WebKitSite/blog/wp-includes/wp-diff.php - WebKit - Git at Google

 <?php

 if ( !class_exists( 'Text_Diff' ) ) {
 	require( dirname(__FILE__).'/Text/Diff.php' );
 	require( dirname(__FILE__).'/Text/Diff/Renderer.php' );
 	require( dirname(__FILE__).'/Text/Diff/Renderer/inline.php' );
 }


 /* Descendent of a bastard child of piece of an old MediaWiki Diff Formatter
  *
  * Basically all that remains is the table structure and some method names.
  */

 class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 	var $_leading_context_lines  = 10000;
 	var $_trailing_context_lines = 10000;
 	var $_diff_threshold = 0.6;

 	var $inline_diff_renderer = 'WP_Text_Diff_Renderer_inline';

 	function Text_Diff_Renderer_Table( $params = array() ) {
 		$parent = get_parent_class($this);
 		$this->$parent( $params );
 	}

 	function _startBlock( $header ) {
 		return '';
 	}

 	function _lines( $lines, $prefix=' ' ) {
 	}

 	// HTML-escape parameter before calling this
 	function addedLine( $line ) {
 		return "<td>+</td><td class='diff-addedline'>{$line}</td>";
 	}

 	// HTML-escape parameter before calling this
 	function deletedLine( $line ) {
 		return "<td>-</td><td class='diff-deletedline'>{$line}</td>";
 	}

 	// HTML-escape parameter before calling this
 	function contextLine( $line ) {
 		return "<td> </td><td class='diff-context'>{$line}</td>";
 	}

 	function emptyLine() {
 		return '<td colspan="2">&nbsp;</td>';
 	}

 	function _added( $lines, $encode = true ) {
 		$r = '';
 		foreach ($lines as $line) {
 			if ( $encode )
 				$line = htmlspecialchars( $line );
 			$r .= '<tr>' . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
 		}
 		return $r;
 	}

 	function _deleted( $lines, $encode = true ) {
 		$r = '';
 		foreach ($lines as $line) {
 			if ( $encode )
 				$line = htmlspecialchars( $line );
 			$r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . "</tr>\n";
 		}
 		return $r;
 	}

 	function _context( $lines, $encode = true ) {
 		$r = '';
 		foreach ($lines as $line) {
 			if ( $encode )
 				$line = htmlspecialchars( $line );
 			$r .= '<tr>' .
 				$this->contextLine( $line ) . $this->contextLine( $line ) . "</tr>\n";
 		}
 		return $r;
 	}

 	// Process changed lines to do word-by-word diffs for extra highlighting (TRAC style)
 	// sometimes these lines can actually be deleted or added rows - we do additional processing
 	// to figure that out
 	function _changed( $orig, $final ) {
 		$r = '';

 		// Does the aforementioned additional processing
 		// *_matches tell what rows are "the same" in orig and final.  Those pairs will be diffed to get word changes
 		//	match is numeric: an index in other column
 		//	match is 'X': no match.  It is a new row
 		// *_rows are column vectors for the orig column and the final column.
 		//	row >= 0: an indix of the $orig or $final array
 		//	row  < 0: a blank row for that column
 		list($orig_matches, $final_matches, $orig_rows, $final_rows) = $this->interleave_changed_lines( $orig, $final );


 		// These will hold the word changes as determined by an inline diff
 		$orig_diffs  = array();
 		$final_diffs = array();

 		// Compute word diffs for each matched pair using the inline diff
 		foreach ( $orig_matches as $o => $f ) {
 			if ( is_numeric($o) && is_numeric($f) ) {
 				$text_diff = new Text_Diff( 'auto', array( array($orig[$o]), array($final[$f]) ) );
 				$renderer = new $this->inline_diff_renderer;
 				$diff = $renderer->render( $text_diff );

