includes/profiler/Profiler.php

   1 <?php
   2 /**
   3  * Base class and functions for profiling.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Profiler
  22  * This file is only included if profiling is enabled
  23  */
  24
  25 /**
  26  * @defgroup Profiler Profiler
  27  */
  28
  29 /**
  30  * Begin profiling of a function
  31  * @param string $functionname name of the function we will profile
  32  */
  33 function wfProfileIn( $functionname ) {
  34         if ( Profiler::$__instance === null ) { // use this directly to reduce overhead
  35                 Profiler::instance();
  36         }
  37         if ( !( Profiler::$__instance instanceof ProfilerStub ) ) {
  38                 Profiler::$__instance->profileIn( $functionname );
  39         }
  40 }
  41
  42 /**
  43  * Stop profiling of a function
  44  * @param string $functionname name of the function we have profiled
  45  */
  46 function wfProfileOut( $functionname = 'missing' ) {
  47         if ( Profiler::$__instance === null ) { // use this directly to reduce overhead
  48                 Profiler::instance();
  49         }
  50         if ( !( Profiler::$__instance instanceof ProfilerStub ) ) {
  51                 Profiler::$__instance->profileOut( $functionname );
  52         }
  53 }
  54
  55 /**
  56  * Class for handling function-scope profiling
  57  *
  58  * @since 1.22
  59  */
  60 class ProfileSection {
  61         protected $name; // string; method name
  62         protected $enabled = false; // boolean; whether profiling is enabled
  63
  64         /**
  65          * Begin profiling of a function and return an object that ends profiling of
  66          * the function when that object leaves scope. As long as the object is not
  67          * specifically linked to other objects, it will fall out of scope at the same
  68          * moment that the function to be profiled terminates.
  69          *
  70          * This is typically called like:
  71          * <code>$section = new ProfileSection( __METHOD__ );</code>
  72          *
  73          * @param string $name Name of the function to profile
  74          */
  75         public function __construct( $name ) {
  76                 $this->name = $name;
  77                 if ( Profiler::$__instance === null ) { // use this directly to reduce overhead
  78                         Profiler::instance();
  79                 }
  80                 if ( !( Profiler::$__instance instanceof ProfilerStub ) ) {
  81                         $this->enabled = true;
  82                         Profiler::$__instance->profileIn( $this->name );
  83                 }
  84         }
  85
  86         function __destruct() {
  87                 if ( $this->enabled ) {
  88                         Profiler::$__instance->profileOut( $this->name );
  89                 }
  90         }
  91 }
  92
  93 /**
  94  * @ingroup Profiler
  95  * @todo document
  96  */
  97 class Profiler {
  98         protected $mStack = array(), $mWorkStack = array(), $mCollated = array(),
  99                 $mCalls = array(), $mTotals = array();
 100         protected $mTimeMetric = 'wall';
 101         protected $mProfileID = false, $mCollateDone = false, $mTemplated = false;
 102
 103         protected $mDBLockThreshold = 5.0; // float; seconds
 104         /** @var Array DB/server name => (active trx count,timestamp) */
 105         protected $mDBTrxHoldingLocks = array();
 106         /** @var Array DB/server name => list of (method, elapsed time) */
 107         protected $mDBTrxMethodTimes = array();
 108
 109         /** @var Profiler */
 110         public static $__instance = null; // do not call this outside Profiler and ProfileSection
 111
 112         function __construct( $params ) {
 113                 if ( isset( $params['timeMetric'] ) ) {
 114                         $this->mTimeMetric = $params['timeMetric'];
 115                 }
 116                 if ( isset( $params['profileID'] ) ) {
 117                         $this->mProfileID = $params['profileID'];
 118                 }
 119
 120                 $this->addInitialStack();
 121         }
 122
 123         /**
 124          * Singleton
 125          * @return Profiler
 126          */
 127         public static function instance() {
 128                 if ( self::$__instance === null ) {
 129                         global $wgProfiler;
 130                         if ( is_array( $wgProfiler ) ) {
 131                                 if ( !isset( $wgProfiler['class'] ) ) {
 132                                         $class = 'ProfilerStub';
 133                                 } else {
 134                                         $class = $wgProfiler['class'];
 135                                 }
 136                                 self::$__instance = new $class( $wgProfiler );
 137                         } elseif ( $wgProfiler instanceof Profiler ) {
 138                                 self::$__instance = $wgProfiler; // back-compat
