includes/profiler/SectionProfiler.php

   1 <?php
   2 /**
   3  * Arbitrary section name based PHP 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  * @author Aaron Schulz
  23  */
  24
  25 /**
  26  * Custom PHP profiler for parser/DB type section names that xhprof/xdebug can't handle
  27  *
  28  * @since 1.25
  29  */
  30 class SectionProfiler {
  31         /** @var array Map of (mem,real,cpu) */
  32         protected $start;
  33         /** @var array Map of (mem,real,cpu) */
  34         protected $end;
  35         /** @var array List of resolved profile calls with start/end data */
  36         protected $stack = [];
  37         /** @var array Queue of open profile calls with start data */
  38         protected $workStack = [];
  39
  40         /** @var array Map of (function name => aggregate data array) */
  41         protected $collated = [];
  42         /** @var bool */
  43         protected $collateDone = false;
  44
  45         /** @var bool Whether to collect the full stack trace or just aggregates */
  46         protected $collateOnly = true;
  47         /** @var array Cache of a standard broken collation entry */
  48         protected $errorEntry;
  49         /** @var callable Cache of a profile out callback */
  50         protected $profileOutCallback;
  51
  52         /**
  53          * @param array $params
  54          */
  55         public function __construct( array $params = [] ) {
  56                 $this->errorEntry = $this->getErrorEntry();
  57                 $this->collateOnly = empty( $params['trace'] );
  58                 $this->profileOutCallback = function ( $profiler, $section ) {
  59                         $profiler->profileOutInternal( $section );
  60                 };
  61         }
  62
  63         /**
  64          * @param string $section
  65          * @return ScopedCallback
  66          */
  67         public function scopedProfileIn( $section ) {
  68                 $this->profileInInternal( $section );
  69
  70                 return new SectionProfileCallback( $this, $section );
  71         }
  72
  73         /**
  74          * @param ScopedCallback $section
  75          */
  76         public function scopedProfileOut( ScopedCallback &$section ) {
  77                 $section = null;
  78         }
  79
  80         /**
  81          * Get the aggregated inclusive profiling data for each method
  82          *
  83          * The percent time for each time is based on the current "total" time
  84          * used is based on all methods so far. This method can therefore be
  85          * called several times in between several profiling calls without the
  86          * delays in usage of the profiler skewing the results. A "-total" entry
  87          * is always included in the results.
  88          *
  89          * @return array List of method entries arrays, each having:
  90          *   - name    : method name
  91          *   - calls   : the number of invoking calls
  92          *   - real    : real time elapsed (ms)
  93          *   - %real   : percent real time
  94          *   - cpu     : real time elapsed (ms)
  95          *   - %cpu    : percent real time
  96          *   - memory  : memory used (bytes)
  97          *   - %memory : percent memory used
  98          *   - min_real : min real time in a call (ms)
  99          *   - max_real : max real time in a call (ms)
 100          */
 101         public function getFunctionStats() {
 102                 $this->collateData();
 103
 104                 $totalCpu = max( $this->end['cpu'] - $this->start['cpu'], 0 );
 105                 $totalReal = max( $this->end['real'] - $this->start['real'], 0 );
 106                 $totalMem = max( $this->end['memory'] - $this->start['memory'], 0 );
 107
 108                 $profile = [];
 109                 foreach ( $this->collated as $fname => $data ) {
 110                         $profile[] = [
 111                                 'name' => $fname,
 112                                 'calls' => $data['count'],
 113                                 'real' => $data['real'] * 1000,
 114                                 '%real' => $totalReal ? 100 * $data['real'] / $totalReal : 0,
 115                                 'cpu' => $data['cpu'] * 1000,
 116                                 '%cpu' => $totalCpu ? 100 * $data['cpu'] / $totalCpu : 0,
 117                                 'memory' => $data['memory'],
 118                                 '%memory' => $totalMem ? 100 * $data['memory'] / $totalMem : 0,
 119                                 'min_real' => 1000 * $data['min_real'],
 120                                 'max_real' => 1000 * $data['max_real']
 121                         ];
 122                 }
 123
 124                 $profile[] = [
 125                         'name' => '-total',
 126                         'calls' => 1,
 127                         'real' => 1000 * $totalReal,
 128                         '%real' => 100,
 129                         'cpu' => 1000 * $totalCpu,
 130                         '%cpu' => 100,
 131                         'memory' => $totalMem,
 132                         '%memory' => 100,
 133                         'min_real' => 1000 * $totalReal,
 134                         'max_real' => 1000 * $totalReal
 135                 ];
 136
 137                 return $profile;
 138         }
 139
 140         /**
 141          * Clear all of the profiling data for another run
 142          */
 143         public function reset() {
 144                 $this->start = null;
