function cache_clear_all in Memcache API and Integration 5

Same name in this branch

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

Same name and namespace in other branches

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

Expire data from the cache. If called without arguments, expirable entries will be cleared from the cache_page table.

Memcache logic is simpler than the core cache because memcache doesn't have a minimum cache lifetime consideration (it handles it internally), and doesn't support wildcards. Wildcard flushes result in the entire table being flushed.

Parameters

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

$table: If set, the table delete from.

$wildcard: If set to TRUE, the $cid is treated as a substring to match rather than a complete ID. The match is a right hand match. If '*' is given as $cid, the table $table will be emptied.

1 call to cache_clear_all()

filter_user in ./memcache-session.inc

Implement hook_user() using a required module's namespace since memcache is not a module and thus can't implement hooks directly.

File

./memcache.db.inc, line 170

Code

function cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE) {
  global $user;
  if (!isset($cid) && !isset($table)) {
    $cid = '*';
    $wildcard = TRUE;
    $table = 'cache_page';
  }
  if (empty($cid) || $cid == '*' && $wildcard !== TRUE) {

    # don't do anything if cid is unset. this matches the default drupal behavior...
    if ($wildcard && $cid != '*') {
      if (variable_get('memcache_debug', FALSE)) {

        // call watchdog, since you probably didn't want to flush the entire bin.
        watchdog('memcache', "illegal wildcard in cache_clear_all - not flushing entire bin. table: {$table}. cid: {$cid}", WATCHDOG_WARNING);
      }
    }
  }
  else {
    if ($cid == '*' || $wildcard === TRUE) {
      dmemcache_flush($table);
    }
    else {
      dmemcache_delete($cid, $table);
    }
  }
  if (empty($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 = $_SERVER['REQUEST_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', $_SERVER['REQUEST_TIME']);
      }
      else {
        if ($_SERVER['REQUEST_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 {" . $table . "} WHERE expire != %d AND expire < %d", CACHE_PERMANENT, $_SERVER['REQUEST_TIME']);
          variable_set('cache_flush', 0);
        }
      }
    }
    else {

      // No minimum cache lifetime, flush all temporary cache entries now.
      db_query("DELETE FROM {" . $table . "} WHERE expire != %d AND expire < %d", CACHE_PERMANENT, $_SERVER['REQUEST_TIME']);
    }
  }
  else {
    if ($wildcard) {
      if ($cid == '*') {
        db_query("DELETE FROM {" . $table . "}");
      }
      else {
        db_query("DELETE FROM {" . $table . "} WHERE cid LIKE '%s%%'", $cid);
      }
    }
    else {
      db_query("DELETE FROM {" . $table . "} WHERE cid = '%s'", $cid);
    }
  }
}