 139                         } else {
 140                                 self::$__instance = new ProfilerStub( $wgProfiler );
 141                         }
 142                 }
 143                 return self::$__instance;
 144         }
 145
 146         /**
 147          * Set the profiler to a specific profiler instance. Mostly for dumpHTML
 148          * @param $p Profiler object
 149          */
 150         public static function setInstance( Profiler $p ) {
 151                 self::$__instance = $p;
 152         }
 153
 154         /**
 155          * Return whether this a stub profiler
 156          *
 157          * @return Boolean
 158          */
 159         public function isStub() {
 160                 return false;
 161         }
 162
 163         /**
 164          * Return whether this profiler stores data
 165          *
 166          * @see Profiler::logData()
 167          * @return Boolean
 168          */
 169         public function isPersistent() {
 170                 return true;
 171         }
 172
 173         public function setProfileID( $id ) {
 174                 $this->mProfileID = $id;
 175         }
 176
 177         public function getProfileID() {
 178                 if ( $this->mProfileID === false ) {
 179                         return wfWikiID();
 180                 } else {
 181                         return $this->mProfileID;
 182                 }
 183         }
 184
 185         /**
 186          * Add the inital item in the stack.
 187          */
 188         protected function addInitialStack() {
 189                 // Push an entry for the pre-profile setup time onto the stack
 190                 $initial = $this->getInitialTime();
 191                 if ( $initial !== null ) {
 192                         $this->mWorkStack[] = array( '-total', 0, $initial, 0 );
 193                         $this->mStack[] = array( '-setup', 1, $initial, 0, $this->getTime(), 0 );
 194                 } else {
 195                         $this->profileIn( '-total' );
 196                 }
 197         }
 198
 199         /**
 200          * Called by wfProfieIn()
 201          *
 202          * @param $functionname String
 203          */
 204         public function profileIn( $functionname ) {
 205                 global $wgDebugFunctionEntry;
 206                 if ( $wgDebugFunctionEntry ) {
 207                         $this->debug( str_repeat( ' ', count( $this->mWorkStack ) ) . 'Entering ' . $functionname . "\n" );
 208                 }
 209
 210                 $this->mWorkStack[] = array( $functionname, count( $this->mWorkStack ), $this->getTime(), memory_get_usage() );
 211         }
 212
 213         /**
 214          * Called by wfProfieOut()
 215          *
 216          * @param $functionname String
 217          */
 218         public function profileOut( $functionname ) {
 219                 global $wgDebugFunctionEntry;
 220                 $memory = memory_get_usage();
 221                 $time = $this->getTime();
 222
 223                 if ( $wgDebugFunctionEntry ) {
 224                         $this->debug( str_repeat( ' ', count( $this->mWorkStack ) - 1 ) . 'Exiting ' . $functionname . "\n" );
 225                 }
 226
 227                 $bit = array_pop( $this->mWorkStack );
 228
 229                 if ( !$bit ) {
 230                         $this->debugGroup( 'profileerror', "Profiling error, !\$bit: $functionname" );
 231                 } else {
 232                         if ( $functionname == 'close' ) {
 233                                 if ( $bit[0] != '-total' ) {
 234                                         $message = "Profile section ended by close(): {$bit[0]}";
 235                                         $this->debugGroup( 'profileerror', $message );
 236                                         $this->mStack[] = array( $message, 0, 0.0, 0, 0.0, 0 );
 237                                 }
 238                         } elseif ( $bit[0] != $functionname ) {
 239                                 $message = "Profiling error: in({$bit[0]}), out($functionname)";
 240                                 $this->debugGroup( 'profileerror', $message );
 241                                 $this->mStack[] = array( $message, 0, 0.0, 0, 0.0, 0 );
 242                         }
 243                         $bit[] = $time;
 244                         $bit[] = $memory;
 245                         $this->mStack[] = $bit;
 246                         $this->updateTrxProfiling( $functionname, $time );
 247                 }
 248         }
 249
 250         /**
 251          * Close opened profiling sections
 252          */
 253         public function close() {
 254                 while ( count( $this->mWorkStack ) ) {
 255                         $this->profileOut( 'close' );
 256                 }
 257         }
 258
 259         /**
 260          * Mark a DB as in a transaction with one or more writes pending
 261          *
 262          * Note that there can be multiple connections to a single DB.
