筆記：後端 - Redis

Redis學習

最近在向node後臺開發看齊，所以瞭解了一些關於redis的知識，這裡作為筆記

• 安裝redis

  使用home-brew

  brew install redis

成功的提示資訊

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
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使用cat命令檢視配置資訊

cat /usr/local/etc/redis.conf

其中指定了埠等資訊

bind 127.0.0.1 ::1
bind 127.0.0.1
port 6379
tcp-backlog 511
timeout 0
tcp-keepalive 300
...
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• 啟動redis redis-server /usr/local/etc/redis.conf 終端輸出

    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
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這裡可以看到redis啟動成功，監聽的埠是6379 新開一個tab視窗 輸入redis-cli ping 可以看到控制檯輸出PONG 這就說明redis啟動成功

• 關閉redis
  • 在啟動視窗按cmd+c或者直接關掉視窗結束程式
  • 執行redis-cli shutdown 輸出redis-cli ping檢驗 控制檯列印Could not connect to Redis at 127.0.0.1:6379: Connection refused 說明關閉成功

node端的簡單使用

• node安裝redis npm install redis --save

• 啟動redis客戶端

  const redis = require('redis');
  // 你啟動的redis埠和ip地址+options（可去官網自行查閱資料）
  const client = redis.createClient(6379, '127.0.0.1', {});
  // 監聽錯誤
  client.on('error', (err) => {
    console.log(err);
  })
  // 設定普通的string
  client.set("string key", "string val", redis.print);
  // 設定hash值
  client.hset("hash key", "hashtest 1", "some value", redis.print);
  client.hset(["hash key", "hashtest 2", "some other value"], redis.print);
  // 設定map值
  client.mset('key1', 'val1', ... 'keyn', 'valn', '[callback]'); 
  
  //迴圈遍歷
  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();
  }); 
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  更多命令使用請參考: 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選擇資料庫編號*/
              client.SELECT(type[bottle.type], function (event) {
                console.log(event);
                /*client.HMSET 儲存雜湊鍵值*/
                  client.HMSET(bottleId, bottle, function (err, result) {
                    if (err) {
                      return callback({
                        code: 0,
                        msg: "過會兒再來試試吧！"
                      });
                    }
                    console.log('at redis.js:', result);
                    callback({
                      code: 1,
                      msg: result
                    });
                    /*設定過期時間為1天*/
                    client.EXPIRE(bottleId, 86400);
                  });
              });
          }
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  • 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 () {
                /*隨機返回當前資料庫的一個鍵*/
                client.RANDOMKEY(function (err, bottleId) {
                  if (!bottleId) {
                    return callback({
                      code: 0,
                      msg: "大海空空如也..."
                    });
                  }
                  /*根據key返回雜湊物件*/
                  client.HGETALL(bottleId, function (err, bottle) {
                    if (err) {
                      return callback({
                        code: 0,
                        msg: "漂流瓶破損了..."
                      });
                    }
                    callback({
                      code: 1,
                      msg: bottle
                    });
                    /*根據key刪除鍵值*/
                    client.DEL(bottleId);
                  });
                });
              });
            }
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    • 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);
              });
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    到這裡已經跑通了程式，盡情享受redis吧～

    專案地址