<?php /** * Smarty Internal Plugin * * @package Smarty * @subpackage Cacher */ /** * Smarty Cache Handler Base for Key/Value Storage Implementations * This class implements the functionality required to use simple key/value stores * for hierarchical cache groups. key/value stores like memcache or APC do not support * wildcards in keys, therefore a cache group cannot be cleared like "a|*" - which * is no problem to filesystem and RDBMS implementations. * This implementation is based on the concept of invalidation. While one specific cache * can be identified and cleared, any range of caches cannot be identified. For this reason * each level of the cache group hierarchy can have its own value in the store. These values * are nothing but microtimes, telling us when a particular cache group was cleared for the * last time. These keys are evaluated for every cache read to determine if the cache has * been invalidated since it was created and should hence be treated as inexistent. * Although deep hierarchies are possible, they are not recommended. Try to keep your * cache groups as shallow as possible. Anything up 3-5 parents should be ok. So * »a|b|c« is a good depth where »a|b|c|d|e|f|g|h|i|j|k« isn't. Try to join correlating * cache groups: if your cache groups look somewhat like »a|b|$page|$items|$whatever« * consider using »a|b|c|$page-$items-$whatever« instead. * * @package Smarty * @subpackage Cacher * @author Rodney Rehm */ abstract class Smarty_CacheResource_KeyValueStore extends Smarty_CacheResource { /** * cache for contents * * @var array */ protected $contents = array(); /** * cache for timestamps * * @var array */ protected $timestamps = array(); /** * populate Cached Object with meta data from Resource * * @param Smarty_Template_Cached $cached cached object * @param Smarty_Internal_Template $_template template object * * @return void */ public function populate(Smarty_Template_Cached $cached, Smarty_Internal_Template $_template) { $cached->filepath = $_template->source->uid . '#' . $this->sanitize($cached->source->resource) . '#' . $this->sanitize($cached->cache_id) . '#' . $this->sanitize($cached->compile_id); $this->populateTimestamp($cached); } /** * populate Cached Object with timestamp and exists from Resource * * @param Smarty_Template_Cached $cached cached object * * @return void */ public function populateTimestamp(Smarty_Template_Cached $cached) { if (!$this->fetch( $cached->filepath, $cached->source->name, $cached->cache_id, $cached->compile_id, $content, $timestamp, $cached->source->uid ) ) { return; } $cached->content = $content; $cached->timestamp = (int)$timestamp; $cached->exists = !!$cached->timestamp; } /** * Read the cached template and process the header * * @param \Smarty_Internal_Template $_smarty_tpl do not change variable name, is used by compiled template * @param Smarty_Template_Cached $cached cached object * @param boolean $update flag if called because cache update * * @return boolean true or false if the cached content does not exist */ public function process( Smarty_Internal_Template $_smarty_tpl, Smarty_Template_Cached $cached = null, $update = false ) { if (!$cached) { $cached = $_smarty_tpl->cached; } $content = $cached->content ? $cached->content : null; $timestamp = $cached->timestamp ? $cached->timestamp : null; if ($content === null || !$timestamp) { if (!$this->fetch( $_smarty_tpl->cached->filepath, $_smarty_tpl->source->name, $_smarty_tpl->cache_id, $_smarty_tpl->compile_id, $content, $timestamp, $_smarty_tpl->source->uid ) ) { return false; } } if (isset($content)) { eval('?>' . $content); return true; } return false; } /** * Write the rendered template output to cache * * @param Smarty_Internal_Template $_template template object * @param string $content content to cache * * @return boolean success */ public function writeCachedContent(Smarty_Internal_Template $_template, $content) { $this->addMetaTimestamp($content); return $this->write(array($_template->cached->filepath => $content), $_template->cache_lifetime); } /** * Read cached template from cache * * @param Smarty_Internal_Template $_template template object * * @return string|false content */ public function readCachedContent(Smarty_Internal_Template $_template) { $content = $_template->cached->content ? $_template->cached->content : null; $timestamp = null; if ($content === null) { if (!