From 0f1af0ad595d111196bcef0869035ba85e20b834 Mon Sep 17 00:00:00 2001
From: Nathaniel Catchpole <catch@35733.no-reply.drupal.org>
Date: Wed, 4 Jun 2014 11:05:31 +0100
Subject: [PATCH] Issue #1848266 by alexpott: Convert Diff into a proper,
PSR-0-compatible PHP component.
---
core/core.services.yml | 3 +
core/lib/Drupal/Component/Diff/Diff.php | 172 +++
core/lib/Drupal/Component/Diff/DiffEngine.php | 1226 -----------------
.../Drupal/Component/Diff/DiffFormatter.php | 187 +++
.../Component/Diff/Engine/DiffEngine.php | 456 ++++++
.../Drupal/Component/Diff/Engine/DiffOp.php | 26 +
.../Component/Diff/Engine/DiffOpAdd.php | 21 +
.../Component/Diff/Engine/DiffOpChange.php | 21 +
.../Component/Diff/Engine/DiffOpCopy.php | 24 +
.../Component/Diff/Engine/DiffOpDelete.php | 21 +
.../Diff/Engine/HWLDFWordAccumulator.php | 80 ++
core/lib/Drupal/Component/Diff/MappedDiff.php | 59 +
.../Drupal/Component/Diff/WordLevelDiff.php | 81 ++
core/lib/Drupal/Core/Config/ConfigManager.php | 7 +-
core/lib/Drupal/Core/Diff/DiffFormatter.php | 217 +++
.../src/Controller/ConfigController.php | 21 +-
.../config/src/Tests/ConfigDiffTest.php | 55 +-
.../system/config/install/system.diff.yml | 3 +
.../system/config/schema/system.schema.yml | 15 +
19 files changed, 1434 insertions(+), 1261 deletions(-)
create mode 100644 core/lib/Drupal/Component/Diff/Diff.php
delete mode 100644 core/lib/Drupal/Component/Diff/DiffEngine.php
create mode 100644 core/lib/Drupal/Component/Diff/DiffFormatter.php
create mode 100644 core/lib/Drupal/Component/Diff/Engine/DiffEngine.php
create mode 100644 core/lib/Drupal/Component/Diff/Engine/DiffOp.php
create mode 100644 core/lib/Drupal/Component/Diff/Engine/DiffOpAdd.php
create mode 100644 core/lib/Drupal/Component/Diff/Engine/DiffOpChange.php
create mode 100644 core/lib/Drupal/Component/Diff/Engine/DiffOpCopy.php
create mode 100644 core/lib/Drupal/Component/Diff/Engine/DiffOpDelete.php
create mode 100644 core/lib/Drupal/Component/Diff/Engine/HWLDFWordAccumulator.php
create mode 100644 core/lib/Drupal/Component/Diff/MappedDiff.php
create mode 100644 core/lib/Drupal/Component/Diff/WordLevelDiff.php
create mode 100644 core/lib/Drupal/Core/Diff/DiffFormatter.php
create mode 100644 core/modules/system/config/install/system.diff.yml
diff --git a/core/core.services.yml b/core/core.services.yml
index be51f0345a7f..6a2a46825a78 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -114,6 +114,9 @@ services:
cron:
class: Drupal\Core\Cron
arguments: ['@module_handler', '@lock', '@queue', '@state', '@current_user', '@session_manager']
+ diff.formatter:
+ class: Drupal\Core\Diff\DiffFormatter
+ arguments: ['@config.factory']
database:
class: Drupal\Core\Database\Connection
factory_class: Drupal\Core\Database\Database
diff --git a/core/lib/Drupal/Component/Diff/Diff.php b/core/lib/Drupal/Component/Diff/Diff.php
new file mode 100644
index 000000000000..92affb048506
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Diff.php
@@ -0,0 +1,172 @@
+<?php
+
+namespace Drupal\Component\Diff;
+
+use Drupal\Component\Diff\Engine\DiffEngine;
+
+/**
+ * Class representing a 'diff' between two sequences of strings.
+ * @todo document
+ * @subpackage DifferenceEngine
+ *
+ * Copied from https://drupal.org/project/diff which was based PHP diff engine
+ * for phpwiki. (Taken from phpwiki-1.3.3) The original code in phpwiki was
+ * copyright (C) 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org> and
+ * licensed under GPL.
+ */
+class Diff {
+
+ /**
+ * The list of differences as an array of diff operations.
+ *
+ * @var \Drupal\Component\Diff\Engine\DiffOp[]
+ */
+ protected $edits;
+
+ /**
+ * Constructor.
+ * Computes diff between sequences of strings.
+ *
+ * @param $from_lines array An array of strings.
+ * (Typically these are lines from a file.)
+ * @param $to_lines array An array of strings.
+ */
+ public function __construct($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.
+ */
+ public function reverse() {
+ $rev = $this;
+ $rev->edits = array();
+ foreach ($this->edits as $edit) {
+ $rev->edits[] = $edit->reverse();
+ }
+ return $rev;
+ }
+
+ /**
+ * Check for empty diff.
