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- <?php
- /**
- * @file
- * A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
- *
- * Copyright (C) 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org>
- * You may copy this code freely under the conditions of the GPL.
- */
- define('USE_ASSERTS', FALSE);
- /**
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class _DiffOp {
- var $type;
- var $orig;
- var $closing;
- function reverse() {
- trigger_error('pure virtual', E_USER_ERROR);
- }
- function norig() {
- return $this->orig ? sizeof($this->orig) : 0;
- }
- function nclosing() {
- return $this->closing ? sizeof($this->closing) : 0;
- }
- }
- /**
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class _DiffOp_Copy extends _DiffOp {
- var $type = 'copy';
- function _DiffOp_Copy($orig, $closing = FALSE) {
- if (!is_array($closing)) {
- $closing = $orig;
- }
- $this->orig = $orig;
- $this->closing = $closing;
- }
- function reverse() {
- return new _DiffOp_Copy($this->closing, $this->orig);
- }
- }
- /**
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class _DiffOp_Delete extends _DiffOp {
- var $type = 'delete';
- function _DiffOp_Delete($lines) {
- $this->orig = $lines;
- $this->closing = FALSE;
- }
- function reverse() {
- return new _DiffOp_Add($this->orig);
- }
- }
- /**
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class _DiffOp_Add extends _DiffOp {
- var $type = 'add';
- function _DiffOp_Add($lines) {
- $this->closing = $lines;
- $this->orig = FALSE;
- }
- function reverse() {
- return new _DiffOp_Delete($this->closing);
- }
- }
- /**
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class _DiffOp_Change extends _DiffOp {
- var $type = 'change';
- function _DiffOp_Change($orig, $closing) {
- $this->orig = $orig;
- $this->closing = $closing;
- }
- function reverse() {
- return new _DiffOp_Change($this->closing, $this->orig);
- }
- }
- /**
- * Class used internally by Diff to actually compute the diffs.
- *
- * The algorithm used here is mostly lifted from the perl module
- * Algorithm::Diff (version 1.06) by Ned Konz, which is available at:
- * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip
- *
- * More ideas are taken from:
- * http://www.ics.uci.edu/~eppstein/161/960229.html
- *
- * Some ideas are (and a bit of code) are from from analyze.c, from GNU
- * diffutils-2.7, which can be found at:
- * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz
- *
- * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations)
- * are my own.
- *
- * Line length limits for robustness added by Tim Starling, 2005-08-31
- *
- * @author Geoffrey T. Dairiki, Tim Starling
- * @private
- * @subpackage DifferenceEngine
- */
- class _DiffEngine {
- function MAX_XREF_LENGTH() {
- return 10000;
- }
- function diff($from_lines, $to_lines) {
- $n_from = sizeof($from_lines);
- $n_to = sizeof($to_lines);
- $this->xchanged = $this->ychanged = array();
- $this->xv = $this->yv = array();
- $this->xind = $this->yind = array();
- unset($this->seq);
- unset($this->in_seq);
- unset($this->lcs);
- // Skip leading common lines.
- for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) {
- if ($from_lines[$skip] !== $to_lines[$skip]) {
- break;
- }
- $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE;
- }
- // Skip trailing common lines.
- $xi = $n_from;
- $yi = $n_to;
- for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) {
- if ($from_lines[$xi] !== $to_lines[$yi]) {
- break;
- }
- $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE;
- }
- // Ignore lines which do not exist in both files.
- for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
- $xhash[$this->_line_hash($from_lines[$xi])] = 1;
- }
- for ($yi = $skip; $yi < $n_to - $endskip; $yi++) {
- $line = $to_lines[$yi];
- if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) {
- continue;
- }
- $yhash[$this->_line_hash($line)] = 1;
- $this->yv[] = $line;
- $this->yind[] = $yi;
- }
- for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
- $line = $from_lines[$xi];
- if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) {
- continue;
- }
- $this->xv[] = $line;
- $this->xind[] = $xi;
- }
- // Find the LCS.
