Update to MediaWiki 1.25.1

19 files changed, 1743 insertions, 1464 deletions

diff --git a/includes/profiler/ProfileSection.php b/includes/profiler/ProfileSection.php
new file mode 100644
index 00000000..68ef6680
--- /dev/null
+++ b/includes/profiler/ProfileSection.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * Function scope profiling assistant
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ */
+
+/**
+ * Class for handling function-scope profiling
+ *
+ * @since 1.22
+ * @deprecated 1.25 No-op now
+ */
+class ProfileSection {
+	/**
+	 * Begin profiling of a function and return an object that ends profiling
+	 * of the function when that object leaves scope. As long as the object is
+	 * not specifically linked to other objects, it will fall out of scope at
+	 * the same moment that the function to be profiled terminates.
+	 *
+	 * This is typically called like:
+	 * <code>$section = new ProfileSection( __METHOD__ );</code>
+	 *
+	 * @param string $name Name of the function to profile
+	 */
+	public function __construct( $name ) {}
+}
diff --git a/includes/profiler/Profiler.php b/includes/profiler/Profiler.php
index 418b5d48..dbf80fa1 100644
--- a/includes/profiler/Profiler.php
+++ b/includes/profiler/Profiler.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Base class and functions for profiling.
+ * Base class for profiling.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -23,113 +23,33 @@
  */
 
 /**
- * Get system resource usage of current request context.
- * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
- * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
- *
- * @since 1.24
- * @return array|bool Resource usage data or false if no data available.
- */
-function wfGetRusage() {
-	if ( !function_exists( 'getrusage' ) ) {
-		return false;
-	} elseif ( defined ( 'HHVM_VERSION' ) ) {
-		return getrusage( 2 /* RUSAGE_THREAD */ );
-	} else {
-		return getrusage( 0 /* RUSAGE_SELF */ );
-	}
-}
-
-/**
- * Begin profiling of a function
- * @param string $functionname Name of the function we will profile
- */
-function wfProfileIn( $functionname ) {
-	if ( Profiler::$__instance === null ) { // use this directly to reduce overhead
-		Profiler::instance();
-	}
-	if ( !( Profiler::$__instance instanceof ProfilerStub ) ) {
-		Profiler::$__instance->profileIn( $functionname );
-	}
-}
-
-/**
- * Stop profiling of a function
- * @param string $functionname Name of the function we have profiled
- */
-function wfProfileOut( $functionname = 'missing' ) {
-	if ( Profiler::$__instance === null ) { // use this directly to reduce overhead
-		Profiler::instance();
-	}
-	if ( !( Profiler::$__instance instanceof ProfilerStub ) ) {
-		Profiler::$__instance->profileOut( $functionname );
-	}
-}
-
-/**
- * Class for handling function-scope profiling
- *
- * @since 1.22
- */
-class ProfileSection {
-	protected $name; // string; method name
-	protected $enabled = false; // boolean; whether profiling is enabled
-
-	/**
-	 * Begin profiling of a function and return an object that ends profiling of
-	 * the function when that object leaves scope. As long as the object is not
-	 * specifically linked to other objects, it will fall out of scope at the same
-	 * moment that the function to be profiled terminates.
-	 *
-	 * This is typically called like:
-	 * <code>$section = new ProfileSection( __METHOD__ );</code>
-	 *
-	 * @param string $name Name of the function to profile
-	 */
-	public function __construct( $name ) {
-		$this->name = $name;
-		if ( Profiler::$__instance === null ) { // use this directly to reduce overhead
-			Profiler::instance();
-		}
-		if ( !( Profiler::$__instance instanceof ProfilerStub ) ) {
-			$this->enabled = true;
-			Profiler::$__instance->profileIn( $this->name );
-		}
-	}
-
-	function __destruct() {
-		if ( $this->enabled ) {
-			Profiler::$__instance->profileOut( $this->name );
-		}
-	}
-}
-
-/**
- * Profiler base class that defines the interface and some trivial functionality
+ * Profiler base class that defines the interface and some trivial
+ * functionality
  *
  * @ingroup Profiler
  */
 abstract class Profiler {
 	/** @var string|bool Profiler ID for bucketing data */
-	protected $mProfileID = false;
+	protected $profileID = false;
 	/** @var bool Whether MediaWiki is in a SkinTemplate output context */
-	protected $mTemplated = false;
-
+	protected $templated = false;
+	/** @var array All of the params passed from $wgProfiler */
+	protected $params = array();
+	/** @var IContextSource Current request context */
+	protected $context = null;
 	/** @var TransactionProfiler */
 	protected $trxProfiler;
-
-	// @codingStandardsIgnoreStart PSR2.Classes.PropertyDeclaration.Underscore
-	/** @var Profiler Do not call this outside Profiler and ProfileSection */
-	public static $__instance = null;
-	// @codingStandardsIgnoreEnd
+	/** @var Profiler */
+	private static $instance = null;
 
 	/**
 	 * @param array $params
 	 */
 	public function __construct( array $params ) {
 		if ( isset( $params['profileID'] ) ) {
-			$this->mProfileID = $params['profileID'];
+			$this->profileID = $params['profileID'];
 		}
+		$this->params = $params;
 		$this->trxProfiler = new TransactionProfiler();
 	}
 
@@ -138,332 +58,243 @@ abstract class Profiler {
 	 * @return Profiler
 	 */
 	final public static function instance() {
-		if ( self::$__instance === null ) {
-			global $wgProfiler;
+		if ( self::$instance === null ) {
+			global $wgProfiler, $wgProfileLimit;
+
+			$params = array(
+				'class'     => 'ProfilerStub',
+				'sampling'  => 1,
+				'threshold' => $wgProfileLimit,
+				'output'    => array(),
+			);
 			if ( is_array( $wgProfiler ) ) {
-				if ( !isset( $wgProfiler['class'] ) ) {
-					$class = 'ProfilerStub';
-				} elseif ( $wgProfiler['class'] === 'Profiler' ) {
-					$class = 'ProfilerStub'; // b/c; don't explode
-				} else {
-					$class = $wgProfiler['class'];
-				}
-				self::$__instance = new $class( $wgProfiler );
-			} elseif ( $wgProfiler instanceof Profiler ) {
-				self::$__instance = $wgProfiler; // back-compat
-			} else {
-				self::$__instance = new ProfilerStub( array() );
+				$params = array_merge( $params, $wgProfiler );
 			}
-		}
-		return self::$__instance;
-	}
 
-	/**
-	 * Set the profiler to a specific profiler instance. Mostly for dumpHTML
-	 * @param Profiler $p
-	 */
-	final public static function setInstance( Profiler $p ) {
-		self::$__instance = $p;
-	}
+			$inSample = mt_rand( 0, $params['sampling'] - 1 ) === 0;
+			if ( PHP_SAPI === 'cli' || !$inSample ) {
+				$params['class'] = 'ProfilerStub';
+			}
 
-	/**
-	 * Return whether this a stub profiler
-	 *
-	 * @return bool
-	 */
-	abstract public function isStub();
+			if ( !is_array( $params['output'] ) ) {
+				$params['output'] = array( $params['output'] );
+			}
+
+			self::$instance = new $params['class']( $params );
+		}
+		return self::$instance;
+	}
 
 	/**
-	 * Return whether this profiler stores data
-	 *
-	 * Called by Parser::braceSubstitution. If true, the parser will not
-	 * generate per-title profiling sections, to avoid overloading the
-	 * profiling data collector.
+	 * Replace the current profiler with $profiler if no non-stub profiler is set
 	 *
-	 * @see Profiler::logData()
-	 * @return bool
+	 * @param Profiler $profiler
+	 * @throws MWException
+	 * @since 1.25
 	 */
-	abstract public function isPersistent();
+	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;
+		}
+	}
 
 	/**
 	 * @param string $id
 	 */
 	public function setProfileID( $id ) {
-		$this->mProfileID = $id;
+		$this->profileID = $id;
 	}
 
 	/**
 	 * @return string
 	 */
 	public function getProfileID() {
-		if ( $this->mProfileID === false ) {
+		if ( $this->profileID === false ) {
 			return wfWikiID();
 		} else {
-			return $this->mProfileID;
+			return $this->profileID;
 		}
 	}
 
 	/**
-	 * Called by wfProfieIn()
-	 *
-	 * @param string $functionname
-	 */
-	abstract public function profileIn( $functionname );
-
-	/**
-	 * Called by wfProfieOut()
-	 *
-	 * @param string $functionname
-	 */
-	abstract public function profileOut( $functionname );
-
-	/**
-	 * Mark a DB as in a transaction with one or more writes pending
+	 * Sets the context for this Profiler
 	 *
-	 * Note that there can be multiple connections to a single DB.
-	 *
-	 * @param string $server DB server
-	 * @param string $db DB name
-	 * @param string $id Resource ID string of connection
+	 * @param IContextSource $context
+	 * @since 1.25
 	 */
-	public function transactionWritingIn( $server, $db, $id = '' ) {
-		$this->trxProfiler->transactionWritingIn( $server, $db, $id );
+	public function setContext( $context ) {
+		$this->context = $context;
 	}
 
 	/**
-	 * Mark a DB as no longer in a transaction
-	 *
-	 * This will check if locks are possibly held for longer than
-	 * needed and log any affected transactions to a special DB log.
-	 * Note that there can be multiple connections to a single DB.
+	 * Gets the context for this Profiler
 	 *
-	 * @param string $server DB server
-	 * @param string $db DB name
-	 * @param string $id Resource ID string of connection
+	 * @return IContextSource
+	 * @since 1.25
 	 */
-	public function transactionWritingOut( $server, $db, $id = '' ) {
-		$this->trxProfiler->transactionWritingOut( $server, $db, $id );
+	public function getContext() {
+		if ( $this->context ) {
+			return $this->context;
+		} else {
+			wfDebug( __METHOD__ . " called and \$context is null. " .
+				"Return RequestContext::getMain(); for sanity\n" );
+			return RequestContext::getMain();
+		}
 	}
 
-	/**
-	 * Close opened profiling sections
-	 */
-	abstract public function close();
+	// Kept BC for now, remove when possible
+	public function profileIn( $functionname ) {}
+	public function profileOut( $functionname ) {}
 
 	/**
-	 * Log the data to some store or even the page output
+	 * Mark the start of a custom profiling frame (e.g. DB queries).
+	 * The frame ends when the result of this method falls out of scope.
+	 *
+	 * @param string $section
+	 * @return ScopedCallback|null
+	 * @since 1.25
 	 */
-	abstract public function logData();
+	abstract public function scopedProfileIn( $section );
 
 	/**
-	 * Mark this call as templated or not
-	 *
-	 * @param bool $t
+	 * @param ScopedCallback $section
 	 */
-	public function setTemplated( $t ) {
-		$this->mTemplated = $t;
+	public function scopedProfileOut( ScopedCallback &$section = null ) {
+		$section = null;
 	}
 
 	/**
-	 * Returns a profiling output to be stored in debug file
-	 *
-	 * @return string
+	 * @return TransactionProfiler
+	 * @since 1.25
 	 */
-	abstract public function getOutput();
+	public function getTransactionProfiler() {
+		return $this->trxProfiler;
+	}
 
 	/**
-	 * @return array
+	 * Close opened profiling sections
 	 */
-	abstract public function getRawData();
+	abstract public function close();
 
 	/**
-	 * Get the initial time of the request, based either on $wgRequestTime or
-	 * $wgRUstart. Will return null if not able to find data.
+	 * Get all usable outputs.
 	 *
-	 * @param string|bool $metric Metric to use, with the following possibilities:
-	 *   - user: User CPU time (without system calls)
-	 *   - cpu: Total CPU time (user and system calls)
-	 *   - wall (or any other string): elapsed time
-	 *   - false (default): will fall back to default metric
-	 * @return float|null
+	 * @throws MWException
+	 * @return array Array of ProfilerOutput instances.
+	 * @since 1.25
 	 */
-	protected function getTime( $metric = 'wall' ) {
-		if ( $metric === 'cpu' || $metric === 'user' ) {
-			$ru = wfGetRusage();
-			if ( !$ru ) {
-				return 0;
+	private function getOutputs() {
+		$outputs = array();
+		foreach ( $this->params['output'] as $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" );
 			}
-			$time = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
-			if ( $metric === 'cpu' ) {
-				# This is the time of system calls, added to the user time
-				# it gives the total CPU time
-				$time += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
+			$outputInstance = new $outputClass( $this, $this->params );
+			if ( $outputInstance->canUse() ) {
+				$outputs[] = $outputInstance;
 			}
-			return $time;
-		} else {
-			return microtime( true );
 		}
+		return $outputs;
 	}
 
 	/**
-	 * Get the initial time of the request, based either on $wgRequestTime or
-	 * $wgRUstart. Will return null if not able to find data.
+	 * Log the data to some store or even the page output
 	 *
-	 * @param string|bool $metric Metric to use, with the following possibilities:
-	 *   - user: User CPU time (without system calls)
-	 *   - cpu: Total CPU time (user and system calls)
-	 *   - wall (or any other string): elapsed time
-	 *   - false (default): will fall back to default metric
-	 * @return float|null
+	 * @since 1.25
 	 */
-	protected function getInitialTime( $metric = 'wall' ) {
-		global $wgRequestTime, $wgRUstart;
+	public function logData() {
+		$request = $this->getContext()->getRequest();
 
