kit/concurrency/atomicmap.go

112 lines
2.3 KiB
Go

/*
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"
"golang.org/x/exp/constraints"
)
type AtomicValue[T constraints.Integer] struct {
lock sync.RWMutex
value T
}
func (a *AtomicValue[T]) Load() T {
a.lock.RLock()
defer a.lock.RUnlock()
return a.value
}
func (a *AtomicValue[T]) Store(v T) {
a.lock.Lock()
defer a.lock.Unlock()
a.value = v
}
func (a *AtomicValue[T]) Add(v T) T {
a.lock.Lock()
defer a.lock.Unlock()
a.value += v
return a.value
}
type AtomicMap[K comparable, T constraints.Integer] interface {
Get(key K) (*AtomicValue[T], bool)
GetOrCreate(key K, createT T) *AtomicValue[T]
Delete(key K)
ForEach(fn func(key K, value *AtomicValue[T]))
Clear()
}
type atomicMap[K comparable, T constraints.Integer] struct {
lock sync.RWMutex
items map[K]*AtomicValue[T]
}
func NewAtomicMap[K comparable, T constraints.Integer]() AtomicMap[K, T] {
return &atomicMap[K, T]{
items: make(map[K]*AtomicValue[T]),
}
}
func (a *atomicMap[K, T]) Get(key K) (*AtomicValue[T], bool) {
a.lock.RLock()
defer a.lock.RUnlock()
item, ok := a.items[key]
if !ok {
return nil, false
}
return item, true
}
func (a *atomicMap[K, T]) GetOrCreate(key K, createT T) *AtomicValue[T] {
a.lock.RLock()
item, ok := a.items[key]
a.lock.RUnlock()
if !ok {
a.lock.Lock()
// Double-check the key exists to avoid race condition
item, ok = a.items[key]
if !ok {
item = &AtomicValue[T]{value: createT}
a.items[key] = item
}
a.lock.Unlock()
}
return item
}
func (a *atomicMap[K, T]) Delete(key K) {
a.lock.Lock()
delete(a.items, key)
a.lock.Unlock()
}
func (a *atomicMap[K, T]) ForEach(fn func(key K, value *AtomicValue[T])) {
a.lock.RLock()
defer a.lock.RUnlock()
for k, v := range a.items {
fn(k, v)
}
}
func (a *atomicMap[K, T]) Clear() {
a.lock.Lock()
defer a.lock.Unlock()
clear(a.items)
}