feat(wshub): per-task event hub with non-blocking publish

internal/wshub/wshub.go

@@ -0,0 +1,57 @@
+package wshub
+
+import "sync"
+
+type Event struct {
+	Type   string `json:"type"`
+	TaskID int64  `json:"task_id"`
+	Data   any    `json:"data,omitempty"`
+}
+
+type Hub struct {
+	mu     sync.Mutex
+	nextID int64
+	subs   map[int64]map[int64]chan Event // taskID -> subID -> ch
+}
+
+func New() *Hub {
+	return &Hub{subs: make(map[int64]map[int64]chan Event)}
+}
+
+func (h *Hub) Subscribe(taskID int64) (int64, <-chan Event) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	h.nextID++
+	id := h.nextID
+	ch := make(chan Event, 64)
+	if h.subs[taskID] == nil {
+		h.subs[taskID] = make(map[int64]chan Event)
+	}
+	h.subs[taskID][id] = ch
+	return id, ch
+}
+
+func (h *Hub) Unsubscribe(taskID, id int64) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	if m := h.subs[taskID]; m != nil {
+		if ch, ok := m[id]; ok {
+			close(ch)
+			delete(m, id)
+		}
+		if len(m) == 0 {
+			delete(h.subs, taskID)
+		}
+	}
+}
+
+func (h *Hub) Publish(ev Event) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	for _, ch := range h.subs[ev.TaskID] {
+		select {
+		case ch <- ev:
+		default: // медленный подписчик — событие дропаем, не блокируем воркер
+		}
+	}
+}