-		if ( $metric === 'cpu' || $metric === 'user' ) {
-			if ( !count( $wgRUstart ) ) {
-				return null;
-			}
+		$timeElapsed = $request->getElapsedTime();
+		$timeElapsedThreshold = $this->params['threshold'];
+		if ( $timeElapsed <= $timeElapsedThreshold ) {
+			return;
+		}
 
-			$time = $wgRUstart['ru_utime.tv_sec'] + $wgRUstart['ru_utime.tv_usec'] / 1e6;
-			if ( $metric === 'cpu' ) {
-				# This is the time of system calls, added to the user time
-				# it gives the total CPU time
-				$time += $wgRUstart['ru_stime.tv_sec'] + $wgRUstart['ru_stime.tv_usec'] / 1e6;
-			}
-			return $time;
-		} else {
-			if ( empty( $wgRequestTime ) ) {
-				return null;
-			} else {
-				return $wgRequestTime;
-			}
+		$outputs = $this->getOutputs();
+		if ( !$outputs ) {
+			return;
+		}
+
+		$stats = $this->getFunctionStats();
+		foreach ( $outputs as $output ) {
+			$output->log( $stats );
 		}
 	}
 
 	/**
-	 * Add an entry in the debug log file
-	 *
-	 * @param string $s String to output
+	 * Get the content type sent out to the client.
+	 * Used for profilers that output instead of store data.
+	 * @return string
+	 * @since 1.25
 	 */
-	protected function debug( $s ) {
-		if ( function_exists( 'wfDebug' ) ) {
-			wfDebug( $s );
+	public function getContentType() {
+		foreach ( headers_list() as $header ) {
+			if ( preg_match( '#^content-type: (\w+/\w+);?#i', $header, $m ) ) {
+				return $m[1];
+			}
 		}
+		return null;
 	}
 
 	/**
-	 * Add an entry in the debug log group
+	 * Mark this call as templated or not
 	 *
-	 * @param string $group Group to send the message to
-	 * @param string $s String to output
+	 * @param bool $t
 	 */
-	protected function debugGroup( $group, $s ) {
-		if ( function_exists( 'wfDebugLog' ) ) {
-			wfDebugLog( $group, $s );
-		}
+	public function setTemplated( $t ) {
+		$this->templated = $t;
 	}
-}
-
-/**
- * Helper class that detects high-contention DB queries via profiling calls
- *
- * This class is meant to work with a Profiler, as the later already knows
- * when methods start and finish (which may take place during transactions).
- *
- * @since 1.24
- */
-class TransactionProfiler {
-	/** @var float Seconds */
-	protected $mDBLockThreshold = 3.0;
-	/** @var array DB/server name => (active trx count, time, DBs involved) */
-	protected $mDBTrxHoldingLocks = array();
-	/** @var array DB/server name => list of (function name, elapsed time) */
-	protected $mDBTrxMethodTimes = array();
 
 	/**
-	 * Mark a DB as in a transaction with one or more writes pending
-	 *
-	 * Note that there can be multiple connections to a single DB.
+	 * Was this call as templated or not
 	 *
-	 * @param string $server DB server
-	 * @param string $db DB name
-	 * @param string $id ID string of transaction
+	 * @return bool
 	 */
-	public function transactionWritingIn( $server, $db, $id ) {
-		$name = "{$server} ({$db}) (TRX#$id)";
-		if ( isset( $this->mDBTrxHoldingLocks[$name] ) ) {
-			wfDebugLog( 'DBPerformance', "Nested transaction for '$name' - out of sync." );
-		}
-		$this->mDBTrxHoldingLocks[$name] =
-			array( 'start' => microtime( true ), 'conns' => array() );
-		$this->mDBTrxMethodTimes[$name] = array();
-
-		foreach ( $this->mDBTrxHoldingLocks as $name => &$info ) {
-			$info['conns'][$name] = 1; // track all DBs in transactions for this transaction
-		}
+	public function getTemplated() {
+		return $this->templated;
 	}
 
 	/**
-	 * Register the name and time of a method for slow DB trx detection
+	 * Get the aggregated inclusive profiling data for each method
 	 *
-	 * This method is only to be called by the Profiler class as methods finish
+	 * The percent time for each time is based on the current "total" time
+	 * used is based on all methods so far. This method can therefore be
+	 * called several times in between several profiling calls without the
+	 * delays in usage of the profiler skewing the results. A "-total" entry
+	 * is always included in the results.
 	 *
-	 * @param string $method Function name
-	 * @param float $realtime Wal time ellapsed
+	 * When a call chain involves a method invoked within itself, any
+	 * entries for the cyclic invocation should be be demarked with "@".
+	 * This makes filtering them out easier and follows the xhprof style.
+	 *
+	 * @return array List of method entries arrays, each having:
+	 *   - name     : method name
+	 *   - calls    : the number of invoking calls
+	 *   - real     : real time ellapsed (ms)
+	 *   - %real    : percent real time
+	 *   - cpu      : CPU time ellapsed (ms)
+	 *   - %cpu     : percent CPU time
+	 *   - memory   : memory used (bytes)
+	 *   - %memory  : percent memory used
+	 *   - min_real : min real time in a call (ms)
+	 *   - max_real : max real time in a call (ms)
+	 * @since 1.25
 	 */
-	public function recordFunctionCompletion( $method, $realtime ) {
-		if ( !$this->mDBTrxHoldingLocks ) {
-			return; // short-circuit
-		// @todo hardcoded check is a tad janky (what about FOR UPDATE?)
-		} elseif ( !preg_match( '/^query-m: (?!SELECT)/', $method )
-			&& $realtime < $this->mDBLockThreshold
-		) {
-			return; // not a DB master query nor slow enough
-		}
-		$now = microtime( true );
-		foreach ( $this->mDBTrxHoldingLocks as $name => $info ) {
-			// Hacky check to exclude entries from before the first TRX write
-			if ( ( $now - $realtime ) >= $info['start'] ) {
-				$this->mDBTrxMethodTimes[$name][] = array( $method, $realtime );
-			}
-		}
-	}
+	abstract public function getFunctionStats();
 
