Fixes for r81936 per Tim's review

[mediawiki.git] / includes / Profiler.php

<?php
/**
 * @defgroup Profiler Profiler
 *
 * @file
 * @ingroup Profiler
 * This file is only included if profiling is enabled
 */

/** backward compatibility */
$wgProfiling = true;

/**
 * Begin profiling of a function
 * @param $functionname String: name of the function we will profile
 */
function wfProfileIn( $functionname ) {
        global $wgProfiler;
        $wgProfiler->profileIn( $functionname );
}

/**
 * Stop profiling of a function
 * @param $functionname String: name of the function we have profiled
 */
function wfProfileOut( $functionname = 'missing' ) {
        global $wgProfiler;
        $wgProfiler->profileOut( $functionname );
}

/**
 * Returns a profiling output to be stored in debug file
 *
 * @param $start Float
 * @param $elapsed Float: time elapsed since the beginning of the request
 */
function wfGetProfilingOutput( $start, $elapsed ) {
        global $wgProfiler;
        return $wgProfiler->getOutput( $start, $elapsed );
}

/**
 * Close opened profiling sections
 */
function wfProfileClose() {
        global $wgProfiler;
        $wgProfiler->close();
}

if (!function_exists('memory_get_usage')) {
        # Old PHP or --enable-memory-limit not compiled in
        function memory_get_usage() {
                return 0;
        }
}

/**
 * @ingroup Profiler
 * @todo document
 */
class Profiler {
        var $mStack = array (), $mWorkStack = array (), $mCollated = array ();
        var $mCalls = array (), $mTotals = array ();
        var $mTemplated = false;

        function __construct() {
                // Push an entry for the pre-profile setup time onto the stack
                global $wgRequestTime;
                if ( !empty( $wgRequestTime ) ) {
                        $this->mWorkStack[] = array( '-total', 0, $wgRequestTime, 0 );
                        $this->mStack[] = array( '-setup', 1, $wgRequestTime, 0, microtime(true), 0 );
                } else {
                        $this->profileIn( '-total' );
                }
        }

        /**
         * Called by wfProfieIn()
         *
         * @param $functionname String
         */
        function profileIn( $functionname ) {
                global $wgDebugFunctionEntry, $wgProfiling;
                if( !$wgProfiling ) return;
                if( $wgDebugFunctionEntry ){
                        $this->debug( str_repeat( ' ', count( $this->mWorkStack ) ) . 'Entering ' . $functionname . "\n" );
                }

                $this->mWorkStack[] = array( $functionname, count( $this->mWorkStack ), $this->getTime(), memory_get_usage() );
        }

        /**
         * Called by wfProfieOut()
         *
         * @param $functionname String
         */
        function profileOut($functionname) {
                global $wgDebugFunctionEntry, $wgProfiling;
                if( !$wgProfiling ) return;
                $memory = memory_get_usage();
                $time = $this->getTime();

                if( $wgDebugFunctionEntry ){
                        $this->debug( str_repeat( ' ', count( $this->mWorkStack ) - 1 ) . 'Exiting ' . $functionname . "\n" );
                }

                $bit = array_pop($this->mWorkStack);

                if (!$bit) {
                        $this->debug("Profiling error, !\$bit: $functionname\n");
                } else {
                        //if( $wgDebugProfiling ){
                                if( $functionname == 'close' ){
                                        $message = "Profile section ended by close(): {$bit[0]}";
                                        $this->debug( "$message\n" );
                                        $this->mStack[] = array( $message, 0, '0 0', 0, '0 0', 0 );
                                }
                                elseif( $bit[0] != $functionname ){
                                        $message = "Profiling error: in({$bit[0]}), out($functionname)";
                                        $this->debug( "$message\n" );
                                        $this->mStack[] = array( $message, 0, '0 0', 0, '0 0', 0 );
                                }
                        //}
                        $bit[] = $time;
                        $bit[] = $memory;
                        $this->mStack[] = $bit;
                }
        }

        /**
         * called by wfProfileClose()
         */
        function close() {
                global $wgProfiling;

                # Avoid infinite loop
                if( !$wgProfiling )
                        return;

                while( count( $this->mWorkStack ) ){
                        $this->profileOut( 'close' );
                }
        }

        /**
         * Mark this call as templated or not
         *
         * @param $t Boolean
         */
        function setTemplated( $t ) {
                $this->mTemplated = $t;
        }

        /**
         * Called by wfGetProfilingOutput()
         */
        function getOutput() {
                global $wgDebugFunctionEntry, $wgProfileCallTree;
                $wgDebugFunctionEntry = false;

                if( !count( $this->mStack ) && !count( $this->mCollated ) ){
                        return "No profiling output\n";
                }
                $this->close();

                if( $wgProfileCallTree ) {
                        global $wgProfileToDatabase;
                        # XXX: We must call $this->getFunctionReport() to log to the DB
                        if( $wgProfileToDatabase ) {
                                $this->getFunctionReport();
                        }
                        return $this->getCallTree();
                } else {
                        return $this->getFunctionReport();
                }
        }