$this->fetch( $_template->cached->filepath, $_template->source->name, $_template->cache_id, $_template->compile_id, $content, $timestamp, $_template->source->uid ) ) { return false; } } if (isset($content)) { return $content; } return false; } /** * Empty cache * {@internal the $exp_time argument is ignored altogether }} * * @param Smarty $smarty Smarty object * @param integer $exp_time expiration time [being ignored] * * @return integer number of cache files deleted [always -1] * @uses purge() to clear the whole store * @uses invalidate() to mark everything outdated if purge() is inapplicable */ public function clearAll(Smarty $smarty, $exp_time = null) { if (!$this->purge()) { $this->invalidate(null); } return -1; } /** * Empty cache for a specific template * {@internal the $exp_time argument is ignored altogether}} * * @param Smarty $smarty Smarty object * @param string $resource_name template name * @param string $cache_id cache id * @param string $compile_id compile id * @param integer $exp_time expiration time [being ignored] * * @return int number of cache files deleted [always -1] * @throws \SmartyException * @uses buildCachedFilepath() to generate the CacheID * @uses invalidate() to mark CacheIDs parent chain as outdated * @uses delete() to remove CacheID from cache */ public function clear(Smarty $smarty, $resource_name, $cache_id, $compile_id, $exp_time) { $uid = $this->getTemplateUid($smarty, $resource_name); $cid = $uid . '#' . $this->sanitize($resource_name) . '#' . $this->sanitize($cache_id) . '#' . $this->sanitize($compile_id); $this->delete(array($cid)); $this->invalidate($cid, $resource_name, $cache_id, $compile_id, $uid); return -1; } /** * Get template's unique ID * * @param Smarty $smarty Smarty object * @param string $resource_name template name * * @return string filepath of cache file * @throws \SmartyException */ protected function getTemplateUid(Smarty $smarty, $resource_name) { if (isset($resource_name)) { $source = Smarty_Template_Source::load(null, $smarty, $resource_name); if ($source->exists) { return $source->uid; } } return ''; } /** * Sanitize CacheID components * * @param string $string CacheID component to sanitize * * @return string sanitized CacheID component */ protected function sanitize($string) { $string = trim($string, '|'); if (!$string) { return ''; } return preg_replace('#[^\w\|]+#S', '_', $string); } /** * Fetch and prepare a cache object. * * @param string $cid CacheID to fetch * @param string $resource_name template name * @param string $cache_id cache id * @param string $compile_id compile id * @param string $content cached content * @param integer &$timestamp cached timestamp (epoch) * @param string $resource_uid resource's uid * * @return boolean success */ protected function fetch( $cid, $resource_name = null, $cache_id = null, $compile_id = null, &$content = null, &$timestamp = null, $resource_uid = null ) { $t = $this->read(array($cid)); $content = !empty($t[ $cid ]) ? $t[ $cid ] : null; $timestamp = null; if ($content && ($timestamp = $this->getMetaTimestamp($content))) { $invalidated = $this->getLatestInvalidationTimestamp($cid, $resource_name, $cache_id, $compile_id, $resource_uid); if ($invalidated > $timestamp) { $timestamp = null; $content = null; } } return !!$content; } /** * Add current microtime to the beginning of $cache_content * {@internal the header uses 8 Bytes, the first 4 Bytes are the seconds, the second 4 Bytes are the microseconds}} * * @param string &$content the content to be cached */ protected function addMetaTimestamp(&$content) { $mt = explode(' ', microtime()); $ts = pack('NN', $mt[ 1 ], (int)($mt[ 0 ] * 100000000)); $content = $ts . $content; } /** * Extract the timestamp the $content was cached * * @param string &$content the cached content * * @return float the microtime the content was cached */ protected function getMetaTimestamp(&$content) { extract(unpack('N1s/N1m/a*content', $content)); /** * @var int $s * @var int $m */ return $s + ($m / 100000000); } /** * Invalidate CacheID * * @param string $cid CacheID * @param string $resource_name template name * @param string $cache_id cache id * @param string $compile_id compile id * @param string $resource_uid source's uid * * @return void */ protected function invalidate( $cid = null, $resource_name = null, $cache_id = null, $compile_id = null, $resource_uid = null ) { $now = microtime(true); $key = null; // invalidate everything if (!$resource_name && !$cache_id && !$compile_id) { $key = 'IVK#ALL'; } // invalidate all caches by template else { if ($resource_name && !$cache_id && !