+ *
+ * @return bool True iff two sequences were identical.
+ */
+ public function isEmpty() {
+ foreach ($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.
+ */
+ public 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.
+ */
+ public 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.
+ */
+ public function closing() {
+ $lines = array();
+
+ foreach ($this->edits as $edit) {
+ if ($edit->closing) {
+ array_splice($lines, sizeof($lines), 0, $edit->closing);
+ }
+ }
+ return $lines;
+ }
+
+ /**
+ * Check a Diff for validity.
+ *
+ * This is here only for debugging purposes.
+ */
+ public function check($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);
+ }
+
+ /**
+ * Gets the list of differences as an array of diff operations.
+ *
+ * @return \Drupal\Component\Diff\Engine\DiffOp[]
+ * The list of differences as an array of diff operations.
+ */
+ public function getEdits() {
+ return $this->edits;
+ }
+}
+
diff --git a/core/lib/Drupal/Component/Diff/DiffEngine.php b/core/lib/Drupal/Component/Diff/DiffEngine.php
deleted file mode 100644
index 2dd377f7125b..000000000000
--- a/core/lib/Drupal/Component/Diff/DiffEngine.php
+++ /dev/null
@@ -1,1226 +0,0 @@
-<?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.
- */
-
-use Drupal\Component\Utility\String;
-use Drupal\Component\Utility\Unicode;
-use Drupal\Core\Site\Settings;
-
-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 (Unicode::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') {
- $this->_line .= '<span class="diffchange">' . String::checkPlain($this->_group) . '</span>';
- }
- else {
- $this->_line .= String::checkPlain($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);
- $word = Unicode::substr($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 ( Unicode::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 = Settings::get('diff_context_lines_leading', 2);
- $this->trailing_context_lines = Settings::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' => $xbeg + $this->line_stats['offset']['x'],
- 'colspan' => 2,
- ),
- array(
- 'data' => $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' => $line,
- 'class' => 'diff-context diff-addedline',
- )
- );
- }
-
- /**
- * Note: you should HTML-escape parameter before calling this.
- */
- function deletedLine($line) {
- return array(
- array(
- 'data' => '-',
- 'class' => 'diff-marker',
- ),
- array(
- 'data' => $line,
- 'class' => 'diff-context diff-deletedline',
- )
- );
- }
-
- /**
- * Note: you should HTML-escape parameter before calling this.
- */
- function contextLine($line) {
- return array(
- ' ',
- array(
- 'data' => $line,
- 'class' => 'diff-context',
- )
- );
- }
-
- function emptyLine() {
- return array(
- ' ',
- ' ',
- );
- }
-
- function _added($lines) {
- foreach ($lines as $line) {
- $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(String::checkPlain($line)));
- }
- }
-
- function _deleted($lines) {
- foreach ($lines as $line) {
- $this->rows[] = array_merge($this->deletedLine(String::checkPlain($line)), $this->emptyLine());
- }
- }
-
- function _context($lines) {
- foreach ($lines as $line) {
- $this->rows[] = array_merge($this->contextLine(String::checkPlain($line)), $this->contextLine(String::checkPlain($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));
- }
- }
-}
diff --git a/core/lib/Drupal/Component/Diff/DiffFormatter.php b/core/lib/Drupal/Component/Diff/DiffFormatter.php
new file mode 100644
index 000000000000..5dc9e1b15bf7
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/DiffFormatter.php
@@ -0,0 +1,187 @@
+<?php
+
+namespace Drupal\Component\Diff;
+
+use Drupal\Component\Diff\Engine\DiffOpCopy;
+
+/**
+ * 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 \Drupal\Component\Diff\Diff $diff
+ * A Diff object.
+ *
+ * @return string
+ * The formatted output.
