-/*istanbul ignore next */
-// jscs:disable maximumLineLength
-/*
- * This file is a modified version of google-diff-match-patch's JavaScript implementation
- * (https://code.google.com/p/google-diff-match-patch/source/browse/trunk/javascript/diff_match_patch_uncompressed.js),
- * modifications are licensed as more fully set forth in LICENSE.txt.
- *
- * The original source of google-diff-match-patch is attributable and licensed as follows:
- *
- * Copyright 2006 Google Inc.
- * http://code.google.com/p/google-diff-match-patch/
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * More Info:
- * https://code.google.com/p/google-diff-match-patch/
- *
- * Usage: QUnit.diff(expected, actual)
- *
- * QUnit.diff( "the quick brown fox jumped over", "the quick fox jumps over" ) === "the quick <del>brown </del> fox jump<ins>s</ins><del>ed</del over"
- */
-QUnit.diff = (function() {
-
- function DiffMatchPatch() {
-
- // Defaults.
- // Redefine these in your program to override the defaults.
-
- // Number of seconds to map a diff before giving up (0 for infinity).
- this.DiffTimeout = 1.0;
- // Cost of an empty edit operation in terms of edit characters.
- this.DiffEditCost = 4;
- }
-
- // DIFF FUNCTIONS
-
- /**
- * The data structure representing a diff is an array of tuples:
- * [[DIFF_DELETE, 'Hello'], [DIFF_INSERT, 'Goodbye'], [DIFF_EQUAL, ' world.']]
- * which means: delete 'Hello', add 'Goodbye' and keep ' world.'
- */
- var DIFF_DELETE = -1,
- DIFF_INSERT = 1,
- DIFF_EQUAL = 0;
-
- /**
- * Find the differences between two texts. Simplifies the problem by stripping
- * any common prefix or suffix off the texts before diffing.
- * @param {string} text1 Old string to be diffed.
- * @param {string} text2 New string to be diffed.
- * @param {boolean=} optChecklines Optional speedup flag. If present and false,
- * then don't run a line-level diff first to identify the changed areas.
- * Defaults to true, which does a faster, slightly less optimal diff.
- * @param {number} optDeadline Optional time when the diff should be complete
- * by. Used internally for recursive calls. Users should set DiffTimeout
- * instead.
- * @return {!Array.<!DiffMatchPatch.Diff>} Array of diff tuples.
- */
- DiffMatchPatch.prototype.DiffMain = function( text1, text2, optChecklines, optDeadline ) {
- var deadline, checklines, commonlength,
- commonprefix, commonsuffix, diffs;
- // Set a deadline by which time the diff must be complete.
- if ( typeof optDeadline === "undefined" ) {
- if ( this.DiffTimeout <= 0 ) {
- optDeadline = Number.MAX_VALUE;
- } else {
- optDeadline = ( new Date() ).getTime() + this.DiffTimeout * 1000;
- }
- }
- deadline = optDeadline;
-
- // Check for null inputs.
- if ( text1 === null || text2 === null ) {
- throw new Error( "Null input. (DiffMain)" );
- }
-
- // Check for equality (speedup).
- if ( text1 === text2 ) {
- if ( text1 ) {
- return [
- [ DIFF_EQUAL, text1 ]
- ];
- }
- return [];
- }
-
- if ( typeof optChecklines === "undefined" ) {
- optChecklines = true;
- }
-
- checklines = optChecklines;
-
- // Trim off common prefix (speedup).
- commonlength = this.diffCommonPrefix( text1, text2 );
- commonprefix = text1.substring( 0, commonlength );
- text1 = text1.substring( commonlength );
- text2 = text2.substring( commonlength );
-
- // Trim off common suffix (speedup).
- /////////
- commonlength = this.diffCommonSuffix( text1, text2 );
- commonsuffix = text1.substring( text1.length - commonlength );
- text1 = text1.substring( 0, text1.length - commonlength );
- text2 = text2.substring( 0, text2.length - commonlength );
-
- // Compute the diff on the middle block.
- diffs = this.diffCompute( text1, text2, checklines, deadline );
-
- // Restore the prefix and suffix.
- if ( commonprefix ) {
- diffs.unshift( [ DIFF_EQUAL, commonprefix ] );
- }
- if ( commonsuffix ) {
- diffs.push( [ DIFF_EQUAL, commonsuffix ] );
- }
- this.diffCleanupMerge( diffs );
- return diffs;
- };
-
- /**
- * Reduce the number of edits by eliminating operationally trivial equalities.
- * @param {!Array.<!DiffMatchPatch.Diff>} diffs Array of diff tuples.
- */
- DiffMatchPatch.prototype.diffCleanupEfficiency = function( diffs ) {
- var changes, equalities, equalitiesLength, lastequality,
- pointer, preIns, preDel, postIns, postDel;
- changes = false;
- equalities = []; // Stack of indices where equalities are found.
- equalitiesLength = 0; // Keeping our own length var is faster in JS.
- /** @type {?string} */
- lastequality = null;
- // Always equal to diffs[equalities[equalitiesLength - 1]][1]
- pointer = 0; // Index of current position.
