9.go开源cache2go项目笔记——dataloader调用

9.go开源cache2go项目笔记——dataloader调用

测试dataloader相关功能。

1      代码

packagemain

import(

    "fmt"

    "strconv"

    "github.com/muesli/cache2go"

)

funcmain(){

    cache:=cache2go.Cache("myCache")

    cache.SetDataLoader(func(keyinterface{},args...interface{})*cache2go.CacheItem{

        val:="Thisisatestwithkey"+key.(string)

        item:=cache2go.CreateCacheItem(key,0,val)

        return&item

    })

    fori:=0;i<10;i++{

        res,err:=cache.Value("someKey_"+strconv.Itoa(i))

        iferr==nil{

            fmt.Println("Foundvalueincache:",res.Data())

        }else{

            fmt.Println("Errorretrievingvaluefromcache:",err)

        }

    }

}

2      执行如下

Found value in cache: Thisis a test with key someKey_0

Found value in cache: Thisis a test with key someKey_1

Found value in cache: Thisis a test with key someKey_2

Found value in cache: Thisis a test with key someKey_3

Found value in cache: Thisis a test with key someKey_4

Found value in cache: Thisis a test with key someKey_5

Found value in cache: Thisis a test with key someKey_6

Found value in cache: Thisis a test with key someKey_7

Found value in cache: Thisis a test with key someKey_8

Found value in cache: This is a test with key someKey_9

3      代码说明

cache:=cache2go.Cache("myCache")创建一个CACHE TABLE。

cache.SetDataLoader(func(keyinterface{},args...interface{}) 设置函数loadData函数，入参是CACHE ITEM的指针。当从CACHE TABLE中获取不存在的键时候会调用该函数，其中调用CreateCacheItem函数来创建CACHE ITEM。

然后一个循环10次，查找CACHE值，因为查找之前没有加载所以每次查找都不存在，然后就调用SetDataLoader（这个通过value函数来调用loadData）来创建CACHE。