/** @odoo-module */ /** * @odoo * This file contains 2 modifications from the original 'diff_match_patch.js' file: * * 1. it has been trimmed to only keep the 'diff' functions (as is), without the * 'match' and 'patch' functions, to reduce file size; * * 2. this comment block has been prepended and an extra 'export' block has been * appended at the end as to make it fit into the Odoo module system. */ /** * Diff Match and Patch * Copyright 2018 The diff-match-patch Authors. * https://github.com/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. */ /** * @fileoverview Computes the difference between two texts to create a patch. * Applies the patch onto another text, allowing for errors. * @author fraser@google.com (Neil Fraser) */ /** * Class containing the diff, match and patch methods. * @constructor */ var diff_match_patch = function () { // Defaults. // Redefine these in your program to override the defaults. // Number of seconds to map a diff before giving up (0 for infinity). this.Diff_Timeout = 1.0; // Cost of an empty edit operation in terms of edit characters. this.Diff_EditCost = 4; // At what point is no match declared (0.0 = perfection, 1.0 = very loose). this.Match_Threshold = 0.5; // How far to search for a match (0 = exact location, 1000+ = broad match). // A match this many characters away from the expected location will add // 1.0 to the score (0.0 is a perfect match). this.Match_Distance = 1000; // When deleting a large block of text (over ~64 characters), how close do // the contents have to be to match the expected contents. (0.0 = perfection, // 1.0 = very loose). Note that Match_Threshold controls how closely the // end points of a delete need to match. this.Patch_DeleteThreshold = 0.5; // Chunk size for context length. this.Patch_Margin = 4; // The number of bits in an int. this.Match_MaxBits = 32; }; // 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; var DIFF_INSERT = 1; var DIFF_EQUAL = 0; /** * Class representing one diff tuple. * Attempts to look like a two-element array (which is what this used to be). * @param {number} op Operation, one of: DIFF_DELETE, DIFF_INSERT, DIFF_EQUAL. * @param {string} text Text to be deleted, inserted, or retained. * @constructor */ diff_match_patch.Diff = function (op, text) { this[0] = op; this[1] = text; }; diff_match_patch.Diff.prototype.length = 2; /** * Emulate the output of a two-element array. * @return {string} Diff operation as a string. */ diff_match_patch.Diff.prototype.toString = function () { return this[0] + "," + this[1]; }; /** * 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=} opt_checklines 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=} opt_deadline Optional time when the diff should be complete * by. Used internally for recursive calls. Users should set DiffTimeout * instead. * @return {!Array.} Array of diff tuples. */ diff_match_patch.prototype.diff_main = function (text1, text2, opt_checklines, opt_deadline) { // Set a deadline by which time the diff must be complete. if (typeof opt_deadline == "undefined") { if (this.Diff_Timeout <= 0) { opt_deadline = Number.MAX_VALUE; } else { opt_deadline = new Date().getTime() + this.Diff_Timeout * 1000; } } var deadline = opt_deadline; // Check for null inputs. if (text1 == null || text2 == null) { throw new Error("Null input. (diff_main)"); } // Check for equality (speedup). if (text1 == text2) { if (text1) { return [new diff_match_patch.Diff(DIFF_EQUAL, text1)]; } return []; } if (typeof opt_checklines == "undefined") { opt_checklines = true; } var checklines = opt_checklines; // Trim off common prefix (speedup). var commonlength = this.diff_commonPrefix(text1, text2); var commonprefix = text1.substring(0, commonlength); text1 = text1.substring(commonlength); text2 = text2.substring(commonlength); // Trim off common suffix (speedup). commonlength = this.diff_commonSuffix(text1, text2); var 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. var diffs = this.diff_compute_(text1, text2, checklines, deadline); // Restore the prefix and suffix. if (commonprefix) { diffs.unshift(new diff_match_patch.Diff(DIFF_EQUAL, commonprefix)); } if (commonsuffix) { diffs.push(new diff_match_patch.Diff(DIFF_EQUAL, commonsuffix)); } this.diff_cleanupMerge(diffs); return diffs; }; /** * 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.