        /**
         * Returns a tree of function call instead of a list of functions
         */
        function getCallTree() {
                return implode( '', array_map( array( &$this, 'getCallTreeLine' ), $this->remapCallTree( $this->mStack ) ) );
        }

        /**
         * Recursive function the format the current profiling array into a tree
         *
         * @param $stack profiling array
         */
        function remapCallTree( $stack ) {
                if( count( $stack ) < 2 ){
                        return $stack;
                }
                $outputs = array ();
                for( $max = count( $stack ) - 1; $max > 0; ){
                        /* Find all items under this entry */
                        $level = $stack[$max][1];
                        $working = array ();
                        for( $i = $max -1; $i >= 0; $i-- ){
                                if( $stack[$i][1] > $level ){
                                        $working[] = $stack[$i];
                                } else {
                                        break;
                                }
                        }
                        $working = $this->remapCallTree( array_reverse( $working ) );
                        $output = array();
                        foreach( $working as $item ){
                                array_push( $output, $item );
                        }
                        array_unshift( $output, $stack[$max] );
                        $max = $i;

                        array_unshift( $outputs, $output );
                }
                $final = array();
                foreach( $outputs as $output ){
                        foreach( $output as $item ){
                                $final[] = $item;
                        }
                }
                return $final;
        }

        /**
         * Callback to get a formatted line for the call tree
         */
        function getCallTreeLine( $entry ) {
                list( $fname, $level, $start, /* $x */, $end)  = $entry;
                $delta = $end - $start;
                $space = str_repeat(' ', $level);
                # The ugly double sprintf is to work around a PHP bug,
                # which has been fixed in recent releases.
                return sprintf( "%10s %s %s\n", trim( sprintf( "%7.3f", $delta * 1000.0 ) ), $space, $fname );
        }

        function getTime() {
                return microtime(true);
                #return $this->getUserTime();
        }

        function getUserTime() {
                $ru = getrusage();
                return $ru['ru_utime.tv_sec'].' '.$ru['ru_utime.tv_usec'] / 1e6;
        }

        /**
         * Returns a list of profiled functions.
         * Also log it into the database if $wgProfileToDatabase is set to true.
         */
        function getFunctionReport() {
                global $wgProfileToDatabase;

                $width = 140;
                $nameWidth = $width - 65;
                $format =      "%-{$nameWidth}s %6d %13.3f %13.3f %13.3f%% %9d  (%13.3f -%13.3f) [%d]\n";
                $titleFormat = "%-{$nameWidth}s %6s %13s %13s %13s %9s\n";
                $prof = "\nProfiling data\n";
                $prof .= sprintf( $titleFormat, 'Name', 'Calls', 'Total', 'Each', '%', 'Mem' );
                $this->mCollated = array ();
                $this->mCalls = array ();
                $this->mMemory = array ();

                # Estimate profiling overhead
                $profileCount = count($this->mStack);
                self::calculateOverhead( $profileCount );

                # First, subtract the overhead!
                $overheadTotal = $overheadMemory = $overheadInternal = array();
                foreach( $this->mStack as $entry ){
                        $fname = $entry[0];
                        $start = $entry[2];
                        $end = $entry[4];
                        $elapsed = $end - $start;
                        $memory = $entry[5] - $entry[3];

                        if( $fname == '-overhead-total' ){
                                $overheadTotal[] = $elapsed;
                                $overheadMemory[] = $memory;
                        }
                        elseif( $fname == '-overhead-internal' ){
                                $overheadInternal[] = $elapsed;
                        }
                }
                $overheadTotal = $overheadTotal ? array_sum( $overheadTotal ) / count( $overheadInternal ) : 0;
                $overheadMemory = $overheadMemory ? array_sum( $overheadMemory ) / count( $overheadInternal ) : 0;
                $overheadInternal = $overheadInternal ? array_sum( $overheadInternal ) / count( $overheadInternal ) : 0;

                # Collate
                foreach( $this->mStack as $index => $entry ){
                        $fname = $entry[0];
                        $start = $entry[2];
                        $end = $entry[4];
                        $elapsed = $end - $start;

                        $memory = $entry[5] - $entry[3];
                        $subcalls = $this->calltreeCount( $this->mStack, $index );

                        if( !preg_match( '/^-overhead/', $fname ) ){
                                # Adjust for profiling overhead (except special values with elapsed=0
                                if( $elapsed ) {
                                        $elapsed -= $overheadInternal;
                                        $elapsed -= ($subcalls * $overheadTotal);
                                        $memory -= ($subcalls * $overheadMemory);
                                }
                        }

                        if( !array_key_exists( $fname, $this->mCollated ) ){
                                $this->mCollated[$fname] = 0;
                                $this->mCalls[$fname] = 0;
                                $this->mMemory[$fname] = 0;
                                $this->mMin[$fname] = 1 << 24;
                                $this->mMax[$fname] = 0;
                                $this->mOverhead[$fname] = 0;
                        }