 				// If they're too different, don't include any <ins> or <dels>
 				if ( $diff_count = preg_match_all( '!(<ins>.*?</ins>|<del>.*?</del>)!', $diff, $diff_matches ) ) {
 					// length of all text between <ins> or <del>
 					$stripped_matches = strlen(strip_tags( join(' ', $diff_matches[0]) ));
 					// since we count lengith of text between <ins> or <del> (instead of picking just one),
 					//	we double the length of chars not in those tags.
 					$stripped_diff = strlen(strip_tags( $diff )) * 2 - $stripped_matches;
 					$diff_ratio = $stripped_matches / $stripped_diff;
 					if ( $diff_ratio > $this->_diff_threshold )
 						continue; // Too different.  Don't save diffs.
 				}

 				// Un-inline the diffs by removing del or ins
 				$orig_diffs[$o]  = preg_replace( '|<ins>.*?</ins>|', '', $diff );
 				$final_diffs[$f] = preg_replace( '|<del>.*?</del>|', '', $diff );
 			}
 		}

 		foreach ( array_keys($orig_rows) as $row ) {
 			// Both columns have blanks.  Ignore them.
 			if ( $orig_rows[$row] < 0 && $final_rows[$row] < 0 )
 				continue;

 			// If we have a word based diff, use it.  Otherwise, use the normal line.
 			$orig_line  = isset($orig_diffs[$orig_rows[$row]])
 				? $orig_diffs[$orig_rows[$row]]
 				: htmlspecialchars($orig[$orig_rows[$row]]);
 			$final_line = isset($final_diffs[$final_rows[$row]])
 				? $final_diffs[$final_rows[$row]]
 				: htmlspecialchars($final[$final_rows[$row]]);

 			if ( $orig_rows[$row] < 0 ) { // Orig is blank.  This is really an added row.
 				$r .= $this->_added( array($final_line), false );
 			} elseif ( $final_rows[$row] < 0 ) { // Final is blank.  This is really a deleted row.
 				$r .= $this->_deleted( array($orig_line), false );
 			} else { // A true changed row.
 				$r .= '<tr>' . $this->deletedLine( $orig_line ) . $this->addedLine( $final_line ) . "</tr>\n";
 			}
 		}

 		return $r;
 	}

 	// Takes changed blocks and matches which rows in orig turned into which rows in final.
 	// Returns
 	//	*_matches ( which rows match with which )
 	//	*_rows ( order of rows in each column interleaved with blank rows as necessary )
 	function interleave_changed_lines( $orig, $final ) {

 		// Contains all pairwise string comparisons.  Keys are such that this need only be a one dimensional array.
 		$matches = array();
 		foreach ( array_keys($orig) as $o ) {
 			foreach ( array_keys($final) as $f ) {
 				$matches["$o,$f"] = $this->compute_string_distance( $orig[$o], $final[$f] );
 			}
 		}
 		asort($matches); // Order by string distance.

 		$orig_matches  = array();
 		$final_matches = array();

 		foreach ( $matches as $keys => $difference ) {
 			list($o, $f) = explode(',', $keys);
 			$o = (int) $o;
 			$f = (int) $f;

 			// Already have better matches for these guys
 			if ( isset($orig_matches[$o]) && isset($final_matches[$f]) )
 				continue;

 			// First match for these guys.  Must be best match
 			if ( !isset($orig_matches[$o]) && !isset($final_matches[$f]) ) {
 				$orig_matches[$o] = $f;
 				$final_matches[$f] = $o;
 				continue;
 			}

 			// Best match of this final is already taken?  Must mean this final is a new row.
 			if ( isset($orig_matches[$o]) )
 				$final_matches[$f] = 'x';

 			// Best match of this orig is already taken?  Must mean this orig is a deleted row.
 			elseif ( isset($final_matches[$f]) )
 				$orig_matches[$o] = 'x';
 		}

 		// We read the text in this order
 		ksort($orig_matches);
 		ksort($final_matches);


