includes/profiler/SectionProfiler.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 use MediaWiki\Logger\LoggerFactory;
  22 use Psr\Log\LoggerInterface;
  23 use Wikimedia\ScopedCallback;
  24
  25 /**
  26  * Arbitrary section name based PHP profiling.
  27  *
  28  * This custom profiler can track code execution that doesn't cleanly map to a
  29  * function call and thus can't be handled by ProfilerXhprof or ProfilerExcimer.
  30  * For example, parser invocations or DB queries.
  31  *
  32  * @since 1.25
  33  * @ingroup Profiler
  34  */
  35 class SectionProfiler {
  36         /** @var array|null Map of (mem,real,cpu) */
  37         protected $start;
  38         /** @var array|null Map of (mem,real,cpu) */
  39         protected $end;
  40         /** @var array[] List of resolved profile calls with start/end data */
  41         protected $stack = [];
  42         /** @var array Queue of open profile calls with start data */
  43         protected $workStack = [];
  44         /** @var array[] Map of (function name => aggregate data array) */
  45         protected $collated = [];
  46         /** @var bool */
  47         protected $collateDone = false;
  48
  49         /** @var array Cache of a standard broken collation entry */
  50         protected $errorEntry;
  51         /** @var LoggerInterface */
  52         protected $logger;
  53
  54         /**
  55          * @param array $params
  56          */
  57         public function __construct( array $params = [] ) {
  58                 $this->errorEntry = $this->getErrorEntry();
  59                 $this->logger = LoggerFactory::getInstance( 'profiler' );
  60         }
  61
  62         /**
  63          * @param string $section
  64          * @return SectionProfileCallback
  65          */
  66         public function scopedProfileIn( $section ) {
  67                 $this->profileInInternal( $section );
  68
  69                 return new SectionProfileCallback( $this, $section );
  70         }
  71
  72         /**
  73          * @param ScopedCallback &$section
  74          */
  75         public function scopedProfileOut( ScopedCallback &$section ) {
  76                 $section = null;
  77         }
  78
  79         /**
  80          * Get the aggregated inclusive profiling data for each method
  81          *
  82          * The percent time for each time is based on the current "total" time
  83          * used is based on all methods so far. This method can therefore be
  84          * called several times in between several profiling calls without the
  85          * delays in usage of the profiler skewing the results. A "-total" entry
  86          * is always included in the results.
  87          *
  88          * @return array[] List of method entries arrays, each having:
  89          *   - name    : method name
  90          *   - calls   : the number of invoking calls
  91          *   - real    : real time elapsed (ms)
  92          *   - %real   : percent real time
  93          *   - cpu     : real time elapsed (ms)
  94          *   - %cpu    : percent real time
  95          *   - memory  : memory used (bytes)
  96          *   - %memory : percent memory used
  97          *   - min_real : min real time in a call (ms)
  98          *   - max_real : max real time in a call (ms)
  99          */
 100         public function getFunctionStats() {
 101                 $this->collateData();
 102
 103                 if ( is_array( $this->start ) && is_array( $this->end ) ) {
 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                 } else {
 108                         $totalCpu = 0;
 109                         $totalReal = 0;
 110                         $totalMem = 0;
 111                 }
 112
 113                 $profile = [];
 114                 foreach ( $this->collated as $fname => $data ) {
 115                         $profile[] = [
 116                                 'name' => $fname,
 117                                 'calls' => $data['count'],
 118                                 'real' => $data['real'] * 1000,
 119                                 '%real' => $totalReal ? 100 * $data['real'] / $totalReal : 0,
 120                                 'cpu' => $data['cpu'] * 1000,
 121                                 '%cpu' => $totalCpu ? 100 * $data['cpu'] / $totalCpu : 0,
 122                                 'memory' => $data['memory'],
 123                                 '%memory' => $totalMem ? 100 * $data['memory'] / $totalMem : 0,
 124                                 'min_real' => 1000 * $data['min_real'],
 125                                 'max_real' => 1000 * $data['max_real']
 126                         ];
 127                 }
 128
 129                 $profile[] = [
 130                         'name' => '-total',
 131                         'calls' => 1,
 132                         'real' => 1000 * $totalReal,
 133                         '%real' => 100,
 134                         'cpu' => 1000 * $totalCpu,
 135                         '%cpu' => 100,
 136                         'memory' => $totalMem,
 137                         '%memory' => 100,
 138                         'min_real' => 1000 * $totalReal,
 139                         'max_real' => 1000 * $totalReal
 140                 ];
 141
 142                 return $profile;
 143         }
 144
 145         /**
 146          * Clear all of the profiling data for another run
 147          */
 148         public function reset() {
 149                 $this->start = null;
 150                 $this->end = null;
 151                 $this->stack = [];
 152                 $this->workStack = [];
 153                 $this->collated = [];
 154                 $this->collateDone = false;
 155         }
 156
 157         /**
 158          * @return array Initial collation entry
 159          */
 160         protected function getZeroEntry() {
 161                 return [
 162                         'cpu'      => 0.0,
 163                         'real'     => 0.0,
 164                         'memory'   => 0,
 165                         'count'    => 0,
 166                         'min_real' => 0.0,
 167                         'max_real' => 0.0
