--- a/includes/clientside/tinymce/plugins/devkit/jscripts/diff.js Wed Dec 26 00:37:26 2007 -0500
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,1192 +0,0 @@
-// Diff_Match_Patch v1.3
-// Computes the difference between two texts to create a patch.
-// Applies the patch onto another text, allowing for errors.
-// Copyright (C) 2006 Neil Fraser
-// http://neil.fraser.name/software/diff_match_patch/
-
-// This program is free software; you can redistribute it and/or
-// modify it under the terms of the GNU General Public License
-// as published by the Free Software Foundation.
-
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License (www.gnu.org) for more details.
-
-
-// Constants.
-// Redefine these in your program to override the defaults.
-
-// Number of seconds to map a diff before giving up. (0 for infinity)
-var DIFF_TIMEOUT = 1.0;
-// Cost of an empty edit operation in terms of edit characters.
-var DIFF_EDIT_COST = 4;
-// Tweak the relative importance (0.0 = accuracy, 1.0 = proximity)
-var MATCH_BALANCE = 0.5;
-// At what point is no match declared (0.0 = perfection, 1.0 = very loose)
-var MATCH_THRESHOLD = 0.5;
-// The min and max cutoffs used when computing text lengths.
-var MATCH_MINLENGTH = 100;
-var MATCH_MAXLENGTH = 1000;
-// Chunk size for context length.
-var PATCH_MARGIN = 4;
-
-
- //////////////////////////////////////////////////////////////////////
- // Diff //
-//////////////////////////////////////////////////////////////////////
-
-// The data structure representing a diff is an array of tuples:
-// [[-1, "Hello"], [1, "Goodbye"], [0, " world."]]
-// which means: delete "Hello", add "Goodbye" and keep " world."
-
-
-function diff_main(text1, text2, checklines) {
- // Find the differences between two texts. Return an array of changes.
- // If checklines is present and false, then don't run a line-level diff first to identify the changed areas.
- // Check for equality (speedup)
- if (text1 == text2)
- return [[0, text1]];
-
- if (typeof checklines == 'undefined')
- checklines = true;
-
- var a;
- // Trim off common prefix (speedup)
- a = diff_prefix(text1, text2);
- text1 = a[0];
- text2 = a[1];
- var commonprefix = a[2];
-
- // Trim off common suffix (speedup)
- a = diff_suffix(text1, text2);
- text1 = a[0];
- text2 = a[1];
- var commonsuffix = a[2];
-
- var diff, i;
- var longtext = text1.length > text2.length ? text1 : text2;
- var shorttext = text1.length > text2.length ? text2 : text1;
-
- if (!text1) { // Just add some text (speedup)
- diff = [[1, text2]];
- } else if (!text2) { // Just delete some text (speedup)
- diff = [[-1, text1]];
- } else if ((i = longtext.indexOf(shorttext)) != -1) {
- // Shorter text is inside the longer text (speedup)
- diff = [[1, longtext.substring(0, i)], [0, shorttext], [1, longtext.substring(i+shorttext.length)]];
- // Swap insertions for deletions if diff is reversed.
- if (text1.length > text2.length)
- diff[0][0] = diff[2][0] = -1;
- } else {
- longtext = shorttext = null; // Garbage collect
- // Check to see if the problem can be split in two.
- var hm = diff_halfmatch(text1, text2);
- if (hm) {
- // A half-match was found, sort out the return data.
- var text1_a = hm[0];
- var text1_b = hm[1];
- var text2_a = hm[2];
- var text2_b = hm[3];
- var mid_common = hm[4];
- // Send both pairs off for separate processing.
- var diff_a = diff_main(text1_a, text2_a, checklines);
- var diff_b = diff_main(text1_b, text2_b, checklines);
- // Merge the results.
- diff = diff_a.concat([[0, mid_common]], diff_b);
- } else {
- // Perform a real diff.
- if (checklines && text1.length + text2.length < 250)
- checklines = false; // Too trivial for the overhead.
- if (checklines) {
- // Scan the text on a line-by-line basis first.
- a = diff_lines2chars(text1, text2);
- text1 = a[0];
- text2 = a[1];
- var linearray = a[2];
- }
- diff = diff_map(text1, text2);
- if (!diff) // No acceptable result.
- diff = [[-1, text1], [1, text2]];
- if (checklines) {
- diff_chars2lines(diff, linearray); // Convert the diff back to original text.
- diff_cleanup_semantic(diff); // Eliminate freak matches (e.g. blank lines)
-
- // Rediff any replacement blocks, this time on character-by-character basis.
- diff.push([0, '']); // Add a dummy entry at the end.
- var pointer = 0;
- var count_delete = 0;
- var count_insert = 0;
- var text_delete = '';
- var text_insert = '';
- while(pointer < diff.length) {
- if (diff[pointer][0] == 1) {
- count_insert++;
- text_insert += diff[pointer][1];
- } else if (diff[pointer][0] == -1) {
- count_delete++;
- text_delete += diff[pointer][1];
- } else { // Upon reaching an equality, check for prior redundancies.
- if (count_delete >= 1 && count_insert >= 1) {
- // Delete the offending records and add the merged ones.
- a = diff_main(text_delete, text_insert, false);
- diff.splice(pointer - count_delete - count_insert, count_delete + count_insert);
- pointer = pointer - count_delete - count_insert;
- for (i=a.length-1; i>=0; i--)
- diff.splice(pointer, 0, a[i]);
- pointer = pointer + a.length;
- }
- count_insert = 0;
- count_delete = 0;
- text_delete = '';
- text_insert = '';
- }
- pointer++;
- }
- diff.pop(); // Remove the dummy entry at the end.