+ */
+ public function format(Diff $diff) {
+ $xi = $yi = 1;
+ $block = FALSE;
+ $context = array();
+
+ $nlead = $this->leading_context_lines;
+ $ntrail = $this->trailing_context_lines;
+
+ $this->_start_diff();
+
+ foreach ($diff->getEdits() 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);
+ $block[] = new DiffOpCopy($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) {
+ $block[] = new DiffOpCopy($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 $end;
+ }
+
+ protected function _block($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();
+ }
+
+ protected function _start_diff() {
+ ob_start();
+ }
+
+ protected function _end_diff() {
+ $val = ob_get_contents();
+ ob_end_clean();
+ return $val;
+ }
+
+ protected function _block_header($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') . $ybeg;
+ }
+
+ protected function _start_block($header) {
+ if ($this->show_header) {
+ echo $header . "\n";
+ }
+ }
+
+ protected function _end_block() {
+ }
+
+ protected function _lines($lines, $prefix = ' ') {
+ foreach ($lines as $line) {
+ echo "$prefix $line\n";
+ }
+ }
+
+ protected function _context($lines) {
+ $this->_lines($lines);
+ }
+
+ protected function _added($lines) {
+ $this->_lines($lines, '>');
+ }
+
+ protected function _deleted($lines) {
+ $this->_lines($lines, '<');
+ }
+
+ protected function _changed($orig, $closing) {
+ $this->_deleted($orig);
+ echo "---\n";
+ $this->_added($closing);
+ }
+
+}
diff --git a/core/lib/Drupal/Component/Diff/Engine/DiffEngine.php b/core/lib/Drupal/Component/Diff/Engine/DiffEngine.php
new file mode 100644
index 000000000000..9fe90ce8a4e2
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Engine/DiffEngine.php
@@ -0,0 +1,456 @@
+<?php
+
+namespace Drupal\Component\Diff\Engine;
+
+use Drupal\Component\Utility\Unicode;
+
+/**
+ * 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 {
+
+ const USE_ASSERTS = FALSE;
+
+ const MAX_XREF_LENGTH = 10000;
+
+ public 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) {
+ $this::USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]);
+ $this::USE_ASSERTS && assert($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) {
+ $edits[] = new DiffOpCopy($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) {
+ $edits[] = new DiffOpChange($delete, $add);
+ }
+ elseif ($delete) {
+ $edits[] = new DiffOpDelete($delete);
+ }
+ elseif ($add) {
+ $edits[] = new DiffOpAdd($add);
+ }
+ }
+ return $edits;
+ }
+
+ /**
+ * Returns the whole line if it's small enough, or the MD5 hash otherwise.
+ */
+ protected function _line_hash($line) {
+ if (Unicode::strlen($line) > $this::MAX_XREF_LENGTH) {
+ return md5($line);
+ }
+ else {
+ return $line;
+ }
+ }
+
+
+ /**
+ * Divide the Largest Common Subsequence (LCS) of the sequences
+ * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally
+ * sized segments.
+ *
+ * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an
+ * array of NCHUNKS+1 (X, Y) indexes giving the diving points between
+ * sub sequences. The first sub-sequence is contained in [X0, X1),
+ * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note
+ * that (X0, Y0) == (XOFF, YOFF) and
+ * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM).
+ *
+ * This function assumes that the first lines of the specified portions
+ * of the two files do not match, and likewise that the last lines do not
+ * match. The caller must trim matching lines from the beginning and end
+ * of the portions it is going to specify.
+ */
+ protected function _diag($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);
+ $this::USE_ASSERTS && assert($k > 0);
+ $ymids[$k] = $ymids[$k-1];
+ break;
+ }
+ }
+ while (list ($junk, $y) = each($matches)) {
+ if ($y > $this->seq[$k-1]) {
+ $this::USE_ASSERTS && assert($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);
+ $this::USE_ASSERTS && assert($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, $seps);
+ }
+
+ protected function _lcs_pos($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;
+ }
+ }
+
+ $this::USE_ASSERTS && assert($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 $this->{x,y}changed[], by
+ * storing a 1 in the element for each line that is an insertion
+ * or deletion (ie. is not in the LCS).
+ *
+ * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.
+ *
+ * Note that XLIM, YLIM are exclusive bounds.
+ * All line numbers are origin-0 and discarded lines are not counted.
+ */
+ protected function _compareseq($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 = $pt2;
+ }
+ }
+ }
+
+ /**
+ * Adjust inserts/deletes of identical lines to join changes
+ * as much as possible.
+ *
+ * We do something when a run of changed lines include a
+ * line at one end and has an excluded, identical line at the other.
+ * We are free to choose which identical line is included.
+ * `compareseq' usually chooses the one at the beginning,
+ * but usually it is cleaner to consider the following identical line
+ * to be the "change".
+ *
+ * This is extracted verbatim from analyze.c (GNU diffutils-2.7).
