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

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

pkg/utils/changenotifier.go

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2023 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"
+
+type ChangeNotifier struct {
+	lock      sync.Mutex
+	observers map[string]func()
+}
+
+func NewChangeNotifier() *ChangeNotifier {
+	return &ChangeNotifier{
+		observers: make(map[string]func()),
+	}
+}
+
+func (n *ChangeNotifier) AddObserver(key string, onChanged func()) {
+	n.lock.Lock()
+	defer n.lock.Unlock()
+
+	n.observers[key] = onChanged
+}
+
+func (n *ChangeNotifier) RemoveObserver(key string) {
+	n.lock.Lock()
+	defer n.lock.Unlock()
+
+	delete(n.observers, key)
+}
+
+func (n *ChangeNotifier) HasObservers() bool {
+	n.lock.Lock()
+	defer n.lock.Unlock()
+
+	return len(n.observers) > 0
+}
+
+func (n *ChangeNotifier) NotifyChanged() {
+	n.lock.Lock()
+	if len(n.observers) == 0 {
+		n.lock.Unlock()
+		return
+	}
+	observers := make([]func(), 0, len(n.observers))
+	for _, f := range n.observers {
+		observers = append(observers, f)
+	}
+	n.lock.Unlock()
+
+	go func() {
+		for _, f := range observers {
+			f()
+		}
+	}()
+}
+
+type ChangeNotifierManager struct {
+	lock      sync.Mutex
+	notifiers map[string]*ChangeNotifier
+}
+
+func NewChangeNotifierManager() *ChangeNotifierManager {
+	return &ChangeNotifierManager{
+		notifiers: make(map[string]*ChangeNotifier),
+	}
+}
+
+func (m *ChangeNotifierManager) GetNotifier(key string) *ChangeNotifier {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	return m.notifiers[key]
+}
+
+func (m *ChangeNotifierManager) GetOrCreateNotifier(key string) *ChangeNotifier {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if notifier, ok := m.notifiers[key]; ok {
+		return notifier
+	}
+
+	notifier := NewChangeNotifier()
+	m.notifiers[key] = notifier
+	return notifier
+}
+
+func (m *ChangeNotifierManager) RemoveNotifier(key string, force bool) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if notifier, ok := m.notifiers[key]; ok {
+		if force || !notifier.HasObservers() {
+			delete(m.notifiers, key)
+		}
+	}
+}