go-mlcache

go-mlcache is a Multiple layer cache library.

Features:

• Caching and negative caching with TTLs.
• Prevent dog pile effect.

      ┌────────────────────────────┐
 L1   │           memory           │
      └────────────────────────────┘
                    │ mutex & callback
                    ▼
      ┌────────────────────────────┐
 L2   │      redis/memcached       │
      └────────────────────────────┘
                    │ callback
                    ▼
      ┌────────────────────────────┐
 L3   │      mysql/postgresql      │
      └────────────────────────────┘

Installation

go get github.com/hongliang5316/go-mlcache

Example Usage

package main

import (
        "fmt"
        "log"
        "time"

        "github.com/gomodule/redigo/redis"
        mlcache "github.com/hongliang5316/go-mlcache"
        cache "github.com/patrickmn/go-cache"
)

func gh(key string, ctx interface{}) (interface{}, bool, error) {
        c, err := redis.Dial("tcp", "127.0.0.1:6379")
        if err != nil {
                return nil, false, err
        }

        val, err := c.Do("GET", key)
        return val, true, err
}

func main() {
        mlc := mlcache.New(3, cache.DefaultExpiration, 10*time.Minute, nil, nil)
        lc := &mlcache.LC{GetCacheHandler: gh}
        val, cs, err := mlc.Get("foo", mlcache.Opt{Ttl: 3 * time.Second, L2: lc}, nil)
        if err != nil {
                log.Fatalf("Call mlc.Get failed, err:%+v", err)
                return
        }

        // first get val from L2 cache
        fmt.Println("get key: foo from cache layer:", cs.CacheFlag)

        if val == nil {
                fmt.Println("key: foo, not found")
        } else {
                fmt.Println("key: foo, val:", string(val.([]byte)))
        }

        val, cs, err = mlc.Get("foo", mlcache.Opt{Ttl: 3 * time.Second, L2: lc}, nil)
        if err != nil {
                log.Fatalf("Call mlc.Get failed, err:%+v", err)
                return
        }

        // second get val from L1 cache
        fmt.Println("get key: foo from cache layer:", cs.CacheFlag)

        if val == nil {
                fmt.Println("key: foo, not found")
        } else {
                fmt.Println("key: foo, val:", string(val.([]byte)))
        }
}