wiki.techinc.nl/includes/libs/objectcache/WinCacheBagOStuff.php
Aaron Schulz fea9ebbd6f objectcache: make the BagOStuff::add() operation more atomic for WinCache
Change-Id: I285ed9a7d0894adfe29b0bdc106b7518f655ba45
2019-03-15 00:38:18 +00:00

127 lines
3.6 KiB
PHP

<?php
/**
* Object caching using WinCache.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Cache
*/
/**
* Wrapper for WinCache object caching functions; identical interface
* to the APC wrapper
*
* @ingroup Cache
*/
class WinCacheBagOStuff extends BagOStuff {
protected function doGet( $key, $flags = 0 ) {
$val = wincache_ucache_get( $key );
if ( is_string( $val ) ) {
$val = unserialize( $val );
}
return $val;
}
public function set( $key, $value, $expire = 0, $flags = 0 ) {
$result = wincache_ucache_set( $key, serialize( $value ), $expire );
return ( $result === [] || $result === true );
}
public function add( $key, $value, $exptime = 0, $flags = 0 ) {
$result = wincache_ucache_add( $key, serialize( $value ), $exptime );
return ( $result === [] || $result === true );
}
public function delete( $key, $flags = 0 ) {
wincache_ucache_delete( $key );
return true;
}
public function merge( $key, callable $callback, $exptime = 0, $attempts = 10, $flags = 0 ) {
if ( wincache_lock( $key ) ) { // optimize with FIFO lock
$ok = $this->mergeViaLock( $key, $callback, $exptime, $attempts, $flags );
wincache_unlock( $key );
} else {
$ok = false;
}
return $ok;
}
/**
* Construct a cache key.
*
* @since 1.27
* @param string $keyspace
* @param array $args
* @return string
*/
public function makeKeyInternal( $keyspace, $args ) {
// WinCache keys have a maximum length of 150 characters. From that,
// subtract the number of characters we need for the keyspace and for
// the separator character needed for each argument. To handle some
// custom prefixes used by thing like WANObjectCache, limit to 125.
// NOTE: Same as in memcached, except the max key length there is 255.
$charsLeft = 125 - strlen( $keyspace ) - count( $args );
$args = array_map(
function ( $arg ) use ( &$charsLeft ) {
// 33 = 32 characters for the MD5 + 1 for the '#' prefix.
if ( $charsLeft > 33 && strlen( $arg ) > $charsLeft ) {
$arg = '#' . md5( $arg );
}
$charsLeft -= strlen( $arg );
return $arg;
},
$args
);
if ( $charsLeft < 0 ) {
return $keyspace . ':BagOStuff-long-key:##' . md5( implode( ':', $args ) );
}
return $keyspace . ':' . implode( ':', $args );
}
/**
* Increase stored value of $key by $value while preserving its original TTL
* @param string $key Key to increase
* @param int $value Value to add to $key (Default 1)
* @return int|bool New value or false on failure
*/
public function incr( $key, $value = 1 ) {
if ( !$this->lock( $key ) ) {
return false;
}
$n = $this->get( $key );
if ( $this->isInteger( $n ) ) { // key exists?
$n += intval( $value );
$oldTTL = wincache_ucache_info( false, $key )["ucache_entries"][1]["ttl_seconds"];
$this->set( $key, max( 0, $n ), $oldTTL );
} else {
$n = false;
}
$this->unlock( $key );
return $n;
}
}