4c143ad3b2
Summary: Ref T4205. This is an initial implementation of Phragment. You can create and browse fragments in the system (but you can't yet view a fragment's patches / history). Test Plan: Clicked around and created fragments. Reviewers: epriestley, #blessed_reviewers Reviewed By: epriestley CC: Korvin, epriestley, aran Maniphest Tasks: T4205 Differential Revision: https://secure.phabricator.com/D7726
2117 lines
70 KiB
PHP
2117 lines
70 KiB
PHP
<?php
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/**
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* Diff Match and Patch
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*
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* Copyright 2006 Google Inc.
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* http://code.google.com/p/google-diff-match-patch/
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*
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* php port by Tobias Buschor shwups.ch
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/**
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* @fileoverview Computes the difference between two texts to create a patch.
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* Applies the patch onto another text, allowing for errors.
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* @author fraser@google.com (Neil Fraser)
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*/
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/**
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* Class containing the diff, match and patch methods.
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* @constructor
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*/
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class diff_match_patch {
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// Defaults.
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// Redefine these in your program to override the defaults.
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// Number of seconds to map a diff before giving up (0 for infinity).
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public $Diff_Timeout = 1.0;
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// Cost of an empty edit operation in terms of edit characters.
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public $Diff_EditCost = 4;
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// The size beyond which the double-ended diff activates.
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// Double-ending is twice as fast, but less accurate.
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public $Diff_DualThreshold = 32;
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// At what point is no match declared (0.0 = perfection, 1.0 = very loose).
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public $Match_Threshold = 0.5;
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// How far to search for a match (0 = exact location, 1000+ = broad match).
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// A match this many characters away from the expected location will add
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// 1.0 to the score (0.0 is a perfect match).
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public $Match_Distance = 1000;
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// When deleting a large block of text (over ~64 characters), how close does
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// the contents have to match the expected contents. (0.0 = perfection,
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// 1.0 = very loose). Note that Match_Threshold controls how closely the
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// end points of a delete need to match.
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public $Patch_DeleteThreshold = 0.5;
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// Chunk size for context length.
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public $Patch_Margin = 4;
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/**
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* Compute the number of bits in an int.
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* The normal answer for JavaScript is 32.
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* @return {number} Max bits
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function getMaxBits() {
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var maxbits = 0;
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var oldi = 1;
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var newi = 2;
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while (oldi != newi) {
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maxbits++;
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oldi = newi;
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newi = newi << 1;
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}
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return maxbits;
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}
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// How many bits in a number?
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this.Match_MaxBits = getMaxBits();
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*/
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// DIFF FUNCTIONS
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/**
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* Find the differences between two texts. Simplifies the problem by stripping
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* any common prefix or suffix off the texts before diffing.
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* @param {string} text1 Old string to be diffed.
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* @param {string} text2 New string to be diffed.
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* @param {boolean} opt_checklines Optional speedup flag. If present and false,
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* then don't run a line-level diff first to identify the changed areas.
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* Defaults to true, which does a faster, slightly less optimal diff
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* @return {Array.<Array.<number|string>>} Array of diff tuples.
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*/
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function diff_main($text1, $text2, $checklines = true) {
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// Check for equality (speedup)
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if ($text1 === $text2) {
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return array ( array ( DIFF_EQUAL, $text1) );
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}
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// Trim off common prefix (speedup)
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$commonlength = $this->diff_commonPrefix($text1, $text2);
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$commonprefix = mb_substr($text1, 0, $commonlength);
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$text1 = mb_substr($text1, $commonlength);
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$text2 = mb_substr($text2, $commonlength);
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// Trim off common suffix (speedup)
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$commonlength = $this->diff_commonSuffix($text1, $text2);
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$commonsuffix = mb_substr($text1, mb_strlen($text1) - $commonlength);
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$text1 = mb_substr($text1, 0, mb_strlen($text1) - $commonlength);
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$text2 = mb_substr($text2, 0, mb_strlen($text2) - $commonlength);
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// Compute the diff on the middle block
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$diffs = $this->diff_compute($text1, $text2, $checklines);
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// Restore the prefix and suffix
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if ($commonprefix !== '') {
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array_unshift($diffs, array ( DIFF_EQUAL, $commonprefix ));
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}
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if ($commonsuffix !== '') {
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array_push($diffs, array ( DIFF_EQUAL, $commonsuffix ));
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}
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$this->diff_cleanupMerge($diffs);
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return $diffs;
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}
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/**
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* Find the differences between two texts. Assumes that the texts do not
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* have any common prefix or suffix.