 	/**
-	 * Mark a DB as no longer in a transaction
-	 *
-	 * This will check if locks are possibly held for longer than
-	 * needed and log any affected transactions to a special DB log.
-	 * Note that there can be multiple connections to a single DB.
+	 * Returns a profiling output to be stored in debug file
 	 *
-	 * @param string $server DB server
-	 * @param string $db DB name
-	 * @param string $id ID string of transaction
+	 * @return string
 	 */
-	public function transactionWritingOut( $server, $db, $id ) {
-		$name = "{$server} ({$db}) (TRX#$id)";
-		if ( !isset( $this->mDBTrxMethodTimes[$name] ) ) {
-			wfDebugLog( 'DBPerformance', "Detected no transaction for '$name' - out of sync." );
-			return;
-		}
-		$slow = false;
-		foreach ( $this->mDBTrxMethodTimes[$name] as $info ) {
-			$realtime = $info[1];
-			if ( $realtime >= $this->mDBLockThreshold ) {
-				$slow = true;
-				break;
-			}
-		}
-		if ( $slow ) {
-			$dbs = implode( ', ', array_keys( $this->mDBTrxHoldingLocks[$name]['conns'] ) );
-			$msg = "Sub-optimal transaction on DB(s) [{$dbs}]:\n";
-			foreach ( $this->mDBTrxMethodTimes[$name] as $i => $info ) {
-				list( $method, $realtime ) = $info;
-				$msg .= sprintf( "%d\t%.6f\t%s\n", $i, $realtime, $method );
-			}
-			wfDebugLog( 'DBPerformance', $msg );
-		}
-		unset( $this->mDBTrxHoldingLocks[$name] );
-		unset( $this->mDBTrxMethodTimes[$name] );
-	}
+	abstract public function getOutput();
 }
diff --git a/includes/profiler/ProfilerFunctions.php b/includes/profiler/ProfilerFunctions.php
new file mode 100644
index 00000000..4984e77d
--- /dev/null
+++ b/includes/profiler/ProfilerFunctions.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * Core profiling functions. Have to exist before basically anything.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ */
+
+/**
+ * Get system resource usage of current request context.
+ * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
+ * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
+ *
+ * @since 1.24
+ * @return array|bool Resource usage data or false if no data available.
+ */
+function wfGetRusage() {
+	if ( !function_exists( 'getrusage' ) ) {
+		return false;
+	} elseif ( defined ( 'HHVM_VERSION' ) ) {
+		return getrusage( 2 /* RUSAGE_THREAD */ );
+	} else {
+		return getrusage( 0 /* RUSAGE_SELF */ );
+	}
+}
+
+/**
+ * Begin profiling of a function
+ * @param string $functionname Name of the function we will profile
+ * @deprecated 1.25
+ */
+function wfProfileIn( $functionname ) {
+}
+
+/**
+ * Stop profiling of a function
+ * @param string $functionname Name of the function we have profiled
+ * @deprecated 1.25
+ */
+function wfProfileOut( $functionname = 'missing' ) {
+}
diff --git a/includes/profiler/ProfilerMwprof.php b/includes/profiler/ProfilerMwprof.php
deleted file mode 100644
index af3c7741..00000000
--- a/includes/profiler/ProfilerMwprof.php
+++ /dev/null
@@ -1,256 +0,0 @@
-<?php
-/**
- * Profiler class for Mwprof.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- * @ingroup Profiler
- */
-
-/**
- * Profiler class for Mwprof.
- *
- * Mwprof is a high-performance MediaWiki profiling data collector, designed to
- * collect profiling data from multiple hosts running in tandem. This class
- * serializes profiling samples into MessagePack arrays and sends them to an
- * Mwprof instance via UDP.
- *
- * @see https://github.com/wikimedia/operations-software-mwprof
- * @since 1.23
- */
-class ProfilerMwprof extends Profiler {
-	/** @var array Queue of open profile calls with start data */
-	protected $mWorkStack = array();
-
-	/** @var array Map of (function name => aggregate data array) */
-	protected $mCollated = array();
-	/** @var array Cache of a standard broken collation entry */
-	protected $mErrorEntry;
-
-	// Message types
-	const TYPE_SINGLE = 1;
-	const TYPE_RUNNING = 2;
-
-	public function isStub() {
-		return false;
-	}
-
-	public function isPersistent() {
-		return true;
-	}
-
-	/**
-	 * Start a profiling section.
-	 *
-	 * Marks the beginning of the function or code-block that should be time
-	 * and logged under some specific name.
-	 *
-	 * @param string $inName Section to start
-	 */
-	public function profileIn( $inName ) {
-		$this->mWorkStack[] = array( $inName, count( $this->mWorkStack ),
-			$this->getTime(), $this->getTime( 'cpu' ), 0 );
-	}
-
-	/**
-	 * Close a profiling section.
-	 *
-	 * Marks the end of the function or code-block that should be timed and
-	 * logged under some specific name.
-	 *
-	 * @param string $outName Section to close
-	 */
-	public function profileOut( $outName ) {
-		list( $inName, $inCount, $inWall, $inCpu ) = array_pop( $this->mWorkStack );
-
-		// Check for unbalanced profileIn / profileOut calls.
-		// Bad entries are logged but not sent.
-		if ( $inName !== $outName ) {
-			$this->debugGroup( 'ProfilerUnbalanced', json_encode( array( $inName, $outName ) ) );
-			return;
-		}
-
-		$elapsedCpu = $this->getTime( 'cpu' ) - $inCpu;
-		$elapsedWall = $this->getTime() - $inWall;
-		$this->updateRunningEntry( $outName, $elapsedCpu, $elapsedWall );
-		$this->trxProfiler->recordFunctionCompletion( $outName, $elapsedWall );
-	}
-
-	/**
-	 * Update an entry with timing data.
-	 *
-	 * @param string $name Section name
-	 * @param float $elapsedCpu Elapsed CPU time
-	 * @param float $elapsedWall Elapsed wall-clock time
-	 */
-	public function updateRunningEntry( $name, $elapsedCpu, $elapsedWall ) {
-		// If this is the first measurement for this entry, store plain values.
-		// Many profiled functions will only be called once per request.
-		if ( !isset( $this->mCollated[$name] ) ) {
-			$this->mCollated[$name] = array(
-				'cpu'   => $elapsedCpu,
-				'wall'  => $elapsedWall,
-				'count' => 1,
-			);
-			return;
-		}
-
-		$entry = &$this->mCollated[$name];
-
-		// If it's the second measurement, convert the plain values to
-		// RunningStat instances, so we can push the incoming values on top.
-		if ( $entry['count'] === 1 ) {
-			$cpu = new RunningStat();
-			$cpu->push( $entry['cpu'] );
-			$entry['cpu'] = $cpu;
-
-			$wall = new RunningStat();
-			$wall->push( $entry['wall'] );
-			$entry['wall'] = $wall;
-		}
-
-		$entry['count']++;
-		$entry['cpu']->push( $elapsedCpu );
-		$entry['wall']->push( $elapsedWall );
-	}
-
-	/**
-	 * @return array
-	 */
-	public function getRawData() {
-		// This method is called before shutdown in the footer method on Skins.
-		// If some outer methods have not yet called wfProfileOut(), work around
-		// that by clearing anything in the work stack to just the "-total" entry.
-		if ( count( $this->mWorkStack ) > 1 ) {
-			$oldWorkStack = $this->mWorkStack;
-			$this->mWorkStack = array( $this->mWorkStack[0] ); // just the "-total" one
-		} else {
-			$oldWorkStack = null;
-		}
-		$this->close();
-		// If this trick is used, then the old work stack is swapped back afterwards.
-		// This means that logData() will still make use of all the method data since
-		// the missing wfProfileOut() calls should be made by the time it is called.
-		if ( $oldWorkStack ) {
-			$this->mWorkStack = $oldWorkStack;
-		}
-
-		$totalWall = 0.0;
-		$profile = array();
-		foreach ( $this->mCollated as $fname => $data ) {
-			if ( $data['count'] == 1 ) {
-				$profile[] = array(
-					'name' => $fname,
-					'calls' => $data['count'],
-					'elapsed' => $data['wall'] * 1000,
-					'memory' => 0, // not supported
-					'min' => $data['wall'] * 1000,
-					'max' => $data['wall'] * 1000,
-					'overhead' => 0, // not supported
-					'periods' => array() // not supported
-				);
-				$totalWall += $data['wall'];
-			} else {
-				$profile[] = array(
-					'name' => $fname,
-					'calls' => $data['count'],
-					'elapsed' => $data['wall']->n * $data['wall']->getMean() * 1000,
-					'memory' => 0, // not supported
-					'min' => $data['wall']->min * 1000,
-					'max' => $data['wall']->max * 1000,
-					'overhead' => 0, // not supported
-					'periods' => array() // not supported
-				);
-				$totalWall += $data['wall']->n * $data['wall']->getMean();
-			}
-		}
-		$totalWall = $totalWall * 1000;
-
-		foreach ( $profile as &$item ) {
-			$item['percent'] = $totalWall ? 100 * $item['elapsed'] / $totalWall : 0;
-		}
-
-		return $profile;
-	}
-
-	/**
-	 * Serialize profiling data and send to a profiling data aggregator.
-	 *
-	 * Individual entries are represented as arrays and then encoded using
-	 * MessagePack, an efficient binary data-interchange format. Encoded
-	 * entries are accumulated into a buffer and sent in batch via UDP to the
-	 * profiling data aggregator.
-	 */
-	public function logData() {
-		global $wgUDPProfilerHost, $wgUDPProfilerPort;
-
-		$this->close();
-
-		if ( !function_exists( 'socket_create' ) ) {
-			return; // avoid fatal
-		}
-
-		$sock = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
-		socket_connect( $sock, $wgUDPProfilerHost, $wgUDPProfilerPort );
-		$bufferLength = 0;
-		$buffer = '';
-		foreach ( $this->mCollated as $name => $entry ) {
-			$count = $entry['count'];
-			$cpu = $entry['cpu'];
-			$wall = $entry['wall'];
-
-			if ( $count === 1 ) {
-				$data = array( self::TYPE_SINGLE, $name, $cpu, $wall );
-			} else {
-				$data = array( self::TYPE_RUNNING, $name, $count,
-					$cpu->m1, $cpu->m2, $cpu->min, $cpu->max,
-					$wall->m1, $wall->m2, $wall->min, $wall->max );
-			}
-
-			$encoded = MWMessagePack::pack( $data );
-			$length = strlen( $encoded );
-
-			// If adding this entry would cause the size of the buffer to
-			// exceed the standard ethernet MTU size less the UDP header,
-			// send all pending data and reset the buffer. Otherwise, continue
-			// accumulating entries into the current buffer.
-			if ( $length + $bufferLength > 1450 ) {
-				socket_send( $sock, $buffer, $bufferLength, 0 );
-				$buffer = '';
-				$bufferLength = 0;
-			}
-			$buffer .= $encoded;
-			$bufferLength += $length;
-		}
-		if ( $bufferLength !== 0 ) {
-			socket_send( $sock, $buffer, $bufferLength, 0 );
-		}
-	}
-
-	/**
-	 * Close opened profiling sections
-	 */
-	public function close() {
-		while ( count( $this->mWorkStack ) ) {
-			$this->profileOut( 'close' );
-		}
-	}
-
-	public function getOutput() {
-		return ''; // no report
-	}
-}
diff --git a/includes/profiler/ProfilerSectionOnly.php b/includes/profiler/ProfilerSectionOnly.php
new file mode 100644
index 00000000..1f8d33b1
--- /dev/null
+++ b/includes/profiler/ProfilerSectionOnly.php
@@ -0,0 +1,104 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * Profiler that only tracks explicit profiling sections
+ *
+ * @code
+ * $wgProfiler['class'] = 'ProfilerSectionOnly';
+ * $wgProfiler['output'] = 'text';
+ * $wgProfiler['visible'] = true;
+ * @endcode
+ *
+ * @author Aaron Schulz
+ * @ingroup Profiler
+ * @since 1.25
+ */
+class ProfilerSectionOnly extends Profiler {
+	/** @var SectionProfiler */
+	protected $sprofiler;
+
+	public function __construct( array $params = array() ) {
+		parent::__construct( $params );
+		$this->sprofiler = new SectionProfiler();
+	}
+
+	public function scopedProfileIn( $section ) {
+		return $this->sprofiler->scopedProfileIn( $section );
+	}
+
+	public function close() {
+	}
+
+	public function getFunctionStats() {
+		return $this->sprofiler->getFunctionStats();
+	}
+
+	public function getOutput() {
+		return $this->getFunctionReport();
+	}
+
+	/**
+	 * Get a report of profiled functions sorted by inclusive wall clock time
+	 * in descending order.
+	 *
+	 * Each line of the report includes this data:
+	 * - Function name
+	 * - Number of times function was called
+	 * - Total wall clock time spent in function in microseconds
+	 * - Minimum wall clock time spent in function in microseconds
+	 * - Average wall clock time spent in function in microseconds
+	 * - Maximum wall clock time spent in function in microseconds
+	 * - Percentage of total wall clock time spent in function
