cache2go开源项目的回调方法使用

https://github.com/muesli/cache2go

结构体

type CacheTable struct {
	sync.RWMutex
.
	name string
	items map[interface{}]*CacheItem

	cleanupTimer *time.Timer
	cleanupInterval time.Duration

	logger *log.Logger

// 回调方法定义
	loadData func(key interface{}, args ...interface{}) *CacheItem
	addedItem func(item *CacheItem)
	aboutToDeleteItem func(item *CacheItem)
}

配置回调方法

func (table *CacheTable) SetAddedItemCallback(f func(*CacheItem)) {
	table.Lock()
	defer table.Unlock()
// 回调方法赋值f函数对象
	table.addedItem = f 
}

添加方法的回调处理

func (table *CacheTable) addInternal(item *CacheItem) {
	table.log("Adding item with key", item.key, "and lifespan of", item.lifeSpan, "to table", table.name)
	table.items[item.key] = item

	expDur := table.cleanupInterval
// 获取回调方法内容
	addedItem := table.addedItem  
	table.Unlock()

// 如果不为空，即已配置回调，执行回调
	if addedItem != nil {
		addedItem(item)
	}

	if item.lifeSpan > 0 && (expDur == 0 || item.lifeSpan < expDur) {
		table.expirationCheck()
	}
}

执行

func main() {
	cache := cache2go.Cache("myCache")

// 配置回调方法
	cache.SetAddedItemCallback(func(entry *cache2go.CacheItem) {
		fmt.Println("Added:", entry.Key(), entry.Data(), entry.CreatedOn())
	})

// 添加将执行回调 
	cache.Add("someKey", 0, "This is a test!")

// Added: someKey This is a test! 2018-11-15 15:32:58.226001519 +0800 CST m=+0.000146463
}