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* @param {string} text1 Old string to be diffed.
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* @param {string} text2 New string to be diffed.
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* @param {boolean} checklines Speedup flag. If false, then don't run a
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* line-level diff first to identify the changed areas.
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* If true, then run a faster, slightly less optimal diff
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* @return {Array.<Array.<number|string>>} Array of diff tuples.
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* @private
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*/
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function diff_compute($text1, $text2, $checklines) {
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if ($text1 === '') {
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// Just add some text (speedup)
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return array ( array ( DIFF_INSERT, $text2 ) );
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}
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if ($text2 === '') {
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// Just delete some text (speedup)
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return array ( array ( DIFF_DELETE, $text1 ) );
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}
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$longtext = mb_strlen($text1) > mb_strlen($text2) ? $text1 : $text2;
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$shorttext = mb_strlen($text1) > mb_strlen($text2) ? $text2 : $text1;
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$i = mb_strpos($longtext, $shorttext);
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if ($i !== false) {
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// Shorter text is inside the longer text (speedup)
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$diffs = array (
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array ( DIFF_INSERT, mb_substr($longtext, 0, $i) ),
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array ( DIFF_EQUAL, $shorttext ),
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array ( DIFF_INSERT, mb_substr($longtext, $i +mb_strlen($shorttext)) )
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);
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// Swap insertions for deletions if diff is reversed.
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if (mb_strlen($text1) > mb_strlen($text2)) {
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$diffs[0][0] = $diffs[2][0] = DIFF_DELETE;
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}
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return $diffs;
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}
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$longtext = $shorttext = null; // Garbage collect
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// Check to see if the problem can be split in two.
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$hm = $this->diff_halfMatch($text1, $text2);
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if ($hm) {
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// A half-match was found, sort out the return data.
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$text1_a = $hm[0];
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$text1_b = $hm[1];
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$text2_a = $hm[2];
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$text2_b = $hm[3];
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$mid_common = $hm[4];
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// Send both pairs off for separate processing.
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$diffs_a = $this->diff_main($text1_a, $text2_a, $checklines);
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$diffs_b = $this->diff_main($text1_b, $text2_b, $checklines);
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// Merge the results.
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return array_merge($diffs_a, array (
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array (
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DIFF_EQUAL,
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$mid_common
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)
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), $diffs_b);
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}
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// Perform a real diff.
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if ($checklines && (mb_strlen($text1) < 100 || mb_strlen($text2) < 100)) {
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// Too trivial for the overhead.
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$checklines = false;
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}
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$linearray = null;
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if ($checklines) {
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// Scan the text on a line-by-line basis first.
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$a = $this->diff_linesToChars($text1, $text2);
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$text1 = $a[0];
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$text2 = $a[1];
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$linearray = $a[2];
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}
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$diffs = $this->diff_map($text1, $text2);
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if (!$diffs) {
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// No acceptable result.
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$diffs = array (
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array (
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DIFF_DELETE,
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$text1
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),
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array (
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DIFF_INSERT,
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$text2
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)
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);
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}
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if ($checklines) {
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// Convert the diff back to original text.
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$this->diff_charsToLines($diffs, $linearray);
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// Eliminate freak matches (e.g. blank lines)
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$this->diff_cleanupSemantic($diffs);
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// Rediff any replacement blocks, this time character-by-character.
