View file File name : Cache_Apc.php Content :<?php namespace W3TC; /** * APC class */ class Cache_Apc 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 apc_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( apc_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; apc_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( apc_fetch( $storage_key ) ); if ( is_array( $v ) ) { $v['key_version'] = 0; apc_store( $storage_key, serialize( $v ), 0 ); return true; } } return apc_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 apc_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( 'apc_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 = apc_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 = '' ) { apc_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 = apc_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 apc_store( $storage_key, $value ); } /** * Get counter's value */ public function counter_get( $key ) { $storage_key = $this->get_item_key( $key ); $v = (int)apc_fetch( $storage_key ); return $v; } }