+	 * - Total delta of memory usage from start to end of function in bytes
+	 *
+	 * @return string
+	 */
+	protected function getFunctionReport() {
+		$data = $this->getFunctionStats();
+		usort( $data, function( $a, $b ) {
+			if ( $a['real'] === $b['real'] ) {
+				return 0;
+			}
+			return ( $a['real'] > $b['real'] ) ? -1 : 1; // descending
+		} );
+
+		$width = 140;
+		$nameWidth = $width - 65;
+		$format = "%-{$nameWidth}s %6d %9d %9d %9d %9d %7.3f%% %9d";
+		$out = array();
+		$out[] = sprintf( "%-{$nameWidth}s %6s %9s %9s %9s %9s %7s %9s",
+			'Name', 'Calls', 'Total', 'Min', 'Each', 'Max', '%', 'Mem'
+		);
+		foreach ( $data as $stats ) {
+			$out[] = sprintf( $format,
+				$stats['name'],
+				$stats['calls'],
+				$stats['real'] * 1000,
+				$stats['min_real'] * 1000,
+				$stats['real'] / $stats['calls'] * 1000,
+				$stats['max_real'] * 1000,
+				$stats['%real'],
+				$stats['memory']
+			);
+		}
+		return implode( "\n", $out );
+	}
+}
diff --git a/includes/profiler/ProfilerSimpleText.php b/includes/profiler/ProfilerSimpleText.php
deleted file mode 100644
index 0ee7aad2..00000000
--- a/includes/profiler/ProfilerSimpleText.php
+++ /dev/null
@@ -1,82 +0,0 @@
-<?php
-/**
- * Profiler showing output in page source.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- * @ingroup Profiler
- */
-
-/**
- * The least sophisticated profiler output class possible, view your source! :)
- *
- * Put the following 2 lines in StartProfiler.php:
- *
- * $wgProfiler['class'] = 'ProfilerSimpleText';
- * $wgProfiler['visible'] = true;
- *
- * @ingroup Profiler
- */
-class ProfilerSimpleText extends ProfilerStandard {
-	public $visible = false; /* Show as <PRE> or <!-- ? */
-	static private $out;
-
-	public function __construct( $profileConfig ) {
-		if ( isset( $profileConfig['visible'] ) && $profileConfig['visible'] ) {
-			$this->visible = true;
-		}
-		parent::__construct( $profileConfig );
-	}
-
-	protected function collateOnly() {
-		return true;
-	}
-
-	public function logData() {
-		if ( $this->mTemplated ) {
-			$this->close();
-			$totalReal = isset( $this->mCollated['-total'] )
-				? $this->mCollated['-total']['real']
-				: 0; // profiling mismatch error?
-			uasort( $this->mCollated, array( 'self', 'sort' ) );
-			array_walk( $this->mCollated, array( 'self', 'format' ), $totalReal );
-			if ( PHP_SAPI === 'cli' ) {
-				print "<!--\n" . self::$out . "\n-->\n";
-			} elseif ( $this->getContentType() === 'text/html' ) {
-				if ( $this->visible ) {
-					print '<pre>' . self::$out . '</pre>';
-				} else {
-					print "<!--\n" . self::$out . "\n-->\n";
-				}
-			} elseif ( $this->getContentType() === 'text/javascript' ) {
-				print "\n/*\n" . self::$out . "*/\n";
-			} elseif ( $this->getContentType() === 'text/css' ) {
-				print "\n/*\n" . self::$out . "*/\n";
-			}
-		}
-	}
-
-	static function sort( $a, $b ) {
-		return $a['real'] < $b['real']; /* sort descending by time elapsed */
-	}
-
-	static function format( $item, $key, $totalReal ) {
-		$perc = $totalReal ? $item['real'] / $totalReal * 100 : 0;
-		self::$out .= sprintf( "%6.2f%% %3.6f %6d - %s\n",
-			$perc, $item['real'], $item['count'], $key );
-	}
-}
diff --git a/includes/profiler/ProfilerSimpleTrace.php b/includes/profiler/ProfilerSimpleTrace.php
deleted file mode 100644
index 2a444948..00000000
--- a/includes/profiler/ProfilerSimpleTrace.php
+++ /dev/null
@@ -1,85 +0,0 @@
-<?php
-/**
- * Profiler showing execution trace.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- * @ingroup Profiler
- */
-
-/**
- * Execution trace profiler
- * @todo document methods (?)
- * @ingroup Profiler
- */
-class ProfilerSimpleTrace extends ProfilerStandard {
-	protected $trace = "Beginning trace: \n";
-	protected $memory = 0;
-
-	protected function collateOnly() {
-		return true;
-	}
-
-	public function profileIn( $functionname ) {
-		parent::profileIn( $functionname );
-
-		$this->trace .= "         " . sprintf( "%6.1f", $this->memoryDiff() ) .
-			str_repeat( " ", count( $this->mWorkStack ) ) . " > " . $functionname . "\n";
-	}
-
-	public function profileOut( $functionname ) {
-		$item = end( $this->mWorkStack );
-
-		parent::profileOut( $functionname );
-
-		if ( !$item ) {
-			$this->trace .= "Profiling error: $functionname\n";
-		} else {
-			list( $ofname, /* $ocount */, $ortime ) = $item;
-			if ( $functionname == 'close' ) {
-				$message = "Profile section ended by close(): {$ofname}";
-				$functionname = $ofname;
-				$this->trace .= $message . "\n";
-			} elseif ( $ofname != $functionname ) {
-				$this->trace .= "Profiling error: in({$ofname}), out($functionname)";
-			}
-			$elapsedreal = $this->getTime() - $ortime;
-			$this->trace .= sprintf( "%03.6f %6.1f", $elapsedreal, $this->memoryDiff() ) .
-				str_repeat( " ", count( $this->mWorkStack ) + 1 ) . " < " . $functionname . "\n";
-		}
-	}
-
-	protected function memoryDiff() {
-		$diff = memory_get_usage() - $this->memory;
-		$this->memory = memory_get_usage();
-		return $diff / 1024;
-	}
-
-	public function logData() {
-		if ( $this->mTemplated ) {
-			if ( PHP_SAPI === 'cli' ) {
-				print "<!-- \n {$this->trace} \n -->";
-			} elseif ( $this->getContentType() === 'text/html' ) {
-				print "<!-- \n {$this->trace} \n -->";
-			} elseif ( $this->getContentType() === 'text/javascript' ) {
-				print "\n/*\n {$this->trace}\n*/";
-			} elseif ( $this->getContentType() === 'text/css' ) {
-				print "\n/*\n {$this->trace}\n*/";
-			}
-		}
-	}
-}
diff --git a/includes/profiler/ProfilerSimpleUDP.php b/includes/profiler/ProfilerSimpleUDP.php
deleted file mode 100644
index 627b4de2..00000000
--- a/includes/profiler/ProfilerSimpleUDP.php
+++ /dev/null
@@ -1,75 +0,0 @@
-<?php
-/**
- * Profiler sending messages over UDP.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- * @ingroup Profiler
- */
-
-/**
- * ProfilerSimpleUDP class, that sends out messages for 'udpprofile' daemon
- * (the one from
- *  http://git.wikimedia.org/tree/operations%2Fsoftware.git/master/udpprofile)
- * @ingroup Profiler
- */
-class ProfilerSimpleUDP extends ProfilerStandard {
-	protected function collateOnly() {
-		return true;
-	}
-
-	public function isPersistent() {
-		return true;
-	}
-
-	public function logData() {
-		global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgUDPProfilerFormatString;
-
-		$this->close();
-
-		if ( !function_exists( 'socket_create' ) ) {
-			# Sockets are not enabled
-			return;
-		}
-
-		$sock = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
-		$plength = 0;
-		$packet = "";
-		foreach ( $this->mCollated as $entry => $pfdata ) {
-			if ( !isset( $pfdata['count'] )
-				|| !isset( $pfdata['cpu'] )
-				|| !isset( $pfdata['cpu_sq'] )
-				|| !isset( $pfdata['real'] )
-				|| !isset( $pfdata['real_sq'] ) ) {
-				continue;
-			}
-			$pfline = sprintf( $wgUDPProfilerFormatString, $this->getProfileID(), $pfdata['count'],
-				$pfdata['cpu'], $pfdata['cpu_sq'], $pfdata['real'], $pfdata['real_sq'], $entry,
-				$pfdata['memory'] );
-			$length = strlen( $pfline );
-			/* printf("<!-- $pfline -->"); */
-			if ( $length + $plength > 1400 ) {
-				socket_sendto( $sock, $packet, $plength, 0, $wgUDPProfilerHost, $wgUDPProfilerPort );
-				$packet = "";
-				$plength = 0;
-			}
-			$packet .= $pfline;
-			$plength += $length;
-		}
-		socket_sendto( $sock, $packet, $plength, 0x100, $wgUDPProfilerHost, $wgUDPProfilerPort );
-	}
-}
diff --git a/includes/profiler/ProfilerStandard.php b/includes/profiler/ProfilerStandard.php
deleted file mode 100644
index cc134165..00000000
--- a/includes/profiler/ProfilerStandard.php
+++ /dev/null
@@ -1,559 +0,0 @@
-<?php
-/**
- * Common implementation class for profiling.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- * @ingroup Profiler
- */
-
-/**
- * Standard profiler that tracks real time, cpu time, and memory deltas
- *
- * This supports profile reports, the debug toolbar, and high-contention
- * DB query warnings. This does not persist the profiling data though.
- *
- * @ingroup Profiler
- * @since 1.24
- */
-class ProfilerStandard extends Profiler {
-	/** @var array List of resolved profile calls with start/end data */
-	protected $mStack = array();
-	/** @var array Queue of open profile calls with start data */
-	protected $mWorkStack = array();
-
-	/** @var array Map of (function name => aggregate data array) */
-	protected $mCollated = array();
-	/** @var bool */
-	protected $mCollateDone = false;
-	/** @var bool */
-	protected $mCollateOnly = false;
-	/** @var array Cache of a standard broken collation entry */
-	protected $mErrorEntry;
-
-	/**
-	 * @param array $params
-	 */
-	public function __construct( array $params ) {
-		parent::__construct( $params );
-
-		$this->mCollateOnly = $this->collateOnly();
-
-		$this->addInitialStack();
-	}
-
-	/**
-	 * Return whether this a stub profiler
-	 *
-	 * @return bool
-	 */
-	public function isStub() {
-		return false;
-	}
-
-	/**
-	 * Return whether this profiler stores data
-	 *
-	 * @see Profiler::logData()
-	 * @return bool
-	 */
-	public function isPersistent() {
-		return false;
-	}
-
-	/**
-	 * Whether to internally just track aggregates and ignore the full stack trace
-	 *
-	 * Only doing collation saves memory overhead but limits the use of certain
-	 * features like that of graph generation for the debug toolbar.
-	 *
-	 * @return bool
-	 */
-	protected function collateOnly() {
-		return false;
-	}
-
-	/**
-	 * Add the inital item in the stack.
-	 */
-	protected function addInitialStack() {
-		$this->mErrorEntry = $this->getErrorEntry();
-
-		$initialTime = $this->getInitialTime( 'wall' );
-		$initialCpu = $this->getInitialTime( 'cpu' );
-		if ( $initialTime !== null && $initialCpu !== null ) {
-			$this->mWorkStack[] = array( '-total', 0, $initialTime, $initialCpu, 0 );
-			if ( $this->mCollateOnly ) {
-				$this->mWorkStack[] = array( '-setup', 1, $initialTime, $initialCpu, 0 );
-				$this->profileOut( '-setup' );
-			} else {
-				$this->mStack[] = array( '-setup', 1, $initialTime, $initialCpu, 0,
-					$this->getTime( 'wall' ), $this->getTime( 'cpu' ), 0 );
-			}
-		} else {
-			$this->profileIn( '-total' );
-		}
-	}
-
-	/**
-	 * @return array Initial collation entry
-	 */
-	protected function getZeroEntry() {
-		return array(
-			'cpu'      => 0.0,
-			'cpu_sq'   => 0.0,
-			'real'     => 0.0,
-			'real_sq'  => 0.0,
-			'memory'   => 0,
-			'count'    => 0,
-			'min_cpu'  => 0.0,
-			'max_cpu'  => 0.0,
-			'min_real' => 0.0,
-			'max_real' => 0.0,
-			'periods'  => array(), // not filled if mCollateOnly
-			'overhead' => 0 // not filled if mCollateOnly
-		);
-	}
-
-	/**
-	 * @return array Initial collation entry for errors
-	 */
-	protected function getErrorEntry() {
-		$entry = $this->getZeroEntry();
-		$entry['count'] = 1;
-		return $entry;
-	}
-
-	/**
-	 * Update the collation entry for a given method name
-	 *
-	 * @param string $name
-	 * @param float $elapsedCpu
-	 * @param float $elapsedReal
-	 * @param int $memChange
-	 * @param int $subcalls
-	 * @param array|null $period Map of ('start','end','memory','subcalls')
-	 */
-	protected function updateEntry(
-		$name, $elapsedCpu, $elapsedReal, $memChange, $subcalls = 0, $period = null
-	) {
-		$entry =& $this->mCollated[$name];
-		if ( !is_array( $entry ) ) {
-			$entry = $this->getZeroEntry();
-			$this->mCollated[$name] =& $entry;
-		}
-		$entry['cpu'] += $elapsedCpu;
-		$entry['cpu_sq'] += $elapsedCpu * $elapsedCpu;
-		$entry['real'] += $elapsedReal;
-		$entry['real_sq'] += $elapsedReal * $elapsedReal;
-		$entry['memory'] += $memChange > 0 ? $memChange : 0;
-		$entry['count']++;
-		$entry['min_cpu'] = $elapsedCpu < $entry['min_cpu'] ? $elapsedCpu : $entry['min_cpu'];
-		$entry['max_cpu'] = $elapsedCpu > $entry['max_cpu'] ? $elapsedCpu : $entry['max_cpu'];
-		$entry['min_real'] = $elapsedReal < $entry['min_real'] ? $elapsedReal : $entry['min_real'];