 145                 $this->end = null;
 146                 $this->stack = [];
 147                 $this->workStack = [];
 148                 $this->collated = [];
 149                 $this->collateDone = false;
 150         }
 151
 152         /**
 153          * @return array Initial collation entry
 154          */
 155         protected function getZeroEntry() {
 156                 return [
 157                         'cpu'      => 0.0,
 158                         'real'     => 0.0,
 159                         'memory'   => 0,
 160                         'count'    => 0,
 161                         'min_real' => 0.0,
 162                         'max_real' => 0.0
 163                 ];
 164         }
 165
 166         /**
 167          * @return array Initial collation entry for errors
 168          */
 169         protected function getErrorEntry() {
 170                 $entry = $this->getZeroEntry();
 171                 $entry['count'] = 1;
 172                 return $entry;
 173         }
 174
 175         /**
 176          * Update the collation entry for a given method name
 177          *
 178          * @param string $name
 179          * @param float $elapsedCpu
 180          * @param float $elapsedReal
 181          * @param int $memChange
 182          */
 183         protected function updateEntry( $name, $elapsedCpu, $elapsedReal, $memChange ) {
 184                 $entry =& $this->collated[$name];
 185                 if ( !is_array( $entry ) ) {
 186                         $entry = $this->getZeroEntry();
 187                         $this->collated[$name] =& $entry;
 188                 }
 189                 $entry['cpu'] += $elapsedCpu;
 190                 $entry['real'] += $elapsedReal;
 191                 $entry['memory'] += $memChange > 0 ? $memChange : 0;
 192                 $entry['count']++;
 193                 $entry['min_real'] = min( $entry['min_real'], $elapsedReal );
 194                 $entry['max_real'] = max( $entry['max_real'], $elapsedReal );
 195         }
 196
 197         /**
 198          * This method should not be called outside SectionProfiler
 199          *
 200          * @param string $functionname
 201          */
 202         public function profileInInternal( $functionname ) {
 203                 // Once the data is collated for reports, any future calls
 204                 // should clear the collation cache so the next report will
 205                 // reflect them. This matters when trace mode is used.
 206                 $this->collateDone = false;
 207
 208                 $cpu = $this->getTime( 'cpu' );
 209                 $real = $this->getTime( 'wall' );
 210                 $memory = memory_get_usage();
 211
 212                 if ( $this->start === null ) {
 213                         $this->start = [ 'cpu' => $cpu, 'real' => $real, 'memory' => $memory ];
 214                 }
 215
 216                 $this->workStack[] = [
 217                         $functionname,
 218                         count( $this->workStack ),
 219                         $real,
 220                         $cpu,
 221                         $memory
 222                 ];
 223         }
 224
 225         /**
 226          * This method should not be called outside SectionProfiler
 227          *
 228          * @param string $functionname
 229          */
 230         public function profileOutInternal( $functionname ) {
 231                 $item = array_pop( $this->workStack );
 232                 if ( $item === null ) {
 233                         $this->debugGroup( 'profileerror', "Profiling error: $functionname" );
 234                         return;
 235                 }
 236                 list( $ofname, /* $ocount */, $ortime, $octime, $omem ) = $item;
 237
 238                 if ( $functionname === 'close' ) {
 239                         $message = "Profile section ended by close(): {$ofname}";
 240                         $this->debugGroup( 'profileerror', $message );
 241                         if ( $this->collateOnly ) {
 242                                 $this->collated[$message] = $this->errorEntry;
 243                         } else {
 244                                 $this->stack[] = [ $message, 0, 0.0, 0.0, 0, 0.0, 0.0, 0 ];
 245                         }
 246                         $functionname = $ofname;
 247                 } elseif ( $ofname !== $functionname ) {
 248                         $message = "Profiling error: in({$ofname}), out($functionname)";
 249                         $this->debugGroup( 'profileerror', $message );
 250                         if ( $this->collateOnly ) {
 251                                 $this->collated[$message] = $this->errorEntry;
 252                         } else {
 253                                 $this->stack[] = [ $message, 0, 0.0, 0.0, 0, 0.0, 0.0, 0 ];
 254                         }
 255                 }
 256
 257                 $realTime = $this->getTime( 'wall' );
 258                 $cpuTime = $this->getTime( 'cpu' );
 259                 $memUsage = memory_get_usage();
 260
 261                 if ( $this->collateOnly ) {
 262                         $elapsedcpu = $cpuTime - $octime;
 263                         $elapsedreal = $realTime - $ortime;
 264                         $memchange = $memUsage - $omem;
 265                         $this->updateEntry( $functionname, $elapsedcpu, $elapsedreal, $memchange );
 266                 } else {
 267                         $this->stack[] = array_merge( $item, [ $realTime, $cpuTime, $memUsage ] );
 268                 }
 269