} Array of diff tuples. * @private */ diff_match_patch.prototype.diff_compute_ = function (text1, text2, checklines, deadline) { var diffs; if (!text1) { // Just add some text (speedup). return [new diff_match_patch.Diff(DIFF_INSERT, text2)]; } if (!text2) { // Just delete some text (speedup). return [new diff_match_patch.Diff(DIFF_DELETE, text1)]; } var longtext = text1.length > text2.length ? text1 : text2; var shorttext = text1.length > text2.length ? text2 : text1; var i = longtext.indexOf(shorttext); if (i != -1) { // Shorter text is inside the longer text (speedup). diffs = [ new diff_match_patch.Diff(DIFF_INSERT, longtext.substring(0, i)), new diff_match_patch.Diff(DIFF_EQUAL, shorttext), new diff_match_patch.Diff(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 [ new diff_match_patch.Diff(DIFF_DELETE, text1), new diff_match_patch.Diff(DIFF_INSERT, text2), ]; } // Check to see if the problem can be split in two. var hm = this.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 diffs_a = this.diff_main(text1_a, text2_a, checklines, deadline); var diffs_b = this.diff_main(text1_b, text2_b, checklines, deadline); // Merge the results. return diffs_a.concat([new diff_match_patch.Diff(DIFF_EQUAL, mid_common)], diffs_b); } if (checklines && text1.length > 100 && text2.length > 100) { return this.diff_lineMode_(text1, text2, deadline); } return this.diff_bisect_(text1, text2, deadline); }; /** * 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.} Array of diff tuples. * @private */ diff_match_patch.prototype.diff_lineMode_ = function (text1, text2, deadline) { // Scan the text on a line-by-line basis first. var a = this.diff_linesToChars_(text1, text2); text1 = a.chars1; text2 = a.chars2; var linearray = a.lineArray; var diffs = this.diff_main(text1, text2, false, deadline); // Convert the diff back to original text. this.diff_charsToLines_(diffs, linearray); // Eliminate freak matches (e.g. blank lines) this.diff_cleanupSemantic(diffs); // Rediff any replacement blocks, this time character-by-character. // Add a dummy entry at the end. diffs.push(new diff_match_patch.Diff(DIFF_EQUAL, "")); var pointer = 0; var count_delete = 0; var count_insert = 0; var text_delete = ""; var text_insert = ""; while (pointer < diffs.length) { switch (diffs[pointer][0]) { case DIFF_INSERT: count_insert++; text_insert += diffs[pointer][1]; break; case DIFF_DELETE: count_delete++; text_delete += diffs[pointer][1]; break; case DIFF_EQUAL: // Upon reaching an equality, check for prior redundancies. if (count_delete >= 1 && count_insert >= 1) { // Delete the offending records and add the merged ones. diffs.splice( pointer - count_delete - count_insert, count_delete + count_insert ); pointer = pointer - count_delete - count_insert; var subDiff = this.diff_main(text_delete, text_insert, false, deadline); for (var j = subDiff.length - 1; j >= 0; j--) { diffs.splice(pointer, 0, subDiff[j]); } pointer = pointer + subDiff.length; } count_insert = 0; count_delete = 0; text_delete = ""; text_insert = ""; 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.} Array of diff tuples. * @private */ diff_match_patch.prototype.diff_bisect_ = function (text1, text2, deadline) { // Cache the text lengths to prevent multiple calls. var text1_length = text1.length; var text2_length = text2.length; var max_d = Math.ceil((text1_length + text2_length) / 2); var v_offset = max_d; var v_length = 2 * max_d; var v1 = new Array(v_length); var v2 = new Array(v_length); // Setting all elements to -1 is faster in Chrome & Firefox than mixing // integers and undefined. for (var x = 0; x < v_length; x++) { v1[x] = -1; v2[x] = -1; } v1[v_offset + 1] = 0; v2[v_offset + 1] = 0; var delta = text1_length - text2_length; // If the total number of characters is odd, then the front path will collide // with the reverse path. var front = delta % 2 != 0; // Offsets for start and end of k loop. // Prevents mapping of space beyond the grid. var k1start = 0; var k1end = 0; var k2start = 0; var k2end = 0; for (var d = 0; d < max_d; d++) { // Bail out if deadline is reached. if (new Date().getTime() > deadline) { break; } // Walk the front path one step. for (var k1 = -d + k1start; k1 <= d - k1end; k1 += 2) { var k1_offset = v_offset + k1; var x1; if (k1 == -d || (k1 != d && v1[k1_offset - 1] < v1[k1_offset + 1])) { x1 = v1[k1_offset + 1]; } else { x1 = v1[k1_offset - 1] + 1; } var y1 = x1 - k1; while ( x1 < text1_length && y1 < text2_length && text1.charAt(x1) == text2.charAt(y1) ) { x1++; y1++; } v1[k1_offset] = x1; if (x1 > text1_length) { // Ran off the right of the graph. k1end += 2; } else if (y1 > text2_length) { // Ran off the bottom of the graph. k1start += 2; } else if (front) { var k2_offset = v_offset + delta - k1; if (k2_offset >= 0 && k2_offset < v_length && v2[k2_offset] != -1) { // Mirror x2 onto top-left coordinate system. var x2 = text1_length - v2[k2_offset]; if (x1 >= x2) { // Overlap detected. return this.diff_bisectSplit_(text1, text2, x1, y1, deadline); } } } } // Walk the reverse path one step. for (var k2 = -d + k2start; k2 <= d - k2end; k2 += 2) { var k2_offset = v_offset + k2; var x2; if (k2 == -d || (k2 != d && v2[k2_offset - 1] < v2[k2_offset + 1])) { x2 = v2[k2_offset + 1]; } else { x2 = v2[k2_offset - 1] + 1; } var y2 = x2 - k2; while ( x2 < text1_length && y2 < text2_length && text1.charAt(text1_length - x2 - 1) == text2.charAt(text2_length - y2 - 1) ) { x2++; y2++; } v2[k2_offset] = x2; if (x2 > text1_length) { // Ran off the left of the graph. k2end += 2; } else if (y2 > text2_length) { // Ran off the top of the graph. k2start += 2; } else if (!front) { var k1_offset = v_offset + delta - k2; if (k1_offset >= 0 && k1_offset < v_length && v1[k1_offset] != -1) { var x1 = v1[k1_offset]; var y1 = v_offset + x1 - k1_offset; // Mirror x2 onto top-left coordinate system. x2 = text1_length - x2; if (x1 >= x2) { // Overlap detected. return this.diff_bisectSplit_(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 [ new diff_match_patch.Diff(DIFF_DELETE, text1), new diff_match_patch.Diff(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.} Array of diff tuples. * @private */ diff_match_patch.prototype.diff_bisectSplit_ = function (text1, text2, x, y, deadline) { var text1a = text1.substring(0, x); var text2a = text2.substring(0, y); var text1b = text1.substring(x); var text2b = text2.substring(y); // Compute both diffs serially. var diffs = this.diff_main(text1a, text2a, false, deadline); var diffsb = this.diff_main(text1b, text2b, false, deadline); return diffs.concat(diffsb); }; /** * 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.}} * 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 */ diff_match_patch.prototype.diff_linesToChars_ = function (text1, text2) { var lineArray = []; // e.g. lineArray[4] == 'Hello\n' var 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 diff_linesToCharsMunge_(text) { var 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. var lineStart = 0; var lineEnd = -1; // Keeping our own length variable is faster than looking it up. var lineArrayLength = lineArray.length; while (lineEnd < text.length - 1) { lineEnd = text.indexOf("\n", lineStart); if (lineEnd == -1) { lineEnd = text.length - 1; } var line = text.substring(lineStart, lineEnd + 1); if ( lineHash.hasOwnProperty ? lineHash.hasOwnProperty(line) : lineHash[line] !== undefined ) { chars += String.fromCharCode(lineHash[line]); } else { if (lineArrayLength == maxLines) { // Bail out at 65535 because // String.fromCharCode(65536) == String.fromCharCode(0) line = text.substring(lineStart); lineEnd = text.length; } chars += String.fromCharCode(lineArrayLength); lineHash[line] = lineArrayLength; lineArray[lineArrayLength++] = line; } lineStart = lineEnd + 1; } return chars; } // Allocate 2/3rds of the space for text1, the rest for text2. var maxLines = 40000; var chars1 = diff_linesToCharsMunge_(text1); maxLines = 65535; var chars2 = diff_linesToCharsMunge_(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.} diffs Array of diff tuples. * @param {!Array.} lineArray Array of unique strings. * @private */ diff_match_patch.prototype.diff_charsToLines_ = function (diffs, lineArray) { for (var i = 0; i < diffs.length; i++) { var chars = diffs[i][1]; var text = []; for (var j = 0; j < chars.length; j++) { text[j] = lineArray[chars.charCodeAt(j)]; } diffs[i][1] = text.