 263          *
 264          * @param string $server DB server
 265          * @param string $db DB name
 266          */
 267         public function transactionWritingIn( $server, $db ) {
 268                 $name = "{$server} ({$db})";
 269                 if ( isset( $this->mDBTrxHoldingLocks[$name] ) ) {
 270                         ++$this->mDBTrxHoldingLocks[$name]['refs'];
 271                 } else {
 272                         $this->mDBTrxHoldingLocks[$name] = array( 'refs' => 1, 'start' => microtime( true ) );
 273                         $this->mDBTrxMethodTimes[$name] = array();
 274                 }
 275         }
 276
 277         /**
 278          * Register the name and time of a method for slow DB trx detection
 279          *
 280          * @param string $method Function name
 281          * @param float $realtime Wal time ellapsed
 282          */
 283         protected function updateTrxProfiling( $method, $realtime ) {
 284                 if ( !$this->mDBTrxHoldingLocks ) {
 285                         return; // short-circuit
 286                 // @TODO: hardcoded check is a tad janky (what about FOR UPDATE?)
 287                 } elseif ( !preg_match( '/^query-m: (?!SELECT)/', $method )
 288                         && $realtime < $this->mDBLockThreshold
 289                 ) {
 290                         return; // not a DB master query nor slow enough
 291                 }
 292                 $now = microtime( true );
 293                 foreach ( $this->mDBTrxHoldingLocks as $name => $info ) {
 294                         // Hacky check to exclude entries from before the first TRX write
 295                         if ( ( $now - $realtime ) >= $info['start'] ) {
 296                                 $this->mDBTrxMethodTimes[$name][] = array( $method, $realtime );
 297                         }
 298                 }
 299         }
 300
 301         /**
 302          * Mark a DB as no longer in a transaction
 303          *
 304          * This will check if locks are possibly held for longer than
 305          * needed and log any affected transactions to a special DB log.
 306          * Note that there can be multiple connections to a single DB.
 307          *
 308          * @param string $server DB server
 309          * @param string $db DB name
 310          */
 311         public function transactionWritingOut( $server, $db ) {
 312                 $name = "{$server} ({$db})";
 313                 if ( --$this->mDBTrxHoldingLocks[$name]['refs'] <= 0 ) {
 314                         $slow = false;
 315                         foreach ( $this->mDBTrxMethodTimes[$name] as $info ) {
 316                                 list( $method, $realtime ) = $info;
 317                                 if ( $realtime >= $this->mDBLockThreshold ) {
 318                                         $slow = true;
 319                                         break;
 320                                 }
 321                         }
 322                         if ( $slow ) {
 323                                 $dbs = implode( ', ', array_keys( $this->mDBTrxHoldingLocks ) );
 324                                 $msg = "Sub-optimal transaction on DB(s) {$dbs}:\n";
 325                                 foreach ( $this->mDBTrxMethodTimes[$name] as $i => $info ) {
 326                                         list( $method, $realtime ) = $info;
 327                                         $msg .= sprintf( "%d\t%.6f\t%s\n", $i, $realtime, $method );
 328                                 }
 329                                 $this->debugGroup( 'DBPerformance', $msg );
 330                         }
 331                         unset( $this->mDBTrxHoldingLocks[$name] );
 332                         unset( $this->mDBTrxMethodTimes[$name] );
 333                 }
 334         }
 335
 336         /**
 337          * Mark this call as templated or not
 338          *
 339          * @param $t Boolean
 340          */
 341         function setTemplated( $t ) {
 342                 $this->mTemplated = $t;
 343         }
 344
 345         /**
 346          * Returns a profiling output to be stored in debug file
 347          *
 348          * @return String
 349          */
 350         public function getOutput() {
 351                 global $wgDebugFunctionEntry, $wgProfileCallTree;
 352                 $wgDebugFunctionEntry = false;
 353
 354                 if ( !count( $this->mStack ) && !count( $this->mCollated ) ) {
 355                         return "No profiling output\n";
 356                 }
 357
 358                 if ( $wgProfileCallTree ) {
 359                         return $this->getCallTree();
 360                 } else {
