* @file
*/
-/**
- * Interface that deferrable updates should implement. Basically required so we
- * can validate input on DeferredUpdates::addUpdate()
- *
- * @since 1.19
- */
-interface DeferrableUpdate {
- /**
- * Perform the actual work
- */
- function doUpdate();
-}
-
/**
* Class for managing the deferred updates
*
- * Deferred updates can be run at the end of the request,
- * after the HTTP response has been sent. In CLI mode, updates
- * are only deferred until there is no local master DB transaction.
- * When updates are deferred, they go into a simple FIFO queue.
+ * In web request mode, deferred updates can be run at the end of the request, either before or
+ * after the HTTP response has been sent. In either case, they run after the DB commit step. If
+ * an update runs after the response is sent, it will not block clients. If sent before, it will
+ * run synchronously. If such an update works via queueing, it will be more likely to complete by
+ * the time the client makes their next request after this one.
+ *
+ * In CLI mode, updates are only deferred until the current wiki has no DB write transaction
+ * active within this request.
+ *
+ * When updates are deferred, they use a FIFO queue (one for pre-send and one for post-send).
*
* @since 1.19
*/
class DeferredUpdates {
- /** @var DeferrableUpdate[] Updates to be deferred until the end of the request */
- private static $updates = array();
- /** @var bool Defer updates fully even in CLI mode */
- private static $forceDeferral = false;
+ /** @var DeferrableUpdate[] Updates to be deferred until before request end */
+ private static $preSendUpdates = [];
+ /** @var DeferrableUpdate[] Updates to be deferred until after request end */
+ private static $postSendUpdates = [];
+
+ const ALL = 0; // all updates
+ const PRESEND = 1; // for updates that should run before flushing output buffer
+ const POSTSEND = 2; // for updates that should run after flushing output buffer
/**
* Add an update to the deferred list
+ *
* @param DeferrableUpdate $update Some object that implements doUpdate()
+ * @param integer $type DeferredUpdates constant (PRESEND or POSTSEND) (since 1.27)
+ */
+ public static function addUpdate( DeferrableUpdate $update, $type = self::POSTSEND ) {
+ if ( $type === self::PRESEND ) {
+ self::push( self::$preSendUpdates, $update );
+ } else {
+ self::push( self::$postSendUpdates, $update );
+ }
+ }
+
+ /**
+ * Add a callable update. In a lot of cases, we just need a callback/closure,
+ * defining a new DeferrableUpdate object is not necessary
+ *
+ * @see MWCallableUpdate::__construct()
+ *
+ * @param callable $callable
+ * @param integer $type DeferredUpdates constant (PRESEND or POSTSEND) (since 1.27)
+ */
+ public static function addCallableUpdate( $callable, $type = self::POSTSEND ) {
+ self::addUpdate( new MWCallableUpdate( $callable ), $type );
+ }
+
+ /**
+ * Do any deferred updates and clear the list
+ *
+ * @param string $mode Use "enqueue" to use the job queue when possible [Default: "run"]
+ * @param integer $type DeferredUpdates constant (PRESEND, POSTSEND, or ALL) (since 1.27)
*/
- public static function addUpdate( DeferrableUpdate $update ) {
+ public static function doUpdates( $mode = 'run', $type = self::ALL ) {
+ if ( $type === self::ALL || $type == self::PRESEND ) {
+ self::execute( self::$preSendUpdates, $mode );
+ }
+
+ if ( $type === self::ALL || $type == self::POSTSEND ) {
+ self::execute( self::$postSendUpdates, $mode );
+ }
+ }
+
+ private static function push( array &$queue, DeferrableUpdate $update ) {
global $wgCommandLineMode;
- array_push( self::$updates, $update );
- if ( self::$forceDeferral ) {
- return;
+ if ( $update instanceof MergeableUpdate ) {
+ $class = get_class( $update ); // fully-qualified class
+ if ( isset( $queue[$class] ) ) {
+ /** @var $existingUpdate MergeableUpdate */
+ $existingUpdate = $queue[$class];
+ $existingUpdate->merge( $update );
+ } else {
+ $queue[$class] = $update;
+ }
+ } else {
+ $queue[] = $update;
}
// CLI scripts may forget to periodically flush these updates,
- // so try to handle that rather than OOMing and losing them.
- // Try to run the updates as soon as there is no local transaction.
+ // so try to handle that rather than OOMing and losing them entirely.
+ // Try to run the updates as soon as there is no current wiki transaction.
static $waitingOnTrx = false; // de-duplicate callback
if ( $wgCommandLineMode && !$waitingOnTrx ) {
$lb = wfGetLB();
}
}
- /**
- * Add a callable update. In a lot of cases, we just need a callback/closure,
- * defining a new DeferrableUpdate object is not necessary
- * @see MWCallableUpdate::__construct()
- * @param callable $callable
- */
- public static function addCallableUpdate( $callable ) {
- self::addUpdate( new MWCallableUpdate( $callable ) );
- }
-
- /**
- * Do any deferred updates and clear the list
- *
- * @param string $mode Use "enqueue" to use the job queue when possible [Default: run]
- * prevent lock contention
- * @param string $oldMode Unused
- */
- public static function doUpdates( $mode = 'run', $oldMode = '' ) {
- // B/C for ( $commit, $mode ) args
- $mode = $oldMode ?: $mode;
- if ( $mode === 'commit' ) {
- $mode = 'run';
- }
-
- $updates = self::$updates;
+ public static function execute( array &$queue, $mode ) {
+ $updates = $queue; // snapshot of queue
+ // Keep doing rounds of updates until none get enqueued
while ( count( $updates ) ) {
- self::clearPendingUpdates();
+ $queue = []; // clear the queue
/** @var DataUpdate[] $dataUpdates */
- $dataUpdates = array();
+ $dataUpdates = [];
/** @var DeferrableUpdate[] $otherUpdates */
- $otherUpdates = array();
+ $otherUpdates = [];
foreach ( $updates as $update ) {
if ( $update instanceof DataUpdate ) {
$dataUpdates[] = $update;
foreach ( $otherUpdates as $update ) {
try {
$update->doUpdate();
- wfGetLBFactory()->commitMasterChanges();
+ wfGetLBFactory()->commitMasterChanges( __METHOD__ );
} catch ( Exception $e ) {
// We don't want exceptions thrown during deferred updates to
// be reported to the user since the output is already sent
}
// Make sure incomplete transactions are not committed and end any
// open atomic sections so that other DB updates have a chance to run
- wfGetLBFactory()->rollbackMasterChanges();
+ wfGetLBFactory()->rollbackMasterChanges( __METHOD__ );
}
}
- $updates = self::$updates;
+ $updates = $queue; // new snapshot of queue (check for new entries)
}
}
* want or need to call this. Unit tests need it though.
*/
public static function clearPendingUpdates() {
- self::$updates = array();
- }
-
- /**
- * @note This method is intended for testing purposes
- * @param bool $value Whether to *always* defer updates, even in CLI mode
- * @since 1.27
- */
- public static function forceDeferral( $value ) {
- self::$forceDeferral = $value;
+ self::$preSendUpdates = [];
+ self::$postSendUpdates = [];
}
}
dépôts / lhc / web / wiklou.git / blobdiff