xdiff.php (2210B)
1 <?php 2 /** 3 * Class used internally by Diff to actually compute the diffs. 4 * 5 * This class uses the xdiff PECL package (http://pecl.php.net/package/xdiff) 6 * to compute the differences between the two input arrays. 7 * 8 * Copyright 2004-2010 The Horde Project (http://www.horde.org/) 9 * 10 * See the enclosed file COPYING for license information (LGPL). If you did 11 * not receive this file, see http://opensource.org/licenses/lgpl-license.php. 12 * 13 * @author Jon Parise <jon@horde.org> 14 * @package Text_Diff 15 */ 16 class Text_Diff_Engine_xdiff { 17 18 /** 19 */ 20 function diff($from_lines, $to_lines) 21 { 22 array_walk($from_lines, array('Text_Diff', 'trimNewlines')); 23 array_walk($to_lines, array('Text_Diff', 'trimNewlines')); 24 25 /* Convert the two input arrays into strings for xdiff processing. */ 26 $from_string = implode("\n", $from_lines); 27 $to_string = implode("\n", $to_lines); 28 29 /* Diff the two strings and convert the result to an array. */ 30 $diff = xdiff_string_diff($from_string, $to_string, count($to_lines)); 31 $diff = explode("\n", $diff); 32 33 /* Walk through the diff one line at a time. We build the $edits 34 * array of diff operations by reading the first character of the 35 * xdiff output (which is in the "unified diff" format). 36 * 37 * Note that we don't have enough information to detect "changed" 38 * lines using this approach, so we can't add Text_Diff_Op_changed 39 * instances to the $edits array. The result is still perfectly 40 * valid, albeit a little less descriptive and efficient. */ 41 $edits = array(); 42 foreach ($diff as $line) { 43 if (!strlen($line)) { 44 continue; 45 } 46 switch ($line[0]) { 47 case ' ': 48 $edits[] = new Text_Diff_Op_copy(array(substr($line, 1))); 49 break; 50 51 case '+': 52 $edits[] = new Text_Diff_Op_add(array(substr($line, 1))); 53 break; 54 55 case '-': 56 $edits[] = new Text_Diff_Op_delete(array(substr($line, 1))); 57 break; 58 } 59 } 60 61 return $edits; 62 } 63 64 }