PHP结合redis实现秒杀活动大并发

本是古典何须时尚 2022-07-15 01:42 211阅读 0赞

设计思路：redis保存2个list，一个是空闲列表简称A，一个是使用中列表简称B，初始化A的个数是1000，B的个数为0,，我们首先控制进入确认订单页的人数最大为1000，即是用户a点击进入确认订单页，先pop A列表，如果能pop出，表示是1000以内，然后push当前时间信息到B列表，用户a处理完后释放B列表，把使用机会换给A列表，这样就能控制最大的并发数为1000。也是需要守护进程定时去查询B列表中过期的机会归还给A列表。具体代码：

操作redis类：

<?php
    
    class SeckillRedis {
    
    	static protected $total_num_50 = 50; // 可允许抢购总数量
    	static protected $total_num_100 = 100;
    	static protected $total_num_500 = 500;
    	static protected $total_num_1000 = 1000;
    	static protected $validity_time = 300; // 有效期 5分钟
    	static protected $seckill_free_num_50_key = 'seckill_free_num_50'; // 空闲允许抢购数量的redis key
    	static protected $seckill_use_num_50_key = 'seckill_use_num_50'; // 被使用的redis key
    	static protected $seckill_free_num_100_key = 'seckill_free_num_100';
    	static protected $seckill_use_num_100_key = 'seckill_use_num_100';
    	static protected $seckill_free_num_500_key = 'seckill_free_num_500';
    	static protected $seckill_use_num_500_key = 'seckill_use_num_500';
    	static protected $seckill_free_num_1000_key = 'seckill_free_num_1000';
    	static protected $seckill_use_num_1000_key = 'seckill_use_num_1000';
    
    	static protected $redisConnect;
    
    	/* 获取redis链接 */
    	static public function getRedis(){
    		if(empty(self::$redisConnect)){
    			self::$redisConnect = MyRedis::connect('redis');
    		}
    		return self::$redisConnect;
    	}
    
    	/* 获取所有key数组 */
    	static public function getRedisKeys(){
    		return array(
    			50 => array('free_key' => self::$seckill_free_num_50_key, 'use_key' => self::$seckill_use_num_50_key, 'total_num' => self::$total_num_50),
    			100 => array('free_key' => self::$seckill_free_num_100_key, 'use_key' => self::$seckill_use_num_100_key, 'total_num' => self::$total_num_100),
    			500 => array('free_key' => self::$seckill_free_num_500_key, 'use_key' => self::$seckill_use_num_500_key, 'total_num' => self::$total_num_500),
    			1000 => array('free_key' => self::$seckill_free_num_1000_key, 'use_key' => self::$seckill_use_num_1000_key, 'total_num' => self::$total_num_1000)
    		);
    	}
    
    	/* 设置--初始化 */
    	static public function setSeckillRedisKey($free_key, $use_key, $total_num){
    		$redis = self::getRedis();
    		$redis->delete($free_key);
    		$redis->delete($use_key);
    
    		for ($i=0; $i < $total_num; $i++) {
    			$redis->rPush($free_key, 1);
    		}
    	}
    
    	/* 定时更新秒杀商品入口人数 */
    	static public function poling_set_seckill_redis(){
    		$seckill_array = self::getRedisKeys();
    
    		$redis = self::getRedis();
    		foreach ($seckill_array as $key => $value) {
    			if($redis->exists($value['free_key']) == true){
    				// 清除过期的使用数量
    				$use_list = $redis->lRange($value['use_key'], 0, -1);
    				foreach ($use_list as $k => $v) {
    					$data = json_decode($v, true);
    					if(time() - $data['time'] > self::$validity_time){
    						// 超过有效期 删除
    						self::returnFree($key, $k);
    					}
    				}
    			}else{
    				self::setSeckillRedisKey($value['free_key'], $value['use_key'], $value['total_num']);
    				echo 'set';
    			}
    		}
    	}
    
    	/* 获取空闲抢购--type:50 100 500 1000 */
    	static public function getFree($type, $uid){
    		$seckill_array = self::getRedisKeys();
    		if(empty($type) || !in_array($type, array_keys($seckill_array))){
    			return array('result' => false, 'message' => '抢购信息:类型不正确');
    		}
    		if(empty($uid)){
    			return array('result' => false, 'message' => '抢购信息:用户ID不能为空');
    		}
    		$redis = self::getRedis();
    		$result = $redis->lPop($seckill_array[$type]['free_key']);
    		if($result == true){
    			// 添加使用数量
    			$index = $redis->rPush($seckill_array[$type]['use_key'], json_encode(array('uid' => $uid, 'time' => time()))) - 1;
    			return array('result' => true, 'index' => $index);
    		}else{
    			return array('result' => false, 'message' => '抢购信息:被抢光啦');
    		}
    	}
    
    	/* 返回空闲抢购--type:50 100 500 1000 */
    	static public function returnFree($type, $index){
    		$seckill_array = self::getRedisKeys();
    		if(empty($type) || !in_array($type, array_keys($seckill_array))){
    			return array('result' => false, 'message' => '抢购信息:类型不正确');
    		}
    		$redis = self::getRedis();
    		$value = $redis->lGet($seckill_array[$type]['use_key'], $index);
    		if(!empty($value)){
    			$redis->lRem($seckill_array[$type]['use_key'], $value, 1);
    			// 添加空闲数量
    			$redis->rPush($seckill_array[$type]['free_key'], 1);
    			return array('result' => true);
    		}else{
    			return array('result' => false, 'message' => '抢购信息:不存在索引');
    		}
    	}
    
    	/* 打印 */
    	static public function printRedis($type){
    		$seckill_array = self::getRedisKeys();
    		$redis = self::getRedis();
    		$free_list = $redis->lRange($seckill_array[$type]['free_key'], 0, -1);
    		print_r($free_list);
    
    		$use_list = $redis->lRange($seckill_array[$type]['use_key'], 0, -1);
    		print_r($use_list);
    	}
    
    
    
    }

使用例子：

<?php
    
    class Index extends controller{
    	
    	/* 某个需要控制并发的控制器方法 */
    	public function getOrderInfo(){
    		// 获取操作机会 工具类提供4中限制数量类型 这里控制最大并发数为100
    		$type = 100;
    		$result = SeckillRedis::getFree($type, $_SESSION['uid']);
    		if($result['result'] == false){
    			// 没有机会 返回错误信息
    			return '网络繁忙，请重试';
    		}
    		// 处理数据库代码
    		...........
    		// 处理完毕，归还操作机会
    		SeckillRedis::returnFree($type, $result['index']);
    	}
    
    
    }