 361                         return $this->getFunctionReport();
 362                 }
 363         }
 364
 365         /**
 366          * Returns a tree of function call instead of a list of functions
 367          * @return string
 368          */
 369         function getCallTree() {
 370                 return implode( '', array_map( array( &$this, 'getCallTreeLine' ), $this->remapCallTree( $this->mStack ) ) );
 371         }
 372
 373         /**
 374          * Recursive function the format the current profiling array into a tree
 375          *
 376          * @param array $stack profiling array
 377          * @return array
 378          */
 379         function remapCallTree( $stack ) {
 380                 if ( count( $stack ) < 2 ) {
 381                         return $stack;
 382                 }
 383                 $outputs = array();
 384                 for ( $max = count( $stack ) - 1; $max > 0; ) {
 385                         /* Find all items under this entry */
 386                         $level = $stack[$max][1];
 387                         $working = array();
 388                         for ( $i = $max -1; $i >= 0; $i-- ) {
 389                                 if ( $stack[$i][1] > $level ) {
 390                                         $working[] = $stack[$i];
 391                                 } else {
 392                                         break;
 393                                 }
 394                         }
 395                         $working = $this->remapCallTree( array_reverse( $working ) );
 396                         $output = array();
 397                         foreach ( $working as $item ) {
 398                                 array_push( $output, $item );
 399                         }
 400                         array_unshift( $output, $stack[$max] );
 401                         $max = $i;
 402
 403                         array_unshift( $outputs, $output );
 404                 }
 405                 $final = array();
 406                 foreach ( $outputs as $output ) {
 407                         foreach ( $output as $item ) {
 408                                 $final[] = $item;
 409                         }
 410                 }
 411                 return $final;
 412         }
 413
 414         /**
 415          * Callback to get a formatted line for the call tree
 416          * @return string
 417          */
 418         function getCallTreeLine( $entry ) {
 419                 list( $fname, $level, $start, /* $x */, $end ) = $entry;
 420                 $delta = $end - $start;
 421                 $space = str_repeat( ' ', $level );
 422                 # The ugly double sprintf is to work around a PHP bug,
 423                 # which has been fixed in recent releases.
 424                 return sprintf( "%10s %s %s\n", trim( sprintf( "%7.3f", $delta * 1000.0 ) ), $space, $fname );
 425         }
 426
 427         /**
 428          * Get the initial time of the request, based either on $wgRequestTime or
 429          * $wgRUstart. Will return null if not able to find data.
 430          *
 431          * @param string|false $metric metric to use, with the following possibilities:
 432          *   - user: User CPU time (without system calls)
 433          *   - cpu: Total CPU time (user and system calls)
 434          *   - wall (or any other string): elapsed time
 435          *   - false (default): will fall back to default metric
 436          * @return float|null
 437          */
 438         function getTime( $metric = false ) {
 439                 if ( $metric === false ) {
 440                         $metric = $this->mTimeMetric;
 441                 }
 442
 443                 if ( $metric === 'cpu' || $this->mTimeMetric === 'user' ) {
 444                         if ( !function_exists( 'getrusage' ) ) {
 445                                 return 0;
 446                         }
 447                         $ru = getrusage();
 448                         $time = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
 449                         if ( $metric === 'cpu' ) {
 450                                 # This is the time of system calls, added to the user time
 451                                 # it gives the total CPU time
 452                                 $time += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
 453                         }
 454                         return $time;
 455                 } else {
 456                         return microtime( true );
 457                 }
 458         }
 459
 460         /**
 461          * Get the initial time of the request, based either on $wgRequestTime or
 462          * $wgRUstart. Will return null if not able to find data.
