#!/usr/bin/php
<?php
#
# Copyright 2018 Miriam Lauter (lauter.miriam@gmail.com). All rights reserved.
#
# 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#
# (http://www.gnu.org/copyleft/gpl.html)
#
# 13-Apr-2018 Miriam Lauter Created this.

ini_set('error_log', null);
$optind = null;
$args = getopt("htc", ["help"], $optind);
if (isset($args['h']) || isset($args['help'])) {
 usage();
}

function usage($exit = 0) {
 echo <<<EOT
stackcollapse-xdebug.php collapse php function traces into single lines.

Parses php samples generated by xdebug with xdebug.trace_format = 1
and outputs stacks as single lines, with methods separated by semicolons,
and then a space and an occurrence count. For use with flamegraph.pl.
See https://github.com/brendangregg/FlameGraph.

USAGE: ./stackcollapse-xdebug.php [OPTIONS] infile > outfile
 -h --help Show this message
 -t Weight stack counts by duration using the time index in the trace (default)
 -c Invocation counts only. Simply count stacks in the trace and sum duplicates, don't weight by duration.

Example input:
For more info on xdebug and generating traces see
https://xdebug.org/docs/execution_trace.

Version: 2.0.0RC4-dev
TRACE START [2007年05月06日 18:29:01]
1 0 0 0.010870 114112 {main} 1 ../trace.php 0
2 1 0 0.032009 114272 str_split 0 ../trace.php 8
2 1 1 0.032073 116632
2 2 0 0.033505 117424 ret_ord 1 ../trace.php 10
3 3 0 0.033531 117584 ord 0 ../trace.php 5
3 3 1 0.033551 117584
...
TRACE END [2007年05月06日 18:29:01]

Example output:

- c
{main};str_split 1
{main};ret_ord;ord 6

-t
{main} 23381
{main};str_split 64
{main};ret_ord 215
{main};ret_ord;ord 106

EOT;

 exit($exit);
}

function collapseStack(array $stack, string $func_name_key): string {
 return implode(';', array_column($stack, $func_name_key));
}

function addCurrentStackToStacks(array $stack, float $dur, array &$stacks) {
 $collapsed = implode(';', $stack);
 $duration = SCALE_FACTOR * $dur;

 if (array_key_exists($collapsed, $stacks)) {
 $stacks[$collapsed] += $duration;
 } else {
 $stacks[$collapsed] = $duration;
 }
}

function isEOTrace(string $l) {
 $pattern = "/^(\\t|TRACE END)/";
 return preg_match($pattern, $l);
}

$filename = $argv[$optind] ?? null;
if ($filename === null) {
 usage(1);
}

$do_time = !isset($args['c']);

// First make sure our file is consistently formatted with only one \t delimiting each field
$out = [];
$retval = null;
exec("sed -in 's/\t\+/\t/g' " . escapeshellarg($filename), $out, $retval);
if ($retval !== 0) {
 usage(1);
}

$handle = fopen($filename, 'r');

if ($handle === false) {
 echo "Unable to open $filename\n\n";
 usage(1);
}

// Loop till we find TRACE START
while ($l = fgets($handle)) {
 if (strpos($l, "TRACE START") === 0) {
 break;
 }
}

const SCALE_FACTOR = 1000000;
$stacks = [];
$current_stack = [];
$was_exit = false;
$prev_start_time = 0;

if ($do_time) {
 // Weight counts by duration
 // Xdebug trace time indices have 6 sigfigs of precision
 // We have a perfect trace, but let's instead pretend that
 // this was collected by sampling at 10^6 Hz
 // then each millionth of a second this stack took to execute is 1 count
 while ($l = fgets($handle)) {
 if (isEOTrace($l)) {
 break;
 }

 $parts = explode("\t", $l);
 list($level, $fn_no, $is_exit, $time) = $parts;

 if ($is_exit) {
 if (empty($current_stack)) {
 echo "[WARNING] Found function exit without corresponding entrance. Discarding line. Check your input.\n";
 continue;
 }

 addCurrentStackToStacks($current_stack, $time - $prev_start_time, $stacks);
 array_pop($current_stack);
 } else {
 $func_name = $parts[5];

 if (!empty($current_stack)) {
 addCurrentStackToStacks($current_stack, $time - $prev_start_time, $stacks);
 }

 $current_stack[] = $func_name;
 }
 $prev_start_time = $time;
 }
} else {
 // Counts only
 while ($l = fgets($handle)) {
 if (isEOTrace($l)) {
 break;
 }

 $parts = explode("\t", $l);
 list($level, $fn_no, $is_exit) = $parts;

 if ($is_exit === "1") {
 if (!$was_exit) {
 $collapsed = implode(";", $current_stack);
 if (array_key_exists($collapsed, $stacks)) {
 $stacks[$collapsed]++;
 } else {
 $stacks[$collapsed] = 1;
 }
 }

 array_pop($current_stack);
 $was_exit = true;
 } else {
 $func_name = $parts[5];
 $current_stack[] = $func_name;
 $was_exit = false;
 }
 }
}

foreach ($stacks as $stack => $count) {
 echo "$stack$count\n";
}