text: <?php
  // +----------------------------------------------------------------------
  // | ThinkPHP [ WE CAN DO IT JUST THINK ]
  // +----------------------------------------------------------------------
  // | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
  // +----------------------------------------------------------------------
  // | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
  // +----------------------------------------------------------------------
  // | Author: liu21st <liu21st@gmail.com>
  // +----------------------------------------------------------------------
  
  namespace think\cache\driver;
  
  use think\cache\Driver;
  
  /**
   * Xcache缓存驱动
   * @author    liu21st <liu21st@gmail.com>
   */
  class Xcache extends Driver
  {
      protected $options = [
          'prefix'    => '',
          'expire'    => 0,
          'serialize' => true,
      ];
  
      /**
       * 架构函数
       * @access public
       * @param  array $options 缓存参数
       * @throws \BadFunctionCallException
       */
      public function __construct($options = [])
      {
          if (!function_exists('xcache_info')) {
              throw new \BadFunctionCallException('not support: Xcache');
          }
  
          if (!empty($options)) {
              $this->options = array_merge($this->options, $options);
          }
      }
  
      /**
       * 判断缓存
       * @access public
       * @param  string $name 缓存变量名
       * @return bool
       */
      public function has($name)
      {
          $key = $this->getCacheKey($name);
  
          return xcache_isset($key);
      }
  
      /**
       * 读取缓存
       * @access public
       * @param  string $name 缓存变量名
       * @param  mixed  $default 默认值
       * @return mixed
       */
      public function get($name, $default = false)
      {
          $this->readTimes++;
  
          $key = $this->getCacheKey($name);
  
          return xcache_isset($key) ? $this->unserialize(xcache_get($key)) : $default;
      }
  
      /**
       * 写入缓存
       * @access public
       * @param  string            $name 缓存变量名
       * @param  mixed             $value  存储数据
       * @param  integer|\DateTime $expire  有效时间（秒）
       * @return boolean
       */
      public function set($name, $value, $expire = null)
      {
          $this->writeTimes++;
  
          if (is_null($expire)) {
              $expire = $this->options['expire'];
          }
  
          if ($this->tag && !$this->has($name)) {
              $first = true;
          }
  
          $key    = $this->getCacheKey($name);
          $expire = $this->getExpireTime($expire);
          $value  = $this->serialize($value);
  
          if (xcache_set($key, $value, $expire)) {
              isset($first) && $this->setTagItem($key);
              return true;
          }
  
          return false;
      }
  
      /**
       * 自增缓存（针对数值缓存）
       * @access public
       * @param  string    $name 缓存变量名
       * @param  int       $step 步长
       * @return false|int
       */
      public function inc($name, $step = 1)
      {
          $this->writeTimes++;
  
          $key = $this->getCacheKey($name);
  
          return xcache_inc($key, $step);
      }
  
      /**
       * 自减缓存（针对数值缓存）
       * @access public
       * @param  string    $name 缓存变量名
       * @param  int       $step 步长
       * @return false|int
       */
      public function dec($name, $step = 1)
      {
          $this->writeTimes++;
  
          $key = $this->getCacheKey($name);
  
          return xcache_dec($key, $step);
      }
  
      /**
       * 删除缓存
       * @access public
       * @param  string $name 缓存变量名
       * @return boolean
       */
      public function rm($name)
      {
          $this->writeTimes++;
  
          return xcache_unset($this->getCacheKey($name));
      }
  
      /**
       * 清除缓存
       * @access public
       * @param  string $tag 标签名
       * @return boolean
       */
      public function clear($tag = null)
      {
          if ($tag) {
              // 指定标签清除
              $keys = $this->getTagItem($tag);
  
              foreach ($keys as $key) {
                  xcache_unset($key);
              }
  
              $this->rm($this->getTagKey($tag));
              return true;
          }
  
          $this->writeTimes++;
  
          if (function_exists('xcache_unset_by_prefix')) {
              return xcache_unset_by_prefix($this->options['prefix']);
          } else {
              return false;
          }
      }
  }
  