$compile_id) { $key = 'IVK#TEMPLATE#' . $resource_uid . '#' . $this->sanitize($resource_name); } // invalidate all caches by cache group else { if (!$resource_name && $cache_id && !$compile_id) { $key = 'IVK#CACHE#' . $this->sanitize($cache_id); } // invalidate all caches by compile id else { if (!$resource_name && !$cache_id && $compile_id) { $key = 'IVK#COMPILE#' . $this->sanitize($compile_id); } // invalidate by combination else { $key = 'IVK#CID#' . $cid; } } } } $this->write(array($key => $now)); } /** * Determine the latest timestamp known to the invalidation chain * * @param string $cid CacheID to determine latest invalidation timestamp of * @param string $resource_name template name * @param string $cache_id cache id * @param string $compile_id compile id * @param string $resource_uid source's filepath * * @return float the microtime the CacheID was invalidated */ protected function getLatestInvalidationTimestamp( $cid, $resource_name = null, $cache_id = null, $compile_id = null, $resource_uid = null ) { // abort if there is no CacheID if (false && !$cid) { return 0; } // abort if there are no InvalidationKeys to check if (!($_cid = $this->listInvalidationKeys($cid, $resource_name, $cache_id, $compile_id, $resource_uid))) { return 0; } // there are no InValidationKeys if (!($values = $this->read($_cid))) { return 0; } // make sure we're dealing with floats $values = array_map('floatval', $values); return max($values); } /** * Translate a CacheID into the list of applicable InvalidationKeys. * Splits 'some|chain|into|an|array' into array( '#clearAll#', 'some', 'some|chain', 'some|chain|into', ... ) * * @param string $cid CacheID to translate * @param string $resource_name template name * @param string $cache_id cache id * @param string $compile_id compile id * @param string $resource_uid source's filepath * * @return array list of InvalidationKeys * @uses $invalidationKeyPrefix to prepend to each InvalidationKey */ protected function listInvalidationKeys( $cid, $resource_name = null, $cache_id = null, $compile_id = null, $resource_uid = null ) { $t = array('IVK#ALL'); $_name = $_compile = '#'; if ($resource_name) { $_name .= $resource_uid . '#' . $this->sanitize($resource_name); $t[] = 'IVK#TEMPLATE' . $_name; } if ($compile_id) { $_compile .= $this->sanitize($compile_id); $t[] = 'IVK#COMPILE' . $_compile; } $_name .= '#'; $cid = trim($cache_id, '|'); if (!$cid) { return $t; } $i = 0; while (true) { // determine next delimiter position $i = strpos($cid, '|', $i); // add complete CacheID if there are no more delimiters if ($i === false) { $t[] = 'IVK#CACHE#' . $cid; $t[] = 'IVK#CID' . $_name . $cid . $_compile; $t[] = 'IVK#CID' . $_name . $_compile; break; } $part = substr($cid, 0, $i); // add slice to list $t[] = 'IVK#CACHE#' . $part; $t[] = 'IVK#CID' . $_name . $part . $_compile; // skip past delimiter position $i++; } return $t; } /** * Check is cache is locked for this template * * @param Smarty $smarty Smarty object * @param Smarty_Template_Cached $cached cached object * * @return boolean true or false if cache is locked */ public function hasLock(Smarty $smarty, Smarty_Template_Cached $cached) { $key = 'LOCK#' . $cached->filepath; $data = $this->read(array($key)); return $data && time() - $data[ $key ] < $smarty->locking_timeout; } /** * Lock cache for this template * * @param Smarty $smarty Smarty object * @param Smarty_Template_Cached $cached cached object * * @return bool|void */ public function acquireLock(Smarty $smarty, Smarty_Template_Cached $cached) { $cached->is_locked = true; $key = 'LOCK#' . $cached->filepath; $this->write(array($key => time()), $smarty->locking_timeout); } /** * Unlock cache for this template * * @param Smarty $smarty Smarty object * @param Smarty_Template_Cached $cached cached object * * @return bool|void */ public function releaseLock(Smarty $smarty, Smarty_Template_Cached $cached) { $cached->is_locked = false; $key = 'LOCK#' . $cached->filepath; $this->delete(array($key)); } /** * 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 */ abstract protected function read(array $keys); /** * 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 */ abstract protected function write(array $keys, $expire = null); /** * Remove values from cache * * @param array $keys list of keys to delete * * @return boolean true on success, false on failure */ abstract protected function delete(array $keys); /** * Remove *all* values from cache * * @return boolean true on success, false on failure */ protected function purge() { return false; } }