+ */
+ protected function _shift_boundaries($lines, &$changed, $other_changed) {
+ $i = 0;
+ $j = 0;
+
+ $this::USE_ASSERTS && assert('sizeof($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]) {
+ $this::USE_ASSERTS && assert('$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--;
+ }
+ $this::USE_ASSERTS && assert('$j > 0');
+ while ($other_changed[--$j]) {
+ continue;
+ }
+ $this::USE_ASSERTS && assert('$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++;
+ }
+ $this::USE_ASSERTS && assert('$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;
+ $this::USE_ASSERTS && assert('$j > 0');
+ while ($other_changed[--$j]) {
+ continue;
+ }
+ $this::USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]');
+ }
+ }
+ }
+}
diff --git a/core/lib/Drupal/Component/Diff/Engine/DiffOp.php b/core/lib/Drupal/Component/Diff/Engine/DiffOp.php
new file mode 100644
index 000000000000..120ac9ecdfb5
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Engine/DiffOp.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Drupal\Component\Diff\Engine;
+
+/**
+ * @todo document
+ * @private
+ * @subpackage DifferenceEngine
+ */
+class DiffOp {
+ var $type;
+ var $orig;
+ var $closing;
+
+ public function reverse() {
+ trigger_error('pure virtual', E_USER_ERROR);
+ }
+
+ public function norig() {
+ return $this->orig ? sizeof($this->orig) : 0;
+ }
+
+ public function nclosing() {
+ return $this->closing ? sizeof($this->closing) : 0;
+ }
+}
diff --git a/core/lib/Drupal/Component/Diff/Engine/DiffOpAdd.php b/core/lib/Drupal/Component/Diff/Engine/DiffOpAdd.php
new file mode 100644
index 000000000000..2def622d4cfe
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Engine/DiffOpAdd.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Drupal\Component\Diff\Engine;
+
+/**
+ * @todo document
+ * @private
+ * @subpackage DifferenceEngine
+ */
+class DiffOpAdd extends DiffOp {
+ var $type = 'add';
+
+ public function __construct($lines) {
+ $this->closing = $lines;
+ $this->orig = FALSE;
+ }
+
+ public function reverse() {
+ return new DiffOpDelete($this->closing);
+ }
+}
diff --git a/core/lib/Drupal/Component/Diff/Engine/DiffOpChange.php b/core/lib/Drupal/Component/Diff/Engine/DiffOpChange.php
new file mode 100644
index 000000000000..404b9964cbb1
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Engine/DiffOpChange.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Drupal\Component\Diff\Engine;
+
+/**
+ * @todo document
+ * @private
+ * @subpackage DifferenceEngine
+ */
+class DiffOpChange extends DiffOp {
+ var $type = 'change';
+
+ public function __construct($orig, $closing) {
+ $this->orig = $orig;
+ $this->closing = $closing;
+ }
+
+ public function reverse() {
+ return new DiffOpChange($this->closing, $this->orig);
+ }
+}
diff --git a/core/lib/Drupal/Component/Diff/Engine/DiffOpCopy.php b/core/lib/Drupal/Component/Diff/Engine/DiffOpCopy.php
new file mode 100644
index 000000000000..9792fb0ce84d
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Engine/DiffOpCopy.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\Component\Diff\Engine;
+
+/**
+ * @todo document
+ * @private
+ * @subpackage DifferenceEngine
+ */
+class DiffOpCopy extends DiffOp {
+ var $type = 'copy';
+
+ public function __construct($orig, $closing = FALSE) {
+ if (!is_array($closing)) {
+ $closing = $orig;
+ }
+ $this->orig = $orig;
+ $this->closing = $closing;
+ }
+
+ public function reverse() {
+ return new DiffOpCopy($this->closing, $this->orig);
+ }
+}
diff --git a/core/lib/Drupal/Component/Diff/Engine/DiffOpDelete.php b/core/lib/Drupal/Component/Diff/Engine/DiffOpDelete.php
new file mode 100644
index 000000000000..3b3b5672d08a
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Engine/DiffOpDelete.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Drupal\Component\Diff\Engine;
+
+/**
+ * @todo document
+ * @private
+ * @subpackage DifferenceEngine
+ */
+class DiffOpDelete extends DiffOp {
+ var $type = 'delete';
+
+ public function __construct($lines) {
+ $this->orig = $lines;
+ $this->closing = FALSE;
+ }
+
+ public function reverse() {
+ return new DiffOpAdd($this->orig);
+ }
+}
diff --git a/core/lib/Drupal/Component/Diff/Engine/HWLDFWordAccumulator.php b/core/lib/Drupal/Component/Diff/Engine/HWLDFWordAccumulator.php
new file mode 100644
index 000000000000..384593b2c759
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/Engine/HWLDFWordAccumulator.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace Drupal\Component\Diff\Engine;
+
+use Drupal\Component\Utility\String;
+use Drupal\Component\Utility\Unicode;
+
+/**
+ * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3
+ *
+ */
+
+/**
+ * @todo document
+ * @private
+ * @subpackage DifferenceEngine
+ */
+class HWLDFWordAccumulator {
+
+ /**
+ * An iso-8859-x non-breaking space.
+ */
+ const NBSP = ' ';
+
+ protected $lines = array();
+
+ protected $line = '';
+
+ protected $group = '';
+
+ protected $tag = '';
+
+ protected function _flushGroup($new_tag) {
+ if ($this->group !== '') {
+ if ($this->tag == 'mark') {
+ $this->line .= '<span class="diffchange">' . String::checkPlain($this->group) . '</span>';
+ }
+ else {
+ $this->line .= String::checkPlain($this->group);
+ }
+ }
+ $this->group = '';
+ $this->tag = $new_tag;
+ }
+
+ protected function _flushLine($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, $this::NBSP);
+ }
+ $this->line = '';
+ }
+
+ public function addWords($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);
+ $word = Unicode::substr($word, 1);
+ }
+ assert(!strstr($word, "\n"));
+ $this->group .= $word;
+ }
+ }
+
+ public function getLines() {
+ $this->_flushLine('~done');
+ return $this->lines;
+ }
+}
diff --git a/core/lib/Drupal/Component/Diff/MappedDiff.php b/core/lib/Drupal/Component/Diff/MappedDiff.php
new file mode 100644
index 000000000000..5350a6949bb9
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/MappedDiff.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Drupal\Component\Diff;
+
+/**
+ * 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-insensitive 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 $to_lines.