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// Add a dummy entry at the end.
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array_push($diffs, array (
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DIFF_EQUAL,
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''
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));
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$pointer = 0;
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$count_delete = 0;
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$count_insert = 0;
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$text_delete = '';
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$text_insert = '';
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while ($pointer < count($diffs)) {
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switch ($diffs[$pointer][0]) {
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case DIFF_INSERT :
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$count_insert++;
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$text_insert .= $diffs[$pointer][1];
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break;
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case DIFF_DELETE :
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$count_delete++;
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$text_delete .= $diffs[$pointer][1];
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break;
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case DIFF_EQUAL :
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// Upon reaching an equality, check for prior redundancies.
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if ($count_delete >= 1 && $count_insert >= 1) {
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// Delete the offending records and add the merged ones.
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$a = $this->diff_main($text_delete, $text_insert, false);
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array_splice($diffs, $pointer - $count_delete - $count_insert, $count_delete + $count_insert);
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$pointer = $pointer - $count_delete - $count_insert;
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for ($j = count($a) - 1; $j >= 0; $j--) {
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array_splice($diffs, $pointer, 0, array($a[$j]));
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}
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$pointer = $pointer +count($a);
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}
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$count_insert = 0;
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$count_delete = 0;
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$text_delete = '';
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$text_insert = '';
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break;
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}
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$pointer++;
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}
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array_pop($diffs); // Remove the dummy entry at the end.
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}
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return $diffs;
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}
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/**
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* Split two texts into an array of strings. Reduce the texts to a string of
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* hashes where each Unicode character represents one line.
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* @param {string} text1 First string.
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* @param {string} text2 Second string.
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* @return {Array.<string|Array.<string>>} Three element Array, containing the
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* encoded text1, the encoded text2 and the array of unique strings. The
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* zeroth element of the array of unique strings is intentionally blank.
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* @private
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*/
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function diff_linesToChars($text1, $text2) {
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$lineArray = array(); // e.g. lineArray[4] == 'Hello\n'
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$lineHash = array(); // e.g. lineHash['Hello\n'] == 4
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// '\x00' is a valid character, but various debuggers don't like it.
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// So we'll insert a junk entry to avoid generating a null character.
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$lineArray[0] = '';
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$chars1 = $this->diff_linesToCharsMunge($text1, $lineArray, $lineHash);
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$chars2 = $this->diff_linesToCharsMunge($text2, $lineArray, $lineHash);
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return array (
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$chars1,
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$chars2,
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$lineArray
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);
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}
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/**
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* Split a text into an array of strings. Reduce the texts to a string of
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* hashes where each Unicode character represents one line.
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* Modifies linearray and linehash through being a closure.
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* @param {string} text String to encode
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* @return {string} Encoded string
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* @private
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*/
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function diff_linesToCharsMunge($text, &$lineArray, &$lineHash) {
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$chars = '';
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// Walk the text, pulling out a mb_substring for each line.
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// text.split('\n') would would temporarily double our memory footprint.
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// Modifying text would create many large strings to garbage collect.
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$lineStart = 0;
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$lineEnd = -1;
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// Keeping our own length variable is faster than looking it up.
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$lineArrayLength = count($lineArray);
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while ($lineEnd < mb_strlen($text) - 1) {
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$lineEnd = mb_strpos($text, "\n", $lineStart);
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if ($lineEnd === false) {
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$lineEnd = mb_strlen($text) - 1;
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}
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$line = mb_substr($text, $lineStart, $lineEnd +1 -$lineStart);
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$lineStart = $lineEnd +1;
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if ( isset($lineHash[$line]) ) {
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$chars .= mb_chr($lineHash[$line]);
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} else {
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$chars .= mb_chr($lineArrayLength);
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$lineHash[$line] = $lineArrayLength;
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$lineArray[$lineArrayLength++] = $line;
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}
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}
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return $chars;
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}
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/**
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* Rehydrate the text in a diff from a string of line hashes to real lines of
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* text.
