, and is used/adapted with his permission. * * $Horde: framework/Text_Diff/Diff.php,v 1.11.2.11 2008/02/24 10:57:46 jan Exp $ * * Copyright 2004 Geoffrey T. Dairiki * Copyright 2004-2008 The Horde Project (http://www.horde.org/) * * See the enclosed file COPYING for license information (LGPL). If you did * not receive this file, see http://opensource.org/licenses/lgpl-license.php. * * @package Text_Diff * @author Geoffrey T. Dairiki */ class Text_Diff { /** * Array of changes. * * @var array */ var $_edits; /** * Computes diffs between sequences of strings. * * @param string $engine Name of the diffing engine to use. 'auto' * will automatically select the best. * @param array $params Parameters to pass to the diffing engine. * Normally an array of two arrays, each * containing the lines from a file. */ function Text_Diff($engine, $params) { // Backward compatibility workaround. if (!is_string($engine)) { $params = array($engine, $params); $engine = 'auto'; } if ($engine == 'auto') { $engine = extension_loaded('xdiff') ? 'xdiff' : 'native'; } else { $engine = basename($engine); } require_once 'Text/Diff/Engine/' . $engine . '.php'; $class = 'Text_Diff_Engine_' . $engine; $diff_engine = new $class(); $this->_edits = call_user_func_array(array($diff_engine, 'diff'), $params); } /** * Returns the array of differences. */ function getDiff() { return $this->_edits; } /** * returns the number of new (added) lines in a given diff. * * @since Text_Diff 1.1.0 * @since Horde 3.2 * * @return integer The number of new lines */ function countAddedLines() { $count = 0; foreach ($this->_edits as $edit) { if (is_a($edit, 'Text_Diff_Op_add') || is_a($edit, 'Text_Diff_Op_change')) { $count += $edit->nfinal(); } } return $count; } /** * Returns the number of deleted (removed) lines in a given diff. * * @since Text_Diff 1.1.0 * @since Horde 3.2 * * @return integer The number of deleted lines */ function countDeletedLines() { $count = 0; foreach ($this->_edits as $edit) { if (is_a($edit, 'Text_Diff_Op_delete') || is_a($edit, 'Text_Diff_Op_change')) { $count += $edit->norig(); } } return $count; } /** * Computes a reversed diff. * * Example: * * $diff = new Text_Diff($lines1, $lines2); * $rev = $diff->reverse(); * * * @return Text_Diff A Diff object representing the inverse of the * original diff. Note that we purposely don't return a * reference here, since this essentially is a clone() * method. */ function reverse() { if (version_compare(zend_version(), '2', '>')) { $rev = clone($this); } else { $rev = $this; } $rev->_edits = array(); foreach ($this->_edits as $edit) { $rev->_edits[] = $edit->reverse(); } return $rev; } /** * Checks for an empty diff. * * @return boolean True if two sequences were identical. */ function isEmpty() { foreach ($this->_edits as $edit) { if (!is_a($edit, 'Text_Diff_Op_copy')) { return false; } } return true; } /** * Computes the length of the Longest Common Subsequence (LCS). * * This is mostly for diagnostic purposes. * * @return integer The length of the LCS. */ function lcs() { $lcs = 0; foreach ($this->_edits as $edit) { if (is_a($edit, 'Text_Diff_Op_copy')) { $lcs += count($edit->orig); } } return $lcs; } /** * Gets the original set of lines. * * This reconstructs the $from_lines parameter passed to the constructor. * * @return array The original sequence of strings. */ function getOriginal() { $lines = array(); foreach ($this->_edits as $edit) { if ($edit->orig) { array_splice($lines, count($lines), 0, $edit->orig); } } return $lines; } /** * Gets the final set of lines. * * This reconstructs the $to_lines parameter passed to the constructor. * * @return array The sequence of strings. */ function getFinal() { $lines = array(); foreach ($this->_edits as $edit) { if ($edit->final) { array_splice($lines, count($lines), 0, $edit->final); } } return $lines; } /** * Removes trailing newlines from a line of text. This is meant to be used * with array_walk(). * * @param string $line The line to trim. * @param integer $key The index of the line in the array. Not used. */ static function trimNewlines(&$line, $key) { $line = str_replace(array("\n", "\r"), '', $line); } /** * Determines the location of the system temporary directory. * * @static * * @access protected * * @return string A directory name which can be used for temp files. * Returns false if one could not be found. */ function _getTempDir() { $tmp_locations = array('/tmp', '/var/tmp', 'c:\WUTemp', 'c:\temp', 'c:\windows\temp', 'c:\winnt\temp'); /* Try PHP's upload_tmp_dir directive. */ $tmp = ini_get('upload_tmp_dir'); /* Otherwise, try to determine the TMPDIR environment variable. */ if (!strlen($tmp)) { $tmp = getenv('TMPDIR'); } /* If we still cannot determine a value, then cycle through a list of * preset possibilities. */ while (!strlen($tmp) && count($tmp_locations)) { $tmp_check = array_shift($tmp_locations); if (@is_dir($tmp_check)) { $tmp = $tmp_check; } } /* If it is still empty, we have failed, so return false; otherwise * return the directory determined. */ return strlen($tmp) ? $tmp : false; } /** * Checks a diff for validity. * * This is here only for debugging purposes. */ function _check($from_lines, $to_lines) { if (serialize($from_lines) != serialize($this->getOriginal())) { trigger_error("Reconstructed original doesn't match", E_USER_ERROR); } if (serialize($to_lines) != serialize($this->getFinal())) { trigger_error("Reconstructed final doesn't match", E_USER_ERROR); } $rev = $this->reverse(); if (serialize($to_lines) != serialize($rev->getOriginal())) { trigger_error("Reversed original doesn't match", E_USER_ERROR); } if (serialize($from_lines) != serialize($rev->getFinal())) { trigger_error("Reversed final doesn't match", E_USER_ERROR); } $prevtype = null; foreach ($this->_edits as $edit) { if ($prevtype == get_class($edit)) { trigger_error("Edit sequence is non-optimal", E_USER_ERROR); } $prevtype = get_class($edit); } return true; } } /** * @package Text_Diff * @author Geoffrey T. Dairiki */ class Text_MappedDiff extends Text_Diff { /** * Computes a diff between sequences of strings. * * This can be used to compute things like case-insensitve diffs, or diffs * which ignore changes in white-space. * * @param array $from_lines An array of strings. * @param array $to_lines An array of strings. * @param array $mapped_from_lines This array should have the same size * number of elements as $from_lines. The * elements in $mapped_from_lines and * $mapped_to_lines are what is actually * compared when computing the diff. * @param array $mapped_to_lines This array should have the same number * of elements as $to_lines. */ function Text_MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { assert(count($from_lines) == count($mapped_from_lines)); assert(count($to_lines) == count($mapped_to_lines)); parent::Text_Diff($mapped_from_lines, $mapped_to_lines); $xi = $yi = 0; for ($i = 0; $i < count($this->_edits); $i++) { $orig = &$this->_edits[$i]->orig; if (is_array($orig)) { $orig = array_slice($from_lines, $xi, count($orig)); $xi += count($orig); } $final = &$this->_edits[$i]->final; if (is_array($final)) { $final = array_slice($to_lines, $yi, count($final)); $yi += count($final); } } } } /** * @package Text_Diff * @author Geoffrey T. Dairiki * * @access private */ class Text_Diff_Op { var $orig; var $final; function &reverse() { trigger_error('Abstract method', E_USER_ERROR); } function norig() { return $this->orig ? count($this->orig) : 0; } function nfinal() { return $this->final ? count($this->final) : 0; } } /** * @package Text_Diff * @author Geoffrey T. Dairiki * * @access private */ class Text_Diff_Op_copy extends Text_Diff_Op { function Text_Diff_Op_copy($orig, $final = false) { if (!is_array($final)) { $final = $orig; } $this->orig = $orig; $this->final = $final; } function &reverse() { $reverse = new Text_Diff_Op_copy($this->final, $this->orig); return $reverse; } } /** * @package Text_Diff * @author Geoffrey T. Dairiki * * @access private */ class Text_Diff_Op_delete extends Text_Diff_Op { function Text_Diff_Op_delete($lines) { $this->orig = $lines; $this->final = false; } function &reverse() { $reverse = new Text_Diff_Op_add($this->orig); return $reverse; } } /** * @package Text_Diff * @author Geoffrey T. Dairiki * * @access private */ class Text_Diff_Op_add extends Text_Diff_Op { function Text_Diff_Op_add($lines) { $this->final = $lines; $this->orig = false; } function &reverse() { $reverse = new Text_Diff_Op_delete($this->final); return $reverse; } } /** * @package Text_Diff * @author Geoffrey T. Dairiki * * @access private */ class Text_Diff_Op_change extends Text_Diff_Op { function Text_Diff_Op_change($orig, $final) { $this->orig = $orig; $this->final = $final; } function &reverse() { $reverse = new Text_Diff_Op_change($this->final, $this->orig); return $reverse; } }