- $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv));
- // Merge edits when possible
- $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged);
- $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged);
- // Compute the edit operations.
- $edits = array();
- $xi = $yi = 0;
- while ($xi < $n_from || $yi < $n_to) {
- USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]);
- USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]);
- // Skip matching "snake".
- $copy = array();
- while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) {
- $copy[] = $from_lines[$xi++];
- ++$yi;
- }
- if ($copy) {
- $edits[] = new _DiffOp_Copy($copy);
- }
- // Find deletes & adds.
- $delete = array();
- while ($xi < $n_from && $this->xchanged[$xi]) {
- $delete[] = $from_lines[$xi++];
- }
- $add = array();
- while ($yi < $n_to && $this->ychanged[$yi]) {
- $add[] = $to_lines[$yi++];
- }
- if ($delete && $add) {
- $edits[] = new _DiffOp_Change($delete, $add);
- }
- elseif ($delete) {
- $edits[] = new _DiffOp_Delete($delete);
- }
- elseif ($add) {
- $edits[] = new _DiffOp_Add($add);
- }
- }
- return $edits;
- }
- /**
- * Returns the whole line if it's small enough, or the MD5 hash otherwise.
- */
- function _line_hash($line) {
- if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) {
- return md5($line);
- }
- else {
- return $line;
- }
- }
- /**
- * Divide the Largest Common Subsequence (LCS) of the sequences
- * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally
- * sized segments.
- *
- * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an
- * array of NCHUNKS+1 (X, Y) indexes giving the diving points between
- * sub sequences. The first sub-sequence is contained in [X0, X1),
- * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note
- * that (X0, Y0) == (XOFF, YOFF) and
- * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM).
- *
- * This function assumes that the first lines of the specified portions
- * of the two files do not match, and likewise that the last lines do not
- * match. The caller must trim matching lines from the beginning and end
- * of the portions it is going to specify.
- */
- function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) {
- $flip = FALSE;
- if ($xlim - $xoff > $ylim - $yoff) {
- // Things seems faster (I'm not sure I understand why)
- // when the shortest sequence in X.
- $flip = TRUE;
- list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim);
- }
- if ($flip) {
- for ($i = $ylim - 1; $i >= $yoff; $i--) {
- $ymatches[$this->xv[$i]][] = $i;
- }
- }
- else {
- for ($i = $ylim - 1; $i >= $yoff; $i--) {
- $ymatches[$this->yv[$i]][] = $i;
- }
- }
- $this->lcs = 0;
- $this->seq[0]= $yoff - 1;
- $this->in_seq = array();
- $ymids[0] = array();
- $numer = $xlim - $xoff + $nchunks - 1;
- $x = $xoff;
- for ($chunk = 0; $chunk < $nchunks; $chunk++) {
- if ($chunk > 0) {
- for ($i = 0; $i <= $this->lcs; $i++) {
- $ymids[$i][$chunk-1] = $this->seq[$i];
- }
- }
- $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks);
- for ( ; $x < $x1; $x++) {
- $line = $flip ? $this->yv[$x] : $this->xv[$x];
- if (empty($ymatches[$line])) {
- continue;
- }
- $matches = $ymatches[$line];
- reset($matches);
- while (list ($junk, $y) = each($matches)) {
- if (empty($this->in_seq[$y])) {
- $k = $this->_lcs_pos($y);
- USE_ASSERTS && assert($k > 0);
- $ymids[$k] = $ymids[$k-1];
- break;
- }
- }
- while (list ($junk, $y) = each($matches)) {
- if ($y > $this->seq[$k-1]) {
- USE_ASSERTS && assert($y < $this->seq[$k]);
- // Optimization: this is a common case:
- // next match is just replacing previous match.