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* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
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* @param {Array.<string>} lineArray Array of unique strings.
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* @private
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*/
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function diff_charsToLines(&$diffs, $lineArray) {
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for ($x = 0; $x < count($diffs); $x++) {
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$chars = $diffs[$x][1];
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$text = array ();
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for ($y = 0; $y < mb_strlen($chars); $y++) {
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$text[$y] = $lineArray[charCodeAt($chars, $y)];
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}
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$diffs[$x][1] = implode('',$text);
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}
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}
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/**
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* Explore the intersection points between the two texts.
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* @param {string} text1 Old string to be diffed.
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* @param {string} text2 New string to be diffed.
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* @return {Array.<Array.<number|string>>?} Array of diff tuples or null if no
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* diff available.
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* @private
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*/
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function diff_map($text1, $text2) {
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// Don't run for too long.
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$ms_end = microtime(true) + $this->Diff_Timeout;
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// Cache the text lengths to prevent multiple calls.
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$text1_length = mb_strlen($text1);
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$text2_length = mb_strlen($text2);
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$max_d = $text1_length + $text2_length -1;
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$doubleEnd = $this->Diff_DualThreshold * 2 < $max_d;
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$v_map1 = array();
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$v_map2 = array();
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$v1 = array();
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$v2 = array();
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$v1[1] = 0;
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$v2[1] = 0;
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$x = null;
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$y = null;
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$footstep = null; // Used to track overlapping paths.
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$footsteps = array();
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$done = false;
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// Safari 1.x doesn't have hasOwnProperty
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//? $hasOwnProperty = !!(footsteps.hasOwnProperty);
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// If the total number of characters is odd, then the front path will collide
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// with the reverse path.
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$front = ($text1_length + $text2_length) % 2;
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for ($d = 0; $d < $max_d; $d++) {
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// Bail out if timeout reached.
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if ($this->Diff_Timeout > 0 && microtime(true) > $ms_end) {
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return null; // zzz
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}
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// Walk the front path one step.
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$v_map1[$d] = array ();
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for ($k = -$d; $k <= $d; $k += 2) {
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if ($k == -$d || $k != $d && $v1[$k -1] < $v1[$k +1]) {
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$x = $v1[$k +1];
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} else {
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$x = $v1[$k -1] + 1;
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}
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$y = $x - $k;
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if ($doubleEnd) {
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$footstep = $x . ',' . $y;
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if ($front && isset ($footsteps[$footstep])) {
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$done = true;
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}
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if (!$front) {
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$footsteps[$footstep] = $d;
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}
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}
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while (!$done && ($x < $text1_length) && ($y < $text2_length) && (mb_substr($text1, $x, 1) == mb_substr($text2, $y, 1)) ) {
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$x++;
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$y++;
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if ($doubleEnd) {
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$footstep = $x . ',' . $y;
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if ($front && isset ($footsteps[$footstep])) {
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$done = true;
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}
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if (!$front) {
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$footsteps[$footstep] = $d;
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}
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}
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}
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$v1[$k] = $x;
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$v_map1[$d][$x . ',' . $y] = true;
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if ($x == $text1_length && $y == $text2_length) {
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// Reached the end in single-path mode.
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return $this->diff_path1($v_map1, $text1, $text2);
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}
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elseif ($done) {
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// Front path ran over reverse path.
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$v_map2 = array_slice($v_map2, 0, $footsteps[$footstep] + 1);
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$a = $this->diff_path1($v_map1, mb_substr($text1, 0, $x), mb_substr($text2, 0, $y));
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return array_merge($a, $this->diff_path2($v_map2, mb_substr($text1, $x), mb_substr($text2, $y)));
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}
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}
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if ($doubleEnd) {
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// Walk the reverse path one step.
