SectionProfiler.php

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<?php
use MediaWiki\Logger\LoggerFactory;
use Psr\Log\LoggerInterface;
use Wikimedia\ScopedCallback;
 
class SectionProfiler {
    protected $start;
    protected $end;
    protected $stack = [];
    protected $workStack = [];
    protected $collated = [];
    protected $collateDone = false;
 
    protected $errorEntry;
    protected $logger;
 
    public function __construct( array $params = [] ) {
        $this->errorEntry = $this->getErrorEntry();
        $this->logger = LoggerFactory::getInstance( 'profiler' );
    }
 
    public function scopedProfileIn( $section ) {
        $this->profileInInternal( $section );
 
        return new SectionProfileCallback( $this, $section );
    }
 
    public function scopedProfileOut( ScopedCallback &$section ) {
        $section = null;
    }
 
    public function getFunctionStats() {
        $this->collateData();
 
        if ( is_array( $this->start ) && is_array( $this->end ) ) {
            $totalCpu = max( $this->end['cpu'] - $this->start['cpu'], 0 );
            $totalReal = max( $this->end['real'] - $this->start['real'], 0 );
            $totalMem = max( $this->end['memory'] - $this->start['memory'], 0 );
        } else {
            $totalCpu = 0;
            $totalReal = 0;
            $totalMem = 0;
        }
 
        $profile = [];
        foreach ( $this->collated as $fname => $data ) {
            $profile[] = [
                'name' => $fname,
                'calls' => $data['count'],
                'real' => $data['real'] * 1000,
                '%real' => $totalReal ? 100 * $data['real'] / $totalReal : 0,
                'cpu' => $data['cpu'] * 1000,
                '%cpu' => $totalCpu ? 100 * $data['cpu'] / $totalCpu : 0,
                'memory' => $data['memory'],
                '%memory' => $totalMem ? 100 * $data['memory'] / $totalMem : 0,
                'min_real' => 1000 * $data['min_real'],
                'max_real' => 1000 * $data['max_real']
            ];
        }
 
        $profile[] = [
            'name' => '-total',
            'calls' => 1,
            'real' => 1000 * $totalReal,
            '%real' => 100,
            'cpu' => 1000 * $totalCpu,
            '%cpu' => 100,
            'memory' => $totalMem,
            '%memory' => 100,
            'min_real' => 1000 * $totalReal,
            'max_real' => 1000 * $totalReal
        ];
 
        return $profile;
    }
 
    public function reset() {
        $this->start = null;
        $this->end = null;
        $this->stack = [];
        $this->workStack = [];
        $this->collated = [];
        $this->collateDone = false;
    }
 
    protected function getZeroEntry() {
        return [
            'cpu'      => 0.0,
            'real'     => 0.0,
            'memory'   => 0,
            'count'    => 0,
            'min_real' => 0.0,
            'max_real' => 0.0
        ];
    }
 
    protected function getErrorEntry() {
        $entry = $this->getZeroEntry();
        $entry['count'] = 1;
        return $entry;
    }
 
    protected function updateEntry( $name, $elapsedCpu, $elapsedReal, $memChange ) {
        $entry =& $this->collated[$name];
        if ( !is_array( $entry ) ) {
            $entry = $this->getZeroEntry();
            $this->collated[$name] =& $entry;
        }
        $entry['cpu'] += $elapsedCpu;
        $entry['real'] += $elapsedReal;
        $entry['memory'] += $memChange > 0 ? $memChange : 0;
        $entry['count']++;
        $entry['min_real'] = min( $entry['min_real'], $elapsedReal );
        $entry['max_real'] = max( $entry['max_real'], $elapsedReal );
    }
 
    public function profileInInternal( $functionname ) {
        // Once the data is collated for reports, any future calls
        // should clear the collation cache so the next report will
        // reflect them. This matters when trace mode is used.
        $this->collateDone = false;
 
        $cpu = $this->getTime( 'cpu' );
        $real = $this->getTime( 'wall' );
        $memory = memory_get_usage();
 
        if ( $this->start === null ) {
            $this->start = [ 'cpu' => $cpu, 'real' => $real, 'memory' => $memory ];
        }
 
        $this->workStack[] = [
            $functionname,
            count( $this->workStack ),
            $real,
            $cpu,
            $memory
        ];
    }
 
    public function profileOutInternal( $functionname ) {
        $item = array_pop( $this->workStack );
        if ( $item === null ) {
            $this->logger->error( "Profiling error: $functionname" );
            return;
        }
        [ $ofname, /* $ocount */, $ortime, $octime, $omem ] = $item;
 
        if ( $functionname === 'close' ) {
            $message = "Profile section ended by close(): {$ofname}";
            $this->logger->error( $message );
            $this->collated[$message] = $this->errorEntry;
            $functionname = $ofname;
        } elseif ( $ofname !== $functionname ) {
            $message = "Profiling error: in({$ofname}), out($functionname)";
            $this->logger->error( $message );
            $this->collated[$message] = $this->errorEntry;
        }
 
        $realTime = $this->getTime( 'wall' );
        $cpuTime = $this->getTime( 'cpu' );
        $memUsage = memory_get_usage();
 
        $elapsedcpu = $cpuTime - $octime;
        $elapsedreal = $realTime - $ortime;
        $memchange = $memUsage - $omem;
        $this->updateEntry( $functionname, $elapsedcpu, $elapsedreal, $memchange );
 
        $this->end = [
            'cpu'      => $cpuTime,
            'real'     => $realTime,
            'memory'   => $memUsage
        ];
    }
 
    protected function collateData() {
        if ( $this->collateDone ) {
            return;
        }
        $this->collateDone = true;
        // Close opened profiling sections
        while ( count( $this->workStack ) ) {
            $this->profileOutInternal( 'close' );
        }
    }
 
    protected function getTime( $metric = 'wall' ) {
        if ( $metric === 'cpu' || $metric === 'user' ) {
            $ru = getrusage( 0 /* RUSAGE_SELF */ );
            $time = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
            if ( $metric === 'cpu' ) {
                # This is the time of system calls, added to the user time
                # it gives the total CPU time
                $time += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
            }
            return $time;
        } else {
            return microtime( true );
        }
    }
}