<?php
/**
 * This file is only included if profiling is enabled
 * @package MediaWiki
 */

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

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

function wfGetProfilingOutput($start, $elapsed) {
	global $wgProfiler;
	return $wgProfiler->getOutput($start, $elapsed);
}

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;
	}
}

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

	function Profiler()
	{
		// 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(), 0 );
		} else {
			$this->profileIn( '-total' );
		}

	}

	function profileIn($functionname) {
		global $wgDebugFunctionEntry;
		if ($wgDebugFunctionEntry && function_exists('wfDebug')) {
			wfDebug(str_repeat(' ', count($this->mWorkStack)).'Entering '.$functionname."\n");
		}
		$this->mWorkStack[] = array($functionname, count( $this->mWorkStack ), $this->getTime(), memory_get_usage());
	}

	function profileOut($functionname) {
		$memory = memory_get_usage();
		$time = $this->getTime();

		global $wgDebugFunctionEntry;

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

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

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

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

	function getOutput() {
		global $wgDebugFunctionEntry;
		$wgDebugFunctionEntry = false;

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

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

	function getCallTree($start = 0) {
		return implode('', array_map(array (& $this, 'getCallTreeLine'), $this->remapCallTree($this->mStack)));
	}

	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;
	}

	function getCallTreeLine($entry) {
		list ($fname, $level, $start, $x, $end) = $entry;
		$delta = $this->microDelta($start, $end);
		$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 micro2Float( $micro ) {
		list( $whole, $fractional ) = explode( ' ', $micro );
		return (float)$whole + (float)$fractional;
	}

	function microDelta( $start, $end ) {
		return $this->micro2Float( $end ) -
		       $this->micro2Float( $start );
	}

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

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

	function getFunctionReport() {
		$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);
		wfProfileIn('-overhead-total');
		for ($i = 0; $i < $profileCount; $i ++) {
			wfProfileIn('-overhead-internal');
			wfProfileOut('-overhead-internal');
		}
		wfProfileOut('-overhead-total');

		# First, subtract the overhead!
		foreach ($this->mStack as $entry) {
			$fname = $entry[0];
			$thislevel = $entry[1];
			$start = explode(' ', $entry[2]);
			$start = (float) $start[0] + (float) $start[1];
			$end = explode(' ', $entry[4]);
			$end = (float) $end[0] + (float) $end[1];
			$elapsed = $end - $start;
			$memory = $entry[5] - $entry[3];

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

		# Collate
		foreach ($this->mStack as $index => $entry) {
			$fname = $entry[0];
			$thislevel = $entry[1];
			$start = explode(' ', $entry[2]);
			$start = (float) $start[0] + (float) $start[1];
			$end = explode(' ', $entry[4]);
			$end = (float) $end[0] + (float) $end[1];
			$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
		asort($this->mCollated, SORT_NUMERIC);
		foreach ($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]);

			global $wgProfileToDatabase;
			if ($wgProfileToDatabase) {
				Profiler :: logToDB($fname, (float) ($elapsed * 1000), $calls);
			}
		}
		$prof .= "\nTotal: $total\n\n";

		return $prof;
	}

	/**
	 * Counts the number of profiled function calls sitting under
	 * the given point in the call graph. Not the most efficient algo.
	 *
	 * @param array $stack
	 * @param int $start
	 * @return int
	 * @access 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;
	}

	/**
	 * @static
	 */
	function logToDB($name, $timeSum, $eventCount) {
		# Warning: $wguname is a live patch, it should be moved to Setup.php
		global $wguname;

		$fname = 'Profiler::logToDB';
		$dbw = & wfGetDB(DB_MASTER);
		if (!is_object($dbw))
			return false;
		$profiling = $dbw->tableName('profiling');

		$name = substr($name, 0, 255);
		$encname = $dbw->strencode($name);
		$sql = "UPDATE $profiling "."SET pf_count=pf_count+{$eventCount}, "."pf_time=pf_time + {$timeSum} ".
			"WHERE pf_name='{$encname}' AND pf_server='{$wguname['nodename']}'";
		$dbw->query($sql);

		$rc = $dbw->affectedRows();
		if ($rc == 0) {
			$dbw->insert('profiling', array ('pf_name' => $name, 'pf_count' => $eventCount,
				'pf_time' => $timeSum, 'pf_server' => $wguname['nodename'] ), $fname, 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)";
	}

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

}

?>
