laipower/wp-content/upgrade-temp-backup/plugins/w3-total-cache/Cache_Apcu.php

239 lines
5.7 KiB
PHP

<?php
namespace W3TC;
/**
* APC class
*/
class Cache_Apcu extends Cache_Base {
/*
* Used for faster flushing
*
* @var integer $_key_version
*/
private $_key_version = array();
/**
* Adds data
*
* @param string $key
* @param mixed $var
* @param integer $expire
* @param string $group Used to differentiate between groups of cache values
* @return boolean
*/
function add( $key, &$var, $expire = 0, $group = '' ) {
if ( $this->get( $key, $group ) === false ) {
return $this->set( $key, $var, $expire, $group );
}
return false;
}
/**
* Sets data
*
* @param string $key
* @param mixed $var
* @param integer $expire
* @param string $group Used to differentiate between groups of cache values
* @return boolean
*/
function set( $key, $var, $expire = 0, $group = '' ) {
$var['key_version'] = $this->_get_key_version( $group );
$storage_key = $this->get_item_key( $key );
return apcu_store( $storage_key, serialize( $var ), $expire );
}
/**
* Returns data
*
* @param string $key
* @param string $group Used to differentiate between groups of cache values
* @return mixed
*/
function get_with_old( $key, $group = '' ) {
$has_old_data = false;
$storage_key = $this->get_item_key( $key );
$v = @unserialize( apcu_fetch( $storage_key ) );
if ( !is_array( $v ) || !isset( $v['key_version'] ) )
return array( null, $has_old_data );
$key_version = $this->_get_key_version( $group );
if ( $v['key_version'] == $key_version )
return array( $v, $has_old_data );
if ( $v['key_version'] > $key_version ) {
$this->_set_key_version( $v['key_version'], $group );
return array( $v, $has_old_data );
}
// key version is old
if ( !$this->_use_expired_data )
return array( null, $has_old_data );
// if we have expired data - update it for future use and let
// current process recalculate it
$expires_at = isset( $v['expires_at'] ) ? $v['expires_at'] : null;
if ( $expires_at == null || time() > $expires_at ) {
$v['expires_at'] = time() + 30;
apcu_store( $storage_key, serialize( $v ), 0 );
$has_old_data = true;
return array( null, $has_old_data );
}
// return old version
return array( $v, $has_old_data );
}
/**
* Replaces data
*
* @param string $key
* @param mixed $var
* @param integer $expire
* @param string $group Used to differentiate between groups of cache values
* @return boolean
*/
function replace( $key, &$var, $expire = 0, $group ='' ) {
if ( $this->get( $key, $group ) !== false ) {
return $this->set( $key, $var, $expire, $group );
}
return false;
}
/**
* Deletes data
*
* @param string $key
* @param string $group
* @return boolean
*/
function delete( $key, $group = '' ) {
$storage_key = $this->get_item_key( $key );
if ( $this->_use_expired_data ) {
$v = @unserialize( apcu_fetch( $storage_key ) );
if ( is_array( $v ) ) {
$v['key_version'] = 0;
apcu_store( $storage_key, serialize( $v ), 0 );
return true;
}
}
return apcu_delete( $storage_key );
}
/**
* Deletes _old and primary if exists.
*
* @param unknown $key
* @return bool
*/
function hard_delete( $key, $group = '' ) {
$storage_key = $this->get_item_key( $key );
return apcu_delete( $storage_key );
}
/**
* Flushes all data
*
* @param string $group Used to differentiate between groups of cache values
* @return boolean
*/
function flush( $group = '' ) {
$this->_get_key_version( $group ); // initialize $this->_key_version
$this->_key_version[$group]++;
$this->_set_key_version( $this->_key_version[$group], $group );
return true;
}
/**
* Checks if engine can function properly in this environment
*
* @return bool
*/
public function available() {
return function_exists( 'apcu_store' );
}
/**
* Returns key postfix
*
* @param string $group Used to differentiate between groups of cache values
* @return integer
*/
private function _get_key_version( $group = '' ) {
if ( !isset( $this->_key_version[$group] ) || $this->_key_version[$group] <= 0 ) {
$v = apcu_fetch( $this->_get_key_version_key( $group ) );
$v = intval( $v );
$this->_key_version[$group] = ( $v > 0 ? $v : 1 );
}
return $this->_key_version[$group];
}
/**
* Sets new key version
*
* @param unknown $v
* @param string $group Used to differentiate between groups of cache values
* @return boolean
*/
private function _set_key_version( $v, $group = '' ) {
apcu_store( $this->_get_key_version_key( $group ), $v, 0 );
}
/**
* Used to replace as atomically as possible known value to new one
*/
public function set_if_maybe_equals( $key, $old_value, $new_value ) {
// apc_cas doesnt fit here, since we are float but it works with
// int only
// cant guarantee atomic action here, filelocks fail often
$value = $this->get( $key );
if ( isset( $old_value['content'] ) &&
$value['content'] != $old_value['content'] )
return false;
return $this->set( $key, $new_value );
}
/**
* Use key as a counter and add integet value to it
*/
public function counter_add( $key, $value ) {
if ( $value == 0 )
return true;
$storage_key = $this->get_item_key( $key );
$r = apcu_inc( $storage_key, $value );
if ( !$r ) // it doesnt initialize counter by itself
$this->counter_set( $key, 0 );
return $r;
}
/**
* Use key as a counter and add integet value to it
*/
public function counter_set( $key, $value ) {
$storage_key = $this->get_item_key( $key );
return apcu_store( $storage_key, $value );
}
/**
* Get counter's value
*/
public function counter_get( $key ) {
$storage_key = $this->get_item_key( $key );
$v = (int)apcu_fetch( $storage_key );
return $v;
}
}