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. */ diff_match_patch.prototype.diff_commonPrefix = function (text1, text2) { // Quick check for common null cases. if (!text1 || !text2 || text1.charAt(0) != text2.charAt(0)) { return 0; } // Binary search. // Performance analysis: https://neil.fraser.name/news/2007/10/09/ var pointermin = 0; var pointermax = Math.min(text1.length, text2.length); var pointermid = pointermax; var 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. */ diff_match_patch.prototype.diff_commonSuffix = function (text1, text2) { // 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: https://neil.fraser.name/news/2007/10/09/ var pointermin = 0; var pointermax = Math.min(text1.length, text2.length); var pointermid = pointermax; var 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; }; /** * 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 */ diff_match_patch.prototype.diff_commonOverlap_ = function (text1, text2) { // Cache the text lengths to prevent multiple calls. var text1_length = text1.length; var text2_length = text2.length; // Eliminate the null case. if (text1_length == 0 || text2_length == 0) { return 0; } // Truncate the longer string. if (text1_length > text2_length) { text1 = text1.substring(text1_length - text2_length); } else if (text1_length < text2_length) { text2 = text2.substring(0, text1_length); } var text_length = Math.min(text1_length, text2_length); // Quick check for the worst case. if (text1 == text2) { return text_length; } // Start by looking for a single character match // and increase length until no match is found. // Performance analysis: https://neil.fraser.name/news/2010/11/04/ var best = 0; var length = 1; while (true) { var pattern = text1.substring(text_length - length); var found = text2.indexOf(pattern); if (found == -1) { return best; } length += found; if (found == 0 || text1.substring(text_length - length) == text2.substring(0, length)) { best = length; length++; } } }; /** * 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.} 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 */ diff_match_patch.prototype.diff_halfMatch_ = function (text1, text2) { if (this.Diff_Timeout <= 0) { // Don't risk returning a non-optimal diff if we have unlimited time. return null; } var longtext = text1.length > text2.length ? text1 : text2; var shorttext = text1.length > text2.length ? text2 : text1; if (longtext.length < 4 || shorttext.length * 2 < longtext.length) { return null; // Pointless. } var 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.} 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 diff_halfMatchI_(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 prefixLength = dmp.diff_commonPrefix( longtext.substring(i), shorttext.substring(j) ); var suffixLength = dmp.diff_commonSuffix( longtext.substring(0, i), shorttext.substring(0, j) ); if (best_common.length < suffixLength + prefixLength) { best_common = shorttext.substring(j - suffixLength, j) + shorttext.substring(j, j + prefixLength); best_longtext_a = longtext.substring(0, i - suffixLength); best_longtext_b = longtext.substring(i + prefixLength); best_shorttext_a = shorttext.substring(0, j - suffixLength); best_shorttext_b = shorttext.substring(j + prefixLength); } } if (best_common.length * 2 >= longtext.length) { 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_halfMatchI_(longtext, shorttext, Math.ceil(longtext.length / 4)); // Check again based on the third quarter. var hm2 = diff_halfMatchI_(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. var text1_a, text1_b, text2_a, text2_b; if (text1.length > text2.length) { text1_a = hm[0]; text1_b = hm[1]; text2_a = hm[2]; text2_b = hm[3]; } else { text2_a = hm[0]; text2_b = hm[1]; text1_a = hm[2]; text1_b = hm[3]; } var mid_common = hm[4]; return [text1_a, text1_b, text2_a, text2_b, mid_common]; }; /** * Reduce the number of edits by eliminating semantically trivial equalities. * @param {!Array.} diffs Array of diff tuples. */ diff_match_patch.prototype.diff_cleanupSemantic = function (diffs) { var changes = false; var equalities = []; // Stack of indices where equalities are found. var equalitiesLength = 0; // Keeping our own length var is faster in JS. /** @type {?string} */ var lastEquality = null; // Always equal to diffs[equalities[equalitiesLength - 1]][1] var pointer = 0; // Index of current position. // Number of characters that changed prior to the equality. var length_insertions1 = 0; var length_deletions1 = 0; // Number of characters that changed after the equality. var length_insertions2 = 0; var length_deletions2 = 0; while (pointer < diffs.length) { if (diffs[pointer][0] == DIFF_EQUAL) { // Equality found. equalities[equalitiesLength++] = pointer; length_insertions1 = length_insertions2; length_deletions1 = length_deletions2; length_insertions2 = 0; length_deletions2 = 0; lastEquality = diffs[pointer][1]; } else { // An insertion or deletion. if (diffs[pointer][0] == DIFF_INSERT) { length_insertions2 += diffs[pointer][1].length; } else { length_deletions2 += 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(length_insertions1, length_deletions1) && lastEquality.length <= Math.max(length_insertions2, length_deletions2) ) { // Duplicate record. diffs.splice( equalities[equalitiesLength - 1], 0, new diff_match_patch.Diff(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; length_insertions1 = 0; // Reset the counters. length_deletions1 = 0; length_insertions2 = 0; length_deletions2 = 0; lastEquality = null; changes = true; } } pointer++; } // Normalize the diff. if (changes) { this.diff_cleanupMerge(diffs); } this.diff_cleanupSemanticLossless(diffs); // Find any overlaps between deletions and insertions. // e.g: abcxxxxxxdef // -> abcxxxdef // e.g: xxxabcdefxxx // -> defxxxabc // 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) { var deletion = diffs[pointer - 1][1]; var insertion = diffs[pointer][1]; var overlap_length1 = this.diff_commonOverlap_(deletion, insertion); var overlap_length2 = this.diff_commonOverlap_(insertion, deletion); if (overlap_length1 >= overlap_length2) { if ( overlap_length1 >= deletion.length / 2 || overlap_length1 >= insertion.length / 2 ) { // Overlap found. Insert an equality and trim the surrounding edits. diffs.splice( pointer, 0, new diff_match_patch.Diff( DIFF_EQUAL, insertion.substring(0, overlap_length1) ) ); diffs[pointer - 1][1] = deletion.substring( 0, deletion.length - overlap_length1 ); diffs[pointer + 1][1] = insertion.substring(overlap_length1); pointer++; } } else { if ( overlap_length2 >= deletion.length / 2 || overlap_length2 >= insertion.length / 2 ) { // Reverse overlap found. // Insert an equality and swap and trim the surrounding edits. diffs.splice( pointer, 0, new diff_match_patch.Diff( DIFF_EQUAL, deletion.substring(0, overlap_length2) ) ); diffs[pointer - 1][0] = DIFF_INSERT; diffs[pointer - 1][1] = insertion.substring( 0, insertion.length - overlap_length2 ); diffs[pointer + 1][0] = DIFF_DELETE; diffs[pointer + 1][1] = deletion.substring(overlap_length2); pointer++; } } pointer++; } pointer++; } }; /** * Look for single edits surrounded on both sides by equalities * which can be shifted sideways to align the edit to a word boundary. * e.g: The cat came. -> The cat came. * @param {!Array.} diffs Array of diff tuples. */ diff_match_patch.prototype.diff_cleanupSemanticLossless = function (diffs) { /** * Given two strings, compute a score representing whether the internal * boundary falls on logical boundaries. * Scores range from 6 (best) to 0 (worst). * Closure, but does not reference any external variables. * @param {string} one First string. * @param {string} two Second string. * @return {number} The score. * @private */ function diff_cleanupSemanticScore_(one, two) { if (!one || !two) { // Edges are the best. return 6; } // Each port of this function behaves slightly differently due to // subtle differences in each language's definition of things like // 'whitespace'. Since this function's purpose is largely cosmetic, // the choice has been made to use each language's native features // rather than force total conformity. var char1 = one.charAt(one.length - 1); var char2 = two.charAt(0); var nonAlphaNumeric1 = char1.match(diff_match_patch.nonAlphaNumericRegex_); var nonAlphaNumeric2 = char2.match(diff_match_patch.nonAlphaNumericRegex_); var whitespace1 = nonAlphaNumeric1 && char1.match(diff_match_patch.whitespaceRegex_); var whitespace2 = nonAlphaNumeric2 && char2.match(diff_match_patch.whitespaceRegex_); var lineBreak1 = whitespace1 && char1.match(diff_match_patch.linebreakRegex_); var lineBreak2 = whitespace2 && char2.match(diff_match_patch.linebreakRegex_); var blankLine1 = lineBreak1 && one.match(diff_match_patch.blanklineEndRegex_); var blankLine2 = lineBreak2 && two.match(diff_match_patch.blanklineStartRegex_); if (blankLine1 || blankLine2) { // Five points for blank lines. return 5; } else if (lineBreak1 || lineBreak2) { // Four points for line breaks. return 4; } else if (nonAlphaNumeric1 && !whitespace1 && whitespace2) { // Three points for end of sentences. return 3; } else if (whitespace1 || whitespace2) { // Two points for whitespace. return 2; } else if (nonAlphaNumeric1 || nonAlphaNumeric2) { // One point for non-alphanumeric. return 1; } return 0; } var 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. var