includes/libs/Timing.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 Psr\Log\LoggerAwareInterface;
  22 use Psr\Log\LoggerInterface;
  23 use Psr\Log\NullLogger;
  24
  25 /**
  26  * An interface to help developers measure the performance of their applications.
  27  * This interface closely matches the W3C's User Timing specification.
  28  * The key differences are:
  29  *
  30  * - The reference point for all measurements which do not explicitly specify
  31  *   a start time is $_SERVER['REQUEST_TIME_FLOAT'], not navigationStart.
  32  * - Successive calls to mark() and measure() with the same entry name cause
  33  *   the previous entry to be overwritten. This ensures that there is a 1:1
  34  *   mapping between names and entries.
  35  * - Because there is a 1:1 mapping, instead of getEntriesByName(), we have
  36  *   getEntryByName().
  37  *
  38  * The in-line documentation incorporates content from the User Timing Specification
  39  * https://www.w3.org/TR/user-timing/
  40  * Copyright © 2013 World Wide Web Consortium, (MIT, ERCIM, Keio, Beihang).
  41  * https://www.w3.org/Consortium/Legal/2015/doc-license
  42  *
  43  * @since 1.27
  44  */
  45 class Timing implements LoggerAwareInterface {
  46
  47         /** @var array[] */
  48         private $entries = [];
  49
  50         /** @var LoggerInterface */
  51         protected $logger;
  52
  53         public function __construct( array $params = [] ) {
  54                 $this->clearMarks();
  55                 $this->setLogger( $params['logger'] ?? new NullLogger() );
  56         }
  57
  58         /**
  59          * Sets a logger instance on the object.
  60          *
  61          * @param LoggerInterface $logger
  62          * @return null
  63          */
  64         public function setLogger( LoggerInterface $logger ) {
  65                 $this->logger = $logger;
  66         }
  67
  68         /**
  69          * Store a timestamp with the associated name (a "mark")
  70          *
  71          * @param string $markName The name associated with the timestamp.
  72          *  If there already exists an entry by that name, it is overwritten.
  73          * @return array The mark that has been created.
  74          */
  75         public function mark( $markName ) {
  76                 $this->entries[$markName] = [
  77                         'name'      => $markName,
  78                         'entryType' => 'mark',
  79                         'startTime' => microtime( true ),
  80                         'duration'  => 0,
  81                 ];
  82                 return $this->entries[$markName];
  83         }
  84
  85         /**
  86          * @param string|null $markName The name of the mark that should
  87          *  be cleared. If not specified, all marks will be cleared.
  88          */
  89         public function clearMarks( $markName = null ) {
  90                 if ( $markName !== null ) {
  91                         unset( $this->entries[$markName] );
  92                 } else {
  93                         $this->entries = [
  94                                 'requestStart' => [
  95                                         'name'      => 'requestStart',
  96                                         'entryType' => 'mark',
  97                                         'startTime' => $_SERVER['REQUEST_TIME_FLOAT'],
  98                                         'duration'  => 0,
  99                                 ],
 100                         ];
 101                 }
 102         }
 103
 104         /**
 105          * This method stores the duration between two marks along with
 106          * the associated name (a "measure").
 107          *
 108          * If neither the startMark nor the endMark argument is specified,
 109          * measure() will store the duration from $_SERVER['REQUEST_TIME_FLOAT'] to
 110          * the current time.
 111          * If the startMark argument is specified, but the endMark argument is not
 112          * specified, measure() will store the duration from the most recent
 113          * occurrence of the start mark to the current time.
 114          * If both the startMark and endMark arguments are specified, measure()
 115          * will store the duration from the most recent occurrence of the start
 116          * mark to the most recent occurrence of the end mark.
 117          *
 118          * @param string $measureName
 119          * @param string $startMark
 120          * @param string|null $endMark
 121          * @return array|bool The measure that has been created, or false if either
 122          *  the start mark or the end mark do not exist.
 123          */
 124         public function measure( $measureName, $startMark = 'requestStart', $endMark = null ) {
 125                 $start = $this->getEntryByName( $startMark );
 126                 if ( $start === null ) {
 127                         $this->logger->error( __METHOD__ . ": The mark '$startMark' does not exist" );
 128                         return false;
 129                 }
 130                 $startTime = $start['startTime'];
 131
 132                 if ( $endMark ) {
 133                         $end = $this->getEntryByName( $endMark );
 134                         if ( $end === null ) {
 135                                 $this->logger->error( __METHOD__ . ": The mark '$endMark' does not exist" );
 136                                 return false;
 137                         }
 138                         $endTime = $end['startTime'];
 139                 } else {
 140                         $endTime = microtime( true );
 141                 }
 142
 143                 $this->entries[$measureName] = [
 144                         'name'      => $measureName,
 145                         'entryType' => 'measure',
 146                         'startTime' => $startTime,
 147                         'duration'  => $endTime - $startTime,
 148                 ];
 149
 150                 return $this->entries[$measureName];
 151         }
 152
 153         /**
 154          * Sort entries in chronological order with respect to startTime.
 155          */
 156         private function sortEntries() {
 157                 uasort( $this->entries, function ( $a, $b ) {
 158                         return $a['startTime'] <=> $b['startTime'];
 159                 } );
 160         }
 161
 162         /**
 163          * @return array[] All entries in chronological order.
 164          */
 165         public function getEntries() {
 166                 $this->sortEntries();
 167                 return $this->entries;
 168         }
 169
 170         /**
 171          * @param string $entryType
 172          * @return array[] Entries (in chronological order) that have the same value
 173          *  for the entryType attribute as the $entryType parameter.
 174          */
 175         public function getEntriesByType( $entryType ) {
 176                 $this->sortEntries();
 177                 $entries = [];
 178                 foreach ( $this->entries as $entry ) {
 179                         if ( $entry['entryType'] === $entryType ) {
 180                                 $entries[] = $entry;
 181                         }
 182                 }
 183                 return $entries;
 184         }
 185
 186         /**
 187          * @param string $name
 188          * @return array|null Entry named $name or null if it does not exist.
 189          */
 190         public function getEntryByName( $name ) {
 191                 return $this->entries[$name] ?? null;
 192         }
 193 }