Merge "[FileBackend] Process cache negatives for SHA1 on file stat."

[mediawiki.git] / includes / profiler / Profiler.php

<?php
/**
 * Base class and functions for profiling.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Profiler
 * This file is only included if profiling is enabled
 */

/**
 * @defgroup Profiler Profiler
 */

/**
 * Begin profiling of a function
 * @param string $functionname name of the function we will profile
 */
function wfProfileIn( $functionname ) {
        global $wgProfiler;
        if ( $wgProfiler instanceof Profiler || isset( $wgProfiler['class'] ) ) {
                Profiler::instance()->profileIn( $functionname );
        }
}

/**
 * Stop profiling of a function
 * @param string $functionname name of the function we have profiled
 */
function wfProfileOut( $functionname = 'missing' ) {
        global $wgProfiler;
        if ( $wgProfiler instanceof Profiler || isset( $wgProfiler['class'] ) ) {
                Profiler::instance()->profileOut( $functionname );
        }
}

/**
 * Class for handling function-scope profiling
 *
 * @since 1.22
 */
class ProfileSection {
        protected $name; // string; method name
        protected $enabled = false; // boolean; whether profiling is enabled

        /**
         * Begin profiling of a function and return an object that ends profiling of
         * the function when that object leaves scope. As long as the object is not
         * specifically linked to other objects, it will fall out of scope at the same
         * moment that the function to be profiled terminates.
         *
         * This is typically called like:
         * <code>$section = new ProfileSection( __METHOD__ );</code>
         *
         * @param string $name Name of the function to profile
         */
        public function __construct( $name ) {
                $this->name = $name;
                if ( Profiler::$__instance === null ) { // use this directly to reduce overhead
                        Profiler::instance();
                }
                if ( Profiler::$__instance && !( Profiler::$__instance instanceof ProfilerStub ) ) {
                        $this->enabled = true;
                        Profiler::$__instance->profileIn( $this->name );
                }
        }

        function __destruct() {
                if ( $this->enabled ) {
                        Profiler::$__instance->profileOut( $this->name );
                }
        }
}

/**
 * @ingroup Profiler
 * @todo document
 */
class Profiler {
        protected $mStack = array(), $mWorkStack = array(), $mCollated = array(),
                $mCalls = array(), $mTotals = array();
        protected $mTimeMetric = 'wall';
        protected $mProfileID = false, $mCollateDone = false, $mTemplated = false;

        /** @var Profiler */
        public static $__instance = null; // do not call this outside Profiler and ProfileSection

        function __construct( $params ) {
                if ( isset( $params['timeMetric'] ) ) {
                        $this->mTimeMetric = $params['timeMetric'];
                }
                if ( isset( $params['profileID'] ) ) {
                        $this->mProfileID = $params['profileID'];
                }

                $this->addInitialStack();
        }

        /**
         * Singleton
         * @return Profiler
         */
        public static function instance() {
                if ( is_null( self::$__instance ) ) {
                        global $wgProfiler;
                        if ( is_array( $wgProfiler ) ) {
                                if ( !isset( $wgProfiler['class'] ) ) {
                                        wfDebug( __METHOD__ . " called without \$wgProfiler['class']"
                                                . " set, falling back to ProfilerStub for safety\n" );
                                        $class = 'ProfilerStub';
                                } else {
                                        $class = $wgProfiler['class'];
                                }
                                self::$__instance = new $class( $wgProfiler );
                        } elseif ( $wgProfiler instanceof Profiler ) {
                                self::$__instance = $wgProfiler; // back-compat
                        } else {
                                wfDebug( __METHOD__ . ' called with bogus $wgProfiler setting,'
                                                . " falling back to ProfilerStub for safety\n" );
                                self::$__instance = new ProfilerStub( $wgProfiler );
                        }
                }
                return self::$__instance;
        }

        /**
         * Set the profiler to a specific profiler instance. Mostly for dumpHTML
         * @param $p Profiler object
         */
        public static function setInstance( Profiler $p ) {
                self::$__instance = $p;
        }

        /**
         * Return whether this a stub profiler
         *
         * @return Boolean
         */
        public function isStub() {
                return false;
        }

        /**
         * Return whether this profiler stores data
         *
         * @see Profiler::logData()
         * @return Boolean
         */
        public function isPersistent() {
                return true;
        }

        public function setProfileID( $id ) {
                $this->mProfileID = $id;
        }

        public function getProfileID() {
                if ( $this->mProfileID === false ) {
                        return wfWikiID();
                } else {
                        return $this->mProfileID;
                }
        }

        /**
         * Add the inital item in the stack.
         */
        protected function addInitialStack() {
                // Push an entry for the pre-profile setup time onto the stack
                $initial = $this->getInitialTime();
                if ( $initial !== null ) {
                        $this->mWorkStack[] = array( '-total', 0, $initial, 0 );
                        $this->mStack[] = array( '-setup', 1, $initial, 0, $this->getTime(), 0 );
                } else {
                        $this->profileIn( '-total' );
                }
        }