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$v_map2[$d] = array();
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for ($k = -$d; $k <= $d; $k += 2) {
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if ($k == -$d || $k != $d && $v2[$k -1] < $v2[$k +1]) {
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$x = $v2[$k +1];
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} else {
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$x = $v2[$k -1] + 1;
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}
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$y = $x - $k;
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$footstep = ($text1_length - $x) . ',' . ($text2_length - $y);
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if (!$front && isset ($footsteps[$footstep])) {
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$done = true;
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}
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if ($front) {
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$footsteps[$footstep] = $d;
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}
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while (!$done && $x < $text1_length && $y < $text2_length && mb_substr($text1, $text1_length - $x -1, 1) == mb_substr($text2, $text2_length - $y -1, 1) ) {
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$x++;
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$y++;
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$footstep = ($text1_length - $x) . ',' . ($text2_length - $y);
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if (!$front && isset ($footsteps[$footstep])) {
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$done = true;
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}
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if ($front) {
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$footsteps[$footstep] = $d;
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}
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}
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$v2[$k] = $x;
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$v_map2[$d][$x . ',' . $y] = true;
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if ($done) {
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// Reverse path ran over front path.
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$v_map1 = array_slice($v_map1, 0, $footsteps[$footstep] + 1);
|
|
$a = $this->diff_path1($v_map1, mb_substr($text1, 0, $text1_length - $x), mb_substr($text2, 0, $text2_length - $y));
|
|
return array_merge($a, $this->diff_path2($v_map2, mb_substr($text1, $text1_length - $x), mb_substr($text2, $text2_length - $y)));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// Number of diffs equals number of characters, no commonality at all.
|
|
return null;
|
|
}
|
|
|
|
/**
|
|
* Work from the middle back to the start to determine the path.
|
|
* @param {Array.<Object>} v_map Array of paths.ers
|
|
* @param {string} text1 Old string fragment to be diffed.
|
|
* @param {string} text2 New string fragment to be diffed.
|
|
* @return {Array.<Array.<number|string>>} Array of diff tuples.
|
|
* @private
|
|
*/
|
|
function diff_path1($v_map, $text1, $text2) {
|
|
$path = array ();
|
|
$x = mb_strlen($text1);
|
|
$y = mb_strlen($text2);
|
|
/** @type {number?} */
|
|
$last_op = null;
|
|
for ($d = count($v_map) - 2; $d >= 0; $d--) {
|
|
while (1) {
|
|
if (isset ($v_map[$d][($x -1) . ',' . $y])) {
|
|
$x--;
|
|
if ($last_op === DIFF_DELETE) {
|
|
$path[0][1] = mb_substr($text1, $x, 1) . $path[0][1];
|
|
} else {
|
|
array_unshift($path, array (
|
|
DIFF_DELETE,
|
|
mb_substr($text1, $x, 1)
|
|
));
|
|
}
|
|
$last_op = DIFF_DELETE;
|
|
break;
|
|
} elseif (isset ($v_map[$d][$x . ',' . ($y -1)])) {
|
|
$y--;
|
|
if ($last_op === DIFF_INSERT) {
|
|
$path[0][1] = mb_substr($text2, $y, 1) . $path[0][1];
|
|
} else {
|
|
array_unshift($path, array (
|
|
DIFF_INSERT,
|
|
mb_substr($text2, $y, 1)
|
|
));
|
|
}
|
|
$last_op = DIFF_INSERT;
|
|
break;
|
|
} else {
|
|
$x--;
|
|
$y--;
|
|
//if (text1.charAt(x) != text2.charAt(y)) {
|
|
// throw new Error('No diagonal. Can\'t happen. (diff_path1)');
|
|
//}
|
|
if ($last_op === DIFF_EQUAL) {
|
|
$path[0][1] = mb_substr($text1, $x, 1) . $path[0][1];
|
|
} else {
|
|
array_unshift($path, array (
|
|
DIFF_EQUAL,
|
|
mb_substr($text1, $x, 1)
|
|
));
|
|
}
|
|
$last_op = DIFF_EQUAL;
|
|
}
|
|
}
|
|
}
|
|
return $path;
|
|
}
|
|
|
|
/**
|
|
* Work from the middle back to the end to determine the path.