                        $this->mCollated[$fname] += $elapsed;
                        $this->mCalls[$fname]++;
                        $this->mMemory[$fname] += $memory;
                        $this->mMin[$fname] = min($this->mMin[$fname], $elapsed);
                        $this->mMax[$fname] = max($this->mMax[$fname], $elapsed);
                        $this->mOverhead[$fname] += $subcalls;
                }

                $total = @$this->mCollated['-total'];
                $this->mCalls['-overhead-total'] = $profileCount;

                # Output
                arsort( $this->mCollated, SORT_NUMERIC );
                foreach( $this->mCollated as $fname => $elapsed ){
                        $calls = $this->mCalls[$fname];
                        $percent = $total ? 100. * $elapsed / $total : 0;
                        $memory = $this->mMemory[$fname];
                        $prof .= sprintf($format, substr($fname, 0, $nameWidth), $calls, (float) ($elapsed * 1000), (float) ($elapsed * 1000) / $calls, $percent, $memory, ($this->mMin[$fname] * 1000.0), ($this->mMax[$fname] * 1000.0), $this->mOverhead[$fname]);
                        # Log to the DB
                        if( $wgProfileToDatabase ) {
                                self::logToDB($fname, (float) ($elapsed * 1000), $calls, (float) ($memory) );
                        }
                }
                $prof .= "\nTotal: $total\n\n";

                return $prof;
        }

        /**
         * Dummy calls to wfProfileIn/wfProfileOut to calculate its overhead
         */
        protected static function calculateOverhead( $profileCount ) {
                wfProfileIn( '-overhead-total' );
                for( $i = 0; $i < $profileCount; $i++ ){
                        wfProfileIn( '-overhead-internal' );
                        wfProfileOut( '-overhead-internal' );
                }
                wfProfileOut( '-overhead-total' );
        }
        
        /**
         * Counts the number of profiled function calls sitting under
         * the given point in the call graph. Not the most efficient algo.
         *
         * @param $stack Array:
         * @param $start Integer:
         * @return Integer
         * @private
         */
        function calltreeCount($stack, $start) {
                $level = $stack[$start][1];
                $count = 0;
                for ($i = $start -1; $i >= 0 && $stack[$i][1] > $level; $i --) {
                        $count ++;
                }
                return $count;
        }

        /**
         * Log a function into the database.
         *
         * @param $name String: function name
         * @param $timeSum Float
         * @param $eventCount Integer: number of times that function was called
         * @param $memorySum Integer: memory used by the function
         */
        static function logToDB( $name, $timeSum, $eventCount, $memorySum ){
                # Do not log anything if database is readonly (bug 5375)
                if( wfReadOnly() ) { return; }

                global $wgProfilePerHost;

                $dbw = wfGetDB( DB_MASTER );
                if( !is_object( $dbw ) )
                        return false;
                $errorState = $dbw->ignoreErrors( true );

                $name = substr($name, 0, 255);

                if( $wgProfilePerHost ){
                        $pfhost = wfHostname();
                } else {
                        $pfhost = '';
                }
                
                // Kludge
                $timeSum = ($timeSum >= 0) ? $timeSum : 0;
                $memorySum = ($memorySum >= 0) ? $memorySum : 0;

                $dbw->update( 'profiling',
                        array(
                                "pf_count=pf_count+{$eventCount}",
                                "pf_time=pf_time+{$timeSum}",
                                "pf_memory=pf_memory+{$memorySum}",
                        ),
                        array(
                                'pf_name' => $name,
                                'pf_server' => $pfhost,
                        ),
                        __METHOD__ );
                                

                $rc = $dbw->affectedRows();
                if ($rc == 0) {
                        $dbw->insert('profiling', array ('pf_name' => $name, 'pf_count' => $eventCount,
                                'pf_time' => $timeSum, 'pf_memory' => $memorySum, 'pf_server' => $pfhost ), 
                                __METHOD__, array ('IGNORE'));
                }
                // When we upgrade to mysql 4.1, the insert+update
                // can be merged into just a insert with this construct added:
                //     "ON DUPLICATE KEY UPDATE ".
                //     "pf_count=pf_count + VALUES(pf_count), ".
                //     "pf_time=pf_time + VALUES(pf_time)";
                $dbw->ignoreErrors( $errorState );
        }

        /**
         * Get the function name of the current profiling section
         */
        function getCurrentSection() {
                $elt = end( $this->mWorkStack );
                return $elt[0];
        }

        /**
         * Get function caller
         *
         * @param $level Integer
         */
        static function getCaller( $level ) {
                $backtrace = wfDebugBacktrace();
                if ( isset( $backtrace[$level] ) ) {
                        if ( isset( $backtrace[$level]['class'] ) ) {
                                $caller = $backtrace[$level]['class'] . '::' . $backtrace[$level]['function'];
                        } else {
                                $caller = $backtrace[$level]['function'];
                        }
                } else {
                        $caller = 'unknown';
                }
                return $caller;
        }

        /**
         * Add an entry in the debug log file
         *
         * @param $s String to output
         */
        function debug( $s ) {
                if( function_exists( 'wfDebug' ) ) {
                        wfDebug( $s );
                }
        }
}