[TOC] > [github.com](https://github.com/muesli/cache2go) ## 概述 帶過期回調的緩存 ## 安裝 `go get github.com/muesli/cache2go ` ## 實例 ### hello ``` package main import ( "github.com/muesli/cache2go" "fmt" "time" ) // Keys & values in cache2go can be of arbitrary types, e.g. a struct. type myStruct struct { text string moreData []byte } func main() { // Accessing a new cache table for the first time will create it. cache := cache2go.Cache("myCache") // We will put a new item in the cache. It will expire after // not being accessed via Value(key) for more than 5 seconds. val := myStruct{"This is a test!", []byte{}} cache.Add("someKey", 5*time.Second, &val) // Let's retrieve the item from the cache. res, err := cache.Value("someKey") if err == nil { fmt.Println("Found value in cache:", res.Data().(*myStruct).text) } else { fmt.Println("Error retrieving value from cache:", err) } // Wait for the item to expire in cache. time.Sleep(6 * time.Second) res, err = cache.Value("someKey") if err != nil { fmt.Println("Item is not cached (anymore).") } // Add another item that never expires. cache.Add("someKey", 0, &val) // cache2go supports a few handy callbacks and loading mechanisms. cache.SetAboutToDeleteItemCallback(func(e *cache2go.CacheItem) { fmt.Println("Deleting:", e.Key(), e.Data().(*myStruct).text, e.CreatedOn()) }) // Remove the item from the cache. cache.Delete("someKey") // And wipe the entire cache table. cache.Flush() } ```