README.md

PeanutCache

The gRPC implementation of groupcache: A high performance, open source, using RPC framework that communicated with each cache node. Cache service can register to etcd, and each cache client can dicovery the service list by etcd.For more information see the groupcache, or geecache.

Prerequisites

• Golang 1.16 or later
• Etcd v3.4.0 or later
• gRPC-go v1.38.0 or later
• protobuf v1.26.0 or later

Installation

With [Go module][] support (Go 1.11+), simply add the following import

import "github.com/peanutzhen/peanutcache"

to your code, and then go [build|run|test] will automatically fetch the necessary dependencies.

Otherwise, to install the peanutcache package, run the following command:

$ go get -u github.com/peanutzhen/peanutcache

Usage

Here, give a example to use it example.go:

// example.go file

package main

import (
	"fmt"
	"github.com/peanutzhen/peanutcache"
	"log"
	"sync"
)

func main() {
	// 模拟MySQL数据库 用于peanutcache从数据源获取值
	var mysql = map[string]string{
		"Tom":  "630",
		"Jack": "589",
		"Sam":  "567",
	}
	// 新建cache实例
	group := peanutcache.NewGroup("scores", 2<<10, peanutcache.RetrieverFunc(
		func(key string) ([]byte, error) {
			log.Println("[Mysql] search key", key)
			if v, ok := mysql[key]; ok {
				return []byte(v), nil
			}
			return nil, fmt.Errorf("%s not exist", key)
		}))
	// New一个服务实例
	var addr string = "localhost:9999"
	svr, err := peanutcache.NewServer(addr)
	if err != nil {
		log.Fatal(err)
	}
	// 设置同伴节点IP(包括自己)
	svr.SetPeers(addr)
	// 将服务与cache绑定 因为cache和server是解耦合的
	group.RegisterSvr(svr)
	log.Println("peanutcache is running at", addr)
	// 启动服务(注册服务至etcd/计算一致性哈希...)
	go func() {
		// Start将不会return 除非服务stop或者抛出error
		err = svr.Start()
		if err != nil {
			log.Fatal(err)
		}
	}()

	// 发出几个Get请求
	var wg sync.WaitGroup
	wg.Add(4)
	go GetTomScore(group, &wg)
	go GetTomScore(group, &wg)
	go GetTomScore(group, &wg)
	go GetTomScore(group, &wg)
	wg.Wait()
}

func GetTomScore(group *peanutcache.Group, wg *sync.WaitGroup) {
	defer wg.Done()
	log.Printf("get Tom...")
	view, err := group.Get("Tom")
	if err != nil {
		fmt.Println(err.Error())
		return
	}
	fmt.Println(view.String())
}

Before go run, you should run etcd local directly(without any spcified parameter) and then execute go run example.go, you will get follows:

$ go run peanutcache_usage.go
2021/08/01 18:09:17 peanutcache is running at localhost:9999
2021/08/01 18:09:17 get Tom...
2021/08/01 18:09:17 get Tom...
2021/08/01 18:09:17 get Tom...
2021/08/01 18:09:17 get Tom...
2021/08/01 18:09:17 ooh! pick myself, I am localhost:9999
2021/08/01 18:09:17 [Mysql] search key Tom
630
630
630
630