equality1 = diffs[pointer - 1][1]; var edit = diffs[pointer][1]; var equality2 = diffs[pointer + 1][1]; // First, shift the edit as far left as possible. var commonOffset = this.diff_commonSuffix(equality1, edit); if (commonOffset) { var commonString = edit.substring(edit.length - commonOffset); equality1 = equality1.substring(0, equality1.length - commonOffset); edit = commonString + edit.substring(0, edit.length - commonOffset); equality2 = commonString + equality2; } // Second, step character by character right, looking for the best fit. var bestEquality1 = equality1; var bestEdit = edit; var bestEquality2 = equality2; var bestScore = diff_cleanupSemanticScore_(equality1, edit) + diff_cleanupSemanticScore_(edit, equality2); while (edit.charAt(0) === equality2.charAt(0)) { equality1 += edit.charAt(0); edit = edit.substring(1) + equality2.charAt(0); equality2 = equality2.substring(1); var score = diff_cleanupSemanticScore_(equality1, edit) + diff_cleanupSemanticScore_(edit, equality2); // The >= encourages trailing rather than leading whitespace on edits. if (score >= bestScore) { bestScore = score; bestEquality1 = equality1; bestEdit = edit; bestEquality2 = equality2; } } if (diffs[pointer - 1][1] != bestEquality1) { // We have an improvement, save it back to the diff. if (bestEquality1) { diffs[pointer - 1][1] = bestEquality1; } else { diffs.splice(pointer - 1, 1); pointer--; } diffs[pointer][1] = bestEdit; if (bestEquality2) { diffs[pointer + 1][1] = bestEquality2; } else { diffs.splice(pointer + 1, 1); pointer--; } } } pointer++; } }; // Define some regex patterns for matching boundaries. diff_match_patch.nonAlphaNumericRegex_ = /[^a-zA-Z0-9]/; diff_match_patch.whitespaceRegex_ = /\s/; diff_match_patch.linebreakRegex_ = /[\r\n]/; diff_match_patch.blanklineEndRegex_ = /\n\r?\n$/; diff_match_patch.blanklineStartRegex_ = /^\r?\n\r?\n/; /** * Reduce the number of edits by eliminating operationally trivial equalities. * @param {!Array.} diffs Array of diff tuples. */ diff_match_patch.prototype.diff_cleanupEfficiency = function (diffs) { var changes = false; var equalities = []; // Stack of indices where equalities are found. var equalitiesLength = 0; // Keeping our own length var is faster in JS. /** @type {?string} */ var lastEquality = null; // Always equal to diffs[equalities[equalitiesLength - 1]][1] var pointer = 0; // Index of current position. // Is there an insertion operation before the last equality. var pre_ins = false; // Is there a deletion operation before the last equality. var pre_del = false; // Is there an insertion operation after the last equality. var post_ins = false; // Is there a deletion operation after the last equality. var post_del = false; while (pointer < diffs.length) { if (diffs[pointer][0] == DIFF_EQUAL) { // Equality found. if (diffs[pointer][1].length < this.Diff_EditCost && (post_ins || post_del)) { // Candidate found. equalities[equalitiesLength++] = pointer; pre_ins = post_ins; pre_del = post_del; lastEquality = diffs[pointer][1]; } else { // Not a candidate, and can never become one. equalitiesLength = 0; lastEquality = null; } post_ins = post_del = false; } else { // An insertion or deletion. if (diffs[pointer][0] == DIFF_DELETE) { post_del = true; } else { post_ins = true; } /* * Five types to be split: * ABXYCD * AXCD * ABXC * AXCD * ABXC */ if ( lastEquality && ((pre_ins && pre_del && post_ins && post_del) || (lastEquality.length < this.Diff_EditCost / 2 && pre_ins + pre_del + post_ins + post_del == 3)) ) { // Duplicate record. diffs.splice( equalities[equalitiesLength - 1], 0, new diff_match_patch.Diff(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 (pre_ins && pre_del) { // No changes made which could affect previous entry, keep going. post_ins = post_del = true; equalitiesLength = 0; } else { equalitiesLength--; // Throw away the previous equality. pointer = equalitiesLength > 0 ? equalities[equalitiesLength - 1] : -1; post_ins = post_del = false; } changes = true; } } pointer++; } if (changes) { this.diff_cleanupMerge(diffs); } }; /** * Reorder and merge like edit sections. Merge equalities. * Any edit section can move as long as it doesn't cross an equality. * @param {!Array.