<?php
-
/**
- * This class stores an arbitrary value along with its dependencies.
+ * This class stores an arbitrary value along with its dependencies.
* Users should typically only use DependencyWrapper::getFromCache(), rather
* than instantiating one of these objects directly.
+ * @ingroup Cache
*/
class DependencyWrapper {
var $value;
/**
* Create an instance.
- * @param mixed $value The user-supplied value
- * @param mixed $deps A dependency or dependency array. All dependencies
+ * @param $value Mixed: the user-supplied value
+ * @param $deps Mixed: a dependency or dependency array. All dependencies
* must be objects implementing CacheDependency.
*/
function __construct( $value = false, $deps = array() ) {
$this->deps = $deps;
}
- /**
+ /**
* Returns true if any of the dependencies have expired
*/
function isExpired() {
}
/**
- * Attempt to get a value from the cache. If the value is expired or missing,
+ * Attempt to get a value from the cache. If the value is expired or missing,
* it will be generated with the callback function (if present), and the newly
- * calculated value will be stored to the cache in a wrapper.
+ * calculated value will be stored to the cache in a wrapper.
*
- * @param object $cache A cache object such as $wgMemc
- * @param string $key The cache key
- * @param integer $expiry The expiry timestamp or interval in seconds
- * @param mixed $callback The callback for generating the value, or false
- * @param array $callbackParams The function parameters for the callback
- * @param array $deps The dependencies to store on a cache miss. Note: these
+ * @param $cache Object: a cache object such as $wgMemc
+ * @param $key String: the cache key
+ * @param $expiry Integer: the expiry timestamp or interval in seconds
+ * @param $callback Mixed: the callback for generating the value, or false
+ * @param $callbackParams Array: the function parameters for the callback
+ * @param $deps Array: the dependencies to store on a cache miss. Note: these
* are not the dependencies used on a cache hit! Cache hits use the stored
* dependency array.
*
* @return mixed The value, or null if it was not present in the cache and no
* callback was defined.
*/
- static function getValueFromCache( $cache, $key, $expiry = 0, $callback = false,
- $callbackParams = array(), $deps = array() )
+ static function getValueFromCache( $cache, $key, $expiry = 0, $callback = false,
+ $callbackParams = array(), $deps = array() )
{
$obj = $cache->get( $key );
- if ( $obj && !$obj->isExpired() ) {
+ if ( is_object( $obj ) && $obj instanceof DependencyWrapper && !$obj->isExpired() ) {
$value = $obj->value;
} elseif ( $callback ) {
$value = call_user_func_array( $callback, $callbackParams );
}
}
+/**
+ * @ingroup Cache
+ */
abstract class CacheDependency {
/**
* Returns true if the dependency is expired, false otherwise
/**
* Hook to perform any expensive pre-serialize loading of dependency values.
*/
- function loadDependencyValues() {}
+ function loadDependencyValues() { }
}
+/**
+ * @ingroup Cache
+ */
class FileDependency extends CacheDependency {
var $filename, $timestamp;
/**
* Create a file dependency
*
- * @param string $filename The name of the file, preferably fully qualified
- * @param mixed $timestamp The unix last modified timestamp, or false if the
- * file does not exist. If omitted, the timestamp will be loaded from
+ * @param $filename String: the name of the file, preferably fully qualified
+ * @param $timestamp Mixed: the unix last modified timestamp, or false if the
+ * file does not exist. If omitted, the timestamp will be loaded from
* the file.
*
- * A dependency on a nonexistent file will be triggered when the file is
- * created. A dependency on an existing file will be triggered when the
+ * A dependency on a nonexistent file will be triggered when the file is
+ * created. A dependency on an existing file will be triggered when the
* file is changed.
*/
function __construct( $filename, $timestamp = null ) {
$this->timestamp = $timestamp;
}
+ function __sleep() {
+ $this->loadDependencyValues();
+ return array( 'filename', 'timestamp' );
+ }
+
function loadDependencyValues() {
if ( is_null( $this->timestamp ) ) {
if ( !file_exists( $this->filename ) ) {
}
}
+/**
+ * @ingroup Cache
+ */
class TitleDependency extends CacheDependency {
var $titleObj;
var $ns, $dbk;
/**
* Construct a title dependency
- * @param Title $title
+ * @param $title Title
*/
function __construct( Title $title ) {
$this->titleObj = $title;
function loadDependencyValues() {
$this->touched = $this->getTitle()->getTouched();
}
-
+
/**
* Get rid of bulky Title object for sleep
*/
function getTitle() {
if ( !isset( $this->titleObj ) ) {
$this->titleObj = Title::makeTitle( $this->ns, $this->dbk );
- }
+ }
return $this->titleObj;
}
function isExpired() {
$touched = $this->getTitle()->getTouched();
+
if ( $this->touched === false ) {
if ( $touched === false ) {
# Still missing
}
}
+/**
+ * @ingroup Cache
+ */
class TitleListDependency extends CacheDependency {
var $linkBatch;
var $timestamps;
-
+
/**
* Construct a dependency on a list of titles
*/
function calculateTimestamps() {
# Initialise values to false
$timestamps = array();
+
foreach ( $this->getLinkBatch()->data as $ns => $dbks ) {
if ( count( $dbks ) > 0 ) {
$timestamps[$ns] = array();
# Do the query
if ( count( $timestamps ) ) {
- $dbr =& wfGetDB( DB_SLAVE );
+ $dbr = wfGetDB( DB_SLAVE );
$where = $this->getLinkBatch()->constructSet( 'page', $dbr );
- $res = $dbr->select( 'page',
+ $res = $dbr->select(
+ 'page',
array( 'page_namespace', 'page_title', 'page_touched' ),
- $where, __METHOD__ );
+ $where,
+ __METHOD__
+ );
+
while ( $row = $dbr->fetchObject( $res ) ) {
$timestamps[$row->page_namespace][$row->page_title] = $row->page_touched;
}
}
function getLinkBatch() {
- if ( !isset( $this->linkBatch ) ){
+ if ( !isset( $this->linkBatch ) ) {
$this->linkBatch = new LinkBatch;
$this->linkBatch->setArray( $this->timestamps );
}
foreach ( $this->timestamps as $ns => $dbks ) {
foreach ( $dbks as $dbk => $oldTimestamp ) {
$newTimestamp = $newTimestamps[$ns][$dbk];
+
if ( $oldTimestamp === false ) {
if ( $newTimestamp === false ) {
# Still missing
}
}
+/**
+ * @ingroup Cache
+ */
class GlobalDependency extends CacheDependency {
var $name, $value;
-
+
function __construct( $name ) {
$this->name = $name;
$this->value = $GLOBALS[$name];
}
}
+/**
+ * @ingroup Cache
+ */
class ConstantDependency extends CacheDependency {
var $name, $value;
return constant( $this->name ) != $this->value;
}
}
-
-?>