Friendica Communications Platform (please note that this is a clone of the repository at github, issues are handled there) https://friendi.ca
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<?php
/**
* @file src/Core/Cache.php
*/
namespace Friendica\Core;
use Friendica\Core\Config;
use Friendica\Database\DBM;
use Friendica\Util\DateTimeFormat;
use dba;
use Memcache;
require_once 'include/dba.php';
/**
* @brief Class for storing data for a short time
*/
class Cache
{
/**
* @brief Check for Memcache and open a connection if configured
*
* @return Memcache|boolean The Memcache object - or "false" if not successful
*/
public static function memcache()
{
if (!class_exists('Memcache', false)) {
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:
default:
$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();
$cache = dba::selectFirst('cache', ['v'], ['k' => $key]);
if (DBM::is_result($cache)) {
$cached = $cache['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 $value The value that is about to be stored
* @param integer $duration The cache lifespan
*
* @return void
*/
public static function set($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;
}
$fields = ['v' => serialize($value), 'expire_mode' => $duration, 'updated' => DateTimeFormat::utcNow()];
$condition = ['k' => $key];
dba::update('cache', $fields, $condition, true);
}
/**
* @brief Remove outdated data from the cache
*
* @param integer $max_level The maximum cache level that is to be cleared
*
* @return void
*/
public static function clear($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) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 30 days"),
CACHE_MONTH];
dba::delete('cache', $condition);
}
if ($max_level <= CACHE_WEEK) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 7 days"),
CACHE_WEEK];
dba::delete('cache', $condition);
}
if ($max_level <= CACHE_DAY) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 1 days"),
CACHE_DAY];
dba::delete('cache', $condition);
}
Config::set("system", "cache_cleared_day", time());
}
if (($max_level <= CACHE_HOUR) && (Config::get("system", "cache_cleared_hour")) < time() - self::duration(CACHE_HOUR)) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 1 hours"),
CACHE_HOUR];
dba::delete('cache', $condition);
Config::set("system", "cache_cleared_hour", time());
}
if (($max_level <= CACHE_HALF_HOUR) && (Config::get("system", "cache_cleared_half_hour")) < time() - self::duration(CACHE_HALF_HOUR)) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 30 minutes"),
CACHE_HALF_HOUR];
dba::delete('cache', $condition);
Config::set("system", "cache_cleared_half_hour", time());
}
if (($max_level <= CACHE_QUARTER_HOUR) && (Config::get("system", "cache_cleared_quarter_hour")) < time() - self::duration(CACHE_QUARTER_HOUR)) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 15 minutes"),
CACHE_QUARTER_HOUR];
dba::delete('cache', $condition);
Config::set("system", "cache_cleared_quarter_hour", time());
}
if (($max_level <= CACHE_FIVE_MINUTES) && (Config::get("system", "cache_cleared_five_minute")) < time() - self::duration(CACHE_FIVE_MINUTES)) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 5 minutes"),
CACHE_FIVE_MINUTES];
dba::delete('cache', $condition);
Config::set("system", "cache_cleared_five_minute", time());
}
if (($max_level <= CACHE_MINUTE) && (Config::get("system", "cache_cleared_minute")) < time() - self::duration(CACHE_MINUTE)) {
$condition = ["`updated` < ? AND `expire_mode` = ?",
DateTimeFormat::utc("now - 1 minutes"),
CACHE_MINUTE];
dba::delete('cache', $condition);
Config::set("system", "cache_cleared_minute", time());
}
}
}