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- <?php
- namespace dokuwiki\Cache;
- use dokuwiki\Debug\PropertyDeprecationHelper;
- use dokuwiki\Extension\Event;
- /**
- * Generic handling of caching
- */
- class Cache
- {
- use PropertyDeprecationHelper;
- public $key = ''; // primary identifier for this item
- public $ext = ''; // file ext for cache data, secondary identifier for this item
- public $cache = ''; // cache file name
- public $depends = array(); // array containing cache dependency information,
- // used by makeDefaultCacheDecision to determine cache validity
- // phpcs:disable
- /**
- * @deprecated since 2019-02-02 use the respective getters instead!
- */
- protected $_event = ''; // event to be triggered during useCache
- protected $_time;
- protected $_nocache = false; // if set to true, cache will not be used or stored
- // phpcs:enable
- /**
- * @param string $key primary identifier
- * @param string $ext file extension
- */
- public function __construct($key, $ext)
- {
- $this->key = $key;
- $this->ext = $ext;
- $this->cache = getCacheName($key, $ext);
- /**
- * @deprecated since 2019-02-02 use the respective getters instead!
- */
- $this->deprecatePublicProperty('_event');
- $this->deprecatePublicProperty('_time');
- $this->deprecatePublicProperty('_nocache');
- }
- public function getTime()
- {
- return $this->_time;
- }
- public function getEvent()
- {
- return $this->_event;
- }
- public function setEvent($event)
- {
- $this->_event = $event;
- }
- /**
- * public method to determine whether the cache can be used
- *
- * to assist in centralisation of event triggering and calculation of cache statistics,
- * don't override this function override makeDefaultCacheDecision()
- *
- * @param array $depends array of cache dependencies, support dependecies:
- * 'age' => max age of the cache in seconds
- * 'files' => cache must be younger than mtime of each file
- * (nb. dependency passes if file doesn't exist)
- *
- * @return bool true if cache can be used, false otherwise
- */
- public function useCache($depends = array())
- {
- $this->depends = $depends;
- $this->addDependencies();
- if ($this->getEvent()) {
- return $this->stats(
- Event::createAndTrigger(
- $this->getEvent(),
- $this,
- array($this, 'makeDefaultCacheDecision')
- )
- );
- }
- return $this->stats($this->makeDefaultCacheDecision());
- }
- /**
- * internal method containing cache use decision logic
- *
- * this function processes the following keys in the depends array
- * purge - force a purge on any non empty value
- * age - expire cache if older than age (seconds)
- * files - expire cache if any file in this array was updated more recently than the cache
- *
- * Note that this function needs to be public as it is used as callback for the event handler
- *
- * can be overridden
- *
- * @internal This method may only be called by the event handler! Call \dokuwiki\Cache\Cache::useCache instead!
- *
- * @return bool see useCache()
- */
- public function makeDefaultCacheDecision()
- {
- if ($this->_nocache) {
- return false;
- } // caching turned off
- if (!empty($this->depends['purge'])) {
- return false;
- } // purge requested?
- if (!($this->_time = @filemtime($this->cache))) {
- return false;
- } // cache exists?
- // cache too old?
- if (!empty($this->depends['age']) && ((time() - $this->_time) > $this->depends['age'])) {
- return false;
- }
- if (!empty($this->depends['files'])) {
- foreach ($this->depends['files'] as $file) {
- if ($this->_time <= @filemtime($file)) {
- return false;
- } // cache older than files it depends on?
- }
- }
- return true;
- }
- /**
- * add dependencies to the depends array
- *
- * this method should only add dependencies,
- * it should not remove any existing dependencies and
- * it should only overwrite a dependency when the new value is more stringent than the old
- */
- protected function addDependencies()
- {
- global $INPUT;
- if ($INPUT->has('purge')) {
- $this->depends['purge'] = true;
- } // purge requested
- }
- /**
- * retrieve the cached data
- *
- * @param bool $clean true to clean line endings, false to leave line endings alone
- * @return string cache contents
- */
- public function retrieveCache($clean = true)
- {
- return io_readFile($this->cache, $clean);
- }
- /**
- * cache $data
- *
- * @param string $data the data to be cached
- * @return bool true on success, false otherwise
- */
- public function storeCache($data)
- {
- if ($this->_nocache) {
- return false;
- }
- return io_saveFile($this->cache, $data);
- }
- /**
- * remove any cached data associated with this cache instance
- */
- public function removeCache()
- {
- @unlink($this->cache);
- }
- /**
- * Record cache hits statistics.
- * (Only when debugging allowed, to reduce overhead.)
- *
- * @param bool $success result of this cache use attempt
- * @return bool pass-thru $success value
- */
- protected function stats($success)
- {
- global $conf;
- static $stats = null;
- static $file;
- if (!$conf['allowdebug']) {
- return $success;
- }
- if (is_null($stats)) {
- $file = $conf['cachedir'] . '/cache_stats.txt';
- $lines = explode("\n", io_readFile($file));
- foreach ($lines as $line) {
- $i = strpos($line, ',');
- $stats[substr($line, 0, $i)] = $line;
- }
- }
- if (isset($stats[$this->ext])) {
- list($ext, $count, $hits) = explode(',', $stats[$this->ext]);
- } else {
- $ext = $this->ext;
- $count = 0;
- $hits = 0;
- }
- $count++;
- if ($success) {
- $hits++;
- }
- $stats[$this->ext] = "$ext,$count,$hits";
- io_saveFile($file, join("\n", $stats));
- return $success;
- }
- /**
- * @return bool
- */
- public function isNoCache()
- {
- return $this->_nocache;
- }
- }
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