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Diffstat (limited to 'vendor/smarty/smarty/docs/programmers/caching/caching-custom.md')
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diff --git a/vendor/smarty/smarty/docs/programmers/caching/caching-custom.md b/vendor/smarty/smarty/docs/programmers/caching/caching-custom.md new file mode 100644 index 000000000..77d2ce7b3 --- /dev/null +++ b/vendor/smarty/smarty/docs/programmers/caching/caching-custom.md @@ -0,0 +1,296 @@ +Custom Cache Implementation {#caching.custom} +=========================== + +As an alternative to using the default file-based caching mechanism, you +can specify a custom cache implementation that will be used to read, +write and clear cached files. + +> **Note** +> +> In Smarty2 this used to be a callback function called +> `$cache_handler_func`. Smarty3 replaced this callback by the +> `Smarty_CacheResource` module. + +With a custom cache implementation you\'re likely trying to achieve at +least one of the following goals: replace the slow filesystem by a +faster storage engine, centralize the cache to be accessible to multiple +servers. + +Smarty allows CacheResource implementations to use one of the APIs +`Smarty_CacheResource_Custom` or `Smarty_CacheResource_KeyValueStore`. +`Smarty_CacheResource_Custom` is a simple API directing all read, write, +clear calls to your implementation. This API allows you to store +wherever and however you deem fit. The +`Smarty_CacheResource_KeyValueStore` API allows you to turn any \"dumb\" +KeyValue-Store (like APC, Memcache, ...) into a full-featured +CacheResource implementation. That is, everything around deep +cache-groups like \"a\|b\|c\" is being handled for you in way that +allows clearing the cache-group \"a\" and all nested groups are cleared +as well - even though KeyValue-Stores don\'t allow this kind of +hierarchy by nature. + +Custom CacheResources may be put in a file `cacheresource.foobarxyz.php` +within your [`$plugins_dir`](#variable.plugins.dir), or registered on +runtime with [`registerCacheResource()`](#api.register.cacheresource). +In either case you need to set [`$caching_type`](#variable.caching.type) +to invoke your custom CacheResource implementation. + + + <?php + + require_once 'libs/Smarty.class.php'; + $smarty = new Smarty(); + $smarty->caching_type = 'mysql'; + + /** + * MySQL CacheResource + * + * CacheResource Implementation based on the Custom API to use + * MySQL as the storage resource for Smarty's output caching. + * + * Table definition: + * <pre>CREATE TABLE IF NOT EXISTS `output_cache` ( + * `id` CHAR(40) NOT NULL COMMENT 'sha1 hash', + * `name` VARCHAR(250) NOT NULL, + * `cache_id` VARCHAR(250) NULL DEFAULT NULL, + * `compile_id` VARCHAR(250) NULL DEFAULT NULL, + * `modified` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP, + * `content` LONGTEXT NOT NULL, + * PRIMARY KEY (`id`), + * INDEX(`name`), + * INDEX(`cache_id`), + * INDEX(`compile_id`), + * INDEX(`modified`) + * ) ENGINE = InnoDB;</pre> + * + * @package CacheResource-examples + * @author Rodney Rehm + */ + class Smarty_CacheResource_Mysql extends Smarty_CacheResource_Custom { + // PDO instance + protected $db; + protected $fetch; + protected $fetchTimestamp; + protected $save; + + public function __construct() { + try { + $this->db = new PDO("mysql:dbname=test;host=127.0.0.1", "smarty", "smarty"); + } catch (PDOException $e) { + throw new SmartyException('Mysql Resource failed: ' . $e->getMessage()); + } + $this->fetch = $this->db->prepare('SELECT modified, content FROM output_cache WHERE id = :id'); + $this->fetchTimestamp = $this->db->prepare('SELECT modified FROM output_cache WHERE id = :id'); + $this->save = $this->db->prepare('REPLACE INTO output_cache (id, name, cache_id, compile_id, content) + VALUES (:id, :name, :cache_id, :compile_id, :content)'); + } + + /** + * fetch cached content and its modification time from data source + * + * @param string $id unique cache content identifier + * @param string $name template name + * @param string $cache_id cache id + * @param string $compile_id compile id + * @param string $content cached content + * @param integer $mtime cache modification timestamp (epoch) + * @return void + */ + protected function fetch($id, $name, $cache_id, $compile_id, &$content, &$mtime) + { + $this->fetch->execute(array('id' => $id)); + $row = $this->fetch->fetch(); + $this->fetch->closeCursor(); + if ($row) { + $content = $row['content']; + $mtime = strtotime($row['modified']); + } else { + $content = null; + $mtime = null; + } + } + + /** + * Fetch cached content's modification timestamp from data source + * + * @note implementing this method is optional. Only implement it if modification times can be accessed faster than loading the