Script to generate a revision mapping table from two SVN and GIT log files

git-svn-create-rev-map.php

<?php

/**
 * This script builds a revision mapping table from two SVN and GIT log files.
 * It uses a commit's date and comment to connect SVN revisions with a GIT commits.
 *
 * Execute it with php git-svn-create-rev-map.php svn.log git.log
 *
 * @author Thomas Bruederli <thomas(at)roundcube(dot)net>
 **/

// read svn log from first argument
$svnlog = file($_SERVER['argv'][1]);
if (!count($svnlog))
	die("Cannot read svnlog");

$revmap = array();
$svnrev = null; $comment = '';
foreach ($svnlog as $line) {
	$line = trim($line);
	if (preg_match('/r(\d+)\s+\|[^|]+\|\s+(2[\d\s:+-]+)/', $line, $m)) {
		if ($comment && $svnrev) {
			$ckey = comment_hash($comment);
			if (isset($revmap[$ckey]))
				fputs(STDERR, "Duplicate entry for $ckey\n");
			else
				$revmap[$ckey] = $svnrev;
		}

		$svnrev = $m[1];
		$comment = gmdate('Y-m-d H:i:s ', strtotime($m[2]));
	}
	else if (!empty($line) && strpos($line, '-----') === false)
		$comment .= $line;
}

unset($svnlog);

// read git log from first argument
$gitlog = file($_SERVER['argv'][2]);
if (!count($gitlog))
	die("Cannot read gitlog");

$gitrev = null;
foreach ($gitlog as $line) {
	$line = trim($line);
	if (preg_match('/^commit\s+([a-f0-9]+)/', $line, $m)) {
		if ($comment && $gitrev) {
			$ckey = comment_hash($comment);
			if (!empty($revmap[$ckey]))
				echo $revmap[$ckey] . "\t" . $gitrev . "\n";
			else
				fputs(STDERR, "Could not find SVN revision for $gitrev; comment = $comment\n");
		}
		$gitrev = $m[1];
		$comment = '';
	}
	else if (preg_match('/^Date:\s+(\w.+)/', $line, $m)) {
		$comment = gmdate('Y-m-d H:i:s ', strtotime($m[1]));
	}
	else if (!empty($line) && !preg_match('/^Author:\s+/', $line)) {
		$comment .= $line;
	}
}

// helper function to create a hash for the given comment
function comment_hash($comment)
{
	return preg_replace('/[^a-z0-9#_()\[\]-]/ims', '', strtolower(iconv('UTF-8', 'US-ASCII//TRANSLIT', $comment)));
}

Could you give an example of exactly what the svn and git log file formats should look like. Using straight git log and svn log to generate the files doesn't work with this script.