From 61df5e785f22748b259c9e71c277e815a0f66e4f Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 26 Feb 2015 15:41:50 -0800
Subject: [PATCH] Made SqlBagOStuff avoid tripping TransactionProfiler

* Set a custom profiler with no expectations to avoid tripping
  the "0 write" expection. This avoids useless log entries.

Change-Id: Iac849a729eb36b1a8affb0dbc8b8c195fab4b03a
---
 includes/db/Database.php              | 30 ++++++++++++++++++++-------
 includes/objectcache/SqlBagOStuff.php |  2 ++
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/includes/db/Database.php b/includes/db/Database.php
index ee1722e606..1a7a97d3ed 100644
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -153,6 +153,9 @@ abstract class DatabaseBase implements IDatabase {
 	 */
 	protected $allViews = null;
 
+	/** @var TransactionProfiler */
+	protected $trxProfiler;
+
 	/**
 	 * A string describing the current software version, and possibly
 	 * other details in a user-friendly way. Will be listed on Special:Version, etc.
@@ -345,6 +348,15 @@ abstract class DatabaseBase implements IDatabase {
 	public function setFakeMaster( $enabled = true ) {
 	}
 
+	/**
+	 * @return TransactionProfiler
+	 */
+	protected function getTransactionProfiler() {
+		return $this->trxProfiler
+			? $this->trxProfiler
+			: Profiler::instance()->getTransactionProfiler();
+	}
+
 	/**
 	 * Returns true if this database supports (and uses) cascading deletes
 	 *
@@ -798,12 +810,16 @@ abstract class DatabaseBase implements IDatabase {
 
 		$this->mForeign = $foreign;
 
+		if ( isset( $params['trxProfiler'] ) ) {
+			$this->trxProfiler = $params['trxProfiler']; // override
+		}
+
 		if ( $user ) {
 			$this->open( $server, $user, $password, $dbName );
 		}
 
 		$isMaster = !is_null( $this->getLBInfo( 'master' ) );
-		$trxProf = Profiler::instance()->getTransactionProfiler();
+		$trxProf = $this->getTransactionProfiler();
 		$trxProf->recordConnection( $this->mServer, $this->mDBname, $isMaster );
 	}
 
@@ -1103,7 +1119,7 @@ abstract class DatabaseBase implements IDatabase {
 		# Keep track of whether the transaction has write queries pending
 		if ( $this->mTrxLevel && !$this->mTrxDoneWrites && $isWriteQuery ) {
 			$this->mTrxDoneWrites = true;
-			Profiler::instance()->getTransactionProfiler()->transactionWritingIn(
+			$this->getTransactionProfiler()->transactionWritingIn(
 				$this->mServer, $this->mDBname, $this->mTrxShortId );
 		}
 
@@ -1149,7 +1165,7 @@ abstract class DatabaseBase implements IDatabase {
 		$startTime = microtime( true );
 		$ret = $this->doQuery( $commentedSql );
 		# Log the query time and feed it into the DB trx profiler
-		$profiler->getTransactionProfiler()->recordQueryCompletion(
+		$this->getTransactionProfiler()->recordQueryCompletion(
 			$queryProf, $startTime, $isWriteQuery, $this->affectedRows() );
 
 		MWDebug::queryTime( $queryId );
@@ -1180,7 +1196,7 @@ abstract class DatabaseBase implements IDatabase {
 					$startTime = microtime( true );
 					$ret = $this->doQuery( $commentedSql );
 					# Log the query time and feed it into the DB trx profiler
-					$profiler->getTransactionProfiler()->recordQueryCompletion(
+					$this->getTransactionProfiler()->recordQueryCompletion(
 						$queryProf, $startTime, $isWriteQuery, $this->affectedRows() );
 				}
 			} else {
@@ -3599,7 +3615,7 @@ abstract class DatabaseBase implements IDatabase {
 			$this->runOnTransactionPreCommitCallbacks();
 			$this->doCommit( $fname );
 			if ( $this->mTrxDoneWrites ) {
-				Profiler::instance()->getTransactionProfiler()->transactionWritingOut(
+				$this->getTransactionProfiler()->transactionWritingOut(
 					$this->mServer, $this->mDBname, $this->mTrxShortId );
 			}
 			$this->runOnTransactionIdleCallbacks();
@@ -3679,7 +3695,7 @@ abstract class DatabaseBase implements IDatabase {
 		$this->runOnTransactionPreCommitCallbacks();
 		$this->doCommit( $fname );
 		if ( $this->mTrxDoneWrites ) {
-			Profiler::instance()->getTransactionProfiler()->transactionWritingOut(
+			$this->getTransactionProfiler()->transactionWritingOut(
 				$this->mServer, $this->mDBname, $this->mTrxShortId );
 		}
 		$this->runOnTransactionIdleCallbacks();
@@ -3738,7 +3754,7 @@ abstract class DatabaseBase implements IDatabase {
 		$this->mTrxPreCommitCallbacks = array(); // cancel
 		$this->mTrxAtomicLevels = new SplStack;
 		if ( $this->mTrxDoneWrites ) {
-			Profiler::instance()->getTransactionProfiler()->transactionWritingOut(
+			$this->getTransactionProfiler()->transactionWritingOut(
 				$this->mServer, $this->mDBname, $this->mTrxShortId );
 		}
 	}
diff --git a/includes/objectcache/SqlBagOStuff.php b/includes/objectcache/SqlBagOStuff.php
index 2fb9ff992d..82eeb842e8 100644
--- a/includes/objectcache/SqlBagOStuff.php
+++ b/includes/objectcache/SqlBagOStuff.php
@@ -145,6 +145,8 @@ class SqlBagOStuff extends BagOStuff {
 				$type = isset( $info['type'] ) ? $info['type'] : 'mysql';
 				$host = isset( $info['host'] ) ? $info['host'] : '[unknown]';
 				$this->logger->debug( __CLASS__ . ": connecting to $host" );
+				// Use a blank trx profiler to ignore expections as this is a cache
+				$info['trxProfiler'] = new TransactionProfiler();
 				$db = DatabaseBase::factory( $type, $info );
 				$db->clearFlag( DBO_TRX );
 			} else {
-- 
2.20.1