Club Drupal

<?php

/**

 * @file

 * The non-volatile object cache is used to store an object while it is

 * being edited, so that we don't have to save until we're completely

 * done. The cache should be 'cleaned' on a regular basis, meaning to

 * remove old objects from the cache, but otherwise the data in this

 * cache must remain stable, as it includes unsaved changes.

 */

/**

 * Get an object from the non-volatile ctools cache.

 *

 * This function caches in memory as well, so that multiple calls to this

 * will not result in multiple database reads.

 *

 * @param $obj

 *   A 128 character or less string to define what kind of object is being

 *   stored; primarily this is used to prevent collisions.

 * @param $name

 *   The name of the object being stored.

 * @param $skip_cache

 *   Deprecated in favor of drupal_static*

 *   Skip the memory cache, meaning this must be read from the db again.

 * @param $sid

 *   The session id, allowing someone to use Session API or their own solution;

 *   defaults to session_id().

 *

 * @return

 *   The data that was cached.

 */

function ctools_object_cache_get($obj, $name, $skip_cache = FALSE, $sid = NULL) {

  $cache = &drupal_static(__FUNCTION__, array());

  $key = "$obj:$name";

  if ($skip_cache) {

    unset($cache[$key]);

  }

  if (!$sid) {

    $sid = session_id();

  }

  if (!array_key_exists($key, $cache)) {

    $data = db_query('SELECT * FROM {ctools_object_cache} WHERE sid = :session_id AND obj = :object AND name = :name', array(

      ':session_id' => $sid,

      ':object' => $obj,

      ':name' => md5($name),

    ))->fetchObject();

    if ($data) {

      $cache[$key] = unserialize($data->data);

    }

  }

  return isset($cache[$key]) ? $cache[$key] : NULL;

}

/**

 * Store an object in the non-volatile ctools cache.

 *

 * @param $obj

 *   A 128 character or less string to define what kind of object is being

 *   stored; primarily this is used to prevent collisions.

 * @param $name

 *   The name of the object being stored.

 * @param $cache

 *   The object to be cached. This will be serialized prior to writing.

 * @param $sid

 *   The session id, allowing someone to use Session API or their own solution;

 *   defaults to session_id().

 */

function ctools_object_cache_set($obj, $name, $cache, $sid = NULL) {

  // Store the CTools session id in the user session to force a

  // session for anonymous users in Drupal 7 and Drupal 6 Pressflow.

  // see http://drupal.org/node/562374, http://drupal.org/node/861778

  if (empty($GLOBALS['user']->uid) && empty($_SESSION['ctools_session_id'])) {

    $_SESSION['ctools_hold_session'] = TRUE;

  }

  ctools_object_cache_clear($obj, $name, $sid);

  if (!$sid) {

    $sid = session_id();

  }

  db_insert('ctools_object_cache')

    ->fields(array(

      'sid' => $sid,

      'obj' => $obj,

      'name' => md5($name),

      'data' => serialize($cache),

      'updated' => REQUEST_TIME,

    ))

    ->execute();

}

/**

 * Remove an object from the non-volatile ctools cache.

 *

 * @param $obj

 *   A 128 character or less string to define what kind of object is being

 *   stored; primarily this is used to prevent collisions.

 * @param $name

 *   The name of the object being removed.

 * @param $sid

 *   The session id, allowing someone to use Session API or their own solution;

 *   defaults to session_id().

 */

function ctools_object_cache_clear($obj, $name, $sid = NULL) {

  if (!$sid) {

    $sid = session_id();

  }

  db_delete('ctools_object_cache')

    ->condition('sid', $sid)

    ->condition('obj', $obj)

    ->condition('name', md5($name))

    ->execute();

  // Ensure the static cache is emptied of this obj:name set.

  drupal_static_reset('ctools_object_cache_get');

}

/**

 * Determine if another user has a given object cached.

 *

 * This is very useful for 'locking' objects so that only one user can

 * modify them.

 *

 * @param $obj

 *   A 128 character or less string to define what kind of object is being

 *   stored; primarily this is used to prevent collisions.

 * @param $name

 *   The name of the object being removed.

 * @param $sid

 *   The session id, allowing someone to use Session API or their own solution;

 *   defaults to session_id().

 *

 * @return

 *   An object containing the UID and updated date if found; NULL if not.

 */

function ctools_object_cache_test($obj, $name, $sid = NULL) {

  if (!$sid) {

    $sid = session_id();

  }

  return db_query('SELECT s.uid, c.updated FROM {ctools_object_cache} c INNER JOIN {sessions} s ON c.sid = s.sid WHERE s.sid <> :session_id AND c.obj = :obj AND c.name = :name ORDER BY c.updated ASC', array(

    ':session_id' => $sid,

    ':obj' => $obj,

    ':name' => md5($name),

  ))->fetchObject();

}

/**

 * Get the cache status of a group of objects.

 *

 * This is useful for displaying lock status when listing a number of objects

 * an an administration UI.

 *

 * @param $obj

 *   A 128 character or less string to define what kind of object is being

 *   stored; primarily this is used to prevent collisions.

 * @param $names

 *   An array of names of objects

 *

 * @return

 *   An array of objects containing the UID and updated date for each name found.

 */

function ctools_object_cache_test_objects($obj, $names) {

  array_walk($names, 'md5');

  return db_query("SELECT c.name, s.uid, c.updated FROM {ctools_object_cache} c INNER JOIN {sessions} s ON c.sid = s.sid WHERE c.obj = :obj AND c.name IN (:names) ORDER BY c.updated ASC", array(':obj' => $obj, ':names' => $names))

    ->fetchAllAssoc('name');

}

/**

 * Remove an object from the non-volatile ctools cache for all session IDs.

 *

 * This is useful for clearing a lock.

 *

 * @param $obj

 *   A 128 character or less string to define what kind of object is being

 *   stored; primarily this is used to prevent collisions.

 * @param $name

 *   The name of the object being removed.

 */

function ctools_object_cache_clear_all($obj, $name) {

  db_delete('ctools_object_cache')

    ->condition('obj', $obj)

    ->condition('name', md5($name))

    ->execute();

  // Ensure the static cache is emptied of this obj:name set.

  $cache = &drupal_static('ctools_object_cache_get', array());

  unset($cache["$obj:$name"]);

}

/**

 * Remove all objects in the object cache that are older than the

 * specified age.

 *

 * @param $age

 *   The minimum age of objects to remove, in seconds. For example, 86400 is

 *   one day. Defaults to 7 days.

 */

function ctools_object_cache_clean($age = NULL) {

  if (empty($age)) {

    // 7 days.

    $age = 86400 * 7;

  }

  db_delete('ctools_object_cache')

    ->condition('updated', REQUEST_TIME - $age, '<')

    ->execute();

}