- // Is there an insertion operation before the last equality.
- preIns = false;
- // Is there a deletion operation before the last equality.
- preDel = false;
- // Is there an insertion operation after the last equality.
- postIns = false;
- // Is there a deletion operation after the last equality.
- postDel = false;
- while ( pointer < diffs.length ) {
- if ( diffs[ pointer ][ 0 ] === DIFF_EQUAL ) { // Equality found.
- if ( diffs[ pointer ][ 1 ].length < this.DiffEditCost && ( postIns || postDel ) ) {
- // Candidate found.
- equalities[ equalitiesLength++ ] = pointer;
- preIns = postIns;
- preDel = postDel;
- lastequality = diffs[ pointer ][ 1 ];
- } else {
- // Not a candidate, and can never become one.
- equalitiesLength = 0;
- lastequality = null;
- }
- postIns = postDel = false;
- } else { // An insertion or deletion.
- if ( diffs[ pointer ][ 0 ] === DIFF_DELETE ) {
- postDel = true;
- } else {
- postIns = 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 && ( ( preIns && preDel && postIns && postDel ) ||
- ( ( lastequality.length < this.DiffEditCost / 2 ) &&
- ( preIns + preDel + postIns + postDel ) === 3 ) ) ) {
- // Duplicate record.
- diffs.splice( equalities[equalitiesLength - 1], 0, [ DIFF_DELETE, lastequality ] );
- // Change second copy to insert.
- diffs[ equalities[ equalitiesLength - 1 ] + 1 ][ 0 ] = DIFF_INSERT;
- equalitiesLength--; // Throw away the equality we just deleted;
- lastequality = null;
- if (preIns && preDel) {
- // No changes made which could affect previous entry, keep going.
- postIns = postDel = true;
- equalitiesLength = 0;
- } else {
- equalitiesLength--; // Throw away the previous equality.
- pointer = equalitiesLength > 0 ? equalities[ equalitiesLength - 1 ] : -1;
- postIns = postDel = false;
- }
- changes = true;
- }
- }
- pointer++;
- }
-
- if ( changes ) {
- this.diffCleanupMerge( diffs );
- }
- };
-
- /**
- * Convert a diff array into a pretty HTML report.
- * @param {!Array.<!DiffMatchPatch.Diff>} diffs Array of diff tuples.
- * @param {integer} string to be beautified.
- * @return {string} HTML representation.
- */
- DiffMatchPatch.prototype.diffPrettyHtml = function( diffs ) {
- var op, data, x, html = [];
- for ( x = 0; x < diffs.length; x++ ) {
- op = diffs[x][0]; // Operation (insert, delete, equal)
- data = diffs[x][1]; // Text of change.
- switch ( op ) {
- case DIFF_INSERT:
- html[x] = "<ins>" + data + "</ins>";
- break;
- case DIFF_DELETE:
- html[x] = "<del>" + data + "</del>";
- break;
- case DIFF_EQUAL:
- html[x] = "<span>" + data + "</span>";
- break;
- }
- }
- return html.join("");
- };
-
- /**
- * Determine the common prefix of two strings.
- * @param {string} text1 First string.
- * @param {string} text2 Second string.
- * @return {number} The number of characters common to the start of each
- * string.
- */
- DiffMatchPatch.prototype.diffCommonPrefix = function( text1, text2 ) {
- var pointermid, pointermax, pointermin, pointerstart;
- // Quick check for common null cases.
- if ( !text1 || !text2 || text1.charAt(0) !== text2.charAt(0) ) {
- return 0;
- }
- // Binary search.
- // Performance analysis: http://neil.fraser.name/news/2007/10/09/
- pointermin = 0;
- pointermax = Math.min( text1.length, text2.length );
- pointermid = pointermax;
- pointerstart = 0;
- while ( pointermin < pointermid ) {
- if ( text1.substring( pointerstart, pointermid ) === text2.substring( pointerstart, pointermid ) ) {
- pointermin = pointermid;
- pointerstart = pointermin;
- } else {
- pointermax = pointermid;
- }
- pointermid = Math.floor( ( pointermax - pointermin ) / 2 + pointermin );
- }
- return pointermid;
- };
-
- /**
- * Determine the common suffix of two strings.
- * @param {string} text1 First string.
- * @param {string} text2 Second string.
- * @return {number} The number of characters common to the end of each string.
- */
- DiffMatchPatch.prototype.diffCommonSuffix = function( text1, text2 ) {
- var pointermid, pointermax, pointermin, pointerend;
- // Quick check for common null cases.
- if (!text1 || !text2 || text1.charAt(text1.length - 1) !== text2.charAt(text2.length - 1)) {
- return 0;
- }
- // Binary search.
