初始版本

mqttx/queue.go

@@ -0,0 +1,75 @@
+package mqttx
+
+import "sync"
+
+type MessageQueue[T any] struct {
+	mu     sync.Mutex
+	cond   *sync.Cond
+	items  []T
+	closed bool
+}
+
+func NewMessageQueue[T any]() *MessageQueue[T] {
+	q := &MessageQueue[T]{}
+	q.cond = sync.NewCond(&q.mu)
+	return q
+}
+
+func (q *MessageQueue[T]) Push(item T) bool {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	if q.closed {
+		return false
+	}
+	q.items = append(q.items, item)
+	q.cond.Signal()
+	return true
+}
+
+func (q *MessageQueue[T]) Pop() (T, bool) {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	for len(q.items) == 0 && !q.closed {
+		q.cond.Wait()
+	}
+	var zero T
+	if len(q.items) == 0 {
+		return zero, false
+	}
+	item := q.items[0]
+	q.items[0] = zero
+	q.items = q.items[1:]
+	return item, true
+}
+
+func (q *MessageQueue[T]) Drain(max int) []T {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	if max <= 0 || len(q.items) == 0 {
+		return nil
+	}
+	if max > len(q.items) {
+		max = len(q.items)
+	}
+	items := make([]T, max)
+	copy(items, q.items[:max])
+	var zero T
+	for i := 0; i < max; i++ {
+		q.items[i] = zero
+	}
+	q.items = q.items[max:]
+	return items
+}
+
+func (q *MessageQueue[T]) Len() int {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	return len(q.items)
+}
+
+func (q *MessageQueue[T]) Close() {
+	q.mu.Lock()
+	q.closed = true
+	q.mu.Unlock()
+	q.cond.Broadcast()
+}