-		$entry['max_real'] = $elapsedReal > $entry['max_real'] ? $elapsedReal : $entry['max_real'];
-		// Apply optional fields
-		$entry['overhead'] += $subcalls;
-		if ( $period ) {
-			$entry['periods'][] = $period;
-		}
-	}
-
-	/**
-	 * Called by wfProfieIn()
-	 *
-	 * @param string $functionname
-	 */
-	public function profileIn( $functionname ) {
-		global $wgDebugFunctionEntry;
-
-		if ( $wgDebugFunctionEntry ) {
-			$this->debug( str_repeat( ' ', count( $this->mWorkStack ) ) .
-				'Entering ' . $functionname . "\n" );
-		}
-
-		$this->mWorkStack[] = array(
-			$functionname,
-			count( $this->mWorkStack ),
-			$this->getTime( 'time' ),
-			$this->getTime( 'cpu' ),
-			memory_get_usage()
-		);
-	}
-
-	/**
-	 * Called by wfProfieOut()
-	 *
-	 * @param string $functionname
-	 */
-	public function profileOut( $functionname ) {
-		global $wgDebugFunctionEntry;
-
-		if ( $wgDebugFunctionEntry ) {
-			$this->debug( str_repeat( ' ', count( $this->mWorkStack ) - 1 ) .
-				'Exiting ' . $functionname . "\n" );
-		}
-
-		$item = array_pop( $this->mWorkStack );
-		list( $ofname, /* $ocount */, $ortime, $octime, $omem ) = $item;
-
-		if ( $item === null ) {
-			$this->debugGroup( 'profileerror', "Profiling error: $functionname" );
-		} else {
-			if ( $functionname === 'close' ) {
-				if ( $ofname !== '-total' ) {
-					$message = "Profile section ended by close(): {$ofname}";
-					$this->debugGroup( 'profileerror', $message );
-					if ( $this->mCollateOnly ) {
-						$this->mCollated[$message] = $this->mErrorEntry;
-					} else {
-						$this->mStack[] = array( $message, 0, 0.0, 0.0, 0, 0.0, 0.0, 0 );
-					}
-				}
-				$functionname = $ofname;
-			} elseif ( $ofname !== $functionname ) {
-				$message = "Profiling error: in({$ofname}), out($functionname)";
-				$this->debugGroup( 'profileerror', $message );
-				if ( $this->mCollateOnly ) {
-					$this->mCollated[$message] = $this->mErrorEntry;
-				} else {
-					$this->mStack[] = array( $message, 0, 0.0, 0.0, 0, 0.0, 0.0, 0 );
-				}
-			}
-			$realTime = $this->getTime( 'wall' );
-			$cpuTime = $this->getTime( 'cpu' );
-			if ( $this->mCollateOnly ) {
-				$elapsedcpu = $cpuTime - $octime;
-				$elapsedreal = $realTime - $ortime;
-				$memchange = memory_get_usage() - $omem;
-				$this->updateEntry( $functionname, $elapsedcpu, $elapsedreal, $memchange );
-			} else {
-				$this->mStack[] = array_merge( $item,
-					array( $realTime, $cpuTime,	memory_get_usage() ) );
-			}
-			$this->trxProfiler->recordFunctionCompletion( $functionname, $realTime - $ortime );
-		}
-	}
-
-	/**
-	 * Close opened profiling sections
-	 */
-	public function close() {
-		while ( count( $this->mWorkStack ) ) {
-			$this->profileOut( 'close' );
-		}
-	}
-
-	/**
-	 * Log the data to some store or even the page output
-	 */
-	public function logData() {
-		/* Implement in subclasses */
-	}
-
-	/**
-	 * Returns a profiling output to be stored in debug file
-	 *
-	 * @return string
-	 */
-	public function getOutput() {
-		global $wgDebugFunctionEntry, $wgProfileCallTree;
-
-		$wgDebugFunctionEntry = false; // hack
-
-		if ( !count( $this->mStack ) && !count( $this->mCollated ) ) {
-			return "No profiling output\n";
-		}
-
-		if ( $wgProfileCallTree ) {
-			return $this->getCallTree();
-		} else {
-			return $this->getFunctionReport();
-		}
-	}
-
-	/**
-	 * Returns a tree of function call instead of a list of functions
-	 * @return string
-	 */
-	protected function getCallTree() {
-		return implode( '', array_map(
-			array( &$this, 'getCallTreeLine' ), $this->remapCallTree( $this->mStack )
-		) );
-	}
-
-	/**
-	 * Recursive function the format the current profiling array into a tree
-	 *
-	 * @param array $stack Profiling array
-	 * @return array
-	 */
-	protected function remapCallTree( array $stack ) {
-		if ( count( $stack ) < 2 ) {
-			return $stack;
-		}
-		$outputs = array();
-		for ( $max = count( $stack ) - 1; $max > 0; ) {
-			/* Find all items under this entry */
-			$level = $stack[$max][1];
-			$working = array();
-			for ( $i = $max -1; $i >= 0; $i-- ) {
-				if ( $stack[$i][1] > $level ) {
-					$working[] = $stack[$i];
-				} else {
-					break;
-				}
-			}
-			$working = $this->remapCallTree( array_reverse( $working ) );
-			$output = array();
-			foreach ( $working as $item ) {
-				array_push( $output, $item );
-			}
-			array_unshift( $output, $stack[$max] );
-			$max = $i;
-
-			array_unshift( $outputs, $output );
-		}
-		$final = array();
-		foreach ( $outputs as $output ) {
-			foreach ( $output as $item ) {
-				$final[] = $item;
-			}
-		}
-		return $final;
-	}
-
-	/**
-	 * Callback to get a formatted line for the call tree
-	 * @param array $entry
-	 * @return string
-	 */
-	protected function getCallTreeLine( $entry ) {
-		list( $fname, $level, $startreal, , , $endreal ) = $entry;
-		$delta = $endreal - $startreal;
-		$space = str_repeat( ' ', $level );
-		# The ugly double sprintf is to work around a PHP bug,
-		# which has been fixed in recent releases.
-		return sprintf( "%10s %s %s\n",
-			trim( sprintf( "%7.3f", $delta * 1000.0 ) ), $space, $fname );
-	}
-
-	/**
-	 * Populate mCollated
-	 */
-	protected function collateData() {
-		if ( $this->mCollateDone ) {
-			return;
-		}
-		$this->mCollateDone = true;
-		$this->close(); // set "-total" entry
-
-		if ( $this->mCollateOnly ) {
-			return; // already collated as methods exited
-		}
-
-		$this->mCollated = array();
-
-		# Estimate profiling overhead
-		$profileCount = count( $this->mStack );
-		self::calculateOverhead( $profileCount );
-
-		# First, subtract the overhead!
-		$overheadTotal = $overheadMemory = $overheadInternal = array();
-		foreach ( $this->mStack as $entry ) {
-			// $entry is (name,pos,rtime0,cputime0,mem0,rtime1,cputime1,mem1)
-			$fname = $entry[0];
-			$elapsed = $entry[5] - $entry[2];
-			$memchange = $entry[7] - $entry[4];
-
-			if ( $fname === '-overhead-total' ) {
-				$overheadTotal[] = $elapsed;
-				$overheadMemory[] = max( 0, $memchange );
-			} elseif ( $fname === '-overhead-internal' ) {
-				$overheadInternal[] = $elapsed;
-			}
-		}
-		$overheadTotal = $overheadTotal ?
-			array_sum( $overheadTotal ) / count( $overheadInternal ) : 0;
-		$overheadMemory = $overheadMemory ?
-			array_sum( $overheadMemory ) / count( $overheadInternal ) : 0;
-		$overheadInternal = $overheadInternal ?
-			array_sum( $overheadInternal ) / count( $overheadInternal ) : 0;
-
-		# Collate
-		foreach ( $this->mStack as $index => $entry ) {
-			// $entry is (name,pos,rtime0,cputime0,mem0,rtime1,cputime1,mem1)
-			$fname = $entry[0];
-			$elapsedCpu = $entry[6] - $entry[3];
-			$elapsedReal = $entry[5] - $entry[2];
-			$memchange = $entry[7] - $entry[4];
-			$subcalls = $this->calltreeCount( $this->mStack, $index );
-
-			if ( substr( $fname, 0, 9 ) !== '-overhead' ) {
-				# Adjust for profiling overhead (except special values with elapsed=0
-				if ( $elapsed ) {
-					$elapsed -= $overheadInternal;
-					$elapsed -= ( $subcalls * $overheadTotal );
-					$memchange -= ( $subcalls * $overheadMemory );
-				}
-			}
-
-			$period = array( 'start' => $entry[2], 'end' => $entry[5],
-				'memory' => $memchange, 'subcalls' => $subcalls );
-			$this->updateEntry( $fname, $elapsedCpu, $elapsedReal, $memchange, $subcalls, $period );
-		}
-
-		$this->mCollated['-overhead-total']['count'] = $profileCount;
-		arsort( $this->mCollated, SORT_NUMERIC );
-	}
-
-	/**
-	 * Returns a list of profiled functions.
-	 *
-	 * @return string
-	 */
-	protected function getFunctionReport() {
-		$this->collateData();
-
-		$width = 140;
-		$nameWidth = $width - 65;
-		$format = "%-{$nameWidth}s %6d %13.3f %13.3f %13.3f%% %9d  (%13.3f -%13.3f) [%d]\n";
-		$titleFormat = "%-{$nameWidth}s %6s %13s %13s %13s %9s\n";
-		$prof = "\nProfiling data\n";
-		$prof .= sprintf( $titleFormat, 'Name', 'Calls', 'Total', 'Each', '%', 'Mem' );
-
-		$total = isset( $this->mCollated['-total'] )
-			? $this->mCollated['-total']['real']
-			: 0;
-
-		foreach ( $this->mCollated as $fname => $data ) {
-			$calls = $data['count'];
-			$percent = $total ? 100 * $data['real'] / $total : 0;
-			$memory = $data['memory'];
-			$prof .= sprintf( $format,
-				substr( $fname, 0, $nameWidth ),
-				$calls,
-				(float)( $data['real'] * 1000 ),
-				(float)( $data['real'] * 1000 ) / $calls,
-				$percent,
-				$memory,
-				( $data['min_real'] * 1000.0 ),
-				( $data['max_real'] * 1000.0 ),
-				$data['overhead']
-			);
-		}
-		$prof .= "\nTotal: $total\n\n";
-
-		return $prof;
-	}
-
-	/**
-	 * @return array
-	 */
-	public function getRawData() {
-		// This method is called before shutdown in the footer method on Skins.
-		// If some outer methods have not yet called wfProfileOut(), work around
-		// that by clearing anything in the work stack to just the "-total" entry.
-		// Collate after doing this so the results do not include profile errors.
-		if ( count( $this->mWorkStack ) > 1 ) {
-			$oldWorkStack = $this->mWorkStack;
-			$this->mWorkStack = array( $this->mWorkStack[0] ); // just the "-total" one
-		} else {
-			$oldWorkStack = null;
-		}
-		$this->collateData();
-		// If this trick is used, then the old work stack is swapped back afterwards
-		// and mCollateDone is reset to false. This means that logData() will still
-		// make use of all the method data since the missing wfProfileOut() calls
-		// should be made by the time it is called.
-		if ( $oldWorkStack ) {
-			$this->mWorkStack = $oldWorkStack;
-			$this->mCollateDone = false;
-		}
-
-		$total = isset( $this->mCollated['-total'] )
-			? $this->mCollated['-total']['real']
-			: 0;
-
-		$profile = array();
-		foreach ( $this->mCollated as $fname => $data ) {
-			$periods = array();
-			foreach ( $data['periods'] as $period ) {
-				$period['start'] *= 1000;
-				$period['end'] *= 1000;
-				$periods[] = $period;
-			}
-			$profile[] = array(
-				'name' => $fname,
-				'calls' => $data['count'],
-				'elapsed' => $data['real'] * 1000,
-				'percent' => $total ? 100 * $data['real'] / $total : 0,
-				'memory' => $data['memory'],
-				'min' => $data['min_real'] * 1000,
-				'max' => $data['max_real'] * 1000,
-				'overhead' => $data['overhead'],
-				'periods' => $periods
-			);
-		}
-
-		return $profile;
-	}
-
-	/**
-	 * Dummy calls to wfProfileIn/wfProfileOut to calculate its overhead
-	 * @param int $profileCount
-	 */
-	protected static function calculateOverhead( $profileCount ) {
-		wfProfileIn( '-overhead-total' );
-		for ( $i = 0; $i < $profileCount; $i++ ) {
-			wfProfileIn( '-overhead-internal' );
-			wfProfileOut( '-overhead-internal' );
-		}
-		wfProfileOut( '-overhead-total' );
-	}
-
-	/**
-	 * Counts the number of profiled function calls sitting under
-	 * the given point in the call graph. Not the most efficient algo.
-	 *
-	 * @param array $stack
-	 * @param int $start
-	 * @return int
-	 */
-	protected function calltreeCount( $stack, $start ) {
-		$level = $stack[$start][1];
-		$count = 0;
-		for ( $i = $start -1; $i >= 0 && $stack[$i][1] > $level; $i-- ) {
-			$count ++;
-		}
-		return $count;
-	}
-
-	/**
-	 * Get the content type sent out to the client.
-	 * Used for profilers that output instead of store data.
-	 * @return string
-	 */
-	protected function getContentType() {
-		foreach ( headers_list() as $header ) {
-			if ( preg_match( '#^content-type: (\w+/\w+);?#i', $header, $m ) ) {
-				return $m[1];
-			}
-		}
-		return null;
-	}
-}
diff --git a/includes/profiler/ProfilerStub.php b/includes/profiler/ProfilerStub.php
index 1d3b65d2..244b4e4b 100644
--- a/includes/profiler/ProfilerStub.php
+++ b/includes/profiler/ProfilerStub.php
@@ -27,18 +27,11 @@
  * @ingroup Profiler
  */
 class ProfilerStub extends Profiler {
-	public function isStub() {
-		return true;
+	public function scopedProfileIn( $section ) {
+		return null; // no-op
 	}
 