|
|
* @param {Array.<Object>} v_map Array of paths.
|
|
* @param {string} text1 Old string fragment to be diffed.
|
|
* @param {string} text2 New string fragment to be diffed.
|
|
* @return {Array.<Array.<number|string>>} Array of diff tuples.
|
|
* @private
|
|
*/
|
|
function diff_path2($v_map, $text1, $text2) {
|
|
$path = array ();
|
|
$pathLength = 0;
|
|
$x = mb_strlen($text1);
|
|
$y = mb_strlen($text2);
|
|
/** @type {number?} */
|
|
$last_op = null;
|
|
for ($d = count($v_map) - 2; $d >= 0; $d--) {
|
|
while (1) {
|
|
if (isset ($v_map[$d][($x -1) . ',' . $y])) {
|
|
$x--;
|
|
if ($last_op === DIFF_DELETE) {
|
|
$path[$pathLength -1][1] .= $text1[mb_strlen($text1) - $x -1];
|
|
} else {
|
|
$path[$pathLength++] = array (
|
|
DIFF_DELETE,
|
|
$text1[mb_strlen($text1) - $x -1]
|
|
);
|
|
}
|
|
$last_op = DIFF_DELETE;
|
|
break;
|
|
}
|
|
elseif (isset ($v_map[$d][$x . ',' . ($y -1)])) {
|
|
$y--;
|
|
if ($last_op === DIFF_INSERT) {
|
|
$path[$pathLength -1][1] .= $text2[mb_strlen($text2) - $y -1];
|
|
} else {
|
|
$path[$pathLength++] = array (
|
|
DIFF_INSERT,
|
|
$text2[mb_strlen($text2) - $y -1]
|
|
);
|
|
}
|
|
$last_op = DIFF_INSERT;
|
|
break;
|
|
} else {
|
|
$x--;
|
|
$y--;
|
|
//if (text1.charAt(text1.length - x - 1) !=
|
|
// text2.charAt(text2.length - y - 1)) {
|
|
// throw new Error('No diagonal. Can\'t happen. (diff_path2)');
|
|
//}
|
|
if ($last_op === DIFF_EQUAL) {
|
|
$path[$pathLength -1][1] .= $text1[mb_strlen($text1) - $x -1];
|
|
} else {
|
|
$path[$pathLength++] = array (
|
|
DIFF_EQUAL,
|
|
$text1[mb_strlen($text1) - $x -1]
|
|
);
|
|
}
|
|
$last_op = DIFF_EQUAL;
|
|
}
|
|
}
|
|
}
|
|
return $path;
|
|
}
|
|
|
|
/**
|
|
* Determine the common prefix of two strings
|
|
* @param {string} text1 First string.
|
|
* @param {string} text2 Second string.
|
|
* @return {number} The number of characters common to the start of each
|
|
* string.
|
|
*/
|
|
function diff_commonPrefix($text1, $text2) {
|
|
for ($i = 0; 1; $i++) {
|
|
$t1 = mb_substr($text1, $i, 1);
|
|
$t2 = mb_substr($text2, $i, 1);
|
|
if($t1==='' || $t2==='' || $t1 !== $t2 ){
|
|
return $i;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Determine the common suffix of two strings
|
|
* @param {string} text1 First string.
|
|
* @param {string} text2 Second string.
|
|
* @return {number} The number of characters common to the end of each string.
|
|
*/
|
|
function diff_commonSuffix($text1, $text2) {
|
|
return $this->diff_commonPrefix( strrev($text1), strrev($text2) );
|
|
}
|
|
|
|
/**
|
|
* Do the two texts share a mb_substring which is at least half the length of the
|
|
* longer text?