- // Performance analysis: http://neil.fraser.name/news/2007/10/09/
- pointermin = 0;
- pointermax = Math.min(text1.length, text2.length);
- pointermid = pointermax;
- pointerend = 0;
- while ( pointermin < pointermid ) {
- if (text1.substring( text1.length - pointermid, text1.length - pointerend ) ===
- text2.substring( text2.length - pointermid, text2.length - pointerend ) ) {
- pointermin = pointermid;
- pointerend = pointermin;
- } else {
- pointermax = pointermid;
- }
- pointermid = Math.floor( ( pointermax - pointermin ) / 2 + pointermin );
- }
- return pointermid;
- };
-
- /**
- * Find the differences between two texts. Assumes that the texts do not
- * have any common prefix or suffix.
- * @param {string} text1 Old string to be diffed.
- * @param {string} text2 New string to be diffed.
- * @param {boolean} checklines Speedup flag. If false, then don't run a
- * line-level diff first to identify the changed areas.
- * If true, then run a faster, slightly less optimal diff.
- * @param {number} deadline Time when the diff should be complete by.
- * @return {!Array.<!DiffMatchPatch.Diff>} Array of diff tuples.
- * @private
- */
- DiffMatchPatch.prototype.diffCompute = function( text1, text2, checklines, deadline ) {
- var diffs, longtext, shorttext, i, hm,
- text1A, text2A, text1B, text2B,
- midCommon, diffsA, diffsB;
-
- if ( !text1 ) {
- // Just add some text (speedup).
- return [
- [ DIFF_INSERT, text2 ]
- ];
- }
-
- if (!text2) {
- // Just delete some text (speedup).
- return [
- [ DIFF_DELETE, text1 ]
- ];
- }
-
- longtext = text1.length > text2.length ? text1 : text2;
- shorttext = text1.length > text2.length ? text2 : text1;
- i = longtext.indexOf( shorttext );
- if ( i !== -1 ) {
- // Shorter text is inside the longer text (speedup).
- diffs = [
- [ DIFF_INSERT, longtext.substring( 0, i ) ],
- [ DIFF_EQUAL, shorttext ],
- [ DIFF_INSERT, longtext.substring( i + shorttext.length ) ]
- ];
- // Swap insertions for deletions if diff is reversed.
- if ( text1.length > text2.length ) {
- diffs[0][0] = diffs[2][0] = DIFF_DELETE;
- }
- return diffs;
- }
-
- if ( shorttext.length === 1 ) {
- // Single character string.
- // After the previous speedup, the character can't be an equality.
- return [
- [ DIFF_DELETE, text1 ],
- [ DIFF_INSERT, text2 ]
- ];
- }
-
- // Check to see if the problem can be split in two.
- hm = this.diffHalfMatch(text1, text2);
- if (hm) {
- // A half-match was found, sort out the return data.
- text1A = hm[0];
- text1B = hm[1];
- text2A = hm[2];
- text2B = hm[3];
- midCommon = hm[4];
- // Send both pairs off for separate processing.
- diffsA = this.DiffMain(text1A, text2A, checklines, deadline);
- diffsB = this.DiffMain(text1B, text2B, checklines, deadline);
- // Merge the results.
- return diffsA.concat([
- [ DIFF_EQUAL, midCommon ]
- ], diffsB);
- }
-
- if (checklines && text1.length > 100 && text2.length > 100) {
- return this.diffLineMode(text1, text2, deadline);
- }
-
- return this.diffBisect(text1, text2, deadline);
- };
-
- /**
- * Do the two texts share a substring which is at least half the length of the
- * longer text?
- * This speedup can produce non-minimal diffs.
- * @param {string} text1 First string.
- * @param {string} text2 Second string.
- * @return {Array.<string>} Five element Array, containing the prefix of
- * text1, the suffix of text1, the prefix of text2, the suffix of
- * text2 and the common middle. Or null if there was no match.
- * @private
- */
- DiffMatchPatch.prototype.diffHalfMatch = function(text1, text2) {
- var longtext, shorttext, dmp,
- text1A, text2B, text2A, text1B, midCommon,
- hm1, hm2, hm;
- if (this.DiffTimeout <= 0) {
- // Don't risk returning a non-optimal diff if we have unlimited time.
- return null;
- }
- longtext = text1.length > text2.length ? text1 : text2;
- shorttext = text1.length > text2.length ? text2 : text1;
- if (longtext.length < 4 || shorttext.length * 2 < longtext.length) {
- return null; // Pointless.
- }
- dmp = this; // 'this' becomes 'window' in a closure.
-
- /**
- * Does a substring of shorttext exist within longtext such that the substring
- * is at least half the length of longtext?
- * Closure, but does not reference any external variables.
- * @param {string} longtext Longer string.
- * @param {string} shorttext Shorter string.
- * @param {number} i Start index of quarter length substring within longtext.
- * @return {Array.<string>} Five element Array, containing the prefix of
- * longtext, the suffix of longtext, the prefix of shorttext, the suffix
- * of shorttext and the common middle. Or null if there was no match.
- * @private
- */
- function diffHalfMatchI(longtext, shorttext, i) {
- var seed, j, bestCommon, prefixLength, suffixLength,
- bestLongtextA, bestLongtextB, bestShorttextA, bestShorttextB;
- // Start with a 1/4 length substring at position i as a seed.
