cache_clear_all

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Definition

cache_clear_all($cid = NULL, $wildcard = false)
includes/bootstrap.inc, line 395

Description

Expire data from the cache.

Parameters

$cid If set, the cache ID to delete. Otherwise, all cache entries that can expire are deleted.

$wildcard If set to true, the $cid is treated as a substring to match rather than a complete ID.

Code

<?php
function cache_clear_all($cid = NULL, $wildcard = false) {
  global $user;

  if (empty($cid)) {
    if (variable_get('cache_lifetime', 0)) {
      // We store the time in the current user's $user->cache variable which
      // will be saved into the sessions table by sess_write().  We then
      // simulate that the cache was flushed for this user by not returning
      // cached data that was cached before the timestamp.
      $user->cache = time();

      $cache_flush = variable_get('cache_flush', 0);
      if ($cache_flush == 0) {
        // This is the first request to clear the cache, start a timer.
        variable_set('cache_flush', time());
      }
      else if (time() > ($cache_flush + variable_get('cache_lifetime', 0))) {
        // Clear the cache for everyone, cache_flush_delay seconds have
        // passed since the first request to clear the cache.
        db_query("DELETE FROM {cache} WHERE expire != %d AND expire < %d", CACHE_PERMANENT, time());
        variable_set('cache_flush', 0);
      }
    }
    else {
      // No minimum cache lifetime, flush all temporary cache entries now.
      db_query("DELETE FROM {cache} WHERE expire != %d AND expire < %d", CACHE_PERMANENT, time());
    }
  }
  else {
    if ($wildcard) {
      db_query("DELETE FROM {cache} WHERE cid LIKE '%%%s%%'", $cid);
    }
    else {
      db_query("DELETE FROM {cache} WHERE cid = '%s'", $cid);
    }
  }
}
?>