} diffs Array of diff tuples. */ diff_match_patch.prototype.diff_cleanupMerge = function (diffs) { // Add a dummy entry at the end. diffs.push(new diff_match_patch.Diff(DIFF_EQUAL, "")); var pointer = 0; var count_delete = 0; var count_insert = 0; var text_delete = ""; var text_insert = ""; var commonlength; while (pointer < diffs.length) { switch (diffs[pointer][0]) { case DIFF_INSERT: count_insert++; text_insert += diffs[pointer][1]; pointer++; break; case DIFF_DELETE: count_delete++; text_delete += diffs[pointer][1]; pointer++; break; case DIFF_EQUAL: // Upon reaching an equality, check for prior redundancies. if (count_delete + count_insert > 1) { if (count_delete !== 0 && count_insert !== 0) { // Factor out any common prefixies. commonlength = this.diff_commonPrefix(text_insert, text_delete); if (commonlength !== 0) { if ( pointer - count_delete - count_insert > 0 && diffs[pointer - count_delete - count_insert - 1][0] == DIFF_EQUAL ) { diffs[pointer - count_delete - count_insert - 1][1] += text_insert.substring(0, commonlength); } else { diffs.splice( 0, 0, new diff_match_patch.Diff( DIFF_EQUAL, text_insert.substring(0, commonlength) ) ); pointer++; } text_insert = text_insert.substring(commonlength); text_delete = text_delete.substring(commonlength); } // Factor out any common suffixies. commonlength = this.diff_commonSuffix(text_insert, text_delete); if (commonlength !== 0) { diffs[pointer][1] = text_insert.substring(text_insert.length - commonlength) + diffs[pointer][1]; text_insert = text_insert.substring( 0, text_insert.length - commonlength ); text_delete = text_delete.substring( 0, text_delete.length - commonlength ); } } // Delete the offending records and add the merged ones. pointer -= count_delete + count_insert; diffs.splice(pointer, count_delete + count_insert); if (text_delete.length) { diffs.splice( pointer, 0, new diff_match_patch.Diff(DIFF_DELETE, text_delete) ); pointer++; } if (text_insert.length) { diffs.splice( pointer, 0, new diff_match_patch.Diff(DIFF_INSERT, text_insert) ); pointer++; } pointer++; } 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++; } count_insert = 0; count_delete = 0; text_delete = ""; text_insert = ""; 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: ABAC -> ABAC var 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.diff_cleanupMerge(diffs); } }; /** * 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 * @param {!Array.} diffs Array of diff tuples. * @param {number} loc Location within text1. * @return {number} Location within text2. */ diff_match_patch.prototype.diff_xIndex = function (diffs, loc) { var chars1 = 0; var chars2 = 0; var last_chars1 = 0; var last_chars2 = 0; var x; for (x = 0; x < diffs.length; x++) { if (diffs[x][0] !== DIFF_INSERT) { // Equality or deletion. chars1 += diffs[x][1].length; } if (diffs[x][0] !== DIFF_DELETE) { // Equality or insertion. chars2 += diffs[x][1].length; } if (chars1 > loc) { // Overshot the location. break; } last_chars1 = chars1; last_chars2 = chars2; } // Was the location was deleted? if (diffs.length != x && diffs[x][0] === DIFF_DELETE) { return last_chars2; } // Add the remaining character length. return last_chars2 + (loc - last_chars1); }; /** * Convert a diff array into a pretty HTML report. * @param {!Array.} diffs Array of diff tuples. * @return {string} HTML representation. */ diff_match_patch.prototype.diff_prettyHtml = function (diffs) { var html = []; var pattern_amp = /&/g; var pattern_lt = //g; var pattern_para = /\n/g; for (var x = 0; x < diffs.length; x++) { var op = diffs[x][0]; // Operation (insert, delete, equal) var data = diffs[x][1]; // Text of change. var text = data .replace(pattern_amp, "&") .replace(pattern_lt, "<") .replace(pattern_gt, ">") .replace(pattern_para, "¶
"); switch (op) { case DIFF_INSERT: html[x] = '' + text + ""; break; case DIFF_DELETE: html[x] = '' + text + ""; break; case DIFF_EQUAL: html[x] = "" + text + ""; break; } } return html.join(""); }; /** * Compute and return the source text (all equalities and deletions). * @param {!Array.} diffs Array of diff tuples. * @return {string} Source text. */ diff_match_patch.prototype.diff_text1 = function (diffs) { var text = []; for (var x = 0; x < diffs.length; x++) { if (diffs[x][0] !== DIFF_INSERT) { text[x] = diffs[x][1]; } } return text.join(""); }; /** * Compute and return the destination text (all equalities and insertions). * @param {!Array.} diffs Array of diff tuples. * @return {string} Destination text. */ diff_match_patch.prototype.diff_text2 = function (diffs) { var text = []; for (var x = 0; x < diffs.length; x++) { if (diffs[x][0] !