- seed = longtext.substring(i, i + Math.floor(longtext.length / 4));
- j = -1;
- bestCommon = "";
- while ((j = shorttext.indexOf(seed, j + 1)) !== -1) {
- prefixLength = dmp.diffCommonPrefix(longtext.substring(i),
- shorttext.substring(j));
- suffixLength = dmp.diffCommonSuffix(longtext.substring(0, i),
- shorttext.substring(0, j));
- if (bestCommon.length < suffixLength + prefixLength) {
- bestCommon = shorttext.substring(j - suffixLength, j) +
- shorttext.substring(j, j + prefixLength);
- bestLongtextA = longtext.substring(0, i - suffixLength);
- bestLongtextB = longtext.substring(i + prefixLength);
- bestShorttextA = shorttext.substring(0, j - suffixLength);
- bestShorttextB = shorttext.substring(j + prefixLength);
- }
- }
- if (bestCommon.length * 2 >= longtext.length) {
- return [ bestLongtextA, bestLongtextB,
- bestShorttextA, bestShorttextB, bestCommon
- ];
- } else {
- return null;
- }
- }
-
- // First check if the second quarter is the seed for a half-match.
- hm1 = diffHalfMatchI(longtext, shorttext,
- Math.ceil(longtext.length / 4));
- // Check again based on the third quarter.
- hm2 = diffHalfMatchI(longtext, shorttext,
- Math.ceil(longtext.length / 2));
- 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.
- text1A, text1B, text2A, text2B;
- if (text1.length > text2.length) {
- text1A = hm[0];
- text1B = hm[1];
- text2A = hm[2];
- text2B = hm[3];
- } else {
- text2A = hm[0];
- text2B = hm[1];
- text1A = hm[2];
- text1B = hm[3];
- }
- midCommon = hm[4];
- return [ text1A, text1B, text2A, text2B, midCommon ];
- };
-
- /**
- * Do a quick line-level diff on both strings, then rediff the parts for
- * greater accuracy.
- * This speedup can produce non-minimal diffs.
- * @param {string} text1 Old string to be diffed.
- * @param {string} text2 New string to be diffed.
- * @param {number} deadline Time when the diff should be complete by.
- * @return {!Array.<!DiffMatchPatch.Diff>} Array of diff tuples.
- * @private
- */
- DiffMatchPatch.prototype.diffLineMode = function(text1, text2, deadline) {
- var a, diffs, linearray, pointer, countInsert,
- countDelete, textInsert, textDelete, j;
- // Scan the text on a line-by-line basis first.
- a = this.diffLinesToChars(text1, text2);
- text1 = a.chars1;
- text2 = a.chars2;
- linearray = a.lineArray;
-
- diffs = this.DiffMain(text1, text2, false, deadline);
-
- // Convert the diff back to original text.
- this.diffCharsToLines(diffs, linearray);
- // Eliminate freak matches (e.g. blank lines)
- this.diffCleanupSemantic(diffs);
-
- // Rediff any replacement blocks, this time character-by-character.
- // Add a dummy entry at the end.
- diffs.push( [ DIFF_EQUAL, "" ] );
- pointer = 0;
- countDelete = 0;
- countInsert = 0;
- textDelete = "";
- textInsert = "";
- while (pointer < diffs.length) {
- switch ( diffs[pointer][0] ) {
- case DIFF_INSERT:
- countInsert++;
- textInsert += diffs[pointer][1];
- break;
- case DIFF_DELETE:
- countDelete++;
- textDelete += diffs[pointer][1];
- break;
- case DIFF_EQUAL:
- // Upon reaching an equality, check for prior redundancies.
- if (countDelete >= 1 && countInsert >= 1) {
- // Delete the offending records and add the merged ones.
- diffs.splice(pointer - countDelete - countInsert,
- countDelete + countInsert);
- pointer = pointer - countDelete - countInsert;
- a = this.DiffMain(textDelete, textInsert, false, deadline);
- for (j = a.length - 1; j >= 0; j--) {
- diffs.splice( pointer, 0, a[j] );
- }
- pointer = pointer + a.length;
- }
- countInsert = 0;
- countDelete = 0;
- textDelete = "";
- textInsert = "";
- break;
- }
- pointer++;
- }
- diffs.pop(); // Remove the dummy entry at the end.
-
- return diffs;
- };
-
- /**
- * Find the 'middle snake' of a diff, split the problem in two
- * and return the recursively constructed diff.
- * See Myers 1986 paper: An O(ND) Difference Algorithm and Its Variations.
- * @param {string} text1 Old string to be diffed.
- * @param {string} text2 New string to be diffed.
- * @param {number} deadline Time at which to bail if not yet complete.
- * @return {!Array.<!DiffMatchPatch.Diff>} Array of diff tuples.
- * @private
- */
- DiffMatchPatch.prototype.diffBisect = function(text1, text2, deadline) {
- var text1Length, text2Length, maxD, vOffset, vLength,
- v1, v2, x, delta, front, k1start, k1end, k2start,
- k2end, k2Offset, k1Offset, x1, x2, y1, y2, d, k1, k2;
- // Cache the text lengths to prevent multiple calls.