|
|
* @param {string} text1 First string.
|
|
* @param {string} text2 Second string.
|
|
* @return {Array.<string>?} Five element Array, containing the prefix of
|
|
* text1, the suffix of text1, the prefix of text2, the suffix of
|
|
* text2 and the common middle. Or null if there was no match.
|
|
*/
|
|
function diff_halfMatch($text1, $text2) {
|
|
$longtext = mb_strlen($text1) > mb_strlen($text2) ? $text1 : $text2;
|
|
$shorttext = mb_strlen($text1) > mb_strlen($text2) ? $text2 : $text1;
|
|
if (mb_strlen($longtext) < 10 || mb_strlen($shorttext) < 1) {
|
|
return null; // Pointless.
|
|
}
|
|
|
|
// First check if the second quarter is the seed for a half-match.
|
|
$hm1 = $this->diff_halfMatchI($longtext, $shorttext, ceil(mb_strlen($longtext) / 4));
|
|
// Check again based on the third quarter.
|
|
$hm2 = $this->diff_halfMatchI($longtext, $shorttext, ceil(mb_strlen($longtext) / 2));
|
|
|
|
if (!$hm1 && !$hm2) {
|
|
return null;
|
|
} elseif (!$hm2) {
|
|
$hm = $hm1;
|
|
} elseif (!$hm1) {
|
|
$hm = $hm2;
|
|
} else {
|
|
// Both matched. Select the longest.
|
|
$hm = mb_strlen($hm1[4]) > mb_strlen($hm2[4]) ? $hm1 : $hm2;
|
|
}
|
|
|
|
// A half-match was found, sort out the return data.
|
|
if (mb_strlen($text1) > mb_strlen($text2)) {
|
|
$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];
|
|
}
|
|
$mid_common = $hm[4];
|
|
return array( $text1_a, $text1_b, $text2_a, $text2_b, $mid_common );
|
|
}
|
|
|
|
/**
|
|
* Does a mb_substring of shorttext exist within longtext such that the mb_substring
|
|
* is at least half the length of longtext?
|
|
* Closure, but does not reference any external variables.
|
|
* @param {string} longtext Longer string.
|
|
* @param {string} shorttext Shorter string.
|
|
* @param {number} i Start index of quarter length mb_substring within longtext
|
|
* @return {Array.<string>?} Five element Array, containing the prefix of
|
|
* longtext, the suffix of longtext, the prefix of shorttext, the suffix
|
|
* of shorttext and the common middle. Or null if there was no match.
|
|
* @private
|
|
*/
|
|
function diff_halfMatchI($longtext, $shorttext, $i) {
|
|
// Start with a 1/4 length mb_substring at position i as a seed.
|
|
$seed = mb_substr($longtext, $i, floor(mb_strlen($longtext) / 4));
|
|
|
|
$j = -1;
|
|
$best_common = '';
|
|
$best_longtext_a = null;
|
|
$best_longtext_b = null;
|
|
$best_shorttext_a = null;
|
|
$best_shorttext_b = null;
|
|
while ( ($j = mb_strpos($shorttext, $seed, $j + 1)) !== false ) {
|
|
$prefixLength = $this->diff_commonPrefix(mb_substr($longtext, $i), mb_substr($shorttext, $j));
|
|
$suffixLength = $this->diff_commonSuffix(mb_substr($longtext, 0, $i), mb_substr($shorttext, 0, $j));
|
|
if (mb_strlen($best_common) < $suffixLength + $prefixLength) {
|
|
$best_common = mb_substr($shorttext, $j - $suffixLength, $suffixLength) . mb_substr($shorttext, $j, $prefixLength);
|
|
$best_longtext_a = mb_substr($longtext, 0, $i - $suffixLength);
|
|
$best_longtext_b = mb_substr($longtext, $i + $prefixLength);
|
|
$best_shorttext_a = mb_substr($shorttext, 0, $j - $suffixLength);
|
|
$best_shorttext_b = mb_substr($shorttext, $j + $prefixLength);
|
|
}
|
|
}
|
|
if (mb_strlen($best_common) >= mb_strlen($longtext) / 2) {
|
|
return array (
|
|
$best_longtext_a,
|
|
$best_longtext_b,
|
|
$best_shorttext_a,
|
|
$best_shorttext_b,
|
|
$best_common
|
|
);
|
|
} else {
|
|
return null;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Reduce the number of edits by eliminating semantically trivial equalities.
