Map: Adds concurrency/map (#104)

concurrency/map.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2024 The Dapr Authors
+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 concurrency
+
+import (
+	"sync"
+)
+
+// Map is a simple _typed_ map which is safe for concurrent use.
+// Favoured over sync.Map as it is typed.
+type Map[K comparable, T any] interface {
+	Clear()
+	Delete(key K)
+	Load(key K) (T, bool)
+	LoadAndDelete(key K) (T, bool)
+	Range(fn func(key K, value T) bool)
+	Store(key K, value T)
+}
+
+type mapimpl[K comparable, T any] struct {
+	lock sync.RWMutex
+	m    map[K]T
+}
+
+func NewMap[K comparable, T any]() Map[K, T] {
+	return &mapimpl[K, T]{m: make(map[K]T)}
+}
+
+func (m *mapimpl[K, T]) Clear() {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	m.m = make(map[K]T)
+}
+
+func (m *mapimpl[K, T]) Delete(k K) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	delete(m.m, k)
+}
+
+func (m *mapimpl[K, T]) Load(k K) (T, bool) {
+	m.lock.RLock()
+	defer m.lock.RUnlock()
+	v, ok := m.m[k]
+	return v, ok
+}
+
+func (m *mapimpl[K, T]) LoadAndDelete(k K) (T, bool) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	v, ok := m.m[k]
+	delete(m.m, k)
+	return v, ok
+}
+
+func (m *mapimpl[K, T]) Range(fn func(K, T) bool) {
+	m.lock.RLock()
+	defer m.lock.RUnlock()
+	for k, v := range m.m {
+		if !fn(k, v) {
+			break
+		}
+	}
+}
+
+func (m *mapimpl[K, T]) Store(k K, v T) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	m.m[k] = v
+}