- text1Length = text1.length;
- text2Length = text2.length;
- maxD = Math.ceil((text1Length + text2Length) / 2);
- vOffset = maxD;
- vLength = 2 * maxD;
- v1 = new Array(vLength);
- v2 = new Array(vLength);
- // Setting all elements to -1 is faster in Chrome & Firefox than mixing
- // integers and undefined.
- for (x = 0; x < vLength; x++) {
- v1[x] = -1;
- v2[x] = -1;
- }
- v1[vOffset + 1] = 0;
- v2[vOffset + 1] = 0;
- delta = text1Length - text2Length;
- // If the total number of characters is odd, then the front path will collide
- // with the reverse path.
- front = (delta % 2 !== 0);
- // Offsets for start and end of k loop.
- // Prevents mapping of space beyond the grid.
- k1start = 0;
- k1end = 0;
- k2start = 0;
- k2end = 0;
- for (d = 0; d < maxD; d++) {
- // Bail out if deadline is reached.
- if ((new Date()).getTime() > deadline) {
- break;
- }
-
- // Walk the front path one step.
- for (k1 = -d + k1start; k1 <= d - k1end; k1 += 2) {
- k1Offset = vOffset + k1;
- if ( k1 === -d || ( k1 !== d && v1[ k1Offset - 1 ] < v1[ k1Offset + 1 ] ) ) {
- x1 = v1[k1Offset + 1];
- } else {
- x1 = v1[k1Offset - 1] + 1;
- }
- y1 = x1 - k1;
- while (x1 < text1Length && y1 < text2Length &&
- text1.charAt(x1) === text2.charAt(y1)) {
- x1++;
- y1++;
- }
- v1[k1Offset] = x1;
- if (x1 > text1Length) {
- // Ran off the right of the graph.
- k1end += 2;
- } else if (y1 > text2Length) {
- // Ran off the bottom of the graph.
- k1start += 2;
- } else if (front) {
- k2Offset = vOffset + delta - k1;
- if (k2Offset >= 0 && k2Offset < vLength && v2[k2Offset] !== -1) {
- // Mirror x2 onto top-left coordinate system.
- x2 = text1Length - v2[k2Offset];
- if (x1 >= x2) {
- // Overlap detected.
- return this.diffBisectSplit(text1, text2, x1, y1, deadline);
- }
- }
- }
- }
-
- // Walk the reverse path one step.
- for (k2 = -d + k2start; k2 <= d - k2end; k2 += 2) {
- k2Offset = vOffset + k2;
- if ( k2 === -d || (k2 !== d && v2[ k2Offset - 1 ] < v2[ k2Offset + 1 ] ) ) {
- x2 = v2[k2Offset + 1];
- } else {
- x2 = v2[k2Offset - 1] + 1;
- }
- y2 = x2 - k2;
- while (x2 < text1Length && y2 < text2Length &&
- text1.charAt(text1Length - x2 - 1) ===
- text2.charAt(text2Length - y2 - 1)) {
- x2++;
- y2++;
- }
- v2[k2Offset] = x2;
- if (x2 > text1Length) {
- // Ran off the left of the graph.
- k2end += 2;
- } else if (y2 > text2Length) {
- // Ran off the top of the graph.
- k2start += 2;
- } else if (!front) {
- k1Offset = vOffset + delta - k2;
- if (k1Offset >= 0 && k1Offset < vLength && v1[k1Offset] !== -1) {
- x1 = v1[k1Offset];
- y1 = vOffset + x1 - k1Offset;
- // Mirror x2 onto top-left coordinate system.
- x2 = text1Length - x2;
- if (x1 >= x2) {
- // Overlap detected.
- return this.diffBisectSplit(text1, text2, x1, y1, deadline);
- }
- }
- }
- }
- }
- // Diff took too long and hit the deadline or
- // number of diffs equals number of characters, no commonality at all.
- return [
- [ DIFF_DELETE, text1 ],
- [ DIFF_INSERT, text2 ]
- ];
- };
-
- /**
- * Given the location of the 'middle snake', split the diff in two parts
- * and recurse.
- * @param {string} text1 Old string to be diffed.
- * @param {string} text2 New string to be diffed.
- * @param {number} x Index of split point in text1.
- * @param {number} y Index of split point in text2.
- * @param {number} deadline Time at which to bail if not yet complete.
- * @return {!Array.<!DiffMatchPatch.Diff>} Array of diff tuples.
- * @private
- */
- DiffMatchPatch.prototype.diffBisectSplit = function( text1, text2, x, y, deadline ) {
- var text1a, text1b, text2a, text2b, diffs, diffsb;
- text1a = text1.substring(0, x);
- text2a = text2.substring(0, y);
- text1b = text1.substring(x);
- text2b = text2.substring(y);
-
- // Compute both diffs serially.
- diffs = this.DiffMain(text1a, text2a, false, deadline);
- diffsb = this.DiffMain(text1b, text2b, false, deadline);
-
- return diffs.concat(diffsb);
- };
-
- /**
- * Reduce the number of edits by eliminating semantically trivial equalities.
- * @param {!Array.<!DiffMatchPatch.Diff>} diffs Array of diff tuples.
