From 144245268ddce82b3734281fd1a3fbc09793209e Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Wed, 20 Jul 2016 19:32:55 -0700
Subject: [PATCH] Provide onTransaction* callbacks with the transaction result

This can later be used to cancel certain deferred updates.

Change-Id: Ib6649b6ca400f15ff441531d0fd6aecc3e4619eb
---
 includes/db/Database.php  | 13 +++++++------
 includes/db/IDatabase.php | 11 +++++++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/includes/db/Database.php b/includes/db/Database.php
index 16ea219290..f23e24f39f 100644
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -2460,7 +2460,7 @@ abstract class DatabaseBase implements IDatabase {
 	final public function onTransactionIdle( callable $callback ) {
 		$this->mTrxIdleCallbacks[] = [ $callback, wfGetCaller() ];
 		if ( !$this->mTrxLevel ) {
-			$this->runOnTransactionIdleCallbacks();
+			$this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
 		}
 	}
 
@@ -2475,9 +2475,10 @@ abstract class DatabaseBase implements IDatabase {
 	/**
 	 * Actually any "on transaction idle" callbacks.
 	 *
+	 * @param integer $trigger IDatabase::TRIGGER_* constant
 	 * @since 1.20
 	 */
-	protected function runOnTransactionIdleCallbacks() {
+	protected function runOnTransactionIdleCallbacks( $trigger ) {
 		$autoTrx = $this->getFlag( DBO_TRX ); // automatic begin() enabled?
 
 		$e = $ePrior = null; // last exception
@@ -2492,7 +2493,7 @@ abstract class DatabaseBase implements IDatabase {
 				try {
 					list( $phpCallback ) = $callback;
 					$this->clearFlag( DBO_TRX ); // make each query its own transaction
-					call_user_func( $phpCallback );
+					call_user_func_array( $phpCallback, [ $trigger ] );
 					if ( $autoTrx ) {
 						$this->setFlag( DBO_TRX ); // restore automatic begin()
 					} else {
@@ -2623,7 +2624,7 @@ abstract class DatabaseBase implements IDatabase {
 					$this->mServer, $this->mDBname, $this->mTrxShortId, $writeTime );
 			}
 
-			$this->runOnTransactionIdleCallbacks();
+			$this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
 		}
 
 		// Avoid fatals if close() was called
@@ -2699,7 +2700,7 @@ abstract class DatabaseBase implements IDatabase {
 				$this->mServer, $this->mDBname, $this->mTrxShortId, $writeTime );
 		}
 
-		$this->runOnTransactionIdleCallbacks();
+		$this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
 	}
 
 	/**
@@ -2739,7 +2740,7 @@ abstract class DatabaseBase implements IDatabase {
 
 		$this->mTrxIdleCallbacks = []; // clear
 		$this->mTrxPreCommitCallbacks = []; // clear
-		$this->runOnTransactionIdleCallbacks();
+		$this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
 	}
 
 	/**
diff --git a/includes/db/IDatabase.php b/includes/db/IDatabase.php
index 36772b8048..c024632edf 100644
--- a/includes/db/IDatabase.php
+++ b/includes/db/IDatabase.php
@@ -33,6 +33,11 @@
  * @ingroup Database
  */
 interface IDatabase {
+	/* Constants to onTransactionResolution() callbacks */
+	const TRIGGER_IDLE = 1;
+	const TRIGGER_COMMIT = 2;
+	const TRIGGER_ROLLBACK = 3;
+
 	/**
 	 * A string describing the current software version, and possibly
 	 * other details in a user-friendly way. Will be listed on Special:Version, etc.
@@ -1223,6 +1228,9 @@ interface IDatabase {
 	 *
 	 * This is useful for combining cooperative locks and DB transactions.
 	 *
+	 * The callback takes one argument:
+	 * How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK)
+	 *
 	 * @param callable $callback
 	 * @return mixed
 	 * @since 1.28
@@ -1242,6 +1250,9 @@ interface IDatabase {
 	 *
 	 * Updates will execute in the order they were enqueued.
 	 *
+	 * The callback takes one argument:
+	 * How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_IDLE)
+	 *
 	 * @param callable $callback
 	 * @since 1.20
 	 */
-- 
2.20.1