 		// Stores rows and blanks for each column.
 		$orig_rows = $orig_rows_copy = array_keys($orig_matches);
 		$final_rows = array_keys($final_matches);

 		// Interleaves rows with blanks to keep matches aligned.
 		// We may end up with some extraneous blank rows, but we'll just ignore them later.
 		foreach ( $orig_rows_copy as $orig_row ) {
 			$final_pos = array_search($orig_matches[$orig_row], $final_rows, true);
 			$orig_pos = (int) array_search($orig_row, $orig_rows, true);

 			if ( false === $final_pos ) { // This orig is paired with a blank final.
 				array_splice( $final_rows, $orig_pos, 0, -1 );
 			} elseif ( $final_pos < $orig_pos ) { // This orig's match is up a ways.  Pad final with blank rows.
 				$diff_pos = $final_pos - $orig_pos;
 				while ( $diff_pos < 0 )
 					array_splice( $final_rows, $orig_pos, 0, $diff_pos++ );
 			} elseif ( $final_pos > $orig_pos ) { // This orig's match is down a ways.  Pad orig with blank rows.
 				$diff_pos = $orig_pos - $final_pos;
 				while ( $diff_pos < 0 )
 					array_splice( $orig_rows, $orig_pos, 0, $diff_pos++ );
 			}
 		}


 		// Pad the ends with blank rows if the columns aren't the same length
 		$diff_count = count($orig_rows) - count($final_rows);
 		if ( $diff_count < 0 ) {
 			while ( $diff_count < 0 )
 				array_push($orig_rows, $diff_count++);
 		} elseif ( $diff_count > 0 ) {
 			$diff_count = -1 * $diff_count;
 			while ( $diff_count < 0 )
 				array_push($final_rows, $diff_count++);
 		}

 		return array($orig_matches, $final_matches, $orig_rows, $final_rows);

 /*
 		// Debug
 		echo "\n\n\n\n\n";

 		echo "-- DEBUG Matches: Orig -> Final --";

 		foreach ( $orig_matches as $o => $f ) {
 			echo "\n\n\n\n\n";
 			echo "ORIG: $o, FINAL: $f\n";
 			var_dump($orig[$o],$final[$f]);
 		}
 		echo "\n\n\n\n\n";

 		echo "-- DEBUG Matches: Final -> Orig --";

 		foreach ( $final_matches as $f => $o ) {
 			echo "\n\n\n\n\n";
 			echo "FINAL: $f, ORIG: $o\n";
 			var_dump($final[$f],$orig[$o]);
 		}
 		echo "\n\n\n\n\n";

 		echo "-- DEBUG Rows: Orig -- Final --";

 		echo "\n\n\n\n\n";
 		foreach ( $orig_rows as $row => $o ) {
 			if ( $o < 0 )
 				$o = 'X';
 			$f = $final_rows[$row];
 			if ( $f < 0 )
 				$f = 'X';
 			echo "$o -- $f\n";
 		}
 		echo "\n\n\n\n\n";

 		echo "-- END DEBUG --";

 		echo "\n\n\n\n\n";

 		return array($orig_matches, $final_matches, $orig_rows, $final_rows);
 */
 	}


 	// Computes a number that is intended to reflect the "distance" between two strings.
 	function compute_string_distance( $string1, $string2 ) {
 		// Vectors containing character frequency for all chars in each string
 		$chars1 = count_chars($string1);
 		$chars2 = count_chars($string2);

 		// L1-norm of difference vector.
 		$difference = array_sum( array_map( array(&$this, 'difference'), $chars1, $chars2 ) );

 		// $string1 has zero length? Odd.  Give huge penalty by not dividing.
 		if ( !$string1 )
 			return $difference;

