {
+		case <-st.downStop:
+			return
+		case <-time.After(2 * time.Millisecond):
+		}
+	}
+}
+
+func (st *connState) signalSent(item downItem) {
+	if item.sent == nil {
+		return
+	}
+	select {
+	case <-item.sent:
+	default:
+		close(item.sent)
+	}
+}