<?php
/**
 * @file
 *   WinCache engine class.
 */

class wincacheCacheRouterEngine extends CacheRouterEngine {
  /**
   * page_fast_cache
   *   This tells CacheRouter to use page_fast_cache.
   *
   *   @return bool TRUE
   */
  function page_fast_cache() {
    return $this->fast_cache;
  }

  /**
   * get()
   *   Return item from cache if it is available.
   *
   * @param string $key
   *   The key to fetch.
   * @return mixed object|bool
   *   Returns either the cache object or FALSE on failure
   */
  function get($key) {
    $cache = parent::get($this->key($key));
    if (isset($cache)) {
      return $cache;
    }

    $cache = wincache_ucache_get($this->key($key));
    if (is_object($cache) && $cache->serialized) {
      $cache->data = unserialize($cache->data);
    }
    parent::set($this->key($key), $cache);
    return $cache;
  }

  /**
   * set()
   *   Add item into cache.
   *
   * @param string $key
   *   The key to set.
   * @param string $value
   *   The data to store in the cache.
   * @param string $expire
   *   The time to expire in seconds.
   * @param string $headers
   *   The page headers.
   * @return bool
   *   Returns TRUE on success or FALSE on failure
   */
  function set($key, $value, $expire = CACHE_PERMANENT, $headers = NULL) {
    // Create new cache object.
    $cache = new stdClass;
    $cache->cid = $key;
    $cache->created = time();
    $cache->expire = $expire;
    $cache->headers = $headers;

      // Convert Drupal $expire, which is a timestamp, to a TTL
    if ($expire != CACHE_PERMANENT && $expire != CACHE_TEMPORARY) {
	  if ($expire > 86400) {
        $ttl = $expire - time();
      } else {
	    $ttl = $expire; 
	  }
    }
    else {
      $ttl = 0;
    }

    if (!is_string($value)) {
      $cache->serialized = TRUE;
      $cache->data = serialize($value);
    }
    else {
      $cache->serialized = FALSE;
      $cache->data = $value;
    }

    $return = FALSE;
    if (!empty($key) && $this->lock()) {
      // Get lookup table to be able to keep track of bins
      $lookup = wincache_ucache_get($this->lookup);

      // If the lookup table is empty, initialize table
      if (empty($lookup)) {
        $lookup = array();
      }

      // Set key to 1 so we can keep track of the bin
      $lookup[$this->key($key)] = $expire;

      // Attempt to store full key and value
      if (!wincache_ucache_set($this->key($key), $cache, $ttl)) {
        unset($lookup[$this->key($key)]);
        $return = FALSE;
      }
      else {
        // Update static cache
        parent::set($this->key($key), $cache);
        $return = TRUE;
      }

      // Resave the lookup table (even on failure)
      wincache_ucache_set($this->lookup, $lookup);

      // Remove lock.
      $this->unlock();
    }

    return $return;
  }

  /**
   * delete()
   *   Remove item from cache.
   *
   * @param string $key
   *   The key to set.
   * @return mixed object|bool
   *   Returns either the cache object or FALSE on failure
   */
  function delete($key) {
    // Remove from static array cache.
    parent::delete($this->key($key));

    if (substr($key, strlen($key) - 1, 1) == '*') {
      $key = $this->key(substr($key, 0, strlen($key) - 1));
      $lookup = wincache_ucache_get($this->lookup);
      if (!empty($lookup)) {
        foreach ($lookup as $k => $v) {
          if (substr($k, 0, strlen($key)) == $key) {
            wincache_ucache_delete($k);
            unset($lookup[$k]);
          }
        }
      }

      if ($this->lock()) {
        wincache_ucache_set($this->lookup, $lookup);
        $this->unlock();
      }
    }
    else {
      if (!empty($key)) {
        if (!wincache_ucache_delete($this->key($key))) {
          return FALSE;
        } else {
          return TRUE;
        }
      }
    }
  }

  /**
   * flush()
   *   Flush the entire cache.
   *
   * @param none
   * @return mixed bool
   *   Returns TRUE
   */
  function flush() {
    parent::flush();
    if ($this->lock()) {
      // Get lookup table to be able to keep track of bins
      $lookup = wincache_ucache_get($this->lookup);

      // If the lookup table is empty, remove lock and return
      if (empty($lookup)) {
        $this->unlock();
        return TRUE;
      }

      // Cycle through keys and remove each entry from the cache
      foreach ($lookup as $k => $expire) {
        if ($expire != CACHE_PERMANENT && $expire <= time()) {
          wincache_ucache_delete($k);
          unset($lookup[$k]);
        }
      }

      // Resave the lookup table (even on failure)
      wincache_ucache_set($this->lookup, $lookup);

      // Remove lock
      $this->unlock();
    }

    return TRUE;
  }

 /**
  * lock()
  *   lock the cache from other writes.
  *
  * @param none
  * @return string
  *   Returns TRUE on success, FALSE on failure
  */
  function lock() {
    return wincache_lock(basename($this->lock));
  }

  /**
   * unlock()
   *   unlock the cache from other writes.
   *
   * @param none
   * @return bool
   *   Returns TRUE on success, FALSE on failure
   */
  function unlock() {
    return wincache_unlock(basename($this->lock));
  }


  function stats() {
    $wincache_stats = wincache_ucache_info();
    $wincache_memory_stats = wincache_ucache_meminfo();
    $stats = array(
      'uptime' => $wincache_stats['total_cache_uptime'],
      'bytes_used' => $wincache_memory_stats['memory_total'] - $wincache_memory_stats['memory_free'],
      'bytes_total' => $wincache_memory_stats['memory_total'],
      'gets' => $wincache_stats['total_hit_count'],
      //'sets' => $wincache_stats[''],
      'hits' => $wincache_stats['total_hit_count'] + $wincache_stats['total_miss_count'],
      'misses' => $wincache_stats['total_miss_count'],
      'req_rate' => (($wincache_stats['total_hit_count'] + $wincache_stats['total_miss_count']) / $wincache_stats['total_cache_uptime']),
      'hit_rate' => ($wincache_stats['total_hit_count'] / $wincache_stats['total_cache_uptime']),
      'miss_rate' => ($wincache_stats['total_miss_count'] / $wincache_stats['total_cache_uptime']),
      //'set_rate' => ($wincache_stats['num_inserts'] / $wincache_stats['total_cache_uptime']),
    );
    return $stats;
  }
}