笔记：后端 - Redis

Redis学习

最近在向node后台开发看齐，所以了解了一些关于redis的知识，这里作为笔记

• 安装redis

  使用home-brew

  brew install redis

成功的提示信息

To have launchd start redis at login: 
ln -sfv /usr/local/opt/redis/*.plist ~/Library/LaunchAgents 
Then to load redis now: 
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.redis.plist 
Or, if you don’t want/need launchctl, you can just run: 
redis-server /usr/local/etc/redis.conf

使用cat命令查看配置信息

cat /usr/local/etc/redis.conf

其中指定了端口等信息

bind 127.0.0.1 ::1
bind 127.0.0.1
port 6379
tcp-backlog 511
timeout 0
tcp-keepalive 300
...

• 启动redis redis-server /usr/local/etc/redis.conf 终端输出

    9400:C 17 Sep 21:51:36.794 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
      9400:C 17 Sep 21:51:36.795 # Redis version=4.0.11, bits=64, commit=00000000, modified=0, pid=9400, just started
      9400:C 17 Sep 21:51:36.795 # Configuration loaded
      9400:M 17 Sep 21:51:36.796 * Increased maximum number of open files to 10032 (it was originally set to 7168).
                      _._
                 _.-``__ ''-._
            _.-``    `.  `_.  ''-._           Redis 4.0.11 (00000000/0) 64 bit
        .-`` .-```.  ```\/    _.,_ ''-._
       (    '      ,       .-`  | `,    )     Running in standalone mode
       |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
       |    `-._   `._    /     _.-'    |     PID: 9400
        `-._    `-._  `-./  _.-'    _.-'
       |`-._`-._    `-.__.-'    _.-'_.-'|
       |    `-._`-._        _.-'_.-'    |           http://redis.io
        `-._    `-._`-.__.-'_.-'    _.-'
       |`-._`-._    `-.__.-'    _.-'_.-'|
       |    `-._`-._        _.-'_.-'    |
        `-._    `-._`-.__.-'_.-'    _.-'
            `-._    `-.__.-'    _.-'
                `-._        _.-'
                    `-.__.-'
      
      9400:M 17 Sep 21:51:36.799 # Server initialized
      9400:M 17 Sep 21:51:36.800 * DB loaded from disk: 0.001 seconds
      9400:M 17 Sep 21:51:36.800 * Ready to accept connections

这里可以看到redis启动成功，监听的端口是6379 新开一个tab窗口 输入redis-cli ping 可以看到控制台输出PONG 这就说明redis启动成功

• 关闭redis
  • 在启动窗口按cmd+c或者直接关掉窗口结束进程
  • 执行redis-cli shutdown 输出redis-cli ping检验 控制台打印Could not connect to Redis at 127.0.0.1:6379: Connection refused 说明关闭成功

node端的简单使用

• node安装redis npm install redis --save

• 启动redis客户端

  const redis = require('redis');
  // 你启动的redis端口和ip地址+options（可去官网自行查阅资料）
  const client = redis.createClient(6379, '127.0.0.1', {});
  // 监听错误
  client.on('error', (err) => {
    console.log(err);
  })
  // 设置普通的string
  client.set("string key", "string val", redis.print);
  // 设置hash值
  client.hset("hash key", "hashtest 1", "some value", redis.print);
  client.hset(["hash key", "hashtest 2", "some other value"], redis.print);
  // 设置map值
  client.mset('key1', 'val1', ... 'keyn', 'valn', '[callback]'); 
  
  //循环遍历
  client.hkeys("hash key", function (err, replies) {
      console.log(replies.length + " replies:");
      replies.forEach(function (reply, i) {
          console.log("    " + i + ": " + reply);
      });
      // 退出
      client.quit();
  }); 
  

  更多命令使用请参考: github.com/NodeRedis/n…

• 漂流瓶小功能

  • throw方法

      exports.throw = (bottle, callback) => {
            bottle.time = bottle.time || Date.now();
            const bottleId = Math.random().toString(16);
            const type = {
              male: 0,
              female: 1
            };
            console.log('at redis.js:', bottle);
            /*client.SELECT选择数据库编号*/
              client.SELECT(type[bottle.type], function (event) {
                console.log(event);
                /*client.HMSET 保存哈希键值*/
                  client.HMSET(bottleId, bottle, function (err, result) {
                    if (err) {
                      return callback({
                        code: 0,
                        msg: "过会儿再来试试吧！"
                      });
                    }
                    console.log('at redis.js:', result);
                    callback({
                      code: 1,
                      msg: result
                    });
                    /*设置过期时间为1天*/
                    client.EXPIRE(bottleId, 86400);
                  });
              });
          }
    

  • pick方法

        exports.pick = function (info, callback) {
              const type = {
                all: Math.round(Math.random()),
                male: 0,
                female: 1
              };
              console.log('info is:', info);
              info.type = info.type || 'all';
              client.SELECT(type[info.type], function () {
                /*随机返回当前数据库的一个键*/
                client.RANDOMKEY(function (err, bottleId) {
                  if (!bottleId) {
                    return callback({
                      code: 0,
                      msg: "大海空空如也..."
                    });
                  }
                  /*根据key返回哈希对象*/
                  client.HGETALL(bottleId, function (err, bottle) {
                    if (err) {
                      return callback({
                        code: 0,
                        msg: "漂流瓶破损了..."
                      });
                    }
                    callback({
                      code: 1,
                      msg: bottle
                    });
                    /*根据key删除键值*/
                    client.DEL(bottleId);
                  });
                });
              });
            }
    

    • app.js

      const redislib = require('./lib/redis');
              
              redislib.throw({
                type: 'male',
              }, res => {
                console.log(res);
              })
              redislib.pick({
                type: 'male',
              }, res => {
                console.log('at callback:', res);
              });
    

    到这里已经跑通了程序，尽情享受redis吧～

    项目地址