-
- }
- }
- }
-
- if (commonprefix)
- diff.unshift([0, commonprefix]);
- if (commonsuffix)
- diff.push([0, commonsuffix]);
- diff_cleanup_merge(diff);
- return diff;
-}
-
-
-function diff_lines2chars(text1, text2) {
- // Split text into an array of strings.
- // Reduce the texts to a string of hashes where each character represents one line.
- var linearray = new Array(); // linearray[4] == "Hello\n"
- var linehash = new Object(); // linehash["Hello\n"] == 4
-
- // "\x00" is a valid JavaScript character, but the Venkman debugger doesn't like it (bug 335098)
- // So we'll insert a junk entry to avoid generating a null character.
- linearray.push('');
-
- function diff_lines2chars_munge(text) {
- // My first ever closure!
- var i, line;
- var chars = '';
- while (text) {
- i = text.indexOf('\n');
- if (i == -1)
- i = text.length;
- line = text.substring(0, i+1);
- text = text.substring(i+1);
- if (linehash.hasOwnProperty ? linehash.hasOwnProperty(line) : (linehash[line] !== undefined)) {
- chars += String.fromCharCode(linehash[line]);
- } else {
- linearray.push(line);
- linehash[line] = linearray.length - 1;
- chars += String.fromCharCode(linearray.length - 1);
- }
- }
- return chars;
- }
-
- var chars1 = diff_lines2chars_munge(text1);
- var chars2 = diff_lines2chars_munge(text2);
- return [chars1, chars2, linearray];
-}
-
-
-function diff_chars2lines(diff, linearray) {
- // Rehydrate the text in a diff from a string of line hashes to real lines of text.
- var chars, text;
- for (var x=0; x<diff.length; x++) {
- chars = diff[x][1];
- text = '';
- for (var y=0; y<chars.length; y++)
- text += linearray[chars.charCodeAt(y)];
- diff[x][1] = text;
- }
-}
-
-
-function diff_map(text1, text2) {
- // Explore the intersection points between the two texts.
- var now = new Date();
- var ms_end = now.getTime() + DIFF_TIMEOUT * 1000; // Don't run for too long.
- var max = (text1.length + text2.length) / 2;
- var v_map1 = new Array();
- var v_map2 = new Array();
- var v1 = new Object();
- var v2 = new Object();
- v1[1] = 0;
- v2[1] = 0;
- var x, y;
- var footstep; // Used to track overlapping paths.
- var footsteps = new Object();
- var done = false;
- var hasOwnProperty = !!(footsteps.hasOwnProperty);
- // If the total number of characters is odd, then the front path will collide with the reverse path.
- var front = (text1.length + text2.length) % 2;
- for (var d=0; d<max; d++) {
- now = new Date();
- if (DIFF_TIMEOUT > 0 && now.getTime() > ms_end) // Timeout reached
- return null;
-
- // Walk the front path one step.
- v_map1[d] = new Object();
- for (var k=-d; k<=d; k+=2) {
- if (k == -d || k != d && v1[k-1] < v1[k+1])
- x = v1[k+1];
- else
- x = v1[k-1]+1;
- y = x - k;
- footstep = x+","+y;
- if (front && (hasOwnProperty ? footsteps.hasOwnProperty(footstep) : (footsteps[footstep] !== undefined)))
- done = true;
- if (!front)
- footsteps[footstep] = d;
- while (!done && x < text1.length && y < text2.length && text1.charAt(x) == text2.charAt(y)) {
- x++; y++;
- footstep = x+","+y;
- if (front && (hasOwnProperty ? footsteps.hasOwnProperty(footstep) : (footsteps[footstep] !== undefined)))
- done = true;
- if (!front)
- footsteps[footstep] = d;
- }
- v1[k] = x;
- v_map1[d][x+","+y] = true;
- if (done) {
- // Front path ran over reverse path.
- v_map2 = v_map2.slice(0, footsteps[footstep]+1);
- var a = diff_path1(v_map1, text1.substring(0, x), text2.substring(0, y));
- return a.concat(diff_path2(v_map2, text1.substring(x), text2.substring(y)));
- }
- }
-
- // Walk the reverse path one step.
- v_map2[d] = new Object();
- for (var k=-d; k<=d; k+=2) {
- if (k == -d || k != d && v2[k-1] < v2[k+1])
- x = v2[k+1];
- else
- x = v2[k-1]+1;
- y = x - k;
- footstep = (text1.length-x)+","+(text2.length-y);
- if (!front && (hasOwnProperty ? footsteps.hasOwnProperty(footstep) : (footsteps[footstep] !== undefined)))
- done = true;
- if (front)
- footsteps[footstep] = d;
- while (!done && x < text1.length && y < text2.length && text1.charAt(text1.length-x-1) == text2.charAt(text2.length-y-1)) {
- x++; y++;
- footstep = (text1.length-x)+","+(text2.length-y);
- if (!front && (hasOwnProperty ? footsteps.hasOwnProperty(footstep) : (footsteps[footstep] !== undefined)))
- done = true;
- if (front)
- footsteps[footstep] = d;
- }
- v2[k] = x;
- v_map2[d][x+","+y] = true;
- if (done) {
- // Reverse path ran over front path.
- v_map1 = v_map1.slice(0, footsteps[footstep]+1);
- var a = diff_path1(v_map1, text1.substring(0, text1.length-x), text2.substring(0, text2.length-y));
- return a.concat(diff_path2(v_map2, text1.substring(text1.length-x), text2.substring(text2.length-y)));
- }
- }
- }
- // Number of diffs equals number of characters, no commonality at all.