- $this->in_seq[$this->seq[$k]] = FALSE;
- $this->seq[$k] = $y;
- $this->in_seq[$y] = 1;
- }
- elseif (empty($this->in_seq[$y])) {
- $k = $this->_lcs_pos($y);
- USE_ASSERTS && assert($k > 0);
- $ymids[$k] = $ymids[$k-1];
- }
- }
- }
- }
- $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff);
- $ymid = $ymids[$this->lcs];
- for ($n = 0; $n < $nchunks - 1; $n++) {
- $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks);
- $y1 = $ymid[$n] + 1;
- $seps[] = $flip ? array($y1, $x1) : array($x1, $y1);
- }
- $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim);
- return array($this->lcs, $seps);
- }
- function _lcs_pos($ypos) {
- $end = $this->lcs;
- if ($end == 0 || $ypos > $this->seq[$end]) {
- $this->seq[++$this->lcs] = $ypos;
- $this->in_seq[$ypos] = 1;
- return $this->lcs;
- }
- $beg = 1;
- while ($beg < $end) {
- $mid = (int)(($beg + $end) / 2);
- if ($ypos > $this->seq[$mid]) {
- $beg = $mid + 1;
- }
- else {
- $end = $mid;
- }
- }
- USE_ASSERTS && assert($ypos != $this->seq[$end]);
- $this->in_seq[$this->seq[$end]] = FALSE;
- $this->seq[$end] = $ypos;
- $this->in_seq[$ypos] = 1;
- return $end;
- }
- /**
- * Find LCS of two sequences.
- *
- * The results are recorded in the vectors $this->{x,y}changed[], by
- * storing a 1 in the element for each line that is an insertion
- * or deletion (ie. is not in the LCS).
- *
- * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.
- *
- * Note that XLIM, YLIM are exclusive bounds.
- * All line numbers are origin-0 and discarded lines are not counted.
- */
- function _compareseq($xoff, $xlim, $yoff, $ylim) {
- // Slide down the bottom initial diagonal.
- while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) {
- ++$xoff;
- ++$yoff;
- }
- // Slide up the top initial diagonal.
- while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) {
- --$xlim;
- --$ylim;
- }
- if ($xoff == $xlim || $yoff == $ylim) {
- $lcs = 0;
- }
- else {
- // This is ad hoc but seems to work well.
- //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5);
- //$nchunks = max(2, min(8, (int)$nchunks));
- $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1;
- list($lcs, $seps)
- = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks);
- }
- if ($lcs == 0) {
- // X and Y sequences have no common subsequence:
- // mark all changed.
- while ($yoff < $ylim) {
- $this->ychanged[$this->yind[$yoff++]] = 1;
- }
- while ($xoff < $xlim) {
- $this->xchanged[$this->xind[$xoff++]] = 1;
- }
- }
- else {
- // Use the partitions to split this problem into subproblems.
- reset($seps);
- $pt1 = $seps[0];
- while ($pt2 = next($seps)) {
- $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]);
- $pt1 = $pt2;
- }
- }
- }
- /**
- * Adjust inserts/deletes of identical lines to join changes
- * as much as possible.
- *
- * We do something when a run of changed lines include a
- * line at one end and has an excluded, identical line at the other.
- * We are free to choose which identical line is included.
- * `compareseq' usually chooses the one at the beginning,
- * but usually it is cleaner to consider the following identical line
- * to be the "change".
- *
- * This is extracted verbatim from analyze.c (GNU diffutils-2.7).
- */
- function _shift_boundaries($lines, &$changed, $other_changed) {
- $i = 0;
- $j = 0;
- USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)');
- $len = sizeof($lines);
- $other_len = sizeof($other_changed);
- while (1) {
- /*
- * Scan forwards to find beginning of another run of changes.
- * Also keep track of the corresponding point in the other file.
- *
- * Throughout this code, $i and $j are adjusted together so that
- * the first $i elements of $changed and the first $j elements
- * of $other_changed both contain the same number of zeros
- * (unchanged lines).
- * Furthermore, $j is always kept so that $j == $other_len or
- * $other_changed[$j] == FALSE.