+ */
+ public function __construct($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) {
+
+ assert(sizeof($from_lines) == sizeof($mapped_from_lines));
+ assert(sizeof($to_lines) == sizeof($mapped_to_lines));
+
+ parent::__construct($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);
+ }
+ }
+ }
+}
+
diff --git a/core/lib/Drupal/Component/Diff/WordLevelDiff.php b/core/lib/Drupal/Component/Diff/WordLevelDiff.php
new file mode 100644
index 000000000000..c9114bcb8af5
--- /dev/null
+++ b/core/lib/Drupal/Component/Diff/WordLevelDiff.php
@@ -0,0 +1,81 @@
+<?php
+
+namespace Drupal\Component\Diff;
+
+use Drupal\Component\Diff\Engine\HWLDFWordAccumulator;
+use Drupal\Component\Utility\Unicode;
+
+/**
+ * @todo document
+ * @private
+ * @subpackage DifferenceEngine
+ */
+class WordLevelDiff extends MappedDiff {
+
+ const MAX_LINE_LENGTH = 10000;
+
+ public function __construct($orig_lines, $closing_lines) {
+ list($orig_words, $orig_stripped) = $this->_split($orig_lines);
+ list($closing_words, $closing_stripped) = $this->_split($closing_lines);
+
+ parent::__construct($orig_words, $closing_words, $orig_stripped, $closing_stripped);
+ }
+
+ protected function _split($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";
+ $stripped[] = "\n";
+ }
+ if (Unicode::strlen($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);
+ }
+
+ public function orig() {
+ $orig = new HWLDFWordAccumulator();
+
+ foreach ($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;
+ }
+
+ public function closing() {
+ $closing = new HWLDFWordAccumulator();
+
+ foreach ($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 --git a/core/lib/Drupal/Core/Config/ConfigManager.php b/core/lib/Drupal/Core/Config/ConfigManager.php
index e0d57e186951..cde0eab2a637 100644
--- a/core/lib/Drupal/Core/Config/ConfigManager.php
+++ b/core/lib/Drupal/Core/Config/ConfigManager.php
@@ -7,6 +7,7 @@
namespace Drupal\Core\Config;
+use Drupal\Component\Diff\Diff;
use Drupal\Component\Serialization\Yaml;
use Drupal\Core\Config\Entity\ConfigDependencyManager;
use Drupal\Core\Entity\EntityManagerInterface;
@@ -130,10 +131,6 @@ public function diff(StorageInterface $source_storage, StorageInterface $target_
if (!isset($target_name)) {
$target_name = $source_name;
}
- // @todo Replace with code that can be autoloaded.
- // https://drupal.org/node/1848266
- require_once __DIR__ . '/../../Component/Diff/DiffEngine.php';
-
// The output should show configuration object differences formatted as YAML.
// But the configuration is not necessarily stored in files. Therefore, they
// need to be read and parsed, and lastly, dumped into YAML strings.
@@ -150,7 +147,7 @@ public function diff(StorageInterface $source_storage, StorageInterface $target_
$target_data = array($this->t('File removed'));
}
- return new \Diff($source_data, $target_data);
+ return new Diff($source_data, $target_data);
}
/**
diff --git a/core/lib/Drupal/Core/Diff/DiffFormatter.php b/core/lib/Drupal/Core/Diff/DiffFormatter.php
new file mode 100644
index 000000000000..0e59e88c04a7
--- /dev/null
+++ b/core/lib/Drupal/Core/Diff/DiffFormatter.php
@@ -0,0 +1,217 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Diff\DiffFormatter.
+ */
+
+namespace Drupal\Core\Diff;
+
+use Drupal\Component\Diff\DiffFormatter as DiffFormatterBase;
+use Drupal\Component\Diff\WordLevelDiff;
+use Drupal\Component\Utility\String;
+use Drupal\Core\Config\ConfigFactoryInterface;
+
+/**
+ * Diff formatter which uses returns output that can be rendered to a table.
+ */
+class DiffFormatter extends DiffFormatterBase {
+
+ /**
+ * The diff represented as an array of rows.
+ *
+ * @var array
+ */
+ protected $rows = array();
+
+ /**
+ * The line stats.
+ *
+ * @var array
+ */
+ protected $line_stats = array(
+ 'counter' => array('x' => 0, 'y' => 0),
+ 'offset' => array('x' => 0, 'y' => 0),
+ );
+
+ /**
+ * Creates a DiffFormatter to render diffs in a table.
+ *
+ * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+ * The config factory.