- return null;
-}
-
-
-function diff_path1(v_map, text1, text2) {
- // Work from the middle back to the start to determine the path.
- var path = [];
- var x = text1.length;
- var y = text2.length;
- var last_op = null;
- for (var d=v_map.length-2; d>=0; d--) {
- while(1) {
- if (v_map[d].hasOwnProperty ? v_map[d].hasOwnProperty((x-1)+","+y) : (v_map[d][(x-1)+","+y] !== undefined)) {
- x--;
- if (last_op === -1)
- path[0][1] = text1.charAt(x) + path[0][1];
- else
- path.unshift([-1, text1.charAt(x)]);
- last_op = -1;
- break;
- } else if (v_map[d].hasOwnProperty ? v_map[d].hasOwnProperty(x+","+(y-1)) : (v_map[d][x+","+(y-1)] !== undefined)) {
- y--;
- if (last_op === 1)
- path[0][1] = text2.charAt(y) + path[0][1];
- else
- path.unshift([1, text2.charAt(y)]);
- last_op = 1;
- break;
- } else {
- x--;
- y--;
- //if (text1.charAt(x) != text2.charAt(y))
- // return alert("No diagonal. Can't happen. (diff_path1)");
- if (last_op === 0)
- path[0][1] = text1.charAt(x) + path[0][1];
- else
- path.unshift([0, text1.charAt(x)]);
- last_op = 0;
- }
- }
- }
- return path;
-}
-
-
-function diff_path2(v_map, text1, text2) {
- // Work from the middle back to the end to determine the path.
- var path = [];
- var x = text1.length;
- var y = text2.length;
- var last_op = null;
- for (var d=v_map.length-2; d>=0; d--) {
- while(1) {
- if (v_map[d].hasOwnProperty ? v_map[d].hasOwnProperty((x-1)+","+y) : (v_map[d][(x-1)+","+y] !== undefined)) {
- x--;
- if (last_op === -1)
- path[path.length-1][1] += text1.charAt(text1.length-x-1);
- else
- path.push([-1, text1.charAt(text1.length-x-1)]);
- last_op = -1;
- break;
- } else if (v_map[d].hasOwnProperty ? v_map[d].hasOwnProperty(x+","+(y-1)) : (v_map[d][x+","+(y-1)] !== undefined)) {
- y--;
- if (last_op === 1)
- path[path.length-1][1] += text2.charAt(text2.length-y-1);
- else
- path.push([1, text2.charAt(text2.length-y-1)]);
- last_op = 1;
- break;
- } else {
- x--;
- y--;
- //if (text1.charAt(text1.length-x-1) != text2.charAt(text2.length-y-1))
- // return alert("No diagonal. Can't happen. (diff_path2)");
- if (last_op === 0)
- path[path.length-1][1] += text1.charAt(text1.length-x-1);
- else
- path.push([0, text1.charAt(text1.length-x-1)]);
- last_op = 0;
- }
- }
- }
- return path;
-}
-
-
-function diff_prefix(text1, text2) {
- // Trim off common prefix
- var pointermin = 0;
- var pointermax = Math.min(text1.length, text2.length);
- var pointermid = pointermax;
- while(pointermin < pointermid) {
- if (text1.substring(0, pointermid) == text2.substring(0, pointermid))
- pointermin = pointermid;
- else
- pointermax = pointermid;
- pointermid = Math.floor((pointermax - pointermin) / 2 + pointermin);
- }
- var commonprefix = text1.substring(0, pointermid);
- text1 = text1.substring(pointermid);
- text2 = text2.substring(pointermid);
- return [text1, text2, commonprefix];
-}
-
-
-function diff_suffix(text1, text2) {
- // Trim off common suffix
- var pointermin = 0;
- var pointermax = Math.min(text1.length, text2.length);
- var pointermid = pointermax;
- while(pointermin < pointermid) {
- if (text1.substring(text1.length-pointermid) == text2.substring(text2.length-pointermid))
- pointermin = pointermid;
- else
- pointermax = pointermid;
- pointermid = Math.floor((pointermax - pointermin) / 2 + pointermin);
- }
- var commonsuffix = text1.substring(text1.length-pointermid);
- text1 = text1.substring(0, text1.length-pointermid);
- text2 = text2.substring(0, text2.length-pointermid);
- return [text1, text2, commonsuffix];
-}
-
-
-function diff_halfmatch(text1, text2) {
- // Do the two texts share a substring which is at least half the length of the longer text?
- var longtext = text1.length > text2.length ? text1 : text2;
- var shorttext = text1.length > text2.length ? text2 : text1;
- if (longtext.length < 10 || shorttext.length < 1)
- return null; // Pointless.
-
- function diff_halfmatch_i(longtext, shorttext, i) {
- // Start with a 1/4 length substring at position i as a seed.
- var seed = longtext.substring(i, i+Math.floor(longtext.length/4));
- var j = -1;
- var best_common = '';
- var best_longtext_a, best_longtext_b, best_shorttext_a, best_shorttext_b;
- while ((j = shorttext.indexOf(seed, j+1)) != -1) {
- var my_prefix = diff_prefix(longtext.substring(i), shorttext.substring(j));
- var my_suffix = diff_suffix(longtext.substring(0, i), shorttext.substring(0, j));
- if (best_common.length < (my_suffix[2] + my_prefix[2]).length) {
- best_common = my_suffix[2] + my_prefix[2];
- best_longtext_a = my_suffix[0];
- best_longtext_b = my_prefix[0];
- best_shorttext_a = my_suffix[1];
- best_shorttext_b = my_prefix[1];
- }
- }
- if (best_common.length >= longtext.length/2)
- return [best_longtext_a, best_longtext_b, best_shorttext_a, best_shorttext_b, best_common];
- else
- return null;
- }
-
- // First check if the second quarter is the seed for a half-match.