- */
- DiffMatchPatch.prototype.diffCleanupSemantic = function(diffs) {
- var changes, equalities, equalitiesLength, lastequality,
- pointer, lengthInsertions2, lengthDeletions2, lengthInsertions1,
- lengthDeletions1, deletion, insertion, overlapLength1, overlapLength2;
- changes = false;
- equalities = []; // Stack of indices where equalities are found.
- equalitiesLength = 0; // Keeping our own length var is faster in JS.
- /** @type {?string} */
- lastequality = null;
- // Always equal to diffs[equalities[equalitiesLength - 1]][1]
- pointer = 0; // Index of current position.
- // Number of characters that changed prior to the equality.
- lengthInsertions1 = 0;
- lengthDeletions1 = 0;
- // Number of characters that changed after the equality.
- lengthInsertions2 = 0;
- lengthDeletions2 = 0;
- while (pointer < diffs.length) {
- if (diffs[pointer][0] === DIFF_EQUAL) { // Equality found.
- equalities[equalitiesLength++] = pointer;
- lengthInsertions1 = lengthInsertions2;
- lengthDeletions1 = lengthDeletions2;
- lengthInsertions2 = 0;
- lengthDeletions2 = 0;
- lastequality = diffs[pointer][1];
- } else { // An insertion or deletion.
- if (diffs[pointer][0] === DIFF_INSERT) {
- lengthInsertions2 += diffs[pointer][1].length;
- } else {
- lengthDeletions2 += diffs[pointer][1].length;
- }
- // Eliminate an equality that is smaller or equal to the edits on both
- // sides of it.
- if (lastequality && (lastequality.length <=
- Math.max(lengthInsertions1, lengthDeletions1)) &&
- (lastequality.length <= Math.max(lengthInsertions2,
- lengthDeletions2))) {
- // Duplicate record.
- diffs.splice( equalities[ equalitiesLength - 1 ], 0, [ DIFF_DELETE, lastequality ] );
- // Change second copy to insert.
- diffs[equalities[equalitiesLength - 1] + 1][0] = DIFF_INSERT;
- // Throw away the equality we just deleted.
- equalitiesLength--;
- // Throw away the previous equality (it needs to be reevaluated).
- equalitiesLength--;
- pointer = equalitiesLength > 0 ? equalities[equalitiesLength - 1] : -1;
- lengthInsertions1 = 0; // Reset the counters.
- lengthDeletions1 = 0;
- lengthInsertions2 = 0;
- lengthDeletions2 = 0;
- lastequality = null;
- changes = true;
- }
- }
- pointer++;
- }
-
- // Normalize the diff.
- if (changes) {
- this.diffCleanupMerge(diffs);
- }
-
- // Find any overlaps between deletions and insertions.
- // e.g: <del>abcxxx</del><ins>xxxdef</ins>
- // -> <del>abc</del>xxx<ins>def</ins>
- // e.g: <del>xxxabc</del><ins>defxxx</ins>
- // -> <ins>def</ins>xxx<del>abc</del>
- // Only extract an overlap if it is as big as the edit ahead or behind it.
- pointer = 1;
- while (pointer < diffs.length) {
- if (diffs[pointer - 1][0] === DIFF_DELETE &&
- diffs[pointer][0] === DIFF_INSERT) {
- deletion = diffs[pointer - 1][1];
- insertion = diffs[pointer][1];
- overlapLength1 = this.diffCommonOverlap(deletion, insertion);
- overlapLength2 = this.diffCommonOverlap(insertion, deletion);
- if (overlapLength1 >= overlapLength2) {
- if (overlapLength1 >= deletion.length / 2 ||
- overlapLength1 >= insertion.length / 2) {
- // Overlap found. Insert an equality and trim the surrounding edits.
- diffs.splice( pointer, 0, [ DIFF_EQUAL, insertion.substring( 0, overlapLength1 ) ] );
- diffs[pointer - 1][1] =
- deletion.substring(0, deletion.length - overlapLength1);
- diffs[pointer + 1][1] = insertion.substring(overlapLength1);
- pointer++;
- }
- } else {
- if (overlapLength2 >= deletion.length / 2 ||
- overlapLength2 >= insertion.length / 2) {
- // Reverse overlap found.
- // Insert an equality and swap and trim the surrounding edits.
- diffs.splice( pointer, 0, [ DIFF_EQUAL, deletion.substring( 0, overlapLength2 ) ] );
- diffs[pointer - 1][0] = DIFF_INSERT;
- diffs[pointer - 1][1] =
- insertion.substring(0, insertion.length - overlapLength2);
- diffs[pointer + 1][0] = DIFF_DELETE;
- diffs[pointer + 1][1] =
- deletion.substring(overlapLength2);
- pointer++;
- }
- }
- pointer++;
- }
- pointer++;
- }
- };
-
- /**
- * Determine if the suffix of one string is the prefix of another.
- * @param {string} text1 First string.
- * @param {string} text2 Second string.
- * @return {number} The number of characters common to the end of the first
- * string and the start of the second string.