 463          *
 464          * @param string|false $metric metric to use, with the following possibilities:
 465          *   - user: User CPU time (without system calls)
 466          *   - cpu: Total CPU time (user and system calls)
 467          *   - wall (or any other string): elapsed time
 468          *   - false (default): will fall back to default metric
 469          * @return float|null
 470          */
 471         protected function getInitialTime( $metric = false ) {
 472                 global $wgRequestTime, $wgRUstart;
 473
 474                 if ( $metric === false ) {
 475                         $metric = $this->mTimeMetric;
 476                 }
 477
 478                 if ( $metric === 'cpu' || $this->mTimeMetric === 'user' ) {
 479                         if ( !count( $wgRUstart ) ) {
 480                                 return null;
 481                         }
 482
 483                         $time = $wgRUstart['ru_utime.tv_sec'] + $wgRUstart['ru_utime.tv_usec'] / 1e6;
 484                         if ( $metric === 'cpu' ) {
 485                                 # This is the time of system calls, added to the user time
 486                                 # it gives the total CPU time
 487                                 $time += $wgRUstart['ru_stime.tv_sec'] + $wgRUstart['ru_stime.tv_usec'] / 1e6;
 488                         }
 489                         return $time;
 490                 } else {
 491                         if ( empty( $wgRequestTime ) ) {
 492                                 return null;
 493                         } else {
 494                                 return $wgRequestTime;
 495                         }
 496                 }
 497         }
 498
 499         protected function collateData() {
 500                 if ( $this->mCollateDone ) {
 501                         return;
 502                 }
 503                 $this->mCollateDone = true;
 504
 505                 $this->close();
 506
 507                 $this->mCollated = array();
 508                 $this->mCalls = array();
 509                 $this->mMemory = array();
 510
 511                 # Estimate profiling overhead
 512                 $profileCount = count( $this->mStack );
 513                 self::calculateOverhead( $profileCount );
 514
 515                 # First, subtract the overhead!
 516                 $overheadTotal = $overheadMemory = $overheadInternal = array();
 517                 foreach ( $this->mStack as $entry ) {
 518                         $fname = $entry[0];
 519                         $start = $entry[2];
 520                         $end = $entry[4];
 521                         $elapsed = $end - $start;
 522                         $memory = $entry[5] - $entry[3];
 523
 524                         if ( $fname == '-overhead-total' ) {
 525                                 $overheadTotal[] = $elapsed;
 526                                 $overheadMemory[] = $memory;
 527                         } elseif ( $fname == '-overhead-internal' ) {
 528                                 $overheadInternal[] = $elapsed;
 529                         }
 530                 }
 531                 $overheadTotal = $overheadTotal ? array_sum( $overheadTotal ) / count( $overheadInternal ) : 0;
 532                 $overheadMemory = $overheadMemory ? array_sum( $overheadMemory ) / count( $overheadInternal ) : 0;
 533                 $overheadInternal = $overheadInternal ? array_sum( $overheadInternal ) / count( $overheadInternal ) : 0;
 534
 535                 # Collate
 536                 foreach ( $this->mStack as $index => $entry ) {
 537                         $fname = $entry[0];
 538                         $start = $entry[2];
 539                         $end = $entry[4];
 540                         $elapsed = $end - $start;
 541
 542                         $memory = $entry[5] - $entry[3];
 543                         $subcalls = $this->calltreeCount( $this->mStack, $index );
 544
 545                         if ( !preg_match( '/^-overhead/', $fname ) ) {
 546                                 # Adjust for profiling overhead (except special values with elapsed=0
 547                                 if ( $elapsed ) {
 548                                         $elapsed -= $overheadInternal;
 549                                         $elapsed -= ( $subcalls * $overheadTotal );