 270                 $this->end = [
 271                         'cpu'      => $cpuTime,
 272                         'real'     => $realTime,
 273                         'memory'   => $memUsage
 274                 ];
 275         }
 276
 277         /**
 278          * Returns a tree of function calls with their real times
 279          * @return string
 280          * @throws Exception
 281          */
 282         public function getCallTreeReport() {
 283                 if ( $this->collateOnly ) {
 284                         throw new Exception( "Tree is only available for trace profiling." );
 285                 }
 286                 return implode( '', array_map(
 287                         [ $this, 'getCallTreeLine' ], $this->remapCallTree( $this->stack )
 288                 ) );
 289         }
 290
 291         /**
 292          * Recursive function the format the current profiling array into a tree
 293          *
 294          * @param array $stack Profiling array
 295          * @return array
 296          */
 297         protected function remapCallTree( array $stack ) {
 298                 if ( count( $stack ) < 2 ) {
 299                         return $stack;
 300                 }
 301                 $outputs = [];
 302                 for ( $max = count( $stack ) - 1; $max > 0; ) {
 303                         /* Find all items under this entry */
 304                         $level = $stack[$max][1];
 305                         $working = [];
 306                         for ( $i = $max -1; $i >= 0; $i-- ) {
 307                                 if ( $stack[$i][1] > $level ) {
 308                                         $working[] = $stack[$i];
 309                                 } else {
 310                                         break;
 311                                 }
 312                         }
 313                         $working = $this->remapCallTree( array_reverse( $working ) );
 314                         $output = [];
 315                         foreach ( $working as $item ) {
 316                                 array_push( $output, $item );
 317                         }
 318                         array_unshift( $output, $stack[$max] );
 319                         $max = $i;
 320
 321                         array_unshift( $outputs, $output );
 322                 }
 323                 $final = [];
 324                 foreach ( $outputs as $output ) {
 325                         foreach ( $output as $item ) {
 326                                 $final[] = $item;
 327                         }
 328                 }
 329                 return $final;
 330         }
 331
 332         /**
 333          * Callback to get a formatted line for the call tree
 334          * @param array $entry
 335          * @return string
 336          */
 337         protected function getCallTreeLine( $entry ) {
 338                 // $entry has (name, level, stime, scpu, smem, etime, ecpu, emem)
 339                 list( $fname, $level, $startreal, , , $endreal ) = $entry;
 340                 $delta = $endreal - $startreal;
 341                 $space = str_repeat( ' ', $level );
 342                 # The ugly double sprintf is to work around a PHP bug,
 343                 # which has been fixed in recent releases.
 344                 return sprintf( "%10s %s %s\n",
 345                         trim( sprintf( "%7.3f", $delta * 1000.0 ) ), $space, $fname );
 346         }
 347
 348         /**
 349          * Populate collated data
 350          */
 351         protected function collateData() {
 352                 if ( $this->collateDone ) {
 353                         return;
 354                 }
 355                 $this->collateDone = true;
 356                 // Close opened profiling sections
 357                 while ( count( $this->workStack ) ) {
 358                         $this->profileOutInternal( 'close' );
 359                 }
 360
 361                 if ( $this->collateOnly ) {
 362                         return; // already collated as methods exited
 363                 }
 364
 365                 $this->collated = [];
 366
 367                 # Estimate profiling overhead
 368                 $oldEnd = $this->end;
 369                 $profileCount = count( $this->stack );
 370                 $this->calculateOverhead( $profileCount );
 371
 372                 # First, subtract the overhead!
 373                 $overheadTotal = $overheadMemory = $overheadInternal = [];
 374                 foreach ( $this->stack as $entry ) {
 375                         // $entry is (name,pos,rtime0,cputime0,mem0,rtime1,cputime1,mem1)
 376                         $fname = $entry[0];
 377                         $elapsed = $entry[5] - $entry[2];
 378                         $memchange = $entry[7] - $entry[4];
 379
 380                         if ( $fname === '-overhead-total' ) {
 381                                 $overheadTotal[] = $elapsed;
 382                                 $overheadMemory[] = max( 0, $memchange );
 383                         } elseif ( $fname === '-overhead-internal' ) {
 384                                 $overheadInternal[] = $elapsed;
 385                         }
 386                 }
 387                 $overheadTotal = $overheadTotal ?
 388                         array_sum( $overheadTotal ) / count( $overheadInternal ) : 0;
 389                 $overheadMemory = $overheadMemory ?
 390                         array_sum( $overheadMemory ) / count( $overheadInternal ) : 0;
 391                 $overheadInternal = $overheadInternal ?