-	public function isPersistent() {
-		return false;
-	}
-
-	public function profileIn( $fn ) {
-	}
-
-	public function profileOut( $fn ) {
+	public function getFunctionStats() {
 	}
 
 	public function getOutput() {
@@ -47,20 +40,10 @@ class ProfilerStub extends Profiler {
 	public function close() {
 	}
 
-	public function logData() {
-	}
-
 	public function getCurrentSection() {
 		return '';
 	}
 
-	public function transactionWritingIn( $server, $db, $id = '' ) {
-	}
-
-	public function transactionWritingOut( $server, $db, $id = '' ) {
-	}
-
-	public function getRawData() {
-		return array();
+	public function logData() {
 	}
 }
diff --git a/includes/profiler/ProfilerXhprof.php b/includes/profiler/ProfilerXhprof.php
new file mode 100644
index 00000000..f36cdc1a
--- /dev/null
+++ b/includes/profiler/ProfilerXhprof.php
@@ -0,0 +1,194 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * Profiler wrapper for XHProf extension.
+ *
+ * @code
+ * $wgProfiler['class'] = 'ProfilerXhprof';
+ * $wgProfiler['flags'] = XHPROF_FLAGS_NO_BUILTINS;
+ * $wgProfiler['output'] = 'text';
+ * $wgProfiler['visible'] = true;
+ * @endcode
+ *
+ * @code
+ * $wgProfiler['class'] = 'ProfilerXhprof';
+ * $wgProfiler['flags'] = XHPROF_FLAGS_CPU | XHPROF_FLAGS_MEMORY | XHPROF_FLAGS_NO_BUILTINS;
+ * $wgProfiler['output'] = 'udp';
+ * @endcode
+ *
+ * ProfilerXhprof profiles all functions using the XHProf PHP extenstion.
+ * For PHP5 users, this extension can be installed via PECL or your operating
+ * system's package manager. XHProf support is built into HHVM.
+ *
+ * To restrict the functions for which profiling data is collected, you can
+ * use either a whitelist ($wgProfiler['include']) or a blacklist
+ * ($wgProfiler['exclude']) containing an array of function names. The
+ * blacklist functionality is built into HHVM and will completely exclude the
+ * named functions from profiling collection. The whitelist is implemented by
+ * Xhprof class which will filter the data collected by XHProf before reporting.
+ * See documentation for the Xhprof class and the XHProf extension for
+ * additional information.
+ *
+ * @author Bryan Davis <bd808@wikimedia.org>
+ * @copyright © 2014 Bryan Davis and Wikimedia Foundation.
+ * @ingroup Profiler
+ * @see Xhprof
+ * @see https://php.net/xhprof
+ * @see https://github.com/facebook/hhvm/blob/master/hphp/doc/profiling.md
+ */
+class ProfilerXhprof extends Profiler {
+	/**
+	 * @var Xhprof $xhprof
+	 */
+	protected $xhprof;
+
+	/**
+	 * Profiler for explicit, arbitrary, frame labels
+	 * @var SectionProfiler
+	 */
+	protected $sprofiler;
+
+	/**
+	 * @param array $params
+	 * @see Xhprof::__construct()
+	 */
+	public function __construct( array $params = array() ) {
+		parent::__construct( $params );
+		$this->xhprof = new Xhprof( $params );
+		$this->sprofiler = new SectionProfiler();
+	}
+
+	public function scopedProfileIn( $section ) {
+		return $this->sprofiler->scopedProfileIn( $section );
+	}
+
+	/**
+	 * No-op for xhprof profiling.
+	 */
+	public function close() {
+	}
+
+	public function getFunctionStats() {
+		$metrics = $this->xhprof->getCompleteMetrics();
+		$profile = array();
+
+		$main = null; // units in ms
+		foreach ( $metrics as $fname => $stats ) {
+			// Convert elapsed times from μs to ms to match interface
+			$entry = array(
+				'name' => $fname,
+				'calls' => $stats['ct'],
+				'real' => $stats['wt']['total'] / 1000,
+				'%real' => $stats['wt']['percent'],
+				'cpu' => isset( $stats['cpu'] ) ? $stats['cpu']['total'] / 1000 : 0,
+				'%cpu' => isset( $stats['cpu'] ) ? $stats['cpu']['percent'] : 0,
+				'memory' => isset( $stats['mu'] ) ? $stats['mu']['total'] : 0,
+				'%memory' => isset( $stats['mu'] ) ? $stats['mu']['percent'] : 0,
+				'min_real' => $stats['wt']['min'] / 1000,
+				'max_real' => $stats['wt']['max'] / 1000
+			);
+			$profile[] = $entry;
+			if ( $fname === 'main()' ) {
+				$main = $entry;
+			}
+		}
+
+		// Merge in all of the custom profile sections
+		foreach ( $this->sprofiler->getFunctionStats() as $stats ) {
+			if ( $stats['name'] === '-total' ) {
+				// Discard section profiler running totals
+				continue;
+			}
+
+			// @note: getFunctionStats() values already in ms
+			$stats['%real'] = $main['real'] ? $stats['real'] / $main['real'] * 100 : 0;
+			$stats['%cpu'] = $main['cpu'] ? $stats['cpu'] / $main['cpu'] * 100 : 0;
+			$stats['%memory'] = $main['memory'] ? $stats['memory'] / $main['memory'] * 100 : 0;
+			$profile[] = $stats; // assume no section names collide with $metrics
+		}
+
+		return $profile;
+	}
+
+	/**
+	 * Returns a profiling output to be stored in debug file
+	 *
+	 * @return string
+	 */
+	public function getOutput() {
+		return $this->getFunctionReport();
+	}
+
+	/**
+	 * Get a report of profiled functions sorted by inclusive wall clock time
+	 * in descending order.
+	 *
+	 * Each line of the report includes this data:
+	 * - Function name
+	 * - Number of times function was called
+	 * - Total wall clock time spent in function in microseconds
+	 * - Minimum wall clock time spent in function in microseconds
+	 * - Average wall clock time spent in function in microseconds
+	 * - Maximum wall clock time spent in function in microseconds
+	 * - Percentage of total wall clock time spent in function
+	 * - Total delta of memory usage from start to end of function in bytes
+	 *
+	 * @return string
+	 */
+	protected function getFunctionReport() {
+		$data = $this->getFunctionStats();
+		usort( $data, function( $a, $b ) {
+			if ( $a['real'] === $b['real'] ) {
+				return 0;
+			}
+			return ( $a['real'] > $b['real'] ) ? -1 : 1; // descending
+		} );
+
+		$width = 140;
+		$nameWidth = $width - 65;
+		$format = "%-{$nameWidth}s %6d %9d %9d %9d %9d %7.3f%% %9d";
+		$out = array();
+		$out[] = sprintf( "%-{$nameWidth}s %6s %9s %9s %9s %9s %7s %9s",
+			'Name', 'Calls', 'Total', 'Min', 'Each', 'Max', '%', 'Mem'
+		);
+		foreach ( $data as $stats ) {
+			$out[] = sprintf( $format,
+				$stats['name'],
+				$stats['calls'],
+				$stats['real'] * 1000,
+				$stats['min_real'] * 1000,
+				$stats['real'] / $stats['calls'] * 1000,
+				$stats['max_real'] * 1000,
+				$stats['%real'],
+				$stats['memory']
+			);
+		}
+		return implode( "\n", $out );
+	}
+
+	/**
+	 * Retrieve raw data from xhprof
+	 * @return array
+	 */
+	public function getRawData() {
+		return $this->xhprof->getRawData();
+	}
+}
diff --git a/includes/profiler/SectionProfiler.php b/includes/profiler/SectionProfiler.php
new file mode 100644
index 00000000..245022df
--- /dev/null
+++ b/includes/profiler/SectionProfiler.php
@@ -0,0 +1,530 @@
+<?php
+/**
+ * Arbitrary section name based PHP profiling.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ * @author Aaron Schulz
+ */
+
+/**
+ * Custom PHP profiler for parser/DB type section names that xhprof/xdebug can't handle
+ *
+ * @since 1.25
+ */
+class SectionProfiler {
+	/** @var array Map of (mem,real,cpu) */
+	protected $start;
+	/** @var array Map of (mem,real,cpu) */
+	protected $end;
+	/** @var array List of resolved profile calls with start/end data */
+	protected $stack = array();
+	/** @var array Queue of open profile calls with start data */
+	protected $workStack = array();
+
+	/** @var array Map of (function name => aggregate data array) */
+	protected $collated = array();
+	/** @var bool */
+	protected $collateDone = false;
+
+	/** @var bool Whether to collect the full stack trace or just aggregates */
+	protected $collateOnly = true;
+	/** @var array Cache of a standard broken collation entry */
+	protected $errorEntry;
+	/** @var callable Cache of a profile out callback */
+	protected $profileOutCallback;
+
+	/**
+	 * @param array $params
+	 */
+	public function __construct( array $params = array() ) {
+		$this->errorEntry = $this->getErrorEntry();
+		$this->collateOnly = empty( $params['trace'] );
+		$this->profileOutCallback = function ( $profiler, $section ) {
+			$profiler->profileOutInternal( $section );
+		};
+	}
+
+	/**
+	 * @param string $section
+	 * @return ScopedCallback
+	 */
+	public function scopedProfileIn( $section ) {
+		$this->profileInInternal( $section );
+
+		return new SectionProfileCallback( $this, $section );
+	}
+
+	/**
+	 * @param ScopedCallback $section
+	 */
+	public function scopedProfileOut( ScopedCallback &$section ) {
+		$section = null;
+	}
+
+	/**
+	 * Get the aggregated inclusive profiling data for each method
+	 *
+	 * The percent time for each time is based on the current "total" time
+	 * used is based on all methods so far. This method can therefore be
+	 * called several times in between several profiling calls without the
+	 * delays in usage of the profiler skewing the results. A "-total" entry
+	 * is always included in the results.
+	 *
+	 * @return array List of method entries arrays, each having:
+	 *   - name    : method name
+	 *   - calls   : the number of invoking calls
+	 *   - real    : real time ellapsed (ms)
+	 *   - %real   : percent real time
+	 *   - cpu     : real time ellapsed (ms)
+	 *   - %cpu    : percent real time
+	 *   - memory  : memory used (bytes)
+	 *   - %memory : percent memory used
+	 *   - min_real : min real time in a call (ms)
+	 *   - max_real : max real time in a call (ms)
+	 */
+	public function getFunctionStats() {
+		$this->collateData();
+
+		$totalCpu = max( $this->end['cpu'] - $this->start['cpu'], 0 );
+		$totalReal = max( $this->end['real'] - $this->start['real'], 0 );
+		$totalMem = max( $this->end['memory'] - $this->start['memory'], 0 );
+
+		$profile = array();
+		foreach ( $this->collated as $fname => $data ) {
+			$profile[] = array(
+				'name' => $fname,
+				'calls' => $data['count'],
+				'real' => $data['real'] * 1000,
+				'%real' => $totalReal ? 100 * $data['real'] / $totalReal : 0,
+				'cpu' => $data['cpu'] * 1000,
+				'%cpu' => $totalCpu ? 100 * $data['cpu'] / $totalCpu : 0,
+				'memory' => $data['memory'],
+				'%memory' => $totalMem ? 100 * $data['memory'] / $totalMem : 0,
+				'min_real' => 1000 * $data['min_real'],
+				'max_real' => 1000 * $data['max_real']
+			);
+		}
+
+		$profile[] = array(
+			'name' => '-total',
+			'calls' => 1,
+			'real' => 1000 * $totalReal,
+			'%real' => 100,
+			'cpu' => 1000 * $totalCpu,
+			'%cpu' => 100,
+			'memory' => $totalMem,
+			'%memory' => 100,
+			'min_real' => 1000 * $totalReal,
+			'max_real' => 1000 * $totalReal
+		);
+
+		return $profile;
+	}
+
+	/**
+	 * Clear all of the profiling data for another run
+	 */
+	public function reset() {
+		$this->start = null;
+		$this->end = null;
+		$this->stack = array();
+		$this->workStack = array();
+		$this->collated = array();
+		$this->collateDone = false;
+	}
+
+	/**
+	 * @return array Initial collation entry
+	 */
+	protected function getZeroEntry() {
+		return array(
+			'cpu'      => 0.0,
+			'real'     => 0.0,
+			'memory'   => 0,
+			'count'    => 0,
+			'min_real' => 0.0,
+			'max_real' => 0.0
+		);
+	}
+
+	/**
+	 * @return array Initial collation entry for errors
+	 */
+	protected function getErrorEntry() {
+		$entry = $this->getZeroEntry();
+		$entry['count'] = 1;
+		return $entry;
+	}
+
+	/**
+	 * Update the collation entry for a given method name
+	 *
+	 * @param string $name
+	 * @param float $elapsedCpu
+	 * @param float $elapsedReal
+	 * @param int $memChange
+	 */
+	protected function updateEntry( $name, $elapsedCpu, $elapsedReal, $memChange ) {
+		$entry =& $this->collated[$name];
+		if ( !is_array( $entry ) ) {
+			$entry = $this->getZeroEntry();
+			$this->collated[$name] =& $entry;
+		}
+		$entry['cpu'] += $elapsedCpu;
+		$entry['real'] += $elapsedReal;
+		$entry['memory'] += $memChange > 0 ? $memChange : 0;
+		$entry['count']++;
+		$entry['min_real'] = min( $entry['min_real'], $elapsedReal );
+		$entry['max_real'] = max( $entry['max_real'], $elapsedReal );
+	}
+
+	/**
+	 * This method should not be called outside SectionProfiler
+	 *
+	 * @param string $functionname
+	 */
+	public function profileInInternal( $functionname ) {
+		// Once the data is collated for reports, any future calls
+		// should clear the collation cache so the next report will
+		// reflect them. This matters when trace mode is used.
+		$this->collateDone = false;
+
+		$cpu = $this->getTime( 'cpu' );
+		$real = $this->getTime( 'wall' );
+		$memory = memory_get_usage();
+
+		if ( $this->start === null ) {
+			$this->start = array( 'cpu' => $cpu, 'real' => $real, 'memory' => $memory );
+		}
+
+		$this->workStack[] = array(
+			$functionname,
+			count( $this->workStack ),
+			$real,
+			$cpu,
+			$memory
+		);
+	}
+
+	/**
+	 * This method should not be called outside SectionProfiler
+	 *
+	 * @param string $functionname
+	 */
+	public function profileOutInternal( $functionname ) {
+		$item = array_pop( $this->workStack );
+		if ( $item === null ) {
+			$this->debugGroup( 'profileerror', "Profiling error: $functionname" );
+			return;
+		}
+		list( $ofname, /* $ocount */, $ortime, $octime, $omem ) = $item;
+
+		if ( $functionname === 'close' ) {
+			$message = "Profile section ended by close(): {$ofname}";
+			$this->debugGroup( 'profileerror', $message );
+			if ( $this->collateOnly ) {
+				$this->collated[$message] = $this->errorEntry;
+			} else {
+				$this->stack[] = array( $message, 0, 0.0, 0.0, 0, 0.0, 0.0, 0 );
+			}
+			$functionname = $ofname;
+		} elseif ( $ofname !== $functionname ) {
+			$message = "Profiling error: in({$ofname}), out($functionname)";
+			$this->debugGroup( 'profileerror', $message );
+			if ( $this->collateOnly ) {
+				$this->collated[$message] = $this->errorEntry;
+			} else {
+				$this->stack[] = array( $message, 0, 0.0, 0.0, 0, 0.0, 0.0, 0 );
+			}
+		}
+
+		$realTime = $this->getTime( 'wall' );
+		$cpuTime = $this->getTime( 'cpu' );
+		$memUsage = memory_get_usage();
+
+		if ( $this->collateOnly ) {
+			$elapsedcpu = $cpuTime - $octime;
+			$elapsedreal = $realTime - $ortime;
+			$memchange = $memUsage - $omem;
+			$this->updateEntry( $functionname, $elapsedcpu, $elapsedreal, $memchange );
+		} else {
+			$this->stack[] = array_merge( $item, array( $realTime, $cpuTime, $memUsage ) );
+		}
+
+		$this->end = array(
+			'cpu'      => $cpuTime,
+			'real'     => $realTime,
+			'memory'   => $memUsage
+		);
+	}
+
+	/**
+	 * Returns a tree of function calls with their real times
+	 * @return string
+	 * @throws Exception
+	 */
+	public function getCallTreeReport() {
+		if ( $this->collateOnly ) {
+			throw new Exception( "Tree is only available for trace profiling." );
+		}
+		return implode( '', array_map(
+			array( $this, 'getCallTreeLine' ), $this->remapCallTree( $this->stack )
+		) );
+	}
+
+	/**
+	 * Recursive function the format the current profiling array into a tree
+	 *
+	 * @param array $stack Profiling array
+	 * @return array
+	 */
+	protected function remapCallTree( array $stack ) {
+		if ( count( $stack ) < 2 ) {
+			return $stack;
+		}
+		$outputs = array();
+		for ( $max = count( $stack ) - 1; $max > 0; ) {
+			/* Find all items under this entry */
+			$level = $stack[$max][1];
+			$working = array();
+			for ( $i = $max -1; $i >= 0; $i-- ) {
+				if ( $stack[$i][1] > $level ) {
+					$working[] = $stack[$i];
+				} else {
+					break;
+				}
+			}
+			$working = $this->remapCallTree( array_reverse( $working ) );
+			$output = array();
+			foreach ( $working as $item ) {
+				array_push( $output, $item );
+			}
+			array_unshift( $output, $stack[$max] );
+			$max = $i;
+
+			array_unshift( $outputs, $output );
+		}
+		$final = array();
