7 common usage scenarios of Redis in PHP practice

Redis is an open source log-type Key-Value database written in ANSI C language, supports network, can be memory-based and persistent, and provides APIs in multiple languages.

This article mainly introduces the main application scenarios of using Redis using PHP.

Simple string cache practice

$redis->connect('127.0.0.1', 6379);$strCacheKey  = 'Test_bihu';

//SET 应用$arrCacheData = [	'name' => 'job',	'sex'  => '男',	'age'  => '30'];$redis->set($strCacheKey, json_encode($arrCacheData));$redis->expire($strCacheKey, 30);  # 设置30秒后过期$json_data = $redis->get($strCacheKey);$data = json_decode($json_data);
print_r($data->age); //输出数据

//HSET 应用$arrWebSite = [	'google' => [		'google.com',		'google.com.hk'
	],
];$redis->hSet($strCacheKey, 'google', json_encode($arrWebSite['google']));$json_data = $redis->hGet($strCacheKey, 'google');$data = json_decode($json_data);
print_r($data); //输出数据复制代码

Simple queue practice

$redis->connect('127.0.0.1', 6379);$strQueueName  = 'Test_bihu_queue';

//进队列$redis->rpush($strQueueName, json_encode(['uid' => 1,'name' => 'Job']));$redis->rpush($strQueueName, json_encode(['uid' => 2,'name' => 'Tom']));$redis->rpush($strQueueName, json_encode(['uid' => 3,'name' => 'John']));echo "---- 进队列成功 ---- <br><br>";

//查看队列$strCount = $redis->lrange($strQueueName, 0, -1);echo "当前队列数据为： <br>";
print_r($strCount);

//出队列$redis->lpop($strQueueName);echo "<br><br> ---- 出队列成功 ---- <br><br>";

//查看队列$strCount = $redis->lrange($strQueueName, 0, -1);echo "当前队列数据为： <br>";
print_r($strCount);复制代码

Simple publish and subscribe practice

//以下是 pub.php 文件的内容 cli下运行
ini_set('default_socket_timeout', -1);$redis->connect('127.0.0.1', 6379);$strChannel = 'Test_bihu_channel';

//发布$redis->publish($strChannel, "来自{$strChannel}频道的推送");echo "---- {$strChannel} ---- 频道消息推送成功～ <br>";$redis->close();复制代码

rrree

Simple counter practice

//以下是 sub.php 文件内容 cli下运行
ini_set('default_socket_timeout', -1);$redis->connect('127.0.0.1', 6379);$strChannel = 'Test_bihu_channel';

//订阅echo "---- 订阅{$strChannel}这个频道，等待消息推送...----  <br><br>";$redis->subscribe([$strChannel], 'callBackFun');function callBackFun($redis, $channel, $msg)
{
	print_r([		'redis'   => $redis,		'channel' => $channel,		'msg'     => $msg
	]);
}复制代码

Ranking practice

$redis->connect('127.0.0.1', 6379);$strKey = 'Test_bihu_comments';

//设置初始值$redis->set($strKey, 0);$redis->INCR($strKey);  //+1$redis->INCR($strKey);  //+1$redis->INCR($strKey);  //+1$strNowCount = $redis->get($strKey);echo "---- 当前数量为{$strNowCount}。 ---- ";复制代码

Simple string pessimistic lock practice

Explanation: Pessimistic Lock, as the name suggests, is very pessimistic.

Every time I go to get the data, I think others will modify it, so I lock it every time I get the data.

Scenario: If cache is used in the project and a timeout is set for the cache.

When the amount of concurrency is relatively large, if there is no lock mechanism, then the moment the cache expires,

A large number of concurrent requests will penetrate the cache and directly query the database, causing an avalanche effect.

$redis->connect('127.0.0.1', 6379);$strKey = 'Test_bihu_score';

//存储数据$redis->zadd($strKey, '50', json_encode(['name' => 'Tom']));$redis->zadd($strKey, '70', json_encode(['name' => 'John']));$redis->zadd($strKey, '90', json_encode(['name' => 'Jerry']));$redis->zadd($strKey, '30', json_encode(['name' => 'Job']));$redis->zadd($strKey, '100', json_encode(['name' => 'LiMing']));$dataOne = $redis->ZREVRANGE($strKey, 0, -1, true);echo "---- {$strKey}由大到小的排序 ---- <br><br>";
print_r($dataOne);$dataTwo = $redis->ZRANGE($strKey, 0, -1, true);echo "<br><br>---- {$strKey}由小到大的排序 ---- <br><br>";
print_r($dataTwo);复制代码

Optimistic Lock Practice for Simple Transactions

Explanation: Optimistic Lock, as the name suggests, is very optimistic.

Every time I go to get the data, I think that others will not modify it, so it will not be locked.

The watch command will monitor the given key. If the monitored key has changed since calling watch during exec, the entire transaction will fail.

You can also call watch multiple times to monitor multiple keys. In this way, optimistic locking can be added to the specified key.

Note that the watch key is valid for the entire connection, and the same is true for transactions.

If the connection is disconnected, monitoring and transactions will be automatically cleared.

Of course, the exec, discard, and unwatch commands will clear all monitoring in the connection.

/**
 * 获取锁
 * @param  String  $key    锁标识
 * @param  Int     $expire 锁过期时间
 * @return Boolean
 */
public function lock($key = '', $expire = 5) {	$is_lock = $this->_redis->setnx($key, time()+$expire);
	//不能获取锁	if(!$is_lock){
		//判断锁是否过期		$lock_time = $this->_redis->get($key);
		//锁已过期，删除锁，重新获取		if (time() > $lock_time) {
			unlock($key);			$is_lock = $this->_redis->setnx($key, time() + $expire);
		}
	}	return $is_lock? true : false;
}

/**
 * 释放锁
 * @param  String  $key 锁标识
 * @return Boolean
 */
public function unlock($key = ''){	return $this->_redis->del($key);
}

// 定义锁标识$key = 'Test_bihu_lock';

// 获取锁$is_lock = lock($key, 10);if ($is_lock) {	echo 'get lock success<br>';	echo 'do sth..<br>';
	sleep(5);	echo 'success<br>';
	unlock($key);
} else { //获取锁失败	echo 'request too frequently<br>';
}复制代码

Thanks ~

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