 550                                         $memory -= ( $subcalls * $overheadMemory );
 551                                 }
 552                         }
 553
 554                         if ( !array_key_exists( $fname, $this->mCollated ) ) {
 555                                 $this->mCollated[$fname] = 0;
 556                                 $this->mCalls[$fname] = 0;
 557                                 $this->mMemory[$fname] = 0;
 558                                 $this->mMin[$fname] = 1 << 24;
 559                                 $this->mMax[$fname] = 0;
 560                                 $this->mOverhead[$fname] = 0;
 561                         }
 562
 563                         $this->mCollated[$fname] += $elapsed;
 564                         $this->mCalls[$fname]++;
 565                         $this->mMemory[$fname] += $memory;
 566                         $this->mMin[$fname] = min( $this->mMin[$fname], $elapsed );
 567                         $this->mMax[$fname] = max( $this->mMax[$fname], $elapsed );
 568                         $this->mOverhead[$fname] += $subcalls;
 569                 }
 570
 571                 $this->mCalls['-overhead-total'] = $profileCount;
 572                 arsort( $this->mCollated, SORT_NUMERIC );
 573         }
 574
 575         /**
 576          * Returns a list of profiled functions.
 577          *
 578          * @return string
 579          */
 580         function getFunctionReport() {
 581                 $this->collateData();
 582
 583                 $width = 140;
 584                 $nameWidth = $width - 65;
 585                 $format = "%-{$nameWidth}s %6d %13.3f %13.3f %13.3f%% %9d  (%13.3f -%13.3f) [%d]\n";
 586                 $titleFormat = "%-{$nameWidth}s %6s %13s %13s %13s %9s\n";
 587                 $prof = "\nProfiling data\n";
 588                 $prof .= sprintf( $titleFormat, 'Name', 'Calls', 'Total', 'Each', '%', 'Mem' );
 589
 590                 $total = isset( $this->mCollated['-total'] ) ? $this->mCollated['-total'] : 0;
 591
 592                 foreach ( $this->mCollated as $fname => $elapsed ) {
 593                         $calls = $this->mCalls[$fname];
 594                         $percent = $total ? 100. * $elapsed / $total : 0;
 595                         $memory = $this->mMemory[$fname];
 596                         $prof .= sprintf( $format,
 597                                 substr( $fname, 0, $nameWidth ),
 598                                 $calls,
 599                                 (float)( $elapsed * 1000 ),
 600                                 (float)( $elapsed * 1000 ) / $calls,
 601                                 $percent,
 602                                 $memory,
 603                                 ( $this->mMin[$fname] * 1000.0 ),
 604                                 ( $this->mMax[$fname] * 1000.0 ),
 605                                 $this->mOverhead[$fname]
 606                         );
 607                 }
 608                 $prof .= "\nTotal: $total\n\n";
 609
 610                 return $prof;
 611         }
 612
 613         /**
 614          * Dummy calls to wfProfileIn/wfProfileOut to calculate its overhead
 615          */
 616         protected static function calculateOverhead( $profileCount ) {
 617                 wfProfileIn( '-overhead-total' );
 618                 for ( $i = 0; $i < $profileCount; $i++ ) {
 619                         wfProfileIn( '-overhead-internal' );
 620                         wfProfileOut( '-overhead-internal' );
 621                 }
 622                 wfProfileOut( '-overhead-total' );
 623         }
 624
 625         /**
 626          * Counts the number of profiled function calls sitting under
 627          * the given point in the call graph. Not the most efficient algo.
 628          *
 629          * @param $stack Array:
 630          * @param $start Integer:
 631          * @return Integer
 632          * @private
 633          */
 634         function calltreeCount( $stack, $start ) {
 635                 $level = $stack[$start][1];
 636                 $count = 0;
 637                 for ( $i = $start -1; $i >= 0 && $stack[$i][1] > $level; $i-- ) {
 638                         $count ++;
 639                 }
 640                 return $count;
 641         }
 642
 643         /**
 644          * Log the whole profiling data into the database.