+ */
+ public function __construct(ConfigFactoryInterface $config_factory) {
+ $config = $config_factory->get('system.diff');
+ $this->leading_context_lines = $config->get('context.lines_leading');
+ $this->trailing_context_lines = $config->get('context.lines_trailing');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _start_diff() {
+ $this->rows = array();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _end_diff() {
+ return $this->rows;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _block_header($xbeg, $xlen, $ybeg, $ylen) {
+ return array(
+ array(
+ 'data' => $xbeg + $this->line_stats['offset']['x'],
+ 'colspan' => 2,
+ ),
+ array(
+ 'data' => $ybeg + $this->line_stats['offset']['y'],
+ 'colspan' => 2,
+ )
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _start_block($header) {
+ if ($this->show_header) {
+ $this->rows[] = $header;
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _lines($lines, $prefix=' ', $color='white') {
+ }
+
+ /**
+ * Creates an added line.
+ *
+ * @param string $line
+ * An HTML-escaped line.
+ *
+ * @return array
+ * An array representing a table row.
+ */
+ protected function addedLine($line) {
+ return array(
+ array(
+ 'data' => '+',
+ 'class' => 'diff-marker',
+ ),
+ array(
+ 'data' => $line,
+ 'class' => 'diff-context diff-addedline',
+ )
+ );
+ }
+
+ /**
+ * Creates a deleted line.
+ *
+ * @param string $line
+ * An HTML-escaped line.
+ *
+ * @return array
+ * An array representing a table row.
+ */
+ protected function deletedLine($line) {
+ return array(
+ array(
+ 'data' => '-',
+ 'class' => 'diff-marker',
+ ),
+ array(
+ 'data' => $line,
+ 'class' => 'diff-context diff-deletedline',
+ )
+ );
+ }
+
+ /**
+ * Creates a context line.
+ *
+ * @param string $line
+ * An HTML-escaped line.
+ *
+ * @return array
+ * An array representing a table row.
+ */
+ protected function contextLine($line) {
+ return array(
+ ' ',
+ array(
+ 'data' => $line,
+ 'class' => 'diff-context',
+ )
+ );
+ }
+
+ /**
+ * Creates an empty line.
+ *
+ * @return array
+ * An array representing a table row.
+ */
+ protected function emptyLine() {
+ return array(
+ ' ',
+ ' ',
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _added($lines) {
+ foreach ($lines as $line) {
+ $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(String::checkPlain($line)));
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _deleted($lines) {
+ foreach ($lines as $line) {
+ $this->rows[] = array_merge($this->deletedLine(String::checkPlain($line)), $this->emptyLine());
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function _context($lines) {
+ foreach ($lines as $line) {
+ $this->rows[] = array_merge($this->contextLine(String::checkPlain($line)), $this->contextLine(String::checkPlain($line)));
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected 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) : $this->emptyLine());
+ }
+
+ // If any leftovers.
+ foreach ($add as $line) {
+ $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line));
+ }
+ }
+}
diff --git a/core/modules/config/src/Controller/ConfigController.php b/core/modules/config/src/Controller/ConfigController.php
index eeec671a2fce..48b31df57d9a 100644
--- a/core/modules/config/src/Controller/ConfigController.php
+++ b/core/modules/config/src/Controller/ConfigController.php
@@ -12,6 +12,7 @@
use Drupal\Core\Config\ConfigManagerInterface;
use Drupal\Core\Config\StorageInterface;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\Core\Diff\DiffFormatter;
use Drupal\system\FileDownloadController;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\Request;
@@ -49,6 +50,13 @@ class ConfigController implements ContainerInjectionInterface {
*/
protected $fileDownloadController;
+ /**
+ * The diff formatter.
+ *
+ * @var \Drupal\Core\Diff\DiffFormatter
+ */
+ protected $diffFormatter;
+
/**
* {@inheritdoc}
*/
@@ -57,7 +65,8 @@ public static function create(ContainerInterface $container) {
$container->get('config.storage'),
$container->get('config.storage.staging'),
$container->get('config.manager'),
- new FileDownloadController()
+ new FileDownloadController(),
+ $container->get('diff.formatter')
);
}
@@ -71,11 +80,12 @@ public static function create(ContainerInterface $container) {
* @param \Drupal\system\FileDownloadController $file_download_controller
* The file download controller.
*/
- public function __construct(StorageInterface $target_storage, StorageInterface $source_storage, ConfigManagerInterface $config_manager, FileDownloadController $file_download_controller) {
+ public function __construct(StorageInterface $target_storage, StorageInterface $source_storage, ConfigManagerInterface $config_manager, FileDownloadController $file_download_controller, DiffFormatter $diff_formatter) {
$this->targetStorage = $target_storage;
$this->sourceStorage = $source_storage;
$this->configManager = $config_manager;
$this->fileDownloadController = $file_download_controller;
+ $this->diffFormatter = $diff_formatter;
}
/**
@@ -102,7 +112,7 @@ public function downloadExport() {
}
/**
- * Shows diff of specificed configuration file.