- var hm1 = diff_halfmatch_i(longtext, shorttext, Math.ceil(longtext.length/4));
- // Check again based on the third quarter.
- var hm2 = diff_halfmatch_i(longtext, shorttext, Math.ceil(longtext.length/2));
- var hm;
- if (!hm1 && !hm2)
- return null;
- else if (!hm2)
- hm = hm1;
- else if (!hm1)
- hm = hm2;
- else // Both matched. Select the longest.
- hm = hm1[4].length > hm2[4].length ? hm1 : hm2;
-
- // A half-match was found, sort out the return data.
- if (text1.length > text2.length) {
- var text1_a = hm[0];
- var text1_b = hm[1];
- var text2_a = hm[2];
- var text2_b = hm[3];
- } else {
- var text2_a = hm[0];
- var text2_b = hm[1];
- var text1_a = hm[2];
- var text1_b = hm[3];
- }
- var mid_common = hm[4];
- return [text1_a, text1_b, text2_a, text2_b, mid_common];
-}
-
-
-function diff_cleanup_semantic(diff) {
- // Reduce the number of edits by eliminating semantically trivial equalities.
- var changes = false;
- var equalities = []; // Stack of indices where equalities are found.
- var lastequality = null; // Always equal to equalities[equalities.length-1][1]
- var pointer = 0; // Index of current position.
- var length_changes1 = 0; // Number of characters that changed prior to the equality.
- var length_changes2 = 0; // Number of characters that changed after the equality.
- while (pointer < diff.length) {
- if (diff[pointer][0] == 0) { // equality found
- equalities.push(pointer);
- length_changes1 = length_changes2;
- length_changes2 = 0;
- lastequality = diff[pointer][1];
- } else { // an insertion or deletion
- length_changes2 += diff[pointer][1].length;
- if (lastequality != null && (lastequality.length <= length_changes1) && (lastequality.length <= length_changes2)) {
- //alert("Splitting: '"+lastequality+"'");
- diff.splice(equalities[equalities.length-1], 0, [-1, lastequality]); // Duplicate record
- diff[equalities[equalities.length-1]+1][0] = 1; // Change second copy to insert.
- equalities.pop(); // Throw away the equality we just deleted;
- equalities.pop(); // Throw away the previous equality;
- pointer = equalities.length ? equalities[equalities.length-1] : -1;
- length_changes1 = 0; // Reset the counters.
- length_changes2 = 0;
- lastequality = null;
- changes = true;
- }
- }
- pointer++;
- }
-
- if (changes)
- diff_cleanup_merge(diff);
-}
-
-
-function diff_cleanup_efficiency(diff) {
- // Reduce the number of edits by eliminating operationally trivial equalities.
- var changes = false;
- var equalities = []; // Stack of indices where equalities are found.
- var lastequality = ''; // Always equal to equalities[equalities.length-1][1]
- var pointer = 0; // Index of current position.
- var pre_ins = false; // Is there an insertion operation before the last equality.
- var pre_del = false; // Is there an deletion operation before the last equality.
- var post_ins = false; // Is there an insertion operation after the last equality.
- var post_del = false; // Is there an deletion operation after the last equality.
- while (pointer < diff.length) {
- if (diff[pointer][0] == 0) { // equality found
- if (diff[pointer][1].length < DIFF_EDIT_COST && (post_ins || post_del)) {
- // Candidate found.
- equalities.push(pointer);
- pre_ins = post_ins;
- pre_del = post_del;
- lastequality = diff[pointer][1];
- } else {
- // Not a candidate, and can never become one.
- equalities = [];
- lastequality = '';
- }
- post_ins = post_del = false;
- } else { // an insertion or deletion
- if (diff[pointer][0] == -1)
- post_del = true;
- else
- post_ins = true;
- // Five types to be split:
- // <ins>A</ins><del>B</del>XY<ins>C</ins><del>D</del>
- // <ins>A</ins>X<ins>C</ins><del>D</del>
- // <ins>A</ins><del>B</del>X<ins>C</ins>
- // <ins>A</del>X<ins>C</ins><del>D</del>
- // <ins>A</ins><del>B</del>X<del>C</del>
- if (lastequality && ((pre_ins && pre_del && post_ins && post_del) || ((lastequality.length < DIFF_EDIT_COST/2) && (pre_ins + pre_del + post_ins + post_del) == 3))) {
- //alert("Splitting: '"+lastequality+"'");
- diff.splice(equalities[equalities.length-1], 0, [-1, lastequality]); // Duplicate record
- diff[equalities[equalities.length-1]+1][0] = 1; // Change second copy to insert.
- equalities.pop(); // Throw away the equality we just deleted;
- lastequality = '';
- if (pre_ins && pre_del) {
- // No changes made which could affect previous entry, keep going.
- post_ins = post_del = true;
- equalities = [];
- } else {
- equalities.pop(); // Throw away the previous equality;
- pointer = equalities.length ? equalities[equalities.length-1] : -1;
- post_ins = post_del = false;
- }
- changes = true;
- }
- }
- pointer++;
- }
-
- if (changes)
- diff_cleanup_merge(diff);
-}
-
-
-function diff_cleanup_merge(diff) {
- // Reorder and merge like edit sections. Merge equalities.
- // Any edit section can move as long as it doesn't cross an equality.