        /**
         * Called by wfProfieIn()
         *
         * @param $functionname String
         */
        public function profileIn( $functionname ) {
                global $wgDebugFunctionEntry;
                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
         */
        public function profileOut( $functionname ) {
                global $wgDebugFunctionEntry;
                $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;
                }
        }

        /**
         * Close opened profiling sections
         */
        public function close() {
                while ( count( $this->mWorkStack ) ) {
                        $this->profileOut( 'close' );
                }
        }

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

        /**
         * Returns a profiling output to be stored in debug file
         *
         * @return String
         */
        public function getOutput() {
                global $wgDebugFunctionEntry, $wgProfileCallTree;
                $wgDebugFunctionEntry = false;

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

                if ( $wgProfileCallTree ) {
                        return $this->getCallTree();
                } else {
                        return $this->getFunctionReport();
                }
        }

        /**
         * Returns a tree of function call instead of a list of functions
         * @return string
         */
        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 array $stack profiling array
         * @return 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
         * @return string
         */
        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 );
        }

        /**
         * Get the initial time of the request, based either on $wgRequestTime or
         * $wgRUstart. Will return null if not able to find data.
         *
         * @param string|false $metric metric to use, with the following possibilities:
         *   - user: User CPU time (without system calls)
         *   - cpu: Total CPU time (user and system calls)
         *   - wall (or any other string): elapsed time
         *   - false (default): will fall back to default metric
         * @return float|null
         */
        function getTime( $metric = false ) {
                if ( $metric === false ) {
                        $metric = $this->mTimeMetric;
                }

                if ( $metric === 'cpu' || $this->mTimeMetric === 'user' ) {
                        if ( !function_exists( 'getrusage' ) ) {
                                return 0;
                        }
                        $ru = getrusage();
                        $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 );
                }
        }

        /**
         * Get the initial time of the request, based either on $wgRequestTime or
         * $wgRUstart. Will return null if not able to find data.
         *
         * @param string|false $metric metric to use, with the following possibilities:
         *   - user: User CPU time (without system calls)
         *   - cpu: Total CPU time (user and system calls)
         *   - wall (or any other string): elapsed time
         *   - false (default): will fall back to default metric
         * @return float|null
         */
        protected function getInitialTime( $metric = false ) {
                global $wgRequestTime, $wgRUstart;

                if ( $metric === false ) {
                        $metric = $this->mTimeMetric;
                }

                if ( $metric === 'cpu' || $this->mTimeMetric === 'user' ) {
                        if ( !count( $wgRUstart ) ) {
                                return null;
                        }

                        $time = $wgRUstart['ru_utime.tv_sec'] + $wgRUstart['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 += $wgRUstart['ru_stime.tv_sec'] + $wgRUstart['ru_stime.tv_usec'] / 1e6;
                        }
                        return $time;
                } else {
                        if ( empty( $wgRequestTime ) ) {
                                return null;
                        } else {
                                return $wgRequestTime;
                        }
                }
        }

        protected function collateData() {
                if ( $this->mCollateDone ) {
                        return;
                }
                $this->mCollateDone = true;

                $this->close();

                $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;
                }

                $this->mCalls['-overhead-total'] = $profileCount;
                arsort( $this->mCollated, SORT_NUMERIC );
        }

        /**
         * Returns a list of profiled functions.
         *
         * @return string
         */
        function getFunctionReport() {
                $this->collateData();

                $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' );

                $total = isset( $this->mCollated['-total'] ) ? $this->mCollated['-total'] : 0;

                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] );
                }
                $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 the whole profiling data into the database.
         */
        public function logData() {
                global $wgProfilePerHost, $wgProfileToDatabase;

                # Do not log anything if database is readonly (bug 5375)
                if ( wfReadOnly() || !$wgProfileToDatabase ) {
                        return;
                }

                $dbw = wfGetDB( DB_MASTER );
                if ( !is_object( $dbw ) ) {
                        return;
                }

                if ( $wgProfilePerHost ) {
                        $pfhost = wfHostname();
                } else {
                        $pfhost = '';
                }

                try {
                        $this->collateData();

                        foreach ( $this->mCollated as $name => $elapsed ) {
                                $eventCount = $this->mCalls[$name];
                                $timeSum = (float) ($elapsed * 1000);
                                $memorySum = (float)$this->mMemory[$name];
                                $name = substr( $name, 0, 255 );

                                // 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)";
                        }
                } catch ( DBError $e ) {}
        }

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

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

        /**
         * Get the content type sent out to the client.
         * Used for profilers that output instead of store data.
         * @return string
         */
        protected function getContentType() {
                foreach ( headers_list() as $header ) {
                        if ( preg_match( '#^content-type: (\w+/\w+);?#i', $header, $m ) ) {
                                return $m[1];
                        }
                }
                return null;
        }
}