- */
- while ($j < $other_len && $other_changed[$j]) {
- $j++;
- }
- while ($i < $len && ! $changed[$i]) {
- USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]');
- $i++;
- $j++;
- while ($j < $other_len && $other_changed[$j]) {
- $j++;
- }
- }
- if ($i == $len) {
- break;
- }
- $start = $i;
- // Find the end of this run of changes.
- while (++$i < $len && $changed[$i]) {
- continue;
- }
- do {
- /*
- * Record the length of this run of changes, so that
- * we can later determine whether the run has grown.
- */
- $runlength = $i - $start;
- /*
- * Move the changed region back, so long as the
- * previous unchanged line matches the last changed one.
- * This merges with previous changed regions.
- */
- while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) {
- $changed[--$start] = 1;
- $changed[--$i] = FALSE;
- while ($start > 0 && $changed[$start - 1]) {
- $start--;
- }
- USE_ASSERTS && assert('$j > 0');
- while ($other_changed[--$j]) {
- continue;
- }
- USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]');
- }
- /*
- * Set CORRESPONDING to the end of the changed run, at the last
- * point where it corresponds to a changed run in the other file.
- * CORRESPONDING == LEN means no such point has been found.
- */
- $corresponding = $j < $other_len ? $i : $len;
- /*
- * Move the changed region forward, so long as the
- * first changed line matches the following unchanged one.
- * This merges with following changed regions.
- * Do this second, so that if there are no merges,
- * the changed region is moved forward as far as possible.
- */
- while ($i < $len && $lines[$start] == $lines[$i]) {
- $changed[$start++] = FALSE;
- $changed[$i++] = 1;
- while ($i < $len && $changed[$i]) {
- $i++;
- }
- USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]');
- $j++;
- if ($j < $other_len && $other_changed[$j]) {
- $corresponding = $i;
- while ($j < $other_len && $other_changed[$j]) {
- $j++;
- }
- }
- }
- } while ($runlength != $i - $start);
- /*
- * If possible, move the fully-merged run of changes
- * back to a corresponding run in the other file.
- */
- while ($corresponding < $i) {
- $changed[--$start] = 1;
- $changed[--$i] = 0;
- USE_ASSERTS && assert('$j > 0');
- while ($other_changed[--$j]) {
- continue;
- }
- USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]');
- }
- }
- }
- }
- /**
- * Class representing a 'diff' between two sequences of strings.
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class Diff {
- var $edits;
- /**
- * Constructor.
- * Computes diff between sequences of strings.
- *
- * @param $from_lines array An array of strings.
- * (Typically these are lines from a file.)
- * @param $to_lines array An array of strings.
- */
- function Diff($from_lines, $to_lines) {
- $eng = new _DiffEngine;
- $this->edits = $eng->diff($from_lines, $to_lines);
- //$this->_check($from_lines, $to_lines);
- }
- /**
- * Compute reversed Diff.
- *
- * SYNOPSIS:
- *
- * $diff = new Diff($lines1, $lines2);
- * $rev = $diff->reverse();
- * @return object A Diff object representing the inverse of the
- * original diff.
- */
- function reverse() {
- $rev = $this;
- $rev->edits = array();
- foreach ($this->edits as $edit) {
- $rev->edits[] = $edit->reverse();
- }
- return $rev;
- }
- /**
- * Check for empty diff.
- *
- * @return bool True iff two sequences were identical.
- */
- function isEmpty() {
- foreach ($this->edits as $edit) {
- if ($edit->type != 'copy') {
- return FALSE;
- }
- }
- return TRUE;
- }
- /**
- * Compute the length of the Longest Common Subsequence (LCS).
- *
- * This is mostly for diagnostic purposed.
- *
- * @return int The length of the LCS.
- */
- function lcs() {
- $lcs = 0;
- foreach ($this->edits as $edit) {
- if ($edit->type == 'copy') {
- $lcs += sizeof($edit->orig);
- }
- }
- return $lcs;
- }
- /**
- * Get the original set of lines.
- *
- * This reconstructs the $from_lines parameter passed to the
- * constructor.
- *
- * @return array The original sequence of strings.
