From 27b9c0639d976e8048330c7ee95be30f61ee941b Mon Sep 17 00:00:00 2001
From: Ori Livneh <ori@wikimedia.org>
Date: Thu, 2 Apr 2015 10:46:57 -0700
Subject: [PATCH] Simplify profiler output class selection

Instead of maintaining a mapping of short names to class names ('db' =>
'ProfilerOutputDb', etc.), let us adopt the convention of using the full
class name to indicate the output type. We can maintain backward-compatibility
by using simple string manipulation to transform short names to the full class
names.

Change-Id: I976e0da2873d88b9892fb41823cfe3af0a2d3974
---
 StartProfiler.sample           | 35 +++++++++++++++++++---------------
 includes/profiler/Profiler.php | 22 +++++++--------------
 2 files changed, 27 insertions(+), 30 deletions(-)

diff --git a/StartProfiler.sample b/StartProfiler.sample
index 6681b870cf..7a8895799c 100644
--- a/StartProfiler.sample
+++ b/StartProfiler.sample
@@ -4,30 +4,35 @@
  * To use a profiler, copy this file to StartProfiler.php and add:
  *  $wgProfiler['class'] = 'ProfilerXhprof';
  *
- * For output, add:
- *  $wgProfiler['output'] = array( 'text' );
- *    'text' can be one (or more) of 'text' 'udp' 'db' or 'dump'
- *    'db' requires creating the profiling table, see patch-profiling.sql
+ * For output, set the 'output' key to an array of class names, one for each
+ * output type you want the profiler to generate. For example:
+ *  $wgProfiler['output'] = array( 'ProfilerOutputText' );
  *
- * The 'text' output will be added to the output page in a comment approriate
- * to the output's mime type. For a text/html page, this display can be
- * changed to a preformatted text block by setting the 'visible' configuration
- * flag:
+ * The output classes available to you by default are ProfilerOutputDb,
+ * ProfilerOutputDump, ProfilerOutputStats, ProfilerOutputText, and
+ * ProfilerOutputUdp.
+ *
+ * ProfilerOutputStats outputs profiling data as StatsD metrics. It expects
+ * that you have set the $wgStatsdServer configuration variable to the host (or
+ * host:port) of your statsd server.
+ *
+ * ProfilerOutputText will output profiling data in the page body as a comment.
+ * You can make the profiling data in HTML render as part of the page content
+ * by setting the 'visible' configuration flag:
  *  $wgProfiler['visible'] = true;
  *
- * The 'db' output expects a database table that can be created by applying
+ * 'ProfilerOutputDb' expects a database table that can be created by applying
  * maintenance/archives/patch-profiling.sql to your database.
  *
- * The 'dump' output expects a $wgProfiler['outputDir'] telling it where to
+ * 'ProfilerOutputDump' expects a $wgProfiler['outputDir'] telling it where to
  * write dump files. The files produced are compatible with the XHProf gui.
- *
  * For a rudimentary sampling profiler:
  *   $wgProfiler['class'] = 'ProfilerXhprof';
- *   $wgProfiler['output'] = array( 'db' );
+ *   $wgProfiler['output'] = array( 'ProfilingOutputDb' );
  *   $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.
+ * 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 924bb0372f..dbf80fa13b 100644
--- a/includes/profiler/Profiler.php
+++ b/includes/profiler/Profiler.php
@@ -37,21 +37,8 @@ abstract class Profiler {
 	protected $params = array();
 	/** @var IContextSource Current request context */
 	protected $context = null;
-
 	/** @var TransactionProfiler */
 	protected $trxProfiler;
-
-	/**
-	 * @var array Mapping of output type to class name
-	 */
-	private static $outputTypes = array(
-		'db' => 'ProfilerOutputDb',
-		'text' => 'ProfilerOutputText',
-		'udp' => 'ProfilerOutputUdp',
-		'dump' => 'ProfilerOutputDump',
-		'stats' => 'ProfilerOutputStats',
-	);
-
 	/** @var Profiler */
 	private static $instance = null;
 
@@ -201,10 +188,15 @@ abstract class Profiler {
 	private function getOutputs() {
 		$outputs = array();
 		foreach ( $this->params['output'] as $outputType ) {
-			if ( !isset( self::$outputTypes[$outputType] ) ) {
+			// The class may be specified as either the full class name (for
+			// example, 'ProfilerOutputUdp') or (for backward compatibility)
+			// the trailing portion of the class name (for example, 'udp').
+			$outputClass = strpos( $outputType, 'ProfilerOutput' ) === false
+				? 'ProfilerOutput' . ucfirst( $outputType )
+				: $outputType;
+			if ( !class_exists( $outputClass ) ) {
 				throw new MWException( "'$outputType' is an invalid output type" );
 			}
-			$outputClass = self::$outputTypes[$outputType];
 			$outputInstance = new $outputClass( $this, $this->params );
 			if ( $outputInstance->canUse() ) {
 				$outputs[] = $outputInstance;
-- 
2.20.1