- diff.push([0, '']); // Add a dummy entry at the end.
- var pointer = 0;
- var count_delete = 0;
- var count_insert = 0;
- var text_delete = '';
- var text_insert = '';
- var record_insert, record_delete;
- var my_xfix;
- while(pointer < diff.length) {
- if (diff[pointer][0] == 1) {
- count_insert++;
- text_insert += diff[pointer][1];
- pointer++;
- } else if (diff[pointer][0] == -1) {
- count_delete++;
- text_delete += diff[pointer][1];
- pointer++;
- } else { // Upon reaching an equality, check for prior redundancies.
- if (count_delete > 1 || count_insert > 1) {
- if (count_delete > 1 && count_insert > 1) {
- // Factor out any common prefixies.
- my_xfix = diff_prefix(text_insert, text_delete);
- if (my_xfix[2] != '') {
- if ((pointer - count_delete - count_insert) > 0 && diff[pointer - count_delete - count_insert - 1][0] == 0) {
- text_insert = my_xfix[0];
- text_delete = my_xfix[1];
- diff[pointer - count_delete - count_insert - 1][1] += my_xfix[2];
- }
- }
- // Factor out any common suffixies.
- my_xfix = diff_suffix(text_insert, text_delete);
- if (my_xfix[2] != '') {
- text_insert = my_xfix[0];
- text_delete = my_xfix[1];
- diff[pointer][1] = my_xfix[2] + diff[pointer][1];
- }
- }
- // Delete the offending records and add the merged ones.
- if (count_delete == 0)
- diff.splice(pointer - count_delete - count_insert, count_delete + count_insert, [1, text_insert]);
- else if (count_insert == 0)
- diff.splice(pointer - count_delete - count_insert, count_delete + count_insert, [-1, text_delete]);
- else
- diff.splice(pointer - count_delete - count_insert, count_delete + count_insert, [-1, text_delete], [1, text_insert]);
- pointer = pointer - count_delete - count_insert + (count_delete ? 1 : 0) + (count_insert ? 1 : 0) + 1;
- } else if (pointer != 0 && diff[pointer-1][0] == 0) {
- // Merge this equality with the previous one.
- diff[pointer-1][1] += diff[pointer][1];
- diff.splice(pointer, 1);
- } else {
- pointer++;
- }
- count_insert = 0;
- count_delete = 0;
- text_delete = '';
- text_insert = '';
- }
- }
- if (diff[diff.length-1][1] == '')
- diff.pop(); // Remove the dummy entry at the end.
-}
-
-
-function diff_addindex(diff) {
- // Add an index to each tuple, represents where the tuple is located in text2.
- // e.g. [[-1, 'h', 0], [1, 'c', 0], [0, 'at', 1]]
- var i = 0;
- for (var x=0; x<diff.length; x++) {
- diff[x].push(i);
- if (diff[x][0] != -1)
- i += diff[x][1].length;
- }
-}
-
-
-function diff_xindex(diff, loc) {
- // loc is a location in text1, compute and return the equivalent location in text2.
- // e.g. "The cat" vs "The big cat", 1->1, 5->8
- var chars1 = 0;
- var chars2 = 0;
- var last_chars1 = 0;
- var last_chars2 = 0;
- for (var x=0; x<diff.length; x++) {
- if (diff[x][0] != 1) // Equality or deletion.
- chars1 += diff[x][1].length;
- if (diff[x][0] != -1) // Equality or insertion.
- chars2 += diff[x][1].length;
- if (chars1 > loc) // Overshot the location.
- break;
- last_chars1 = chars1;
- last_chars2 = chars2;
- }
- if (diff.length != x && diff[x][0] == -1) // The location was deleted.
- return last_chars2;
- // Add the remaining character length.
- return last_chars2 + (loc - last_chars1);
-}
-
-
-function diff_prettyhtml(diff) {
- // Convert a diff array into a pretty HTML report.
- diff_addindex(diff);
- var html = '';
- for (var x=0; x<diff.length; x++) {
- var m = diff[x][0]; // Mode (-1=delete, 0=copy, 1=add)
- var t = diff[x][1]; // Text of change.
- var i = diff[x][2]; // Index of change.
- t = t.replace(/&/g, "&").replace(/</g, "<").replace(/>/g, ">");
- t = t.replace(/\n/g, "¶<BR>");
- if (m == -1)
- html += "<DEL STYLE='background:#FFE6E6;' TITLE='i="+i+"'>"+t+"</DEL>";
- else if (m == 1)
- html += "<INS STYLE='background:#E6FFE6;' TITLE='i="+i+"'>"+t+"</INS>";
- else
- html += "<SPAN TITLE='i="+i+"'>"+t+"</SPAN>";
- }
- return html;
-}
-
-
- //////////////////////////////////////////////////////////////////////
- // Match //
-//////////////////////////////////////////////////////////////////////
-
-
-function match_getmaxbits() {
- // Compute the number of bits in an int.
- // The normal answer for JavaScript is 32.
- var maxbits = 0;
- var oldi = 1;
- var newi = 2;
- while (oldi != newi) {
- maxbits++;
- oldi = newi;
- newi = newi << 1;
- }
- return maxbits;
-}
-var MATCH_MAXBITS = match_getmaxbits();
-
-
-function match_main(text, pattern, loc) {
- // Locate the best instance of 'pattern' in 'text' near 'loc'.
- loc = Math.max(0, Math.min(loc, text.length-pattern.length));
- if (text == pattern) {
- // Shortcut (potentially not guaranteed by the algorithm)
- return 0;
- } else if (text.length == 0) {
- // Nothing to match.