+ * Shows diff of specified configuration file.
*
* @param string $source_name
* The name of the configuration file.
@@ -121,8 +131,7 @@ public function diff($source_name, $target_name = NULL, $collection = NULL) {
$collection = StorageInterface::DEFAULT_COLLECTION;
}
$diff = $this->configManager->diff($this->targetStorage, $this->sourceStorage, $source_name, $target_name, $collection);
- $formatter = new \DrupalDiffFormatter();
- $formatter->show_header = FALSE;
+ $this->diffFormatter->show_header = FALSE;
$build = array();
@@ -136,7 +145,7 @@ public function diff($source_name, $target_name = NULL, $collection = NULL) {
array('data' => t('Old'), 'colspan' => '2'),
array('data' => t('New'), 'colspan' => '2'),
),
- '#rows' => $formatter->format($diff),
+ '#rows' => $this->diffFormatter->format($diff),
);
$build['back'] = array(
diff --git a/core/modules/config/src/Tests/ConfigDiffTest.php b/core/modules/config/src/Tests/ConfigDiffTest.php
index 138b861665c2..03902e4938d3 100644
--- a/core/modules/config/src/Tests/ConfigDiffTest.php
+++ b/core/modules/config/src/Tests/ConfigDiffTest.php
@@ -57,9 +57,10 @@ function testDiff() {
// Verify that the diff reflects a change.
$diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name);
- $this->assertEqual($diff->edits[0]->type, 'change', 'The first item in the diff is a change.');
- $this->assertEqual($diff->edits[0]->orig[0], $change_key . ': ' . $original_data[$change_key], format_string("The active value for key '%change_key' is '%original_data'.", array('%change_key' => $change_key, '%original_data' => $original_data[$change_key])));
- $this->assertEqual($diff->edits[0]->closing[0], $change_key . ': ' . $change_data, format_string("The staging value for key '%change_key' is '%change_data'.", array('%change_key' => $change_key, '%change_data' => $change_data)));
+ $edits = $diff->getEdits();
+ $this->assertEqual($edits[0]->type, 'change', 'The first item in the diff is a change.');
+ $this->assertEqual($edits[0]->orig[0], $change_key . ': ' . $original_data[$change_key], format_string("The active value for key '%change_key' is '%original_data'.", array('%change_key' => $change_key, '%original_data' => $original_data[$change_key])));
+ $this->assertEqual($edits[0]->closing[0], $change_key . ': ' . $change_data, format_string("The staging value for key '%change_key' is '%change_data'.", array('%change_key' => $change_key, '%change_data' => $change_data)));
// Reset data back to original, and remove a key
$staging_data = $original_data;
@@ -68,10 +69,11 @@ function testDiff() {
// Verify that the diff reflects a removed key.
$diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name);
- $this->assertEqual($diff->edits[0]->type, 'copy', 'The first item in the diff is a copy.');
- $this->assertEqual($diff->edits[1]->type, 'delete', 'The second item in the diff is a delete.');
- $this->assertEqual($diff->edits[1]->orig[0], $remove_key . ': ' . $original_data[$remove_key], format_string("The active value for key '%remove_key' is '%original_data'.", array('%remove_key' => $remove_key, '%original_data' => $original_data[$remove_key])));
- $this->assertFalse($diff->edits[1]->closing, format_string("The key '%remove_key' does not exist in staging.", array('%remove_key' => $remove_key)));
+ $edits = $diff->getEdits();
+ $this->assertEqual($edits[0]->type, 'copy', 'The first item in the diff is a copy.');
+ $this->assertEqual($edits[1]->type, 'delete', 'The second item in the diff is a delete.');
+ $this->assertEqual($edits[1]->orig[0], $remove_key . ': ' . $original_data[$remove_key], format_string("The active value for key '%remove_key' is '%original_data'.", array('%remove_key' => $remove_key, '%original_data' => $original_data[$remove_key])));
+ $this->assertFalse($edits[1]->closing, format_string("The key '%remove_key' does not exist in staging.", array('%remove_key' => $remove_key)));
// Reset data back to original and add a key
$staging_data = $original_data;
@@ -80,10 +82,11 @@ function testDiff() {
// Verify that the diff reflects an added key.
$diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name);
- $this->assertEqual($diff->edits[0]->type, 'copy', 'The first item in the diff is a copy.');
- $this->assertEqual($diff->edits[1]->type, 'add', 'The second item in the diff is an add.');
- $this->assertFalse($diff->edits[1]->orig, format_string("The key '%add_key' does not exist in active.", array('%add_key' => $add_key)));
- $this->assertEqual($diff->edits[1]->closing[0], $add_key . ': ' . $add_data, format_string("The staging value for key '%add_key' is '%add_data'.", array('%add_key' => $add_key, '%add_data' => $add_data)));
+ $edits = $diff->getEdits();
+ $this->assertEqual($edits[0]->type, 'copy', 'The first item in the diff is a copy.');
+ $this->assertEqual($edits[1]->type, 'add', 'The second item in the diff is an add.');
+ $this->assertFalse($edits[1]->orig, format_string("The key '%add_key' does not exist in active.", array('%add_key' => $add_key)));
+ $this->assertEqual($edits[1]->closing[0], $add_key . ': ' . $add_data, format_string("The staging value for key '%add_key' is '%add_data'.", array('%add_key' => $add_key, '%add_data' => $add_data)));
// Test diffing a renamed config entity.