- */
- function orig() {
- $lines = array();
- foreach ($this->edits as $edit) {
- if ($edit->orig) {
- array_splice($lines, sizeof($lines), 0, $edit->orig);
- }
- }
- return $lines;
- }
- /**
- * Get the closing set of lines.
- *
- * This reconstructs the $to_lines parameter passed to the
- * constructor.
- *
- * @return array The sequence of strings.
- */
- function closing() {
- $lines = array();
- foreach ($this->edits as $edit) {
- if ($edit->closing) {
- array_splice($lines, sizeof($lines), 0, $edit->closing);
- }
- }
- return $lines;
- }
- /**
- * Check a Diff for validity.
- *
- * This is here only for debugging purposes.
- */
- function _check($from_lines, $to_lines) {
- if (serialize($from_lines) != serialize($this->orig())) {
- trigger_error("Reconstructed original doesn't match", E_USER_ERROR);
- }
- if (serialize($to_lines) != serialize($this->closing())) {
- trigger_error("Reconstructed closing doesn't match", E_USER_ERROR);
- }
- $rev = $this->reverse();
- if (serialize($to_lines) != serialize($rev->orig())) {
- trigger_error("Reversed original doesn't match", E_USER_ERROR);
- }
- if (serialize($from_lines) != serialize($rev->closing())) {
- trigger_error("Reversed closing doesn't match", E_USER_ERROR);
- }
- $prevtype = 'none';
- foreach ($this->edits as $edit) {
- if ( $prevtype == $edit->type ) {
- trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
- }
- $prevtype = $edit->type;
- }
- $lcs = $this->lcs();
- trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE);
- }
- }
- /**
- * FIXME: bad name.
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class MappedDiff extends Diff {
- /**
- * Constructor.
- *
- * Computes 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 $from_lines array An array of strings.
- * (Typically these are lines from a file.)
- *
- * @param $to_lines array An array of strings.
- *
- * @param $mapped_from_lines array 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 $mapped_to_lines array This array should
- * have the same number of elements as $to_lines.
- */
- function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) {
- assert(sizeof($from_lines) == sizeof($mapped_from_lines));
- assert(sizeof($to_lines) == sizeof($mapped_to_lines));
- $this->Diff($mapped_from_lines, $mapped_to_lines);
- $xi = $yi = 0;
- for ($i = 0; $i < sizeof($this->edits); $i++) {
- $orig = &$this->edits[$i]->orig;
- if (is_array($orig)) {
- $orig = array_slice($from_lines, $xi, sizeof($orig));
- $xi += sizeof($orig);
- }
- $closing = &$this->edits[$i]->closing;
- if (is_array($closing)) {
- $closing = array_slice($to_lines, $yi, sizeof($closing));
- $yi += sizeof($closing);
- }
- }
- }
- }
- /**
- * A class to format Diffs
- *
- * This class formats the diff in classic diff format.
- * It is intended that this class be customized via inheritance,
- * to obtain fancier outputs.
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class DiffFormatter {
- /**
- * Should a block header be shown?
- */
- var $show_header = TRUE;
- /**
- * Number of leading context "lines" to preserve.
- *
- * This should be left at zero for this class, but subclasses
- * may want to set this to other values.
- */
- var $leading_context_lines = 0;
- /**
- * Number of trailing context "lines" to preserve.
- *
- * This should be left at zero for this class, but subclasses
- * may want to set this to other values.
- */
- var $trailing_context_lines = 0;
- /**
- * Format a diff.
- *
- * @param $diff object A Diff object.
- * @return string The formatted output.
