Sequenzia/vendor/Horde/Text/Diff/Engine/Xdiff.php
2013-10-26 18:06:58 -05:00

68 lines
2.3 KiB
PHP
Executable File

<?php
/**
* Class used internally by Diff to actually compute the diffs.
*
* This class uses the xdiff PECL package (http://pecl.php.net/package/xdiff)
* to compute the differences between the two input arrays.
*
* Copyright 2004-2012 Horde LLC (http://www.horde.org/)
*
* See the enclosed file COPYING for license information (LGPL). If you did
* not receive this file, see http://www.horde.org/licenses/lgpl21.
*
* @author Jon Parise <jon@horde.org>
* @package Text_Diff
*/
class Horde_Text_Diff_Engine_Xdiff
{
/**
*/
public function diff($from_lines, $to_lines)
{
if (!extension_loaded('xdiff')) {
throw new Horde_Text_Diff_Exception('The xdiff extension is required for this diff engine');
}
array_walk($from_lines, array('Horde_Text_Diff', 'trimNewlines'));
array_walk($to_lines, array('Horde_Text_Diff', 'trimNewlines'));
/* Convert the two input arrays into strings for xdiff processing. */
$from_string = implode("\n", $from_lines);
$to_string = implode("\n", $to_lines);
/* Diff the two strings and convert the result to an array. */
$diff = xdiff_string_diff($from_string, $to_string, count($to_lines));
$diff = explode("\n", $diff);
/* Walk through the diff one line at a time. We build the $edits
* array of diff operations by reading the first character of the
* xdiff output (which is in the "unified diff" format).
*
* Note that we don't have enough information to detect "changed"
* lines using this approach, so we can't add Horde_Text_Diff_Op_Changed
* instances to the $edits array. The result is still perfectly
* valid, albeit a little less descriptive and efficient. */
$edits = array();
foreach ($diff as $line) {
if (!strlen($line)) {
continue;
}
switch ($line[0]) {
case ' ':
$edits[] = new Horde_Text_Diff_Op_Copy(array(substr($line, 1)));
break;
case '+':
$edits[] = new Horde_Text_Diff_Op_Add(array(substr($line, 1)));
break;
case '-':
$edits[] = new Horde_Text_Diff_Op_Delete(array(substr($line, 1)));
break;
}
}
return $edits;
}
}