 168                 ];
 169         }
 170
 171         /**
 172          * @return array Initial collation entry for errors
 173          */
 174         protected function getErrorEntry() {
 175                 $entry = $this->getZeroEntry();
 176                 $entry['count'] = 1;
 177                 return $entry;
 178         }
 179
 180         /**
 181          * Update the collation entry for a given method name
 182          *
 183          * @param string $name
 184          * @param float $elapsedCpu
 185          * @param float $elapsedReal
 186          * @param int $memChange
 187          */
 188         protected function updateEntry( $name, $elapsedCpu, $elapsedReal, $memChange ) {
 189                 $entry =& $this->collated[$name];
 190                 if ( !is_array( $entry ) ) {
 191                         $entry = $this->getZeroEntry();
 192                         $this->collated[$name] =& $entry;
 193                 }
 194                 $entry['cpu'] += $elapsedCpu;
 195                 $entry['real'] += $elapsedReal;
 196                 $entry['memory'] += $memChange > 0 ? $memChange : 0;
 197                 $entry['count']++;
 198                 $entry['min_real'] = min( $entry['min_real'], $elapsedReal );
 199                 $entry['max_real'] = max( $entry['max_real'], $elapsedReal );
 200         }
 201
 202         /**
 203          * This method should not be called outside SectionProfiler
 204          *
 205          * @param string $functionname
 206          */
 207         public function profileInInternal( $functionname ) {
 208                 // Once the data is collated for reports, any future calls
 209                 // should clear the collation cache so the next report will
 210                 // reflect them. This matters when trace mode is used.
 211                 $this->collateDone = false;
 212
 213                 $cpu = $this->getTime( 'cpu' );
 214                 $real = $this->getTime( 'wall' );
 215                 $memory = memory_get_usage();
 216
 217                 if ( $this->start === null ) {
 218                         $this->start = [ 'cpu' => $cpu, 'real' => $real, 'memory' => $memory ];
 219                 }
 220
 221                 $this->workStack[] = [
 222                         $functionname,
 223                         count( $this->workStack ),
 224                         $real,
 225                         $cpu,
 226                         $memory
 227                 ];
 228         }
 229
 230         /**
 231          * This method should not be called outside SectionProfiler
 232          *
 233          * @param string $functionname
 234          */
 235         public function profileOutInternal( $functionname ) {
 236                 $item = array_pop( $this->workStack );
 237                 if ( $item === null ) {
 238                         $this->logger->error( "Profiling error: $functionname" );
 239                         return;
 240                 }
 241                 [ $ofname, /* $ocount */, $ortime, $octime, $omem ] = $item;
 242
 243                 if ( $functionname === 'close' ) {
 244                         $message = "Profile section ended by close(): {$ofname}";
 245                         $this->logger->error( $message );
 246                         $this->collated[$message] = $this->errorEntry;
 247                         $functionname = $ofname;
 248                 } elseif ( $ofname !== $functionname ) {
 249                         $message = "Profiling error: in({$ofname}), out($functionname)";
 250                         $this->logger->error( $message );
 251                         $this->collated[$message] = $this->errorEntry;
 252                 }
 253
 254                 $realTime = $this->getTime( 'wall' );
 255                 $cpuTime = $this->getTime( 'cpu' );
 256                 $memUsage = memory_get_usage();
 257
 258                 $elapsedcpu = $cpuTime - $octime;
 259                 $elapsedreal = $realTime - $ortime;
 260                 $memchange = $memUsage - $omem;
 261                 $this->updateEntry( $functionname, $elapsedcpu, $elapsedreal, $memchange );
 262
 263                 $this->end = [
 264                         'cpu'      => $cpuTime,
 265                         'real'     => $realTime,
 266                         'memory'   => $memUsage
 267                 ];
 268         }
 269
 270         /**
 271          * Populate collated data
 272          */
 273         protected function collateData() {
 274                 if ( $this->collateDone ) {
 275                         return;
 276                 }
 277                 $this->collateDone = true;
 278                 // Close opened profiling sections
 279                 while ( count( $this->workStack ) ) {
 280                         $this->profileOutInternal( 'close' );
 281                 }
 282         }
 283
 284         /**
 285          * Get the initial time of the request, based on getrusage()
 286          *
 287          * @param string|bool $metric Metric to use, with the following possibilities:
 288          *   - user: User CPU time (without system calls)
 289          *   - cpu: Total CPU time (user and system calls)
 290          *   - wall (or any other string): elapsed time
 291          *   - false (default): will fall back to default metric
 292          * @return float
 293          */
 294         protected function getTime( $metric = 'wall' ) {
 295                 if ( $metric === 'cpu' || $metric === 'user' ) {
 296                         $ru = getrusage( 0 /* RUSAGE_SELF */ );
 297                         $time = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
 298                         if ( $metric === 'cpu' ) {
 299                                 # This is the time of system calls, added to the user time
 300                                 # it gives the total CPU time
 301                                 $time += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
 302                         }
 303                         return $time;
 304                 } else {
 305                         return microtime( true );
 306                 }
 307         }
 308 }