 645          */
 646         public function logData() {
 647                 global $wgProfilePerHost, $wgProfileToDatabase;
 648
 649                 # Do not log anything if database is readonly (bug 5375)
 650                 if ( wfReadOnly() || !$wgProfileToDatabase ) {
 651                         return;
 652                 }
 653
 654                 $dbw = wfGetDB( DB_MASTER );
 655                 if ( !is_object( $dbw ) ) {
 656                         return;
 657                 }
 658
 659                 if ( $wgProfilePerHost ) {
 660                         $pfhost = wfHostname();
 661                 } else {
 662                         $pfhost = '';
 663                 }
 664
 665                 try {
 666                         $this->collateData();
 667
 668                         foreach ( $this->mCollated as $name => $elapsed ) {
 669                                 $eventCount = $this->mCalls[$name];
 670                                 $timeSum = (float)( $elapsed * 1000 );
 671                                 $memorySum = (float)$this->mMemory[$name];
 672                                 $name = substr( $name, 0, 255 );
 673
 674                                 // Kludge
 675                                 $timeSum = $timeSum >= 0 ? $timeSum : 0;
 676                                 $memorySum = $memorySum >= 0 ? $memorySum : 0;
 677
 678                                 $dbw->update( 'profiling',
 679                                         array(
 680                                                 "pf_count=pf_count+{$eventCount}",
 681                                                 "pf_time=pf_time+{$timeSum}",
 682                                                 "pf_memory=pf_memory+{$memorySum}",
 683                                         ),
 684                                         array(
 685                                                 'pf_name' => $name,
 686                                                 'pf_server' => $pfhost,
 687                                         ),
 688                                         __METHOD__ );
 689
 690                                 $rc = $dbw->affectedRows();
 691                                 if ( $rc == 0 ) {
 692                                         $dbw->insert( 'profiling', array( 'pf_name' => $name, 'pf_count' => $eventCount,
 693                                                 'pf_time' => $timeSum, 'pf_memory' => $memorySum, 'pf_server' => $pfhost ),
 694                                                 __METHOD__, array( 'IGNORE' ) );
 695                                 }
 696                                 // When we upgrade to mysql 4.1, the insert+update
 697                                 // can be merged into just a insert with this construct added:
 698                                 //     "ON DUPLICATE KEY UPDATE ".
 699                                 //     "pf_count=pf_count + VALUES(pf_count), ".
 700                                 //     "pf_time=pf_time + VALUES(pf_time)";
 701                         }
 702                 } catch ( DBError $e ) {}
 703         }
 704
 705         /**
 706          * Get the function name of the current profiling section
 707          * @return
 708          */
 709         function getCurrentSection() {
 710                 $elt = end( $this->mWorkStack );
 711                 return $elt[0];
 712         }
 713
 714         /**
 715          * Add an entry in the debug log file
 716          *
 717          * @param string $s to output
 718          */
 719         function debug( $s ) {
 720                 if ( function_exists( 'wfDebug' ) ) {
 721                         wfDebug( $s );
 722                 }
 723         }
 724
 725         /**
 726          * Add an entry in the debug log group
 727          *
 728          * @param string $group Group to send the message to
 729          * @param string $s to output
 730          */
 731         function debugGroup( $group, $s ) {
 732                 if ( function_exists( 'wfDebugLog' ) ) {
 733                         wfDebugLog( $group, $s );
 734                 }
 735         }
 736
 737         /**
 738          * Get the content type sent out to the client.
 739          * Used for profilers that output instead of store data.
 740          * @return string
 741          */
 742         protected function getContentType() {
 743                 foreach ( headers_list() as $header ) {
 744                         if ( preg_match( '#^content-type: (\w+/\w+);?#i', $header, $m ) ) {
 745                                 return $m[1];
 746                         }
 747                 }
 748                 return null;
 749         }
 750 }