- */
- function format($diff) {
- $xi = $yi = 1;
- $block = FALSE;
- $context = array();
- $nlead = $this->leading_context_lines;
- $ntrail = $this->trailing_context_lines;
- $this->_start_diff();
- foreach ($diff->edits as $edit) {
- if ($edit->type == 'copy') {
- if (is_array($block)) {
- if (sizeof($edit->orig) <= $nlead + $ntrail) {
- $block[] = $edit;
- }
- else {
- if ($ntrail) {
- $context = array_slice($edit->orig, 0, $ntrail);
- $block[] = new _DiffOp_Copy($context);
- }
- $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block);
- $block = FALSE;
- }
- }
- $context = $edit->orig;
- }
- else {
- if (! is_array($block)) {
- $context = array_slice($context, sizeof($context) - $nlead);
- $x0 = $xi - sizeof($context);
- $y0 = $yi - sizeof($context);
- $block = array();
- if ($context) {
- $block[] = new _DiffOp_Copy($context);
- }
- }
- $block[] = $edit;
- }
- if ($edit->orig) {
- $xi += sizeof($edit->orig);
- }
- if ($edit->closing) {
- $yi += sizeof($edit->closing);
- }
- }
- if (is_array($block)) {
- $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block);
- }
- $end = $this->_end_diff();
- if (!empty($xi)) {
- $this->line_stats['counter']['x'] += $xi;
- }
- if (!empty($yi)) {
- $this->line_stats['counter']['y'] += $yi;
- }
- return $end;
- }
- function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) {
- $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen));
- foreach ($edits as $edit) {
- if ($edit->type == 'copy') {
- $this->_context($edit->orig);
- }
- elseif ($edit->type == 'add') {
- $this->_added($edit->closing);
- }
- elseif ($edit->type == 'delete') {
- $this->_deleted($edit->orig);
- }
- elseif ($edit->type == 'change') {
- $this->_changed($edit->orig, $edit->closing);
- }
- else {
- trigger_error('Unknown edit type', E_USER_ERROR);
- }
- }
- $this->_end_block();
- }
- function _start_diff() {
- ob_start();
- }
- function _end_diff() {
- $val = ob_get_contents();
- ob_end_clean();
- return $val;
- }
- function _block_header($xbeg, $xlen, $ybeg, $ylen) {
- if ($xlen > 1) {
- $xbeg .= "," . ($xbeg + $xlen - 1);
- }
- if ($ylen > 1) {
- $ybeg .= "," . ($ybeg + $ylen - 1);
- }
- return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg;
- }
- function _start_block($header) {
- if ($this->show_header) {
- echo $header . "\n";
- }
- }
- function _end_block() {
- }
- function _lines($lines, $prefix = ' ') {
- foreach ($lines as $line) {
- echo "$prefix $line\n";
- }
- }
- function _context($lines) {
- $this->_lines($lines);
- }
- function _added($lines) {
- $this->_lines($lines, '>');
- }
- function _deleted($lines) {
- $this->_lines($lines, '<');
- }
- function _changed($orig, $closing) {
- $this->_deleted($orig);
- echo "---\n";
- $this->_added($closing);
- }
- }
- /**
- * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3
- *
- */
- define('NBSP', ' '); // iso-8859-x non-breaking space.
- /**
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class _HWLDF_WordAccumulator {
- function _HWLDF_WordAccumulator() {
- $this->_lines = array();
- $this->_line = '';
- $this->_group = '';
- $this->_tag = '';
- }
- function _flushGroup($new_tag) {
- if ($this->_group !== '') {
- if ($this->_tag == 'mark') {
- $this->_line .= '<span class="diffchange">' . check_plain($this->_group) . '</span>';
- }
- else {
- $this->_line .= check_plain($this->_group);
- }
- }
- $this->_group = '';
- $this->_tag = $new_tag;
- }
- function _flushLine($new_tag) {
- $this->_flushGroup($new_tag);
- if ($this->_line != '') {
- array_push($this->_lines, $this->_line);
- }
- else {
- // make empty lines visible by inserting an NBSP
- array_push($this->_lines, NBSP);
- }
- $this->_line = '';
- }
- function addWords($words, $tag = '') {
- if ($tag != $this->_tag) {
- $this->_flushGroup($tag);
- }
- foreach ($words as $word) {
- // new-line should only come as first char of word.