+		foreach ( $outputs as $output ) {
+			foreach ( $output as $item ) {
+				$final[] = $item;
+			}
+		}
+		return $final;
+	}
+
+	/**
+	 * Callback to get a formatted line for the call tree
+	 * @param array $entry
+	 * @return string
+	 */
+	protected function getCallTreeLine( $entry ) {
+		// $entry has (name, level, stime, scpu, smem, etime, ecpu, emem)
+		list( $fname, $level, $startreal, , , $endreal ) = $entry;
+		$delta = $endreal - $startreal;
+		$space = str_repeat( ' ', $level );
+		# The ugly double sprintf is to work around a PHP bug,
+		# which has been fixed in recent releases.
+		return sprintf( "%10s %s %s\n",
+			trim( sprintf( "%7.3f", $delta * 1000.0 ) ), $space, $fname );
+	}
+
+	/**
+	 * Populate collated data
+	 */
+	protected function collateData() {
+		if ( $this->collateDone ) {
+			return;
+		}
+		$this->collateDone = true;
+		// Close opened profiling sections
+		while ( count( $this->workStack ) ) {
+			$this->profileOutInternal( 'close' );
+		}
+
+		if ( $this->collateOnly ) {
+			return; // already collated as methods exited
+		}
+
+		$this->collated = array();
+
+		# Estimate profiling overhead
+		$oldEnd = $this->end;
+		$profileCount = count( $this->stack );
+		$this->calculateOverhead( $profileCount );
+
+		# First, subtract the overhead!
+		$overheadTotal = $overheadMemory = $overheadInternal = array();
+		foreach ( $this->stack as $entry ) {
+			// $entry is (name,pos,rtime0,cputime0,mem0,rtime1,cputime1,mem1)
+			$fname = $entry[0];
+			$elapsed = $entry[5] - $entry[2];
+			$memchange = $entry[7] - $entry[4];
+
+			if ( $fname === '-overhead-total' ) {
+				$overheadTotal[] = $elapsed;
+				$overheadMemory[] = max( 0, $memchange );
+			} elseif ( $fname === '-overhead-internal' ) {
+				$overheadInternal[] = $elapsed;
+			}
+		}
+		$overheadTotal = $overheadTotal ?
+			array_sum( $overheadTotal ) / count( $overheadInternal ) : 0;
+		$overheadMemory = $overheadMemory ?
+			array_sum( $overheadMemory ) / count( $overheadInternal ) : 0;
+		$overheadInternal = $overheadInternal ?
+			array_sum( $overheadInternal ) / count( $overheadInternal ) : 0;
+
+		# Collate
+		foreach ( $this->stack as $index => $entry ) {
+			// $entry is (name,pos,rtime0,cputime0,mem0,rtime1,cputime1,mem1)
+			$fname = $entry[0];
+			$elapsedCpu = $entry[6] - $entry[3];
+			$elapsedReal = $entry[5] - $entry[2];
+			$memchange = $entry[7] - $entry[4];
+			$subcalls = $this->calltreeCount( $this->stack, $index );
+
+			if ( substr( $fname, 0, 9 ) !== '-overhead' ) {
+				# Adjust for profiling overhead (except special values with elapsed=0)
+				if ( $elapsed ) {
+					$elapsed -= $overheadInternal;
+					$elapsed -= ( $subcalls * $overheadTotal );
+					$memchange -= ( $subcalls * $overheadMemory );
+				}
+			}
+
+			$this->updateEntry( $fname, $elapsedCpu, $elapsedReal, $memchange );
+		}
+
+		$this->collated['-overhead-total']['count'] = $profileCount;
+		arsort( $this->collated, SORT_NUMERIC );
+
+		// Unclobber the end info map (the overhead checking alters it)
+		$this->end = $oldEnd;
+	}
+
+	/**
+	 * Dummy calls to calculate profiling overhead
+	 *
+	 * @param int $profileCount
+	 */
+	protected function calculateOverhead( $profileCount ) {
+		$this->profileInInternal( '-overhead-total' );
+		for ( $i = 0; $i < $profileCount; $i++ ) {
+			$this->profileInInternal( '-overhead-internal' );
+			$this->profileOutInternal( '-overhead-internal' );
+		}
+		$this->profileOutInternal( '-overhead-total' );
+	}
+
+	/**
+	 * Counts the number of profiled function calls sitting under
+	 * the given point in the call graph. Not the most efficient algo.
+	 *
+	 * @param array $stack
+	 * @param int $start
+	 * @return int
+	 */
+	protected function calltreeCount( $stack, $start ) {
+		$level = $stack[$start][1];
+		$count = 0;
+		for ( $i = $start -1; $i >= 0 && $stack[$i][1] > $level; $i-- ) {
+			$count ++;
+		}
+		return $count;
+	}
+
+	/**
+	 * Get the initial time of the request, based either on $wgRequestTime or
+	 * $wgRUstart. Will return null if not able to find data.
+	 *
+	 * @param string|bool $metric Metric to use, with the following possibilities:
+	 *   - user: User CPU time (without system calls)
+	 *   - cpu: Total CPU time (user and system calls)
+	 *   - wall (or any other string): elapsed time
+	 *   - false (default): will fall back to default metric
+	 * @return float|null
+	 */
+	protected function getTime( $metric = 'wall' ) {
+		if ( $metric === 'cpu' || $metric === 'user' ) {
+			$ru = wfGetRusage();
+			if ( !$ru ) {
+				return 0;
+			}
+			$time = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
+			if ( $metric === 'cpu' ) {
+				# This is the time of system calls, added to the user time
+				# it gives the total CPU time
+				$time += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
+			}
+			return $time;
+		} else {
+			return microtime( true );
+		}
+	}
+
+	/**
+	 * Add an entry in the debug log file
+	 *
+	 * @param string $s String to output
+	 */
+	protected function debug( $s ) {
+		if ( function_exists( 'wfDebug' ) ) {
+			wfDebug( $s );
+		}
+	}
+
+	/**
+	 * Add an entry in the debug log group
+	 *
+	 * @param string $group Group to send the message to
+	 * @param string $s String to output
+	 */
+	protected function debugGroup( $group, $s ) {
+		if ( function_exists( 'wfDebugLog' ) ) {
+			wfDebugLog( $group, $s );
+		}
+	}
+}
+
+/**
+ * Subclass ScopedCallback to avoid call_user_func_array(), which is slow
+ *
+ * This class should not be used outside of SectionProfiler
+ */
+class SectionProfileCallback extends ScopedCallback {
+	/** @var SectionProfiler */
+	protected $profiler;
+	/** @var string */
+	protected $section;
+
+	/**
+	 * @param SectionProfiler $profiler
+	 * @param string $section
+	 */
+	public function __construct( SectionProfiler $profiler, $section ) {
+		parent::__construct( null );
+		$this->profiler = $profiler;
+		$this->section = $section;
+	}
+
+	function __destruct() {
+		$this->profiler->profileOutInternal( $this->section );
+	}
+}
diff --git a/includes/profiler/TransactionProfiler.php b/includes/profiler/TransactionProfiler.php
new file mode 100644
index 00000000..f02d66f8
--- /dev/null
+++ b/includes/profiler/TransactionProfiler.php
@@ -0,0 +1,274 @@
+<?php
+/**
+ * Transaction profiling for contention
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ * @author Aaron Schulz
+ */
+
+use Psr\Log\LoggerInterface;
+use Psr\Log\LoggerAwareInterface;
+use Psr\Log\NullLogger;
+/**
+ * Helper class that detects high-contention DB queries via profiling calls
+ *
+ * This class is meant to work with a DatabaseBase object, which manages queries
+ *
+ * @since 1.24
+ */
+class TransactionProfiler implements LoggerAwareInterface {
+	/** @var float Seconds */
+	protected $dbLockThreshold = 3.0;
+	/** @var float Seconds */
+	protected $eventThreshold = .25;
+
+	/** @var array transaction ID => (write start time, list of DBs involved) */
+	protected $dbTrxHoldingLocks = array();
+	/** @var array transaction ID => list of (query name, start time, end time) */
+	protected $dbTrxMethodTimes = array();
+
+	/** @var array */
+	protected $hits = array(
+		'writes'      => 0,
+		'queries'     => 0,
+		'conns'       => 0,
+		'masterConns' => 0
+	);
+	/** @var array */
+	protected $expect = array(
+		'writes'      => INF,
+		'queries'     => INF,
+		'conns'       => INF,
+		'masterConns' => INF,
+		'maxAffected' => INF
+	);
+	/** @var array */
+	protected $expectBy = array();
+
+	/**
+	 * @var LoggerInterface
+	 */
+	private $logger;
+
+	public function __construct() {
+		$this->setLogger( new NullLogger() );
+	}
+
+	public function setLogger( LoggerInterface $logger ) {
+		$this->logger = $logger;
+	}
+
+	/**
+	 * Set performance expectations
+	 *
+	 * With conflicting expect, the most specific ones will be used
+	 *
+	 * @param string $event (writes,queries,conns,mConns)
+	 * @param integer $value Maximum count of the event
+	 * @param string $fname Caller
+	 * @since 1.25
+	 */
+	public function setExpectation( $event, $value, $fname ) {
+		$this->expect[$event] = isset( $this->expect[$event] )
+			? min( $this->expect[$event], $value )
+			: $value;
+		if ( $this->expect[$event] == $value ) {
+			$this->expectBy[$event] = $fname;
+		}
+	}
+
+	/**
+	 * Reset performance expectations and hit counters
+	 *
+	 * @since 1.25
+	 */
+	public function resetExpectations() {
+		foreach ( $this->hits as &$val ) {
+			$val = 0;
+		}
+		unset( $val );
+		foreach ( $this->expect as &$val ) {
+			$val = INF;
+		}
+		unset( $val );
+		$this->expectBy = array();
+	}
+
+	/**
+	 * Mark a DB as having been connected to with a new handle
+	 *
+	 * Note that there can be multiple connections to a single DB.
+	 *
+	 * @param string $server DB server
+	 * @param string $db DB name
+	 * @param bool $isMaster
+	 */
+	public function recordConnection( $server, $db, $isMaster ) {
+		// Report when too many connections happen...
+		if ( $this->hits['conns']++ == $this->expect['conns'] ) {
+			$this->reportExpectationViolated( 'conns', "[connect to $server ($db)]" );
+		}
+		if ( $isMaster && $this->hits['masterConns']++ == $this->expect['masterConns'] ) {
+			$this->reportExpectationViolated( 'masterConns', "[connect to $server ($db)]" );
+		}
+	}
+
+	/**
+	 * Mark a DB as in a transaction with one or more writes pending
+	 *
+	 * Note that there can be multiple connections to a single DB.
+	 *
+	 * @param string $server DB server
+	 * @param string $db DB name
+	 * @param string $id ID string of transaction
+	 */
+	public function transactionWritingIn( $server, $db, $id ) {
+		$name = "{$server} ({$db}) (TRX#$id)";
+		if ( isset( $this->dbTrxHoldingLocks[$name] ) ) {
+			$this->logger->info( "Nested transaction for '$name' - out of sync." );
+		}
+		$this->dbTrxHoldingLocks[$name] = array(
+			'start' => microtime( true ),
+			'conns' => array(), // all connections involved
+		);
+		$this->dbTrxMethodTimes[$name] = array();
+
+		foreach ( $this->dbTrxHoldingLocks as $name => &$info ) {
+			// Track all DBs in transactions for this transaction
+			$info['conns'][$name] = 1;
+		}
+	}
+
+	/**
+	 * Register the name and time of a method for slow DB trx detection
+	 *
+	 * This assumes that all queries are synchronous (non-overlapping)
+	 *
+	 * @param string $query Function name or generalized SQL
+	 * @param float $sTime Starting UNIX wall time
+	 * @param bool $isWrite Whether this is a write query
+	 * @param integer $n Number of affected rows
+	 */
+	public function recordQueryCompletion( $query, $sTime, $isWrite = false, $n = 0 ) {
+		$eTime = microtime( true );
+		$elapsed = ( $eTime - $sTime );
+
+		if ( $isWrite && $n > $this->expect['maxAffected'] ) {
+			$this->logger->info( "Query affected $n row(s):\n" . $query . "\n" . wfBacktrace( true ) );
+		}
+
+		// Report when too many writes/queries happen...
+		if ( $this->hits['queries']++ == $this->expect['queries'] ) {
+			$this->reportExpectationViolated( 'queries', $query );
+		}
+		if ( $isWrite && $this->hits['writes']++ == $this->expect['writes'] ) {
+			$this->reportExpectationViolated( 'writes', $query );
+		}
+
+		if ( !$this->dbTrxHoldingLocks ) {
+			// Short-circuit
+			return;
+		} elseif ( !$isWrite && $elapsed < $this->eventThreshold ) {
+			// Not an important query nor slow enough
+			return;
+		}
+
+		foreach ( $this->dbTrxHoldingLocks as $name => $info ) {
+			$lastQuery = end( $this->dbTrxMethodTimes[$name] );
+			if ( $lastQuery ) {
+				// Additional query in the trx...
+				$lastEnd = $lastQuery[2];
+				if ( $sTime >= $lastEnd ) { // sanity check
+					if ( ( $sTime - $lastEnd ) > $this->eventThreshold ) {
+						// Add an entry representing the time spent doing non-queries
+						$this->dbTrxMethodTimes[$name][] = array( '...delay...', $lastEnd, $sTime );
+					}
+					$this->dbTrxMethodTimes[$name][] = array( $query, $sTime, $eTime );
+				}
+			} else {
+				// First query in the trx...
+				if ( $sTime >= $info['start'] ) { // sanity check
+					$this->dbTrxMethodTimes[$name][] = array( $query, $sTime, $eTime );
+				}
+			}
+		}
+	}
+
+	/**
+	 * Mark a DB as no longer in a transaction
+	 *
+	 * This will check if locks are possibly held for longer than
+	 * needed and log any affected transactions to a special DB log.
+	 * Note that there can be multiple connections to a single DB.
+	 *
+	 * @param string $server DB server
+	 * @param string $db DB name
+	 * @param string $id ID string of transaction
+	 */
+	public function transactionWritingOut( $server, $db, $id ) {
+		$name = "{$server} ({$db}) (TRX#$id)";
+		if ( !isset( $this->dbTrxMethodTimes[$name] ) ) {
+			$this->logger->info( "Detected no transaction for '$name' - out of sync." );
+			return;
+		}
+		// Fill in the last non-query period...
+		$lastQuery = end( $this->dbTrxMethodTimes[$name] );
+		if ( $lastQuery ) {
+			$now = microtime( true );
+			$lastEnd = $lastQuery[2];
+			if ( ( $now - $lastEnd ) > $this->eventThreshold ) {
+				$this->dbTrxMethodTimes[$name][] = array( '...delay...', $lastEnd, $now );
+			}
+		}
+		// Check for any slow queries or non-query periods...
+		$slow = false;
+		foreach ( $this->dbTrxMethodTimes[$name] as $info ) {
+			$elapsed = ( $info[2] - $info[1] );
+			if ( $elapsed >= $this->dbLockThreshold ) {
+				$slow = true;
+				break;
+			}
+		}
+		if ( $slow ) {
+			$dbs = implode( ', ', array_keys( $this->dbTrxHoldingLocks[$name]['conns'] ) );
+			$msg = "Sub-optimal transaction on DB(s) [{$dbs}]:\n";
+			foreach ( $this->dbTrxMethodTimes[$name] as $i => $info ) {
+				list( $query, $sTime, $end ) = $info;
+				$msg .= sprintf( "%d\t%.6f\t%s\n", $i, ( $end - $sTime ), $query );
+			}
+			$this->logger->info( $msg );
+		}
+		unset( $this->dbTrxHoldingLocks[$name] );
+		unset( $this->dbTrxMethodTimes[$name] );
+	}
+
+	/**
+	 * @param string $expect
+	 * @param string $query
+	 */
+	protected function reportExpectationViolated( $expect, $query ) {
+		global $wgRequest;
+
+		$n = $this->expect[$expect];
+		$by = $this->expectBy[$expect];
+		$this->logger->info(
+			"[{$wgRequest->getMethod()}] Expectation ($expect <= $n) by $by not met:\n$query\n" . wfBacktrace( true )
+		);
+	}
+}
diff --git a/includes/profiler/output/ProfilerOutput.php b/includes/profiler/output/ProfilerOutput.php
new file mode 100644
index 00000000..3473e0b2
--- /dev/null
+++ b/includes/profiler/output/ProfilerOutput.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ */
+
+/**
+ * Base class for profiling output
+ *
+ * Since 1.25
+ */
+abstract class ProfilerOutput {
+	/** @var Profiler */
+	protected $collector;
+	/** @var array Configuration of $wgProfiler */
+	protected $params = array();
+
+	/**
+	 * Constructor
+	 * @param Profiler $collector The actual profiler
+	 * @param array $params Configuration array, passed down from $wgProfiler
+	 */
+	public function __construct( Profiler $collector, array $params ) {
+		$this->collector = $collector;
+		$this->params = $params;
+	}
+
+	/**
+	 * Can this output type be used?
+	 * @return bool
+	 */
+	public function canUse() {
+		return true;
+	}
+
+	/**
+	 * Log MediaWiki-style profiling data
+	 *
+	 * @param array $stats Result of Profiler::getFunctionStats()
+	 */
+	abstract public function log( array $stats );
+}
diff --git a/includes/profiler/ProfilerSimpleDB.php b/includes/profiler/output/ProfilerOutputDb.php
index 7ef0ad05..76d62d2e 100644
--- a/includes/profiler/ProfilerSimpleDB.php
+++ b/includes/profiler/output/ProfilerOutputDb.php
@@ -22,47 +22,45 @@
  */
 