- return null;
- } else if (text.substring(loc, loc + pattern.length) == pattern) {
- // Perfect match at the perfect spot! (Includes case of null pattern)
- return loc;
- } else {
- // Do a fuzzy compare.
- var match = match_bitap(text, pattern, loc);
- return match;
- }
-}
-
-
-function match_bitap(text, pattern, loc) {
- // Locate the best instance of 'pattern' in 'text' near 'loc' using the Bitap algorithm.
- if (pattern.length > MATCH_MAXBITS)
- return alert("Pattern too long for this browser.");
-
- // Initialise the alphabet.
- var s = match_alphabet(pattern);
-
- var score_text_length = text.length;
- // Coerce the text length between reasonable maximums and minimums.
- score_text_length = Math.max(score_text_length, MATCH_MINLENGTH);
- score_text_length = Math.min(score_text_length, MATCH_MAXLENGTH);
-
- function match_bitap_score (e, x) {
- // Compute and return the score for a match with e errors and x location.
- var d = Math.abs(loc-x);
- return (e / pattern.length / MATCH_BALANCE) + (d / score_text_length / (1.0 - MATCH_BALANCE));
- }
-
- // Highest score beyond which we give up.
- var score_threshold = MATCH_THRESHOLD;
- // Is there a nearby exact match? (speedup)
- var best_loc = text.indexOf(pattern, loc);
- if (best_loc != -1)
- score_threshold = Math.min(match_bitap_score(0, best_loc), score_threshold);
- // What about in the other direction? (speedup)
- best_loc = text.lastIndexOf(pattern, loc+pattern.length);
- if (best_loc != -1)
- score_threshold = Math.min(match_bitap_score(0, best_loc), score_threshold);
-
- // Initialise the bit arrays.
- var r = Array();
- var d = -1;
- var matchmask = Math.pow(2, pattern.length-1);
- best_loc = null;
-
- var bin_min, bin_mid;
- var bin_max = Math.max(loc+loc, text.length);
- var last_rd;
- for (var d=0; d<pattern.length; d++) {
- // Scan for the best match; each iteration allows for one more error.
- var rd = Array(text.length);
-
- // Run a binary search to determine how far from 'loc' we can stray at this error level.
- bin_min = loc;
- bin_mid = bin_max;
- while(bin_min < bin_mid) {
- if (match_bitap_score(d, bin_mid) < score_threshold)
- bin_min = bin_mid;
- else
- bin_max = bin_mid;
- bin_mid = Math.floor((bin_max - bin_min) / 2 + bin_min);
- }
- bin_max = bin_mid; // Use the result from this iteration as the maximum for the next.
- var start = Math.max(0, loc - (bin_mid - loc) - 1);
- var finish = Math.min(text.length-1, pattern.length + bin_mid);
-
- if (text.charAt(finish) == pattern.charAt(pattern.length-1))
- rd[finish] = Math.pow(2, d+1)-1;
- else
- rd[finish] = Math.pow(2, d)-1;
- for (var j=finish-1; j>=start; j--) {
- // The alphabet (s) is a sparse hash, so the following lines generate warnings.
- if (d == 0) // First pass: exact match.
- rd[j] = ((rd[j+1] << 1) | 1) & s[text.charAt(j)];
- else // Subsequent passes: fuzzy match.
- rd[j] = ((rd[j+1] << 1) | 1) & s[text.charAt(j)] | ((last_rd[j+1] << 1) | 1) | ((last_rd[j] << 1) | 1) | last_rd[j+1];
- if (rd[j] & matchmask) {
- var score = match_bitap_score(d, j);
- // This match will almost certainly be better than any existing match. But check anyway.
- if (score <= score_threshold) {
- // Told you so.
- score_threshold = score;
- best_loc = j;
- if (j > loc) {
- // When passing loc, don't exceed our current distance from loc.
- start = Math.max(0, loc - (j - loc));
- } else {
- // Already passed loc, downhill from here on in.
- break;
- }
- }
- }
- }
- if (match_bitap_score(d+1, loc) > score_threshold) // No hope for a (better) match at greater error levels.
- break;
- last_rd = rd;
- }
- return best_loc;
-}
-
-
-function match_alphabet(pattern) {
- // Initialise the alphabet for the Bitap algorithm.
- var s = Object();
- for (var i=0; i<pattern.length; i++)
- s[pattern.charAt(i)] = 0;
- for (var i=0; i<pattern.length; i++)
- s[pattern.charAt(i)] |= Math.pow(2, pattern.length-i-1);
- return s;
-}
-
-
- //////////////////////////////////////////////////////////////////////
- // Patch //
-//////////////////////////////////////////////////////////////////////
-
-
-function patch_obj() {
- // Constructor for a patch object.
- this.diffs = [];
- this.start1 = null;
- this.start2 = null;
- this.length1 = 0;
- this.length2 = 0;
-
- this.toString = function() {
- // Emmulate GNU diff's format.
- // Header: @@ -382,8 +481,9 @@
- // Indicies are printed as 1-based, not 0-based.
- var coords1, coords2;
- if (this.length1 == 0)
- coords1 = this.start1+",0";
- else if (this.length1 == 1)
- coords1 = this.start1+1;
- else
- coords1 = (this.start1+1)+","+this.length1;
- if (this.length2 == 0)
- coords2 = this.start2+",0";
- else if (this.length2 == 1)
- coords2 = this.start2+1;
- else
- coords2 = (this.start2+1)+","+this.length2;
- var txt = "@@ -"+coords1+" +"+coords2+" @@\n";
- // Escape the body of the patch with %xx notation.
