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