- * @private
- */
- DiffMatchPatch.prototype.diffCommonOverlap = function(text1, text2) {
- var text1Length, text2Length, textLength,
- best, length, pattern, found;
- // Cache the text lengths to prevent multiple calls.
- text1Length = text1.length;
- text2Length = text2.length;
- // Eliminate the null case.
- if (text1Length === 0 || text2Length === 0) {
- return 0;
- }
- // Truncate the longer string.
- if (text1Length > text2Length) {
- text1 = text1.substring(text1Length - text2Length);
- } else if (text1Length < text2Length) {
- text2 = text2.substring(0, text1Length);
- }
- textLength = Math.min(text1Length, text2Length);
- // Quick check for the worst case.
- if (text1 === text2) {
- return textLength;
- }
-
- // Start by looking for a single character match
- // and increase length until no match is found.
- // Performance analysis: http://neil.fraser.name/news/2010/11/04/
- best = 0;
- length = 1;
- while (true) {
- pattern = text1.substring(textLength - length);
- found = text2.indexOf(pattern);
- if (found === -1) {
- return best;
- }
- length += found;
- if (found === 0 || text1.substring(textLength - length) ===
- text2.substring(0, length)) {
- best = length;
- length++;
- }
- }
- };
-
- /**
- * Split two texts into an array of strings. Reduce the texts to a string of
- * hashes where each Unicode character represents one line.
- * @param {string} text1 First string.
- * @param {string} text2 Second string.
- * @return {{chars1: string, chars2: string, lineArray: !Array.<string>}}
- * An object containing the encoded text1, the encoded text2 and
- * the array of unique strings.
- * The zeroth element of the array of unique strings is intentionally blank.
- * @private
- */
- DiffMatchPatch.prototype.diffLinesToChars = function(text1, text2) {
- var lineArray, lineHash, chars1, chars2;
- lineArray = []; // e.g. lineArray[4] === 'Hello\n'
- lineHash = {}; // e.g. lineHash['Hello\n'] === 4
-
- // '\x00' is a valid character, but various debuggers don't like it.
- // So we'll insert a junk entry to avoid generating a null character.
- lineArray[0] = "";
-
- /**
- * Split a text into an array of strings. Reduce the texts to a string of
- * hashes where each Unicode character represents one line.
- * Modifies linearray and linehash through being a closure.
- * @param {string} text String to encode.
- * @return {string} Encoded string.
- * @private
- */
- function diffLinesToCharsMunge(text) {
- var chars, lineStart, lineEnd, lineArrayLength, line;
- chars = "";
- // Walk the text, pulling out a substring for each line.
- // text.split('\n') would would temporarily double our memory footprint.
- // Modifying text would create many large strings to garbage collect.
- lineStart = 0;
- lineEnd = -1;
- // Keeping our own length variable is faster than looking it up.
- lineArrayLength = lineArray.length;
- while (lineEnd < text.length - 1) {
- lineEnd = text.indexOf("\n", lineStart);
- if (lineEnd === -1) {
- lineEnd = text.length - 1;
- }
- line = text.substring(lineStart, lineEnd + 1);
- lineStart = lineEnd + 1;
-
- if (lineHash.hasOwnProperty ? lineHash.hasOwnProperty(line) :
- (lineHash[line] !== undefined)) {
- chars += String.fromCharCode( lineHash[ line ] );
- } else {
- chars += String.fromCharCode(lineArrayLength);
- lineHash[line] = lineArrayLength;
- lineArray[lineArrayLength++] = line;
- }
- }
- return chars;
- }
-
- chars1 = diffLinesToCharsMunge(text1);
- chars2 = diffLinesToCharsMunge(text2);
- return {
- chars1: chars1,
- chars2: chars2,
- lineArray: lineArray
- };
- };
-
- /**
- * Rehydrate the text in a diff from a string of line hashes to real lines of
- * text.
- * @param {!Array.<!DiffMatchPatch.Diff>} diffs Array of diff tuples.
- * @param {!Array.<string>} lineArray Array of unique strings.
- * @private
- */
- DiffMatchPatch.prototype.diffCharsToLines = function( diffs, lineArray ) {
- var x, chars, text, y;
- for ( x = 0; x < diffs.length; x++ ) {
- chars = diffs[x][1];
- text = [];
- for ( y = 0; y < chars.length; y++ ) {
- text[y] = lineArray[chars.charCodeAt(y)];
- }
- diffs[x][1] = text.join("");
- }
- };
-
- /**
- * Reorder and merge like edit sections. Merge equalities.
- * Any edit section can move as long as it doesn't cross an equality.
- * @param {!Array.<!DiffMatchPatch.Diff>} diffs Array of diff tuples.
- */
- DiffMatchPatch.prototype.diffCleanupMerge = function(diffs) {
- var pointer, countDelete, countInsert, textInsert, textDelete,
- commonlength, changes;
- diffs.push( [ DIFF_EQUAL, "" ] ); // Add a dummy entry at the end.
