Squashed 'livekit-server/' content from commit 154b4d26

git-subtree-dir: livekit-server
git-subtree-split: 154b4d26b769c68a03c096124094b97bf61a996f

pkg/utils/incrementaldispatcher.go

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2024 LiveKit, Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package utils
+
+import (
+	"sync"
+
+	"github.com/frostbyte73/core"
+)
+
+// IncrementalDispatcher is a dispatcher that allows multiple consumers to consume items as they become
+// available, while producers can add items at anytime.
+type IncrementalDispatcher[T any] struct {
+	done  core.Fuse
+	lock  sync.RWMutex
+	cond  *sync.Cond
+	items []T
+}
+
+func NewIncrementalDispatcher[T any]() *IncrementalDispatcher[T] {
+	p := &IncrementalDispatcher[T]{}
+	p.cond = sync.NewCond(&p.lock)
+	return p
+}
+
+func (d *IncrementalDispatcher[T]) Add(item T) {
+	if d.done.IsBroken() {
+		return
+	}
+	d.lock.Lock()
+	d.items = append(d.items, item)
+	d.lock.Unlock()
+	d.cond.Broadcast()
+}
+
+func (d *IncrementalDispatcher[T]) Done() {
+	d.lock.Lock()
+	d.done.Break()
+	d.cond.Broadcast()
+	d.lock.Unlock()
+}
+
+func (d *IncrementalDispatcher[T]) ForEach(fn func(T)) {
+	idx := 0
+	dispatchFromIdx := func() {
+		var itemsToDispatch []T
+		d.lock.RLock()
+		for idx < len(d.items) {
+			itemsToDispatch = append(itemsToDispatch, d.items[idx])
+			idx++
+		}
+		d.lock.RUnlock()
+		for _, item := range itemsToDispatch {
+			fn(item)
+		}
+	}
+	for !d.done.IsBroken() {
+		dispatchFromIdx()
+		d.lock.Lock()
+		// need to check again because Done may have been called while dispatching
+		if d.done.IsBroken() {
+			d.lock.Unlock()
+			break
+		}
+		if idx == len(d.items) {
+			d.cond.Wait()
+		}
+		d.lock.Unlock()
+	}
+
+	dispatchFromIdx()
+}