$test_entity_id = $this->randomName();
@@ -97,8 +100,9 @@ function testDiff() {
$config_name = 'config_test.dynamic.' . $test_entity_id;
$diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name, $config_name);
// Prove the fields match.
- $this->assertEqual($diff->edits[0]->type, 'copy', 'The first item in the diff is a copy.');
- $this->assertEqual(count($diff->edits), 1, 'There is one item in the diff');
+ $edits = $diff->getEdits();
+ $this->assertEqual($edits[0]->type, 'copy', 'The first item in the diff is a copy.');
+ $this->assertEqual(count($edits), 1, 'There is one item in the diff');
// Rename the entity.
$new_test_entity_id = $this->randomName();
@@ -106,11 +110,12 @@ function testDiff() {
$test_entity->save();
$diff = \Drupal::service('config.manager')->diff($active, $staging, 'config_test.dynamic.' . $new_test_entity_id, $config_name);
- $this->assertEqual($diff->edits[0]->type, 'change', 'The second item in the diff is a copy.');
- $this->assertEqual($diff->edits[0]->orig, array('id: ' . $new_test_entity_id));
- $this->assertEqual($diff->edits[0]->closing, array('id: ' . $test_entity_id));
- $this->assertEqual($diff->edits[1]->type, 'copy', 'The second item in the diff is a copy.');
- $this->assertEqual(count($diff->edits), 2, 'There are two items in the diff.');
+ $edits = $diff->getEdits();
+ $this->assertEqual($edits[0]->type, 'change', 'The second item in the diff is a copy.');
+ $this->assertEqual($edits[0]->orig, array('id: ' . $new_test_entity_id));
+ $this->assertEqual($edits[0]->closing, array('id: ' . $test_entity_id));
+ $this->assertEqual($edits[1]->type, 'copy', 'The second item in the diff is a copy.');
+ $this->assertEqual(count($edits), 2, 'There are two items in the diff.');
}
/**
@@ -134,15 +139,17 @@ function testCollectionDiff() {
// Test the fields match in the default collection diff.
$diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name);
- $this->assertEqual($diff->edits[0]->type, 'copy', 'The first item in the diff is a copy.');
- $this->assertEqual(count($diff->edits), 1, 'There is one item in the diff');
+ $edits = $diff->getEdits();
+ $this->assertEqual($edits[0]->type, 'copy', 'The first item in the diff is a copy.');
+ $this->assertEqual(count($edits), 1, 'There is one item in the diff');
// Test that the differences are detected when diffing the collection.
$diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name, NULL, 'test');
- $this->assertEqual($diff->edits[0]->type, 'change', 'The second item in the diff is a copy.');
- $this->assertEqual($diff->edits[0]->orig, array('foo: bar'));
- $this->assertEqual($diff->edits[0]->closing, array('foo: baz'));
- $this->assertEqual($diff->edits[1]->type, 'copy', 'The second item in the diff is a copy.');
+ $edits = $diff->getEdits();
+ $this->assertEqual($edits[0]->type, 'change', 'The second item in the diff is a copy.');
+ $this->assertEqual($edits[0]->orig, array('foo: bar'));
+ $this->assertEqual($edits[0]->closing, array('foo: baz'));
+ $this->assertEqual($edits[1]->type, 'copy', 'The second item in the diff is a copy.');
}
}
diff --git a/core/modules/system/config/install/system.diff.yml b/core/modules/system/config/install/system.diff.yml
new file mode 100644
index 000000000000..925b19ca14e1
--- /dev/null
+++ b/core/modules/system/config/install/system.diff.yml
@@ -0,0 +1,3 @@
+context:
+ lines_leading: 2
+ lines_trailing: 2
diff --git a/core/modules/system/config/schema/system.schema.yml b/core/modules/system/config/schema/system.schema.yml
index 9ed58a297ab7..e2ee096298c3 100644
--- a/core/modules/system/config/schema/system.schema.yml
+++ b/core/modules/system/config/schema/system.schema.yml
@@ -128,6 +128,21 @@ system.date_format.*:
type: string
label: 'Default language'
+system.diff:
+ type: mapping
+ label: 'Diff settings'
+ mapping:
+ context:
+ type: mapping
+ label: 'Context'
+ mapping:
+ lines_leading:
+ type: integer
+ label: 'Number of leading lines in a diff'
+ lines_trailing:
+ type: integer
+ label: 'Number of trailing lines in a diff'
+
system.filter:
type: mapping
label: 'Filter settings'
--
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