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