class MiaoSha{

 const MSG_REPEAT_USER = '请勿重复参与';
 const MSG_EMPTY_STOCK = '库存不足';
 const MSG_KEY_NOT_EXIST = 'key不存在';

 const IP_POOL = 'ip_pool';
 const USER_POOL = 'user_pool';

 /** @var Redis */
 public $redis;
 public $key;

 public function __construct($key = '')
 {
  $this->checkKey($key);
  $this->redis = new Redis(); //todo 连接池
  $this->redis->connect('127.0.0.1');
 }

 public function checkKey($key = '')
 {
  if(!$key) {
   throw new Exception(self::MSG_KEY_NOT_EXIST);
  } else {
   $this->key = $key;
  }
 }

 public function setStock($value = 0)
 {
  if($this->redis->exists($this->key) == 0) {
   $this->redis->set($this->key,$value);
  }
 }

 public function checkIp($ip = 0)
 {
  $sKey = $this->key . self::IP_POOL;
  if(!$ip || $this->redis->sIsMember($sKey,$ip)) {
   throw new Exception(self::MSG_REPEAT_USER);
  }
 }

 public function checkUser($user = 0)
 {
  $sKey = $this->key . self::USER_POOL;
  if(!$user || $this->redis->sIsMember($sKey,$user)) {
   throw new Exception(self::MSG_REPEAT_USER);
  }
 }

 public function checkStock($user = 0, $ip = 0)
 {
  $num = $this->redis->decr($this->key);
  if($num < 0 ) {
   throw new Exception(self::MSG_EMPTY_STOCK);
  } else {
   $this->redis->sAdd($this->key . self::USER_POOL, $user);
   $this->redis->sAdd($this->key . self::IP_POOL, $ip);
   //todo add to mysql
   echo 'success' . PHP_EOL;
   error_log('success' . $user . PHP_EOL,3,'/var/www/html/demo/log/debug.log');
  }
 }

 /**
  * @note:此种做法不能防止并发
  * @func checkStockFail
  * @param int $user
  * @param int $ip
  * @throws Exception
  */
 public function checkStockFail($user = 0,$ip = 0) {
  $num = $this->redis->get($this->key);
  if($num > 0 ){
   $this->redis->sAdd($this->key . self::USER_POOL, $user);
   $this->redis->sAdd($this->key . self::IP_POOL, $ip);
   //todo add to mysql
   echo 'success' . PHP_EOL;
   error_log('success' . $user . PHP_EOL,3,'/var/www/html/demo/log/debug.log');
   $num--;
   $this->redis->set($this->key,$num);
  } else {
   throw new Exception(self::MSG_EMPTY_STOCK);
  }
 }
}

function test()
{
 try{
  $key = 'cup_';
  $handler = new MiaoSha($key);
  $handler->setStock(10);
  $user = rand(1,10000);
  $ip = $user;
  $handler->checkIp($ip);
  $handler->checkUser($user);
  $handler->checkStock($user,$ip);
 } catch (\Exception $e) {
  echo $e->getMessage() . PHP_EOL;
  error_log('fail' . $e->getMessage() .PHP_EOL,3,'/var/www/html/demo/log/debug.log');
 }
}

function test2()
{
 try{
  $key = 'cup_';
  $handler = new MiaoSha($key);
  $handler->setStock(10);
  $user = rand(1,10000);
  $ip = $user;
  $handler->checkIp($ip);
  $handler->checkUser($user);
  $handler->checkStockFail($user,$ip); //不能防止并发的
 } catch (\Exception $e) {
  echo $e->getMessage() . PHP_EOL;
  error_log('fail' . $e->getMessage() .PHP_EOL,3,'/var/www/html/demo/log/debug.log');
 }
}

#第1种情况 500并发下 用客户端的test2()去执行
 ab -n 500 -c 100 www.hello.com/flash-sale.php

#第2种情况 5000并发下 用客户端的test2()去执行
 ab -n 5000 -c 1000 www.hello.com/flash-sale.php

#第3种情况 500并发下 用客户端的test()去执行
 ab -n 500 -c 100 www.hello.com/flash-sale.php

#第4种情况 5000并发下 用客户端的test()去执行
 ab -n 5000 -c 1000 www.hello.com/flash-sale.php