- for (var x=0; x<this.diffs.length; x++)
- txt += ("- +".charAt(this.diffs[x][0]+1)) + encodeURI(this.diffs[x][1]) + "\n";
- return txt.replace(/%20/g, ' ');
- }
-
- this.text1 = function() {
- // Compute and return the source text (all equalities and deletions).
- var txt = '';
- for (var x=0; x<this.diffs.length; x++)
- if (this.diffs[x][0] == 0 || this.diffs[x][0] == -1)
- txt += this.diffs[x][1];
- return txt;
- }
-
- this.text2 = function() {
- // Compute and return the destination text (all equalities and insertions).
- var txt = '';
- for (var x=0; x<this.diffs.length; x++)
- if (this.diffs[x][0] == 0 || this.diffs[x][0] == 1)
- txt += this.diffs[x][1];
- return txt;
- }
-}
-
-
-function patch_addcontext(patch, text) {
- var pattern = text.substring(patch.start2, patch.start2+patch.length1);
- var padding = 0;
- // Increase the context until we're unique (but don't let the pattern expand beyond MATCH_MAXBITS).
- while (text.indexOf(pattern) != text.lastIndexOf(pattern) && pattern.length < MATCH_MAXBITS-PATCH_MARGIN-PATCH_MARGIN) {
- padding += PATCH_MARGIN;
- pattern = text.substring(patch.start2 - padding, patch.start2+patch.length1 + padding);
- }
- // Add one chunk for good luck.
- padding += PATCH_MARGIN;
- // Add the prefix.
- var prefix = text.substring(patch.start2 - padding, patch.start2);
- if (prefix != '')
- patch.diffs.unshift([0, prefix]);
- // Add the suffix
- var suffix = text.substring(patch.start2+patch.length1, patch.start2+patch.length1 + padding);
- if (suffix != '')
- patch.diffs.push([0, suffix]);
-
- // Roll back the start points.
- patch.start1 -= prefix.length;
- patch.start2 -= prefix.length;
- // Extend the lengths.
- patch.length1 += prefix.length + suffix.length;
- patch.length2 += prefix.length + suffix.length;
-}
-
-
-function patch_make(text1, text2, diff) {
- // Compute a list of patches to turn text1 into text2.
- // Use diff if provided, otherwise compute it ourselves.
- if (typeof diff == 'undefined') {
- diff = diff_main(text1, text2, true);
- if (diff.length > 2) {
- diff_cleanup_semantic(diff);
- diff_cleanup_efficiency(diff);
- }
- }
- if (diff.length == 0)
- return []; // Get rid of the null case.
- var patches = [];
- var patch = new patch_obj();
- var char_count1 = 0; // Number of characters into the text1 string.
- var char_count2 = 0; // Number of characters into the text2 string.
- var last_type = null;
- var prepatch_text = text1; // Recreate the patches to determine context info.
- var postpatch_text = text1;
- for (var x=0; x<diff.length; x++) {
- var diff_type = diff[x][0];
- var diff_text = diff[x][1];
-
- if (patch.diffs.length == 0 && diff_type != 0) {
- // A new patch starts here.
- patch.start1 = char_count1;
- patch.start2 = char_count2;
- }
-
- if (diff_type == 1) {
- // Insertion
- patch.diffs.push(diff[x]);
- patch.length2 += diff_text.length;
- postpatch_text = postpatch_text.substring(0, char_count2) + diff_text + postpatch_text.substring(char_count2);
- } else if (diff_type == -1) {
- // Deletion.
- patch.length1 += diff_text.length;
- patch.diffs.push(diff[x]);
- postpatch_text = postpatch_text.substring(0, char_count2) + postpatch_text.substring(char_count2 + diff_text.length);
- } else if (diff_type == 0 && diff_text.length <= 2*PATCH_MARGIN && patch.diffs.length != 0 && diff.length != x+1) {
- // Small equality inside a patch.
- patch.diffs.push(diff[x]);
- patch.length1 += diff_text.length;
- patch.length2 += diff_text.length;
- }
-
- last_type = diff_type;
- if (diff_type == 0 && diff_text.length >= 2*PATCH_MARGIN) {
- // Time for a new patch.
- if (patch.diffs.length != 0) {
- patch_addcontext(patch, prepatch_text);
- patches.push(patch);
- var patch = new patch_obj();
- last_type = null;
- prepatch_text = postpatch_text;
- }
- }
-
- // Update the current character count.
- if (diff_type != 1)
- char_count1 += diff_text.length;
- if (diff_type != -1)
- char_count2 += diff_text.length;
- }
- // Pick up the leftover patch if not empty.
- if (patch.diffs.length != 0) {
- patch_addcontext(patch, prepatch_text);
- patches.push(patch);
- }
-
- return patches;
-}
-
-
-function patch_apply(patches, text) {
- // Merge a set of patches onto the text.
- // Return a patched text, as well as a list of true/false values indicating which patches were applied.
- patch_splitmax(patches);
- var results = [];
- var delta = 0;
- var expected_loc, start_loc;
- var text1, text2;
- var diff, mod, index1, index2;
- for (var x=0; x<patches.length; x++) {
- expected_loc = patches[x].start2 + delta;
- text1 = patches[x].text1();
- start_loc = match_main(text, text1, expected_loc);
- if (start_loc == null) {
- // No match found. :(
- results.push(false);
- } else {
- // Found a match. :)
- results.push(true);
- delta = start_loc - expected_loc;
- text2 = text.substring(start_loc, start_loc + text1.length);
- if (text1 == text2) {
- // Perfect match, just shove the replacement text in.
