web/wp-includes/wp-diff.php
changeset 136 bde1974c263b
child 194 32102edaa81b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/wp-includes/wp-diff.php	Wed Feb 03 15:37:20 2010 +0000
@@ -0,0 +1,471 @@
+<?php
+/**
+ * WordPress Diff bastard child of old MediaWiki Diff Formatter.
+ *
+ * Basically all that remains is the table structure and some method names.
+ *
+ * @package WordPress
+ * @subpackage Diff
+ */
+
+if ( !class_exists( 'Text_Diff' ) ) {
+	/** Text_Diff class */
+	require( dirname(__FILE__).'/Text/Diff.php' );
+	/** Text_Diff_Renderer class */
+	require( dirname(__FILE__).'/Text/Diff/Renderer.php' );
+	/** Text_Diff_Renderer_inline class */
+	require( dirname(__FILE__).'/Text/Diff/Renderer/inline.php' );
+}
+
+/**
+ * Table renderer to display the diff lines.
+ *
+ * @since 2.6.0
+ * @uses Text_Diff_Renderer Extends
+ */
+class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
+
+	/**
+	 * @see Text_Diff_Renderer::_leading_context_lines
+	 * @var int
+	 * @access protected
+	 * @since 2.6.0
+	 */
+	var $_leading_context_lines  = 10000;
+
+	/**
+	 * @see Text_Diff_Renderer::_trailing_context_lines
+	 * @var int
+	 * @access protected
+	 * @since 2.6.0
+	 */
+	var $_trailing_context_lines = 10000;
+
+	/**
+	 * {@internal Missing Description}}
+	 *
+	 * @var float
+	 * @access protected
+	 * @since 2.6.0
+	 */
+	var $_diff_threshold = 0.6;
+
+	/**
+	 * Inline display helper object name.
+	 *
+	 * @var string
+	 * @access protected
+	 * @since 2.6.0
+	 */
+	var $inline_diff_renderer = 'WP_Text_Diff_Renderer_inline';
+
+	/**
+	 * PHP4 Constructor - Call parent constructor with params array.
+	 *
+	 * This will set class properties based on the key value pairs in the array.
+	 *
+	 * @since unknown
+	 *
+	 * @param array $params
+	 */
+	function Text_Diff_Renderer_Table( $params = array() ) {
+		$parent = get_parent_class($this);
+		$this->$parent( $params );
+	}
+
+	/**
+	 * @ignore
+	 *
+	 * @param string $header
+	 * @return string
+	 */
+	function _startBlock( $header ) {
+		return '';
+	}
+
+	/**
+	 * @ignore
+	 *
+	 * @param array $lines
+	 * @param string $prefix
+	 */
+	function _lines( $lines, $prefix=' ' ) {
+	}
+
+	/**
+	 * @ignore
+	 *
+	 * @param string $line HTML-escape the value.
+	 * @return string
+	 */
+	function addedLine( $line ) {
+		return "<td>+</td><td class='diff-addedline'>{$line}</td>";
+	}
+
+	/**
+	 * @ignore
+	 *
+	 * @param string $line HTML-escape the value.
+	 * @return string
+	 */
+	function deletedLine( $line ) {
+		return "<td>-</td><td class='diff-deletedline'>{$line}</td>";
+	}
+
+	/**
+	 * @ignore
+	 *
+	 * @param string $line HTML-escape the value.
+	 * @return string
+	 */
+	function contextLine( $line ) {
+		return "<td> </td><td class='diff-context'>{$line}</td>";
+	}
+
+	/**
+	 * @ignore
+	 *
+	 * @return string
+	 */
+	function emptyLine() {
+		return '<td colspan="2">&nbsp;</td>';
+	}
+
+	/**
+	 * @ignore
+	 * @access private
+	 *
+	 * @param array $lines
+	 * @param bool $encode
+	 * @return string
+	 */
+	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;
+	}
+
+	/**
+	 * @ignore
+	 * @access private
+	 *
+	 * @param array $lines
+	 * @param bool $encode
+	 * @return string
+	 */
+	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;
+	}
+
+	/**
+	 * @ignore
+	 * @access private
+	 *
+	 * @param array $lines
+	 * @param bool $encode
+	 * @return string
+	 */
+	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
+	 *
+	 * @access private
+	 * @since 2.6.0
+	 *
+	 * @param array $orig
+	 * @param array $final
+	 * @return string
+	 */
+	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 )
+	 *
+	 * @since 2.6.0
+	 *
+	 * @param unknown_type $orig
+	 * @param unknown_type $final
+	 * @return unknown
+	 */
+	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.
+	 *
+	 * @since 2.6.0
+	 *
+	 * @param string $string1
+	 * @param string $string2
+	 * @return int
+	 */
+	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);
+	}
+
+	/**
+	 * @ignore
+	 * @since 2.6.0
+	 *
+	 * @param int $a
+	 * @param int $b
+	 * @return int
+	 */
+	function difference( $a, $b ) {
+		return abs( $a - $b );
+	}
+
+}
+
+/**
+ * Better word splitting than the PEAR package provides.
+ *
+ * @since 2.6.0
+ * @uses Text_Diff_Renderer_inline Extends
+ */
+class WP_Text_Diff_Renderer_inline extends Text_Diff_Renderer_inline {
+
+	/**
+	 * @ignore
+	 * @since 2.6.0
+	 *
+	 * @param string $string
+	 * @param string $newlineEscape
+	 * @return string
+	 */
+	function _splitOnWords($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;
+	}
+
+}
+
+?>