memcache.inc in Memcache API and Integration 5
Same filename and directory in other branches
File
memcache.incView source
<?php
require_once 'dmemcache.inc';
/** Implementation of cache.inc with memcache logic included **/
/**
* Return data from the persistent cache.
*
* @param $key
* The cache ID of the data to retrieve.
* @param $table
* The table $table to store the data in. Valid core values are 'cache_filter',
* 'cache_menu', 'cache_page', or 'cache' for the default cache.
*/
function cache_get($key, $table = 'cache') {
return dmemcache_get($key, $table);
}
/**
* Store data in memcache.
*
* @param $cid
* The cache ID of the data to store.
* @param $table
* The table $table to store the data in. Valid core values are 'cache_filter',
* 'cache_menu', 'cache_page', or 'cache'.
* @param $data
* The data to store in the cache. Complex data types must be serialized first.
* @param $expire
* One of the following values:
* - CACHE_PERMANENT: Indicates that the item should never be removed unless
* explicitly told to using cache_clear_all() with a cache ID.
* - CACHE_TEMPORARY: Indicates that the item should be removed at the next
* general cache wipe.
* - A Unix timestamp: Indicates that the item should be kept at least until
* the given time, after which it behaves like CACHE_TEMPORARY.
* @param $headers
* A string containing HTTP header information for cached pages.
* @param $db_storage
* This boolean is unique to the memcache.inc implementation of cache set.
* It allows us to do a cache_set and not write to the database, but only
* to memcache.
*/
function cache_set($cid, $table = 'cache', $data, $expire = CACHE_PERMANENT, $headers = NULL) {
$time = $_SERVER['REQUEST_TIME'];
// Create new cache object.
$cache = new stdClass();
$cache->cid = $cid;
$cache->data = is_object($data) ? memcache_clone($data) : $data;
$cache->created = $time;
$cache->expire = $expire;
$cache->headers = $headers;
// Save to memcache
if ($expire == CACHE_TEMPORARY) {
$expire = variable_get('cache_lifetime', 2591999);
}
// We manually track the expire time in $cache->expire. When the object
// expires, we only allow one request to rebuild it to avoid cache stampedes.
// Other requests for the expired object while it is still being rebuilt get
// the expired object.
dmemcache_set($cid, $cache, 0, $table);
}
/**
*
* 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.
*
* @param $cid
* If set, the cache ID to delete. Otherwise, all cache entries that can
* expire are deleted from the specified table.
*
* @param $table
* If set, the table to delete from.
*
* @param $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 $table will be emptied.
*/
function cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE) {
// If cid and table are not set, we should flush the cache_page table.
if (!isset($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, $table);
}
}
}
/**
* Provide a substitute clone() function for PHP4. This is a copy of drupal_clone
* because common.inc isn't included early enough in the bootstrap process to
* be able to depend on drupal_clone.
*/
function memcache_clone($object) {
return version_compare(phpversion(), '5.0') < 0 ? $object : clone $object;
}
Functions
Name![]() |
Description |
---|---|
cache_clear_all | Expire data from the cache. If called without arguments, expirable entries will be cleared from the cache_page table. |
cache_get | Return data from the persistent cache. |
cache_set | Store data in memcache. |
memcache_clone | Provide a substitute clone() function for PHP4. This is a copy of drupal_clone because common.inc isn't included early enough in the bootstrap process to be able to depend on drupal_clone. |