 /**
- * $wgProfiler['class'] = 'ProfilerSimpleDB';
+ * Logs profiling data into the local DB
  *
  * @ingroup Profiler
+ * @since 1.25
  */
-class ProfilerSimpleDB extends ProfilerStandard {
-	protected function collateOnly() {
-		return true;
-	}
-
-	public function isPersistent() {
-		return true;
-	}
+class ProfilerOutputDb extends ProfilerOutput {
+	/** @var bool Whether to store host data with profiling calls */
+	private $perHost = false;
 
-	/**
-	 * Log the whole profiling data into the database.
-	 */
-	public function logData() {
+	public function __construct( Profiler $collector, array $params ) {
+		parent::__construct( $collector, $params );
 		global $wgProfilePerHost;
 
-		# Do not log anything if database is readonly (bug 5375)
-		if ( wfReadOnly() ) {
-			return;
+		// Initialize per-host profiling from config, back-compat if available
+		if ( isset( $this->params['perHost'] ) ) {
+			$this->perHost = $this->params['perHost'];
+		} elseif ( $wgProfilePerHost ) {
+			$this->perHost = $wgProfilePerHost;
 		}
+	}
 
-		if ( $wgProfilePerHost ) {
-			$pfhost = wfHostname();
-		} else {
-			$pfhost = '';
-		}
+	public function canUse() {
+		# Do not log anything if database is readonly (bug 5375)
+		return !wfReadOnly();
+	}
 
-		try {
-			$this->collateData();
+	public function log( array $stats ) {
+		$pfhost = $this->perHost ? wfHostname() : '';
 
+		try {
 			$dbw = wfGetDB( DB_MASTER );
 			$useTrx = ( $dbw->getType() === 'sqlite' ); // much faster
 			if ( $useTrx ) {
 				$dbw->startAtomic( __METHOD__ );
 			}
-			foreach ( $this->mCollated as $name => $data ) {
-				$eventCount = $data['count'];
-				$timeSum = (float)( $data['real'] * 1000 );
+			foreach ( $stats as $data ) {
+				$name = $data['name'];
+				$eventCount = $data['calls'];
+				$timeSum = (float)$data['real'];
 				$memorySum = (float)$data['memory'];
 				$name = substr( $name, 0, 255 );
 
@@ -70,37 +68,22 @@ class ProfilerSimpleDB extends ProfilerStandard {
 				$timeSum = $timeSum >= 0 ? $timeSum : 0;
 				$memorySum = $memorySum >= 0 ? $memorySum : 0;
 
-				$dbw->update( 'profiling',
+				$dbw->upsert( 'profiling',
+					array(
+						'pf_name' => $name,
+						'pf_count' => $eventCount,
+						'pf_time' => $timeSum,
+						'pf_memory' => $memorySum,
+						'pf_server' => $pfhost
+					),
+					array( array( 'pf_name', 'pf_server' ) ),
 					array(
 						"pf_count=pf_count+{$eventCount}",
 						"pf_time=pf_time+{$timeSum}",
 						"pf_memory=pf_memory+{$memorySum}",
 					),
-					array(
-						'pf_name' => $name,
-						'pf_server' => $pfhost,
-					),
-					__METHOD__ );
-
-				$rc = $dbw->affectedRows();
-				if ( $rc == 0 ) {
-					$dbw->insert( 'profiling',
-						array(
-							'pf_name' => $name,
-							'pf_count' => $eventCount,
-							'pf_time' => $timeSum,
-							'pf_memory' => $memorySum,
-							'pf_server' => $pfhost
-						),
-						__METHOD__,
-						array( 'IGNORE' )
-					);
-				}
-				// When we upgrade to mysql 4.1, the insert+update
-				// can be merged into just a insert with this construct added:
-				//     "ON DUPLICATE KEY UPDATE ".
-				//     "pf_count=pf_count + VALUES(pf_count), ".
-				//     "pf_time=pf_time + VALUES(pf_time)";
+					__METHOD__
+				);
 			}
 			if ( $useTrx ) {
 				$dbw->endAtomic( __METHOD__ );
diff --git a/includes/profiler/output/ProfilerOutputDump.php b/includes/profiler/output/ProfilerOutputDump.php
new file mode 100644
index 00000000..bf4b85c2
--- /dev/null
+++ b/includes/profiler/output/ProfilerOutputDump.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * Profiler dumping output in xhprof dump file
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ */
+
+/**
+ * Profiler dumping output in xhprof dump file
+ * @ingroup Profiler
+ *
+ * @since 1.25
+ */
+class ProfilerOutputDump extends ProfilerOutput {
+
+	protected $suffix = ".xhprof";
+
+	/**
+	 * Can this output type be used?
+	 *
+	 * @return bool
+	 */
+	public function canUse() {
+		if ( empty( $this->params['outputDir'] ) ) {
+			return false;
+		}
+		return true;
+	}
+
+	public function log( array $stats ) {
+		$data = $this->collector->getRawData();
+		$filename = sprintf( "%s/%s.%s%s", $this->params['outputDir'], uniqid(), $this->collector->getProfileID(), $this->suffix );
+		file_put_contents( $filename, serialize( $data ) );
+	}
+}
diff --git a/includes/profiler/output/ProfilerOutputStats.php b/includes/profiler/output/ProfilerOutputStats.php
new file mode 100644
index 00000000..ef6ef7c9
--- /dev/null
+++ b/includes/profiler/output/ProfilerOutputStats.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * ProfilerOutput class that flushes profiling data to the profiling
+ * context's stats buffer.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ */
+
+/**
+ * ProfilerOutput class that flushes profiling data to the profiling
+ * context's stats buffer.
+ *
+ * @ingroup Profiler
+ * @since 1.25
+ */
+class ProfilerOutputStats extends ProfilerOutput {
+
+	/**
+	 * Flush profiling data to the current profiling context's stats buffer.
+	 *
+	 * @param array $stats
+	 */
+	public function log( array $stats ) {
+		$contextStats = $this->collector->getContext()->getStats();
+
+		foreach ( $stats as $stat ) {
+			// Sanitize the key
+			$key = str_replace( '::', '.', $stat['name'] );
+			$key = preg_replace( '/[^a-z.]+/i', '_', $key );
+			$key = trim( $key, '_.' );
+
+			// Convert fractional seconds to whole milliseconds
+			$cpu = round( $stat['cpu'] * 1000 );
+			$real = round( $stat['real'] * 1000 );
+
+			$contextStats->increment( "{$key}.calls" );
+			$contextStats->timing( "{$key}.cpu", $cpu );
+			$contextStats->timing( "{$key}.real", $real );
+		}
+	}
+}
diff --git a/includes/profiler/output/ProfilerOutputText.php b/includes/profiler/output/ProfilerOutputText.php
new file mode 100644
index 00000000..67527798
--- /dev/null
+++ b/includes/profiler/output/ProfilerOutputText.php
@@ -0,0 +1,77 @@
+<?php
+/**
+ * Profiler showing output in page source.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ */
+
+/**
+ * The least sophisticated profiler output class possible, view your source! :)
+ *
+ * @ingroup Profiler
+ * @since 1.25
+ */
+class ProfilerOutputText extends ProfilerOutput {
+	/** @var float Min real time display threshold */
+	protected $thresholdMs;
+
+	function __construct( Profiler $collector, array $params ) {
+		parent::__construct( $collector, $params );
+		$this->thresholdMs = isset( $params['thresholdMs'] )
+			? $params['thresholdMs']
+			: .25;
+	}
+	public function log( array $stats ) {
+		if ( $this->collector->getTemplated() ) {
+			$out = '';
+
+			// Filter out really tiny entries
+			$min = $this->thresholdMs;
+			$stats = array_filter( $stats, function ( $a ) use ( $min ) {
+				return $a['real'] > $min;
+			} );
+			// Sort descending by time elapsed
+			usort( $stats, function ( $a, $b ) {
+				return $a['real'] < $b['real'];
+			} );
+
+			array_walk( $stats,
+				function ( $item ) use ( &$out ) {
+					$out .= sprintf( "%6.2f%% %3.3f %6d - %s\n",
+						$item['%real'], $item['real'], $item['calls'], $item['name'] );
+				}
+			);
+
+			$contentType = $this->collector->getContentType();
+			if ( PHP_SAPI === 'cli' ) {
+				print "<!--\n{$out}\n-->\n";
+			} elseif ( $contentType === 'text/html' ) {
+				$visible = isset( $this->params['visible'] ) ?
+					$this->params['visible'] : false;
+				if ( $visible ) {
+					print "<pre>{$out}</pre>";
+				} else {
+					print "<!--\n{$out}\n-->\n";
+				}
+			} elseif ( $contentType === 'text/javascript' || $contentType === 'text/css' ) {
+				print "\n/*\n{$out}*/\n";
+			}
+		}
+	}
+}
diff --git a/includes/profiler/output/ProfilerOutputUdp.php b/includes/profiler/output/ProfilerOutputUdp.php
new file mode 100644
index 00000000..7da03c11
--- /dev/null
+++ b/includes/profiler/output/ProfilerOutputUdp.php
@@ -0,0 +1,96 @@
+<?php
+/**
+ * Profiler sending messages over UDP.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Profiler
+ */
+
+/**
+ * ProfilerSimpleUDP class, that sends out messages for 'udpprofile' daemon
+ * (see http://git.wikimedia.org/tree/operations%2Fsoftware.git/master/udpprofile)
+ *
+ * @ingroup Profiler
+ * @since 1.25
+ */
+class ProfilerOutputUdp extends ProfilerOutput {
+	/** @var int port to send profiling data to */
+	private $port = 3811;
+
+	/** @var string host to send profiling data to */
+	private $host = '127.0.0.1';
+
+	/** @var string format string for profiling data */
+	private $format = "%s - %d %f %f %f %f %s\n";
+
+	public function __construct( Profiler $collector, array $params ) {
+		parent::__construct( $collector, $params );
+		global $wgUDPProfilerPort, $wgUDPProfilerHost, $wgUDPProfilerFormatString;
+
+		// Initialize port, host, and format from config, back-compat if available
+		if ( isset( $this->params['udpport'] ) ) {
+			$this->port = $this->params['udpport'];
+		} elseif ( $wgUDPProfilerPort ) {
+			$this->port = $wgUDPProfilerPort;
+		}
+
+		if ( isset( $this->params['udphost'] ) ) {
+			$this->host = $this->params['udphost'];
+		} elseif ( $wgUDPProfilerHost ) {
+			$this->host = $wgUDPProfilerHost;
+		}
+
+		if ( isset( $this->params['udpformat'] ) ) {
+			$this->format = $this->params['udpformat'];
+		} elseif ( $wgUDPProfilerFormatString ) {
+			$this->format = $wgUDPProfilerFormatString;
+		}
+	}
+
+	public function canUse() {
+		# Sockets are not enabled
+		return function_exists( 'socket_create' );
+	}
+
+	public function log( array $stats ) {
+		$sock = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
+		$plength = 0;
+		$packet = "";
+		foreach ( $stats as $pfdata ) {
+			$pfline = sprintf( $this->format,
+				$this->collector->getProfileID(),
+				$pfdata['calls'],
+				$pfdata['cpu'] / 1000, // ms => sec
+				0.0, // sum of CPU^2 for each invocation (unused)
+				$pfdata['real'] / 1000, // ms => sec
+				0.0, // sum of real^2 for each invocation (unused)
+				$pfdata['name'],
+				$pfdata['memory']
+			);
+			$length = strlen( $pfline );
+			if ( $length + $plength > 1400 ) {
+				socket_sendto( $sock, $packet, $plength, 0, $this->host, $this->port );
+				$packet = "";
+				$plength = 0;
+			}
+			$packet .= $pfline;
+			$plength += $length;
+		}
+		socket_sendto( $sock, $packet, $plength, 0x100, $this->host, $this->port );
+	}
+}