<?php /** * @file include/cache.php * * @brief Class for storing data for a short time */ use \Friendica\Core\Config; use \Friendica\Core\PConfig; class Cache { /** * @brief Check for memcache and open a connection if configured * * @return object|boolean The memcache object - or "false" if not successful */ public static function memcache() { if (!function_exists('memcache_connect')) { return false; } if (!Config::get('system', 'memcache')) { return false; } $memcache_host = Config::get('system', 'memcache_host', '127.0.0.1'); $memcache_port = Config::get('system', 'memcache_port', 11211); $memcache = new Memcache; if (!$memcache->connect($memcache_host, $memcache_port)) { return false; } return $memcache; } /** * @brief Return the duration for a given cache level * * @param integer $level Cache level * * @return integer The cache duration in seconds */ private function duration($level) { switch($level) { case CACHE_MONTH; $seconds = 2592000; break; case CACHE_WEEK; $seconds = 604800; break; case CACHE_DAY; $seconds = 86400; break; case CACHE_HOUR; $seconds = 3600; break; case CACHE_HALF_HOUR; $seconds = 1800; break; case CACHE_QUARTER_HOUR; $seconds = 900; break; case CACHE_FIVE_MINUTES; $seconds = 300; break; case CACHE_MINUTE; $seconds = 60; break; } return $seconds; } /** * @brief Fetch cached data according to the key * * @param string $key The key to the cached data * * @return mixed Cached $value or "null" if not found */ public static function get($key) { $memcache = self::memcache(); if (is_object($memcache)) { // We fetch with the hostname as key to avoid problems with other applications $cached = $memcache->get(get_app()->get_hostname().":".$key); $value = @unserialize($cached); // Only return a value if the serialized value is valid. // We also check if the db entry is a serialized // boolean 'false' value (which we want to return). if ($cached === serialize(false) || $value !== false) { return $value; } return null; } // Frequently clear cache self::clear($duration); $r = q("SELECT `v` FROM `cache` WHERE `k`='%s' LIMIT 1", dbesc($key) ); if (dbm::is_result($r)) { $cached = $r[0]['v']; $value = @unserialize($cached); // Only return a value if the serialized value is valid. // We also check if the db entry is a serialized // boolean 'false' value (which we want to return). if ($cached === serialize(false) || $value !== false) { return $value; } } return null; } /** * @brief Put data in the cache according to the key * * The input $value can have multiple formats. * * @param string $key The key to the cached data * @param mixed $valie The value that is about to be stored * @param integer $duration The cache lifespan */ public static function set($key, $value, $duration = CACHE_MONTH) { // Do we have an installed memcache? Use it instead. $memcache = self::memcache(); if (is_object($memcache)) { // We store with the hostname as key to avoid problems with other applications $memcache->set(get_app()->get_hostname().":".$key, serialize($value), MEMCACHE_COMPRESSED, self::duration($duration)); return; } /// @todo store the cache data in the same way like the config data q("REPLACE INTO `cache` (`k`,`v`,`expire_mode`,`updated`) VALUES ('%s','%s',%d,'%s')", dbesc($key), dbesc(serialize($value)), intval($duration), dbesc(datetime_convert())); } /** * @brief Remove outdated data from the cache * * @param integer $maxlevel The maximum cache level that is to be cleared */ public static function clear($max_level = CACHE_MONTH) { // Clear long lasting cache entries only once a day if (get_config("system", "cache_cleared_day") < time() - self::duration(CACHE_DAY)) { if ($max_level == CACHE_MONTH) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 30 days")), intval(CACHE_MONTH)); } if ($max_level <= CACHE_WEEK) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 7 days")), intval(CACHE_WEEK)); } if ($max_level <= CACHE_DAY) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 1 days")), intval(CACHE_DAY)); } set_config("system", "cache_cleared_day", time()); } if (($max_level <= CACHE_HOUR) AND (get_config("system", "cache_cleared_hour")) < time() - self::duration(CACHE_HOUR)) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 1 hours")), intval(CACHE_HOUR)); set_config("system", "cache_cleared_hour", time()); } if (($max_level <= CACHE_HALF_HOUR) AND (get_config("system", "cache_cleared_half_hour")) < time() - self::duration(CACHE_HALF_HOUR)) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 30 minutes")), intval(CACHE_HALF_HOUR)); set_config("system", "cache_cleared_half_hour", time()); } if (($max_level <= CACHE_QUARTER_HOUR) AND (get_config("system", "cache_cleared_hour")) < time() - self::duration(CACHE_QUARTER_HOUR)) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 15 minutes")), intval(CACHE_QUARTER_HOUR)); set_config("system", "cache_cleared_quarter_hour", time()); } if (($max_level <= CACHE_FIVE_MINUTES) AND (get_config("system", "cache_cleared_five_minute")) < time() - self::duration(CACHE_FIVE_MINUTES)) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 5 minutes")), intval(CACHE_FIVE_MINUTES)); set_config("system", "cache_cleared_five_minute", time()); } if (($max_level <= CACHE_MINUTE) AND (get_config("system", "cache_cleared_minute")) < time() - self::duration(CACHE_MINUTE)) { q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d", dbesc(datetime_convert('UTC','UTC',"now - 1 minutes")), intval(CACHE_MINUTE)); set_config("system", "cache_cleared_minute", time()); } } }