From: Aaron Schulz <aschulz@wikimedia.org>
Date: Fri, 21 Nov 2014 22:54:57 +0000 (-0800)
Subject: Adding basic profiler sampling support and restored the --profiler script option
X-Git-Tag: 1.31.0-rc.0~13202^2
X-Git-Url: http://git.cyclocoop.org/%40spipnet%40?a=commitdiff_plain;h=66170e7e59171177ccd0538a4b5a5712473135ae;p=lhc%2Fweb%2Fwiklou.git

Adding basic profiler sampling support and restored the --profiler script option

* Also enforce that the profiler is normally off in CLI mode

Change-Id: I35faedff818af2ad459b544c9ad50e77b54b378e
---

diff --git a/StartProfiler.sample b/StartProfiler.sample
index b72d5d59ff..d20c0e1bd9 100644
--- a/StartProfiler.sample
+++ b/StartProfiler.sample
@@ -22,8 +22,12 @@
  * maintenance/archives/patch-profiling.sql to your database.
  *
  * For a rudimentary sampling profiler:
- *   if ( !mt_rand( 0, 100 ) ) {
- *       $wgProfiler['class'] = 'ProfilerStandard';
- *       $wgProfiler['output'] = array( 'db' );
- *   }
+ *   $wgProfiler['class'] = 'ProfilerStandard';
+ *   $wgProfiler['output'] = array( 'db' );
+ *   $wgProfiler['sampling'] = 50; // one every 50 requests
+ * This will use ProfilerStub for non-sampled cases.
+ *
+ * For performance, the profiler is always disabled for CLI scripts
+ * as they could be long running and the data would accumulate. Use
+ * the --profiler parameter of maintenance scripts to override this.
  */
diff --git a/includes/profiler/Profiler.php b/includes/profiler/Profiler.php
index f2bdc849ac..2b3b61675d 100644
--- a/includes/profiler/Profiler.php
+++ b/includes/profiler/Profiler.php
@@ -72,10 +72,10 @@ abstract class Profiler {
 		if ( self::$__instance === null ) {
 			global $wgProfiler;
 			if ( is_array( $wgProfiler ) ) {
-				if ( !isset( $wgProfiler['class'] ) ) {
+				$class = isset( $wgProfiler['class'] ) ? $wgProfiler['class'] : 'ProfilerStub';
+				$factor = isset( $wgProfiler['sampling'] ) ? $wgProfiler['sampling'] : 1;
+				if ( PHP_SAPI === 'cli' || mt_rand( 0, $factor - 1 ) != 0 ) {
 					$class = 'ProfilerStub';
-				} else {
-					$class = $wgProfiler['class'];
 				}
 				self::$__instance = new $class( $wgProfiler );
 			} else {
@@ -85,6 +85,21 @@ abstract class Profiler {
 		return self::$__instance;
 	}
 
+	/**
+	 * Replace the current profiler with $profiler if no non-stub profiler is set
+	 *
+	 * @param Profiler $profiler
+	 * @throws MWException
+	 * @since 1.25
+	 */
+	final public static function replaceStubInstance( Profiler $profiler ) {
+		if ( self::$__instance && !( self::$__instance instanceof ProfilerStub ) ) {
+			throw new MWException( 'Could not replace non-stub profiler instance.' );
+		} else {
+			self::$__instance = $profiler;
+		}
+	}
+
 	/**
 	 * Return whether this a stub profiler
 	 *
@@ -144,8 +159,7 @@ abstract class Profiler {
 	 * @since 1.25
 	 */
 	public function logData() {
-		$output = isset( $this->params['output'] ) ?
-			$this->params['output'] : null;
+		$output = isset( $this->params['output'] ) ? $this->params['output'] : null;
 
 		if ( !$output || $this->isStub() ) {
 			// return early when no output classes defined or we're a stub
diff --git a/maintenance/Maintenance.php b/maintenance/Maintenance.php
index 3f8f6e8a32..1d558d281a 100644
--- a/maintenance/Maintenance.php
+++ b/maintenance/Maintenance.php
@@ -446,6 +446,7 @@ abstract class Maintenance {
 		$this->addOption( 'server', "The protocol and server name to use in URLs, e.g. " .
 			"http://en.wikipedia.org. This is sometimes necessary because " .
 			"server name detection may fail in command line scripts.", false, true );
+		$this->addOption( 'profiler', 'Profiler output format (usually "text")', false, true );
 
 		# Save generic options to display them separately in help
 		$this->mGenericParameters = $this->mParams;
@@ -596,6 +597,23 @@ abstract class Maintenance {
 		}
 	}
 
+	/**
+	 * Activate the profiler (assuming $wgProfiler is set)
+	 */
+	protected function activateProfiler() {
+		global $wgProfiler;
+
+		$output = $this->getOption( 'profiler' );
+		if ( $output && is_array( $wgProfiler ) ) {
+			$class = $wgProfiler['class'];
+			$profiler = new $class(
+				array( 'sampling' => 1, 'output' => $output ) + $wgProfiler
+			);
+			$profiler->setTemplated( true );
+			Profiler::replaceStubInstance( $profiler );
+		}
+	}
+
 	/**
 	 * Clear all params and arguments.
 	 */
@@ -919,6 +937,9 @@ abstract class Maintenance {
 			LBFactory::destroyInstance();
 		}
 
+		// Per-script profiling; useful for debugging
+		$this->activateProfiler();
+
 		$this->afterFinalSetup();
 
 		$wgShowSQLErrors = true;