- text = text.substring(0, start_loc) + patches[x].text2() + text.substring(start_loc + text1.length);
- } else {
- // Imperfect match. Run a diff to get a framework of equivalent indicies.
- diff = diff_main(text1, text2, false);
- index1 = 0;
- for (var y=0; y<patches[x].diffs.length; y++) {
- mod = patches[x].diffs[y];
- if (mod[0] != 0)
- index2 = diff_xindex(diff, index1);
- if (mod[0] == 1) // Insertion
- text = text.substring(0, start_loc + index2) + mod[1] + text.substring(start_loc + index2);
- else if (mod[0] == -1) // Deletion
- text = text.substring(0, start_loc + index2) + text.substring(start_loc + diff_xindex(diff, index1 + mod[1].length));
- if (mod[0] != -1)
- index1 += mod[1].length;
- }
- }
- }
- }
- return [text, results];
-}
-
-
-function patch_splitmax(patches) {
- // Look through the patches and break up any which are longer than the maximum limit of the match algorithm.
- var bigpatch, patch, patch_size, start1, start2, diff_type, diff_text, precontext, postcontext, empty;
- for (var x=0; x<patches.length; x++) {
- if (patches[x].length1 > MATCH_MAXBITS) {
- bigpatch = patches[x];
- // Remove the big old patch.
- patches.splice(x, 1);
- patch_size = MATCH_MAXBITS;
- start1 = bigpatch.start1;
- start2 = bigpatch.start2;
- precontext = '';
- while (bigpatch.diffs.length != 0) {
- // Create one of several smaller patches.
- patch = new patch_obj();
- empty = true;
- patch.start1 = start1 - precontext.length;
- patch.start2 = start2 - precontext.length;
- if (precontext != '') {
- patch.length1 = patch.length2 = precontext.length;
- patch.diffs.push([0, precontext]);
- }
- while (bigpatch.diffs.length != 0 && patch.length1 < patch_size - PATCH_MARGIN) {
- diff_type = bigpatch.diffs[0][0];
- diff_text = bigpatch.diffs[0][1];
- if (diff_type == 1) {
- // Insertions are harmless.
- patch.length2 += diff_text.length;
- start2 += diff_text.length;
- patch.diffs.push(bigpatch.diffs.shift());
- empty = false;
- } else {
- // Deletion or equality. Only take as much as we can stomach.
- diff_text = diff_text.substring(0, patch_size - patch.length1 - PATCH_MARGIN);
- patch.length1 += diff_text.length;
- start1 += diff_text.length;
- if (diff_type == 0) {
- patch.length2 += diff_text.length;
- start2 += diff_text.length;
- } else {
- empty = false;
- }
- patch.diffs.push([diff_type, diff_text]);
- if (diff_text == bigpatch.diffs[0][1])
- bigpatch.diffs.shift();
- else
- bigpatch.diffs[0][1] = bigpatch.diffs[0][1].substring(diff_text.length);
- }
- }
- // Compute the head context for the next patch.
- precontext = patch.text2();
- precontext = precontext.substring(precontext.length - PATCH_MARGIN);
- // Append the end context for this patch.
- postcontext = bigpatch.text1().substring(0, PATCH_MARGIN);
- if (postcontext != '') {
- patch.length1 += postcontext.length;
- patch.length2 += postcontext.length;
- if (patch.diffs.length > 0 && patch.diffs[patch.diffs.length-1][0] == 0)
- patch.diffs[patch.diffs.length-1][1] += postcontext;
- else
- patch.diffs.push([0, postcontext]);
- }
- if (!empty)
- patches.splice(x++, 0, patch);
- }
- }
- }
-}
-
-
-function patch_totext(patches) {
- // Take a list of patches and return a textual representation.
- var text = '';
- for (var x=0; x<patches.length; x++)
- text += patches[x];
- return text;
-}
-
-
-function patch_fromtext(text) {
- // Take a textual representation of patches and return a list of patch objects.
- var patches = [];
- text = text.split('\n');
- var patch, m, chars1, chars2, sign, line;
- while (text.length != 0) {
- m = text[0].match(/^@@ -(\d+),?(\d*) \+(\d+),?(\d*) @@$/);
- if (!m)
- return alert("Invalid patch string:\n"+text[0]);
- patch = new patch_obj();
- patches.push(patch);
- patch.start1 = parseInt(m[1]);
- if (m[2] == '') {
- patch.start1--;
- patch.length1 = 1;
- } else if (m[2] == '0') {
- patch.length1 = 0;
- } else {
- patch.start1--;
- patch.length1 = parseInt(m[2]);
- }
-
- patch.start2 = parseInt(m[3]);
- if (m[4] == '') {
- patch.start2--;
- patch.length2 = 1;
- } else if (m[4] == '0') {
- patch.length2 = 0;
- } else {
- patch.start2--;
- patch.length2 = parseInt(m[4]);
- }
- text.shift();
-
- while (text.length != 0) {
- sign = text[0].charAt(0);
- line = decodeURIComponent(text[0].substring(1));
- if (sign == '-') {
- // Deletion.
- patch.diffs.push([-1, line]);
- } else if (sign == '+') {
- // Insertion.
- patch.diffs.push([1, line]);
- } else if (sign == ' ') {
- // Minor equality.
- patch.diffs.push([0, line]);
- } else if (sign == '@') {
- // Start of next patch.
- break;
- } else if (sign == '') {
- // Blank line? Whatever.
- } else {
- // WTF?
- return alert("Invalid patch mode: '"+sign+"'\n"+line);
- }
- text.shift();
- }
- }
- return patches;
-}
-
-// EOF