 392                         array_sum( $overheadInternal ) / count( $overheadInternal ) : 0;
 393
 394                 # Collate
 395                 foreach ( $this->stack as $index => $entry ) {
 396                         // $entry is (name,pos,rtime0,cputime0,mem0,rtime1,cputime1,mem1)
 397                         $fname = $entry[0];
 398                         $elapsedCpu = $entry[6] - $entry[3];
 399                         $elapsedReal = $entry[5] - $entry[2];
 400                         $memchange = $entry[7] - $entry[4];
 401                         $subcalls = $this->calltreeCount( $this->stack, $index );
 402
 403                         if ( substr( $fname, 0, 9 ) !== '-overhead' ) {
 404                                 # Adjust for profiling overhead (except special values with elapsed=0)
 405                                 if ( $elapsed ) {
 406                                         $elapsed -= $overheadInternal;
 407                                         $elapsed -= ( $subcalls * $overheadTotal );
 408                                         $memchange -= ( $subcalls * $overheadMemory );
 409                                 }
 410                         }
 411
 412                         $this->updateEntry( $fname, $elapsedCpu, $elapsedReal, $memchange );
 413                 }
 414
 415                 $this->collated['-overhead-total']['count'] = $profileCount;
 416                 arsort( $this->collated, SORT_NUMERIC );
 417
 418                 // Unclobber the end info map (the overhead checking alters it)
 419                 $this->end = $oldEnd;
 420         }
 421
 422         /**
 423          * Dummy calls to calculate profiling overhead
 424          *
 425          * @param int $profileCount
 426          */
 427         protected function calculateOverhead( $profileCount ) {
 428                 $this->profileInInternal( '-overhead-total' );
 429                 for ( $i = 0; $i < $profileCount; $i++ ) {
 430                         $this->profileInInternal( '-overhead-internal' );
 431                         $this->profileOutInternal( '-overhead-internal' );
 432                 }
 433                 $this->profileOutInternal( '-overhead-total' );
 434         }
 435
 436         /**
 437          * Counts the number of profiled function calls sitting under
 438          * the given point in the call graph. Not the most efficient algo.
 439          *
 440          * @param array $stack
 441          * @param int $start
 442          * @return int
 443          */
 444         protected function calltreeCount( $stack, $start ) {
 445                 $level = $stack[$start][1];
 446                 $count = 0;
 447                 for ( $i = $start -1; $i >= 0 && $stack[$i][1] > $level; $i-- ) {
 448                         $count ++;
 449                 }
 450                 return $count;
 451         }
 452
 453         /**
 454          * Get the initial time of the request, based on getrusage()
 455          *
 456          * @param string|bool $metric Metric to use, with the following possibilities:
 457          *   - user: User CPU time (without system calls)
 458          *   - cpu: Total CPU time (user and system calls)
 459          *   - wall (or any other string): elapsed time
 460          *   - false (default): will fall back to default metric
 461          * @return float
 462          */
 463         protected function getTime( $metric = 'wall' ) {
 464                 if ( $metric === 'cpu' || $metric === 'user' ) {
 465                         $ru = wfGetRusage();
 466                         if ( !$ru ) {
 467                                 return 0;
 468                         }
 469                         $time = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
 470                         if ( $metric === 'cpu' ) {
 471                                 # This is the time of system calls, added to the user time
 472                                 # it gives the total CPU time
 473                                 $time += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
 474                         }
 475                         return $time;
 476                 } else {
 477                         return microtime( true );
 478                 }
 479         }
 480
 481         /**
 482          * Add an entry in the debug log file
 483          *
 484          * @param string $s String to output
 485          */
 486         protected function debug( $s ) {
 487                 if ( function_exists( 'wfDebug' ) ) {
 488                         wfDebug( $s );
 489                 }
 490         }
 491
 492         /**
 493          * Add an entry in the debug log group
 494          *
 495          * @param string $group Group to send the message to
 496          * @param string $s String to output
 497          */
 498         protected function debugGroup( $group, $s ) {
 499                 if ( function_exists( 'wfDebugLog' ) ) {
 500                         wfDebugLog( $group, $s );
 501                 }
 502         }
 503 }
 504
 505 /**
 506  * Subclass ScopedCallback to avoid call_user_func_array(), which is slow
 507  *
 508  * This class should not be used outside of SectionProfiler
 509  */
 510 class SectionProfileCallback extends ScopedCallback {
 511         /** @var SectionProfiler */
 512         protected $profiler;
 513         /** @var string */
 514         protected $section;
 515
 516         /**
 517          * @param SectionProfiler $profiler
 518          * @param string $section
 519          */
 520         public function __construct( SectionProfiler $profiler, $section ) {
 521                 parent::__construct( null );
 522                 $this->profiler = $profiler;
 523                 $this->section = $section;
 524         }
 525
 526         function __destruct() {
 527                 $this->profiler->profileOutInternal( $this->section );
 528         }
 529 }