<?php
namespace W3TC;
/**
* Redis cache engine
*/
class Cache_Redis extends Cache_Base {
private $_accessors = array();
private $_key_version = array();
private $_persistent;
private $_password;
private $_servers;
private $_dbid;
/**
* constructor
*
* @param array $config
*/
function __construct( $config ) {
parent::__construct( $config );
$this->_persistent = ( isset( $config['persistent'] ) && $config['persistent'] );
$this->_servers = (array)$config['servers'];
$this->_password = $config['password'];
$this->_dbid = $config['dbid'];
// when disabled - no extra requests are made to obtain key version,
// but flush operations not supported as a result
// group should be always empty
if ( isset( $config['key_version_mode'] ) &&
$config['key_version_mode'] == 'disabled' ) {
$this->_key_version[''] = 1;
}
}
/**
* 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 = '' ) {
return $this->set( $key, $var, $expire, $group );
}
/**
* 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, $value, $expire = 0, $group = '' ) {
$value['key_version'] = $this->_get_key_version( $group );
$storage_key = $this->get_item_key( $key );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) ) {
return false;
}
if ( ! $expire ) {
return $accessor->set( $storage_key, serialize( $value ) );
}
return $accessor->setex( $storage_key, $expire, serialize( $value ) );
}
/**
* 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 );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return array( null, false );
$v = $accessor->get( $storage_key );
$v = @unserialize( $v );
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;
$accessor->setex( $storage_key, 60, serialize( $v ) );
$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 = '' ) {
return $this->set( $key, $var, $expire, $group );
}
/**
* Deletes data
*
* @param string $key
* @param string $group
* @return boolean
*/
function delete( $key, $group = '' ) {
$storage_key = $this->get_item_key( $key );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return false;
if ( $this->_use_expired_data ) {
$v = $accessor->get( $storage_key );
$ttl = $accessor->ttl( $storage_key );
if ( is_array( $v ) ) {
$v['key_version'] = 0;
$accessor->setex( $storage_key, $ttl, $v );
return true;
}
}
return $accessor->setex( $storage_key, 1, '' );
}
/**
* Key to delete, deletes _old and primary if exists.
*
* @param unknown $key
* @return bool
*/
function hard_delete( $key, $group = '' ) {
$storage_key = $this->get_item_key( $key );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return false;
return $accessor->setex( $storage_key, 1, '' );
}
/**
* 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 $this->_key_version
if (isset($this->_key_version[$group])) {
$this->_key_version[$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 class_exists( 'Redis' );
}
public function get_statistics() {
$accessor = $this->_get_accessor( '' ); // single-server mode used for stats
if ( is_null( $accessor ) )
return array();
$a = $accessor->info();
return $a;
}
/**
* Returns key version
*
* @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 ) {
$storage_key = $this->_get_key_version_key( $group );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return 0;
$v_original = $accessor->get( $storage_key );
$v = intval( $v_original );
$v = ( $v > 0 ? $v : 1 );
if ( (string)$v_original !== (string)$v ) {
$accessor->set( $storage_key, $v );
}
$this->_key_version[$group] = $v;
}
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 = '' ) {
$storage_key = $this->_get_key_version_key( $group );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return false;
$accessor->set( $storage_key, $v );
return true;
}
/**
* Used to replace as atomically as possible known value to new one
*/
public function set_if_maybe_equals( $key, $old_value, $new_value ) {
$storage_key = $this->get_item_key( $key );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return false;
$accessor->watch( $storage_key );
$value = $accessor->get( $storage_key );
if ( !is_array( $value ) ) {
$accessor->unwatch();
return false;
}
if ( isset( $old_value['content'] ) &&
$value['content'] != $old_value['content'] ) {
$accessor->unwatch();
return false;
}
return $ret = $accessor->multi()
->set( $storage_key, $new_value )
->exec();
}
/**
* 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 );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return false;
$r = $accessor->incrBy( $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 );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return false;
return $accessor->set( $storage_key, $value );
}
/**
* Get counter's value
*/
public function counter_get( $key ) {
$storage_key = $this->get_item_key( $key );
$accessor = $this->_get_accessor( $storage_key );
if ( is_null( $accessor ) )
return 0;
$v = (int)$accessor->get( $storage_key );
return $v;
}
private function _get_accessor( $key ) {
if ( count( $this->_servers ) <= 1 )
$index = 0;
else {
$index = crc32( $key ) % count( $this->_servers );
}
if ( isset( $this->_accessors[$index] ) )
return $this->_accessors[$index];
if ( !isset( $this->_servers[$index] ) )
$this->_accessors[$index] = null;
else {
try {
$server = $this->_servers[$index];
$accessor = new \Redis();
if ( substr( $server, 0, 5 ) == 'unix:' ) {
if ( $this->_persistent ) {
$accessor->pconnect( trim( substr( $server, 5 ) ),
null, null, $this->_instance_id . '_' . $this->_dbid );
} else {
$accessor->connect( trim( substr( $server, 5 ) ) );
}
} else {
list( $ip, $port ) = Util_Content::endpoint_to_host_port( $server, null );
if ( $this->_persistent ) {
$accessor->pconnect( $ip, $port,
null, $this->_instance_id . '_' . $this->_dbid );
} else {
$accessor->connect( $ip, $port );
}
}
if ( !empty( $this->_password ) )
$accessor->auth( $this->_password );
$accessor->select( $this->_dbid );
} catch ( \Exception $e ) {
error_log( $e->getMessage() );
$accessor = null;
}
$this->_accessors[$index] = $accessor;
}
return $this->_accessors[$index];
}
}