- if ($word == '') {
- continue;
- }
- if ($word[0] == "\n") {
- $this->_flushLine($tag);
- $word = drupal_substr($word, 1);
- }
- assert(!strstr($word, "\n"));
- $this->_group .= $word;
- }
- }
- function getLines() {
- $this->_flushLine('~done');
- return $this->_lines;
- }
- }
- /**
- * @todo document
- * @private
- * @subpackage DifferenceEngine
- */
- class WordLevelDiff extends MappedDiff {
- function MAX_LINE_LENGTH() {
- return 10000;
- }
- function WordLevelDiff($orig_lines, $closing_lines) {
- list($orig_words, $orig_stripped) = $this->_split($orig_lines);
- list($closing_words, $closing_stripped) = $this->_split($closing_lines);
- $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped);
- }
- function _split($lines) {
- $words = array();
- $stripped = array();
- $first = TRUE;
- foreach ($lines as $line) {
- // If the line is too long, just pretend the entire line is one big word
- // This prevents resource exhaustion problems
- if ( $first ) {
- $first = FALSE;
- }
- else {
- $words[] = "\n";
- $stripped[] = "\n";
- }
- if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) {
- $words[] = $line;
- $stripped[] = $line;
- }
- else {
- if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) {
- $words = array_merge($words, $m[0]);
- $stripped = array_merge($stripped, $m[1]);
- }
- }
- }
- return array($words, $stripped);
- }
- function orig() {
- $orig = new _HWLDF_WordAccumulator;
- foreach ($this->edits as $edit) {
- if ($edit->type == 'copy') {
- $orig->addWords($edit->orig);
- }
- elseif ($edit->orig) {
- $orig->addWords($edit->orig, 'mark');
- }
- }
- $lines = $orig->getLines();
- return $lines;
- }
- function closing() {
- $closing = new _HWLDF_WordAccumulator;
- foreach ($this->edits as $edit) {
- if ($edit->type == 'copy') {
- $closing->addWords($edit->closing);
- }
- elseif ($edit->closing) {
- $closing->addWords($edit->closing, 'mark');
- }
- }
- $lines = $closing->getLines();
- return $lines;
- }
- }
- /**
- * Diff formatter which uses Drupal theme functions.
- * @private
- * @subpackage DifferenceEngine
- */
- class DrupalDiffFormatter extends DiffFormatter {
- var $rows;
- var $line_stats = array(
- 'counter' => array('x' => 0, 'y' => 0),
- 'offset' => array('x' => 0, 'y' => 0),
- );
- function DrupalDiffFormatter() {
- $this->leading_context_lines = variable_get('diff_context_lines_leading', 2);
- $this->trailing_context_lines = variable_get('diff_context_lines_trailing', 2);
- }
- function _start_diff() {
- $this->rows = array();
- }
- function _end_diff() {
- return $this->rows;
- }
- function _block_header($xbeg, $xlen, $ybeg, $ylen) {
- return array(
- array(
- 'data' => theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])),
- 'colspan' => 2,
- ),
- array(
- 'data' => theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])),
- 'colspan' => 2,
- )
- );
- }
- function _start_block($header) {
- if ($this->show_header) {
- $this->rows[] = $header;
- }
- }
- function _end_block() {
- }
- function _lines($lines, $prefix=' ', $color='white') {
- }
- /**
- * Note: you should HTML-escape parameter before calling this.
- */
- function addedLine($line) {
- return array(
- array(
- 'data' => '+',
- 'class' => 'diff-marker',
- ),
- array(
- 'data' => theme('diff_content_line', array('line' => $line)),
- 'class' => 'diff-context diff-addedline',
- )
- );
- }
- /**
- * Note: you should HTML-escape parameter before calling this.
- */
- function deletedLine($line) {
- return array(
- array(
- 'data' => '-',
- 'class' => 'diff-marker',
- ),
- array(
- 'data' => theme('diff_content_line', array('line' => $line)),
- 'class' => 'diff-context diff-deletedline',
- )
- );
- }
- /**
- * Note: you should HTML-escape parameter before calling this.