 		// Return distance per charcter (of string1)
 		return $difference / strlen($string1);
 	}

 	function difference( $a, $b ) {
 		return abs( $a - $b );
 	}

 }

 // Better word splitting than the PEAR package provides
 class WP_Text_Diff_Renderer_inline extends Text_Diff_Renderer_inline {

 	function _splitOnWords($string, $newlineEscape = "\n") {
 		$string = str_replace("\0", '', $string);
 		$words  = preg_split( '/([^\w])/u', $string, -1, PREG_SPLIT_DELIM_CAPTURE );
 		$words  = str_replace( "\n", $newlineEscape, $words );
 		return $words;
 	}

 }

 ?>
	<?php

	if ( !class_exists( 'Text_Diff' ) ) {
	require( dirname(__FILE__).'/Text/Diff.php' );
	require( dirname(__FILE__).'/Text/Diff/Renderer.php' );
	require( dirname(__FILE__).'/Text/Diff/Renderer/inline.php' );
	}


	/* Descendent of a bastard child of piece of an old MediaWiki Diff Formatter
	*
	* Basically all that remains is the table structure and some method names.
	*/

	class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
	var $_leading_context_lines = 10000;
	var $_trailing_context_lines = 10000;
	var $_diff_threshold = 0.6;

	var $inline_diff_renderer = 'WP_Text_Diff_Renderer_inline';

	function Text_Diff_Renderer_Table( $params = array() ) {
	$parent = get_parent_class($this);
	$this->$parent( $params );
	}

	function _startBlock( $header ) {
	return '';
	}

	function _lines( $lines, $prefix=' ' ) {
	}

	// HTML-escape parameter before calling this
	function addedLine( $line ) {
	return "<td>+</td><td class='diff-addedline'>{$line}</td>";
	}

	// HTML-escape parameter before calling this
	function deletedLine( $line ) {
	return "<td>-</td><td class='diff-deletedline'>{$line}</td>";
	}

	// HTML-escape parameter before calling this
	function contextLine( $line ) {
	return "<td> </td><td class='diff-context'>{$line}</td>";
	}

	function emptyLine() {
	return '<td colspan="2"> </td>';
	}

	function _added( $lines, $encode = true ) {
	$r = '';
	foreach ($lines as $line) {
	if ( $encode )
	$line = htmlspecialchars( $line );
	$r .= '<tr>' . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
	}
	return $r;
	}

	function _deleted( $lines, $encode = true ) {
	$r = '';
	foreach ($lines as $line) {
	if ( $encode )
	$line = htmlspecialchars( $line );
	$r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . "</tr>\n";
	}
	return $r;
	}

	function _context( $lines, $encode = true ) {
	$r = '';
	foreach ($lines as $line) {
	if ( $encode )
	$line = htmlspecialchars( $line );
	$r .= '<tr>' .
	$this->contextLine( $line ) . $this->contextLine( $line ) . "</tr>\n";
	}
	return $r;
	}

	// Process changed lines to do word-by-word diffs for extra highlighting (TRAC style)
	// sometimes these lines can actually be deleted or added rows - we do additional processing
	// to figure that out
	function _changed( $orig, $final ) {
	$r = '';

	// Does the aforementioned additional processing
	// *_matches tell what rows are "the same" in orig and final. Those pairs will be diffed to get word changes
	// match is numeric: an index in other column
	// match is 'X': no match. It is a new row
	// *_rows are column vectors for the orig column and the final column.
	// row >= 0: an indix of the $orig or $final array
	// row < 0: a blank row for that column
	list($orig_matches, $final_matches, $orig_rows, $final_rows) = $this->interleave_changed_lines( $orig, $final );


	// These will hold the word changes as determined by an inline diff
	$orig_diffs = array();
	$final_diffs = array();

	// Compute word diffs for each matched pair using the inline diff
	foreach ( $orig_matches as $o => $f ) {
	if ( is_numeric($o) && is_numeric($f) ) {
	$text_diff = new Text_Diff( 'auto', array( array($orig[$o]), array($final[$f]) ) );
	$renderer = new $this->inline_diff_renderer;
	$diff = $renderer->render( $text_diff );

