friendica-github/include/cache.php
2017-11-08 08:37:03 -05:00

211 lines
6.3 KiB
PHP

<?php
/**
* @file include/cache.php
*
* @brief Class for storing data for a short time
*/
use Friendica\Core\Config;
use Friendica\Core\PConfig;
use Friendica\Database\DBM;
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 $level Cache level
*
* @return integer The cache duration in seconds
*/
private static function duration($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 (Config::get("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 ($max_level <= CACHE_DAY) {
q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
dbesc(datetime_convert('UTC','UTC',"now - 1 days")), intval(CACHE_DAY));
}
Config::set("system", "cache_cleared_day", time());
}
if (($max_level <= CACHE_HOUR) && (Config::get("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));
Config::set("system", "cache_cleared_hour", time());
}
if (($max_level <= CACHE_HALF_HOUR) && (Config::get("system", "cache_cleared_half_hour")) < time() - self::duration(CACHE_HALF_HOUR)) {
q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
dbesc(datetime_convert('UTC','UTC',"now - 30 minutes")), intval(CACHE_HALF_HOUR));
Config::set("system", "cache_cleared_half_hour", time());
}
if (($max_level <= CACHE_QUARTER_HOUR) && (Config::get("system", "cache_cleared_quarter_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));
Config::set("system", "cache_cleared_quarter_hour", time());
}
if (($max_level <= CACHE_FIVE_MINUTES) && (Config::get("system", "cache_cleared_five_minute")) < time() - self::duration(CACHE_FIVE_MINUTES)) {
q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
dbesc(datetime_convert('UTC','UTC',"now - 5 minutes")), intval(CACHE_FIVE_MINUTES));
Config::set("system", "cache_cleared_five_minute", time());
}
if (($max_level <= CACHE_MINUTE) && (Config::get("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));
Config::set("system", "cache_cleared_minute", time());
}
}
}