- */
- function contextLine($line) {
- return array(
- ' ',
- array(
- 'data' => theme('diff_content_line', array('line' => $line)),
- 'class' => 'diff-context',
- )
- );
- }
- function emptyLine() {
- return array(
- ' ',
- theme('diff_empty_line', array('line' => ' ')),
- );
- }
- function _added($lines) {
- foreach ($lines as $line) {
- $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line)));
- }
- }
- function _deleted($lines) {
- foreach ($lines as $line) {
- $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine());
- }
- }
- function _context($lines) {
- foreach ($lines as $line) {
- $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line)));
- }
- }
- function _changed($orig, $closing) {
- $diff = new WordLevelDiff($orig, $closing);
- $del = $diff->orig();
- $add = $diff->closing();
- // Notice that WordLevelDiff returns HTML-escaped output.
- // Hence, we will be calling addedLine/deletedLine without HTML-escaping.
- while ($line = array_shift($del)) {
- $aline = array_shift( $add );
- $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine());
- }
- foreach ($add as $line) { // If any leftovers
- $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line));
- }
- }
- }
- /**
- * Drupal inline Diff formatter.
- * @private
- * @subpackage DifferenceEngine
- */
- class DrupalDiffInline {
- var $a;
- var $b;
- /**
- * Constructor.
- */
- function __construct($a, $b) {
- $this->a = $a;
- $this->b = $b;
- }
- /**
- * Render differences inline using HTML markup.
- */
- function render() {
- $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE);
- $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE);
- $diff = new Diff($a, $b);
- $diff->edits = $this->process_edits($diff->edits);
- // Assemble highlighted output
- $output = '';
- foreach ($diff->edits as $chunk) {
- switch ($chunk->type) {
- case 'copy':
- $output .= implode('', $chunk->closing);
- break;
- case 'delete':
- foreach ($chunk->orig as $i => $piece) {
- if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') {
- $output .= $piece;
- }
- else {
- $output .= theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type));
- }
- }
- break;
- default:
- $chunk->closing = $this->process_chunk($chunk->closing);
- foreach ($chunk->closing as $i => $piece) {
- if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) {
- $output .= $piece;
- }
- else {
- $output .= theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type));
- }
- }
- break;
- }
- }
- return $output;
- }
- /**
- * Merge chunk segments between tag delimiters.
- */
- function process_chunk($chunk) {
- $processed = array();
- $j = 0;
- foreach ($chunk as $i => $piece) {
- $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL;
- if (!isset($processed[$j])) {
- $processed[$j] = '';
- }
- if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') {
- $processed[$j] = $piece;
- $j++;
- }
- elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') {
- $processed[$j] .= $piece;
- $j++;
- }
- else {
- $processed[$j] .= $piece;
- }
- }
- return $processed;
- }
- /**
- * Merge copy and equivalent edits into intelligible chunks.
- */
- function process_edits($edits) {
- $processed = array();
- $current = array_shift($edits);
- // Make two passes -- first merge space delimiter copies back into their originals.
- while ($chunk = array_shift($edits)) {
- if ($chunk->type == 'copy' && $chunk->orig === array(' ')) {
- $current->orig = array_merge((array) $current->orig, (array) $chunk->orig);
- $current->closing = array_merge((array) $current->closing, (array) $chunk->closing);
- }
- else {
- $processed[] = $current;
- $current = $chunk;
- }
- }
- $processed[] = $current;
- // Initial setup
- $edits = $processed;
- $processed = array();
- $current = array_shift($edits);
- // Second, merge equivalent chunks into each other.
- while ($chunk = array_shift($edits)) {
- if ($current->type == $chunk->type) {
- $current->orig = array_merge((array) $current->orig, (array) $chunk->orig);
- $current->closing = array_merge((array) $current->closing, (array) $chunk->closing);
- }
- else {
- $processed[] = $current;
- $current = $chunk;
- }
- }
- $processed[] = $current;
- return $processed;
- }
- }
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