complete cached content. + * @param string $id unique cache content identifier + * @param string $name template name + * @param string $cache_id cache id + * @param string $compile_id compile id + * @return integer|boolean timestamp (epoch) the template was modified, or false if not found + */ + protected function fetchTimestamp($id, $name, $cache_id, $compile_id) + { + $this->fetchTimestamp->execute(array('id' => $id)); + $mtime = strtotime($this->fetchTimestamp->fetchColumn()); + $this->fetchTimestamp->closeCursor(); + return $mtime; + } + + /** + * Save content to cache + * + * @param string $id unique cache content identifier + * @param string $name template name + * @param string $cache_id cache id + * @param string $compile_id compile id + * @param integer|null $exp_time seconds till expiration time in seconds or null + * @param string $content content to cache + * @return boolean success + */ + protected function save($id, $name, $cache_id, $compile_id, $exp_time, $content) + { + $this->save->execute(array( + 'id' => $id, + 'name' => $name, + 'cache_id' => $cache_id, + 'compile_id' => $compile_id, + 'content' => $content, + )); + return !!$this->save->rowCount(); + } + + /** + * Delete content from cache + * + * @param string $name template name + * @param string $cache_id cache id + * @param string $compile_id compile id + * @param integer|null $exp_time seconds till expiration or null + * @return integer number of deleted caches + */ + protected function delete($name, $cache_id, $compile_id, $exp_time) + { + // delete the whole cache + if ($name === null && $cache_id === null && $compile_id === null && $exp_time === null) { + // returning the number of deleted caches would require a second query to count them + $query = $this->db->query('TRUNCATE TABLE output_cache'); + return -1; + } + // build the filter + $where = array(); + // equal test name + if ($name !== null) { + $where[] = 'name = ' . $this->db->quote($name); + } + // equal test compile_id + if ($compile_id !== null) { + $where[] = 'compile_id = ' . $this->db->quote($compile_id); + } + // range test expiration time + if ($exp_time !== null) { + $where[] = 'modified < DATE_SUB(NOW(), INTERVAL ' . intval($exp_time) . ' SECOND)'; + } + // equal test cache_id and match sub-groups + if ($cache_id !== null) { + $where[] = '(cache_id = '. $this->db->quote($cache_id) + . ' OR cache_id LIKE '. $this->db->quote($cache_id .'|%') .')'; + } + // run delete query + $query = $this->db->query('DELETE FROM output_cache WHERE ' . join(' AND ', $where)); + return $query->rowCount(); + } + } + + + + + <?php + + require_once 'libs/Smarty.class.php'; + $smarty = new Smarty(); + $smarty->caching_type = 'memcache'; + + /** + * Memcache CacheResource + * + * CacheResource Implementation based on the KeyValueStore API to use + * memcache as the storage resource for Smarty's output caching. + * + * Note that memcache has a limitation of 256 characters per cache-key. + * To avoid complications all cache-keys are translated to a sha1 hash. + * + * @package CacheResource-examples + * @author Rodney Rehm + */ + class Smarty_CacheResource_Memcache extends Smarty_CacheResource_KeyValueStore { + /** + * memcache instance + * @var Memcache + */ + protected $memcache = null; + + public function __construct() + { + $this->memcache = new Memcache(); + $this->memcache->addServer( '127.0.0.1', 11211 ); + } + + /** + * Read values for a set of keys from cache + * + * @param array $keys list of keys to fetch + * @return array list of values with the given keys used as indexes + * @return boolean true on success, false on failure + */ + protected function read(array $keys) + { + $_keys = $lookup = array(); + foreach ($keys as $k) { + $_k = sha1($k); + $_keys[] = $_k; + $lookup[$_k] = $k; + } + $_res = array(); + $res = $this->memcache->get($_keys); + foreach ($res as $k => $v) { + $_res[$lookup[$k]] = $v; + } + return $_res; + } + + /** + * Save values for a set of keys to cache + * + * @param array $keys list of values to save + * @param int $expire expiration time + * @return boolean true on success, false on failure + */ + protected function write(array $keys, $expire=null) + { + foreach ($keys as $k => $v) { + $k = sha1($k); + $this->memcache->set($k, $v, 0, $expire); + } + return true; + } + + /** + * Remove values from cache + * + * @param array $keys list of keys to delete + * @return boolean true on success, false on failure + */ + protected function delete(array $keys) + { + foreach ($keys as $k) { + $k = sha1($k); + $this->memcache->delete($k); + } + return true; + } + + /** + * Remove *all* values from cache + * + * @return boolean true on success, false on failure + */ + protected function purge() + { + return $this->memcache->flush(); + } + } + + + |