- pointer = 0;
- countDelete = 0;
- countInsert = 0;
- textDelete = "";
- textInsert = "";
- commonlength;
- while (pointer < diffs.length) {
- switch ( diffs[ pointer ][ 0 ] ) {
- case DIFF_INSERT:
- countInsert++;
- textInsert += diffs[pointer][1];
- pointer++;
- break;
- case DIFF_DELETE:
- countDelete++;
- textDelete += diffs[pointer][1];
- pointer++;
- break;
- case DIFF_EQUAL:
- // Upon reaching an equality, check for prior redundancies.
- if (countDelete + countInsert > 1) {
- if (countDelete !== 0 && countInsert !== 0) {
- // Factor out any common prefixies.
- commonlength = this.diffCommonPrefix(textInsert, textDelete);
- if (commonlength !== 0) {
- if ((pointer - countDelete - countInsert) > 0 &&
- diffs[pointer - countDelete - countInsert - 1][0] ===
- DIFF_EQUAL) {
- diffs[pointer - countDelete - countInsert - 1][1] +=
- textInsert.substring(0, commonlength);
- } else {
- diffs.splice( 0, 0, [ DIFF_EQUAL,
- textInsert.substring( 0, commonlength )
- ] );
- pointer++;
- }
- textInsert = textInsert.substring(commonlength);
- textDelete = textDelete.substring(commonlength);
- }
- // Factor out any common suffixies.
- commonlength = this.diffCommonSuffix(textInsert, textDelete);
- if (commonlength !== 0) {
- diffs[pointer][1] = textInsert.substring(textInsert.length -
- commonlength) + diffs[pointer][1];
- textInsert = textInsert.substring(0, textInsert.length -
- commonlength);
- textDelete = textDelete.substring(0, textDelete.length -
- commonlength);
- }
- }
- // Delete the offending records and add the merged ones.
- if (countDelete === 0) {
- diffs.splice( pointer - countInsert,
- countDelete + countInsert, [ DIFF_INSERT, textInsert ] );
- } else if (countInsert === 0) {
- diffs.splice( pointer - countDelete,
- countDelete + countInsert, [ DIFF_DELETE, textDelete ] );
- } else {
- diffs.splice( pointer - countDelete - countInsert,
- countDelete + countInsert, [ DIFF_DELETE, textDelete ], [ DIFF_INSERT, textInsert ] );
- }
- pointer = pointer - countDelete - countInsert +
- (countDelete ? 1 : 0) + (countInsert ? 1 : 0) + 1;
- } else if (pointer !== 0 && diffs[pointer - 1][0] === DIFF_EQUAL) {
- // Merge this equality with the previous one.
- diffs[pointer - 1][1] += diffs[pointer][1];
- diffs.splice(pointer, 1);
- } else {
- pointer++;
- }
- countInsert = 0;
- countDelete = 0;
- textDelete = "";
- textInsert = "";
- break;
- }
- }
- if (diffs[diffs.length - 1][1] === "") {
- diffs.pop(); // Remove the dummy entry at the end.
- }
-
- // Second pass: look for single edits surrounded on both sides by equalities
- // which can be shifted sideways to eliminate an equality.
- // e.g: A<ins>BA</ins>C -> <ins>AB</ins>AC
- changes = false;
- pointer = 1;
- // Intentionally ignore the first and last element (don't need checking).
- while (pointer < diffs.length - 1) {
- if (diffs[pointer - 1][0] === DIFF_EQUAL &&
- diffs[pointer + 1][0] === DIFF_EQUAL) {
- // This is a single edit surrounded by equalities.
- if ( diffs[ pointer ][ 1 ].substring( diffs[ pointer ][ 1 ].length -
- diffs[ pointer - 1 ][ 1 ].length ) === diffs[ pointer - 1 ][ 1 ] ) {
- // Shift the edit over the previous equality.
- diffs[pointer][1] = diffs[pointer - 1][1] +
- diffs[pointer][1].substring(0, diffs[pointer][1].length -
- diffs[pointer - 1][1].length);
- diffs[pointer + 1][1] = diffs[pointer - 1][1] + diffs[pointer + 1][1];
- diffs.splice(pointer - 1, 1);
- changes = true;
- } else if ( diffs[ pointer ][ 1 ].substring( 0, diffs[ pointer + 1 ][ 1 ].length ) ===
- diffs[ pointer + 1 ][ 1 ] ) {
- // Shift the edit over the next equality.
- diffs[pointer - 1][1] += diffs[pointer + 1][1];
- diffs[pointer][1] =
- diffs[pointer][1].substring(diffs[pointer + 1][1].length) +
- diffs[pointer + 1][1];
- diffs.splice(pointer + 1, 1);
- changes = true;
- }
- }
- pointer++;
- }
- // If shifts were made, the diff needs reordering and another shift sweep.
- if (changes) {
- this.diffCleanupMerge(diffs);
- }
- };
-
- return function(o, n) {
- var diff, output, text;
- diff = new DiffMatchPatch();
- output = diff.DiffMain(o, n);
- //console.log(output);
- diff.diffCleanupEfficiency(output);
- text = diff.diffPrettyHtml(output);
-
- return text;
- };
-}());
-// jscs:enable
-