function cache_get in Memcache API and Integration 5

Same name in this branch

1. 5 memcache.db.inc \cache_get()
2. 5 memcache.inc \cache_get()

Same name and namespace in other branches

1. 5.2 memcache.db.inc \cache_get()
2. 5.2 memcache.inc \cache_get()
3. 6 memcache.db.inc \cache_get()
4. 6 memcache.inc \cache_get()

Return data from the persistent cache.

Parameters

$key: The cache ID of the data to retrieve.

$table: The table $table to store the data in. Valid core values are 'cache_filter', 'cache_menu', 'cache_page', or 'cache' for the default cache.

File

./memcache.db.inc, line 16

Code

function cache_get($key, $table = 'cache') {
  global $user;

  // Garbage collection necessary when enforcing a minimum cache lifetime
  $cache_flush = variable_get('cache_flush', 0);
  if ($cache_flush && $cache_flush + variable_get('cache_lifetime', 0) <= $_SERVER['REQUEST_TIME']) {

    // Time to flush old cache data. Reset the variable first so that other processes
    // don't try to delete as well.
    variable_set('cache_flush', 0);
    db_query("DELETE FROM {" . $table . "} WHERE expire != %d AND expire <= %d", CACHE_PERMANENT, $cache_flush);
  }

  // If we have a memcache hit for this, return it.
  if ($cache = dmemcache_get($key, $table)) {
    return $cache;
  }

  // Look for a database cache hit.
  if ($cache = db_fetch_object(db_query("SELECT data, created, headers, expire, serialized FROM {" . $table . "} WHERE cid = '%s'", $key))) {
    if (isset($cache->data)) {

      // If the data is permanent or we're not enforcing a minimum cache lifetime
      // always return the cached data.
      if ($cache->expire == CACHE_PERMANENT || !variable_get('cache_lifetime', 0)) {
        $cache->data = db_decode_blob($cache->data);
        if ($cache->serialized) {
          $cache->data = unserialize($cache->data);
        }
      }
      else {
        if ($user->cache > $cache->created) {

          // This cache data is too old and thus not valid for us, ignore it.
          return 0;
        }
        else {
          $cache->data = db_decode_blob($cache->data);
          if ($cache->serialized) {
            $cache->data = unserialize($cache->data);
          }
        }
      }
    }

    // By calling cache_set with an extra paramater to signify no db storage,
    // we can lazy instantiate memcache that just comes online.
    cache_set($key, $table, $cache->data, $cache->expire, $cache->headers, FALSE);
    return $cache;
  }
  return 0;
}