diff options
Diffstat (limited to 'wp-includes/wp-diff.php')
| -rw-r--r-- | wp-includes/wp-diff.php | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/wp-includes/wp-diff.php b/wp-includes/wp-diff.php new file mode 100644 index 0000000..f60614a --- /dev/null +++ b/wp-includes/wp-diff.php @@ -0,0 +1,318 @@ +<?php + +if ( !class_exists( 'Text_Diff' ) ) { + require( 'Text/Diff.php' ); + require( 'Text/Diff/Renderer.php' ); + require( '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])/', $string, -1, PREG_SPLIT_DELIM_CAPTURE ); + $words = str_replace( "\n", $newlineEscape, $words ); + return $words; + } + +} + +?> |