	// If they're too different, don't include any <ins> or <dels>
	if ( $diff_count = preg_match_all( '!(<ins>.?</ins>\|<del>.?</del>)!', $diff, $diff_matches ) ) {
	// length of all text between <ins> or <del>
	$stripped_matches = strlen(strip_tags( join(' ', $diff_matches[0]) ));
	// since we count lengith of text between <ins> or <del> (instead of picking just one),
	// we double the length of chars not in those tags.
	$stripped_diff = strlen(strip_tags( $diff )) * 2 - $stripped_matches;
	$diff_ratio = $stripped_matches / $stripped_diff;
	if ( $diff_ratio > $this->_diff_threshold )
	continue; // Too different. Don't save diffs.
	}

	// Un-inline the diffs by removing del or ins
	$orig_diffs[$o] = preg_replace( '\|<ins>.*?</ins>\|', '', $diff );
	$final_diffs[$f] = preg_replace( '\|<del>.*?</del>\|', '', $diff );
	}
	}

	foreach ( array_keys($orig_rows) as $row ) {
	// Both columns have blanks. Ignore them.
	if ( $orig_rows[$row] < 0 && $final_rows[$row] < 0 )
	continue;

	// If we have a word based diff, use it. Otherwise, use the normal line.
	$orig_line = isset($orig_diffs[$orig_rows[$row]])
	? $orig_diffs[$orig_rows[$row]]
	: htmlspecialchars($orig[$orig_rows[$row]]);
	$final_line = isset($final_diffs[$final_rows[$row]])
	? $final_diffs[$final_rows[$row]]
	: htmlspecialchars($final[$final_rows[$row]]);

	if ( $orig_rows[$row] < 0 ) { // Orig is blank. This is really an added row.
	$r .= $this->_added( array($final_line), false );
	} elseif ( $final_rows[$row] < 0 ) { // Final is blank. This is really a deleted row.
	$r .= $this->_deleted( array($orig_line), false );
	} else { // A true changed row.
	$r .= '<tr>' . $this->deletedLine( $orig_line ) . $this->addedLine( $final_line ) . "</tr>\n";
	}
	}

	return $r;
	}

	// Takes changed blocks and matches which rows in orig turned into which rows in final.
	// Returns
	// *_matches ( which rows match with which )
	// *_rows ( order of rows in each column interleaved with blank rows as necessary )
	function interleave_changed_lines( $orig, $final ) {

	// Contains all pairwise string comparisons. Keys are such that this need only be a one dimensional array.
	$matches = array();
	foreach ( array_keys($orig) as $o ) {
	foreach ( array_keys($final) as $f ) {
	$matches["$o,$f"] = $this->compute_string_distance( $orig[$o], $final[$f] );
	}
	}
	asort($matches); // Order by string distance.

	$orig_matches = array();
	$final_matches = array();

	foreach ( $matches as $keys => $difference ) {
	list($o, $f) = explode(',', $keys);
	$o = (int) $o;
	$f = (int) $f;

	// Already have better matches for these guys
	if ( isset($orig_matches[$o]) && isset($final_matches[$f]) )
	continue;

	// First match for these guys. Must be best match
	if ( !isset($orig_matches[$o]) && !isset($final_matches[$f]) ) {
	$orig_matches[$o] = $f;
	$final_matches[$f] = $o;
	continue;
	}

	// Best match of this final is already taken? Must mean this final is a new row.
	if ( isset($orig_matches[$o]) )
	$final_matches[$f] = 'x';

	// Best match of this orig is already taken? Must mean this orig is a deleted row.
	elseif ( isset($final_matches[$f]) )
	$orig_matches[$o] = 'x';
	}

	// We read the text in this order
	ksort($orig_matches);
	ksort($final_matches);


	// Stores rows and blanks for each column.
	$orig_rows = $orig_rows_copy = array_keys($orig_matches);
	$final_rows = array_keys($final_matches);

