使用Redis做任务队列(Golang)

//Redis做后台任务队列
//author: Xiong Chuan Liang
//date: 2015-3-25

package main

import (
"bytes"
"encoding/json"
"errors"
"fmt"
"time"

"github.com/garyburd/redigo/redis"
)

func main() {

r, err := newRedisPool("", "")
if err != nil {
fmt.Println(err)
return
}

//将job放入队列
r.Enqueue()

//依次取出两个Job
r.GetJob()
r.GetJob()
}

type RedisPool struct {
pool *redis.Pool
}

func newRedisPool(server, password string) (*RedisPool, error) {

if server == "" {
server = ":6379"
}

pool := &redis.Pool{
MaxIdle:     3,
IdleTimeout: 240 * time.Second,
Dial: func() (redis.Conn, error) {
c, err := redis.Dial("tcp", server)
if err != nil {
return nil, err
}

if password != "" {
if _, err := c.Do("AUTH", password); err != nil {
c.Close()
return nil, err
}
}
return c, err
},
TestOnBorrow: func(c redis.Conn, t time.Time) error {
_, err := c.Do("PING")
return err
},
}

return &RedisPool{pool}, nil
}

type Job struct {
Class string        `json:"Class"`
Args  []interface{} `json:"Args"`
}

//模拟客户端
func (r *RedisPool) Enqueue() error {

c := r.pool.Get()
defer c.Close()

j := &Job{}
j.Class = "mail"
j.Args = append(j.Args, "xcl_168@aliyun.com", "", "body", 2, true)

j2 := &Job{}
j2.Class = "Log"
j2.Args = append(j2.Args, "ccc.log", "ddd.log", []int{222, 333})

for _, v := range []*Job{j, j2} {
b, err := json.Marshal(v)
if err != nil {
return err
}

_, err = c.Do("rpush", "queue", b)
if err != nil {
return err
}
}

fmt.Println("[Enqueue()] succeed!")

return nil
}

//模拟Job Server
func (r *RedisPool) GetJob() error {
count, err := r.QueuedJobCount()
if err != nil || count == 0 {
return errors.New("暂无Job.")
}
fmt.Println("[GetJob()] Jobs count:", count)

c := r.pool.Get()
defer c.Close()

for i := 0; i < int(count); i++ {
reply, err := c.Do("LPOP", "queue")
if err != nil {
return err
}

var j Job
decoder := json.NewDecoder(bytes.NewReader(reply.([]byte)))
if err := decoder.Decode(&j); err != nil {
return err
}

fmt.Println("[GetJob()] ", j.Class, " : ", j.Args)
}
return nil
}

func (r *RedisPool) QueuedJobCount() (int, error) {
c := r.pool.Get()
defer c.Close()

lenqueue, err := c.Do("llen", "queue")
if err != nil {
return 0, err
}

count, ok := lenqueue.(int64)
if !ok {
return 0, errors.New("类型转换错误!")
}
return int(count), nil
}

/*
运行结果:

[Enqueue()] succeed!
[GetJob()] Jobs count: 2
[GetJob()]  mail  :  [xcl_168@aliyun.com  body 2 true]
[GetJob()]  Log  :  [ccc.log ddd.log [222 333]]
[root@xclos src]#

*/