== DIFF_DELETE) { text[x] = diffs[x][1]; } } return text.join(""); }; /** * Compute the Levenshtein distance; the number of inserted, deleted or * substituted characters. * @param {!Array.} diffs Array of diff tuples. * @return {number} Number of changes. */ diff_match_patch.prototype.diff_levenshtein = function (diffs) { var levenshtein = 0; var insertions = 0; var deletions = 0; for (var x = 0; x < diffs.length; x++) { var op = diffs[x][0]; var data = diffs[x][1]; switch (op) { case DIFF_INSERT: insertions += data.length; break; case DIFF_DELETE: deletions += data.length; break; case DIFF_EQUAL: // A deletion and an insertion is one substitution. levenshtein += Math.max(insertions, deletions); insertions = 0; deletions = 0; break; } } levenshtein += Math.max(insertions, deletions); return levenshtein; }; /** * Crush the diff into an encoded string which describes the operations * required to transform text1 into text2. * E.g. =3\t-2\t+ing -> Keep 3 chars, delete 2 chars, insert 'ing'. * Operations are tab-separated. Inserted text is escaped using %xx notation. * @param {!Array.} diffs Array of diff tuples. * @return {string} Delta text. */ diff_match_patch.prototype.diff_toDelta = function (diffs) { var text = []; for (var x = 0; x < diffs.length; x++) { switch (diffs[x][0]) { case DIFF_INSERT: text[x] = "+" + encodeURI(diffs[x][1]); break; case DIFF_DELETE: text[x] = "-" + diffs[x][1].length; break; case DIFF_EQUAL: text[x] = "=" + diffs[x][1].length; break; } } return text.join("\t").replace(/%20/g, " "); }; /** * Given the original text1, and an encoded string which describes the * operations required to transform text1 into text2, compute the full diff. * @param {string} text1 Source string for the diff. * @param {string} delta Delta text. * @return {!Array.} Array of diff tuples. * @throws {!Error} If invalid input. */ diff_match_patch.prototype.diff_fromDelta = function (text1, delta) { var diffs = []; var diffsLength = 0; // Keeping our own length var is faster in JS. var pointer = 0; // Cursor in text1 var tokens = delta.split(/\t/g); for (var x = 0; x < tokens.length; x++) { // Each token begins with a one character parameter which specifies the // operation of this token (delete, insert, equality). var param = tokens[x].substring(1); switch (tokens[x].charAt(0)) { case "+": try { diffs[diffsLength++] = new diff_match_patch.Diff( DIFF_INSERT, decodeURI(param) ); } catch (ex) { // Malformed URI sequence. throw new Error("Illegal escape in diff_fromDelta: " + param); } break; case "-": // Fall through. case "=": var n = parseInt(param, 10); if (isNaN(n) || n < 0) { throw new Error("Invalid number in diff_fromDelta: " + param); } var text = text1.substring(pointer, (pointer += n)); if (tokens[x].charAt(0) == "=") { diffs[diffsLength++] = new diff_match_patch.Diff(DIFF_EQUAL, text); } else { diffs[diffsLength++] = new diff_match_patch.Diff(DIFF_DELETE, text); } break; default: // Blank tokens are ok (from a trailing \t). // Anything else is an error. if (tokens[x]) { throw new Error("Invalid diff operation in diff_fromDelta: " + tokens[x]); } } } if (pointer != text1.length) { throw new Error( "Delta length (" + pointer + ") does not equal source text length (" + text1.length + ")." ); } return diffs; }; /** * Class representing one patch operation. * @constructor */ diff_match_patch.patch_obj = function () { /** @type {!Array.} */ this.diffs = []; /** @type {?number} */ this.start1 = null; /** @type {?number} */ this.start2 = null; /** @type {number} */ this.length1 = 0; /** @type {number} */ this.length2 = 0; }; /** * Emulate GNU diff's format. * Header: @@ -382,8 +481,9 @@ * Indices are printed as 1-based, not 0-based. * @return {string} The GNU diff string. */ diff_match_patch.patch_obj.prototype.toString = function () { 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 text = ["@@ -" + coords1 + " +" + coords2 + " @@\n"]; var op; // Escape the body of the patch with %xx notation. for (var x = 0; x < this.diffs.length; x++) { switch (this.diffs[x][0]) { case DIFF_INSERT: op = "+"; break; case DIFF_DELETE: op = "-"; break; case DIFF_EQUAL: op = " "; break; } text[x + 1] = op + encodeURI(this.diffs[x][1]) + "\n"; } return text.join("").replace(/%20/g, " "); }; /** * @odoo * Export main object and attach useful variables */ export const DiffMatchPatch = Object.assign(diff_match_patch, { DIFF_DELETE, DIFF_INSERT, DIFF_EQUAL });