	// Interleaves rows with blanks to keep matches aligned.
	// We may end up with some extraneous blank rows, but we'll just ignore them later.
	foreach ( $orig_rows_copy as $orig_row ) {
	$final_pos = array_search($orig_matches[$orig_row], $final_rows, true);
	$orig_pos = (int) array_search($orig_row, $orig_rows, true);

	if ( false === $final_pos ) { // This orig is paired with a blank final.
	array_splice( $final_rows, $orig_pos, 0, -1 );
	} elseif ( $final_pos < $orig_pos ) { // This orig's match is up a ways. Pad final with blank rows.
	$diff_pos = $final_pos - $orig_pos;
	while ( $diff_pos < 0 )
	array_splice( $final_rows, $orig_pos, 0, $diff_pos++ );
	} elseif ( $final_pos > $orig_pos ) { // This orig's match is down a ways. Pad orig with blank rows.
	$diff_pos = $orig_pos - $final_pos;
	while ( $diff_pos < 0 )
	array_splice( $orig_rows, $orig_pos, 0, $diff_pos++ );
	}
	}


	// Pad the ends with blank rows if the columns aren't the same length
	$diff_count = count($orig_rows) - count($final_rows);
	if ( $diff_count < 0 ) {
	while ( $diff_count < 0 )
	array_push($orig_rows, $diff_count++);
	} elseif ( $diff_count > 0 ) {
	$diff_count = -1 * $diff_count;
	while ( $diff_count < 0 )
	array_push($final_rows, $diff_count++);
	}

	return array($orig_matches, $final_matches, $orig_rows, $final_rows);

	/*
	// Debug
	echo "\n\n\n\n\n";

	echo "-- DEBUG Matches: Orig -> Final --";

	foreach ( $orig_matches as $o => $f ) {
	echo "\n\n\n\n\n";
	echo "ORIG: $o, FINAL: $f\n";
	var_dump($orig[$o],$final[$f]);
	}
	echo "\n\n\n\n\n";

	echo "-- DEBUG Matches: Final -> Orig --";

	foreach ( $final_matches as $f => $o ) {
	echo "\n\n\n\n\n";
	echo "FINAL: $f, ORIG: $o\n";
	var_dump($final[$f],$orig[$o]);
	}
	echo "\n\n\n\n\n";

	echo "-- DEBUG Rows: Orig -- Final --";

	echo "\n\n\n\n\n";
	foreach ( $orig_rows as $row => $o ) {
	if ( $o < 0 )
	$o = 'X';
	$f = $final_rows[$row];
	if ( $f < 0 )
	$f = 'X';
	echo "$o -- $f\n";
	}
	echo "\n\n\n\n\n";

	echo "-- END DEBUG --";

	echo "\n\n\n\n\n";

	return array($orig_matches, $final_matches, $orig_rows, $final_rows);
	*/
	}


	// Computes a number that is intended to reflect the "distance" between two strings.
	function compute_string_distance( $string1, $string2 ) {
	// Vectors containing character frequency for all chars in each string
	$chars1 = count_chars($string1);
	$chars2 = count_chars($string2);

	// L1-norm of difference vector.
	$difference = array_sum( array_map( array(&$this, 'difference'), $chars1, $chars2 ) );

	// $string1 has zero length? Odd. Give huge penalty by not dividing.
	if ( !$string1 )
	return $difference;

	// Return distance per charcter (of string1)
	return $difference / strlen($string1);
	}

	function difference( $a, $b ) {
	return abs( $a - $b );
	}

	}

	// Better word splitting than the PEAR package provides
	class WP_Text_Diff_Renderer_inline extends Text_Diff_Renderer_inline {

	function _splitOnWords($string, $newlineEscape = "\n") {
	$string = str_replace("\0", '', $string);
	$words = preg_split( '/([^\w])/u', $string, -1, PREG_SPLIT_DELIM_CAPTURE );
	$words = str_replace( "\n", $newlineEscape, $words );
	return $words;
	}

	}

	?>