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
*/
|
|
function diff_cleanupSemantic(&$diffs) {
|
|
$changes = false;
|
|
$equalities = array (); // Stack of indices where equalities are found.
|
|
$equalitiesLength = 0; // Keeping our own length var is faster in JS.
|
|
$lastequality = null; // Always equal to equalities[equalitiesLength-1][1]
|
|
$pointer = 0; // Index of current position.
|
|
// Number of characters that changed prior to the equality.
|
|
$length_changes1 = 0;
|
|
// Number of characters that changed after the equality.
|
|
$length_changes2 = 0;
|
|
while ($pointer < count($diffs)) {
|
|
if ($diffs[$pointer][0] == DIFF_EQUAL) { // equality found
|
|
$equalities[$equalitiesLength++] = $pointer;
|
|
$length_changes1 = $length_changes2;
|
|
$length_changes2 = 0;
|
|
$lastequality = $diffs[$pointer][1];
|
|
} else { // an insertion or deletion
|
|
$length_changes2 += mb_strlen($diffs[$pointer][1]);
|
|
if ($lastequality !== null && (mb_strlen($lastequality) <= $length_changes1) && (mb_strlen($lastequality) <= $length_changes2)) {
|
|
// Duplicate record
|
|
$zzz_diffs = array_splice($diffs, $equalities[$equalitiesLength -1], 0, array(array (
|
|
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_changes1 = 0; // Reset the counters.
|
|
$length_changes2 = 0;
|
|
$lastequality = null;
|
|
$changes = true;
|
|
}
|
|
}
|
|
$pointer++;
|
|
}
|
|
if ($changes) {
|
|
$this->diff_cleanupMerge($diffs);
|
|
}
|
|
$this->diff_cleanupSemanticLossless($diffs);
|
|
}
|
|
|
|
/**
|
|
* 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 c<ins>at c</ins>ame. -> The <ins>cat </ins>came.
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
*/
|
|
function diff_cleanupSemanticLossless(&$diffs) {
|
|
|
|
$pointer = 1;
|
|
// Intentionally ignore the first and last element (don't need checking).
|
|
while ($pointer < count($diffs) - 1) {
|
|
if ($diffs[$pointer -1][0] == DIFF_EQUAL && $diffs[$pointer +1][0] == DIFF_EQUAL) {
|
|
// This is a single edit surrounded by equalities.
|
|
$equality1 = $diffs[$pointer -1][1];
|
|
$edit = $diffs[$pointer][1];
|
|
$equality2 = $diffs[$pointer +1][1];
|
|
|
|
// First, shift the edit as far left as possible.
|
|
$commonOffset = $this->diff_commonSuffix($equality1, $edit);
|
|
if ($commonOffset !== '') {
|
|
$commonString = mb_substr($edit, mb_strlen($edit) - $commonOffset);
|
|
$equality1 = mb_substr($equality1, 0, mb_strlen($equality1) - $commonOffset);
|
|
$edit = $commonString . mb_substr($edit, 0, mb_strlen($edit) - $commonOffset);
|
|
$equality2 = $commonString . $equality2;
|
|
}
|
|
|
|
// Second, step character by character right, looking for the best fit.
|
|
$bestEquality1 = $equality1;
|
|
$bestEdit = $edit;
|
|
$bestEquality2 = $equality2;
|
|
$bestScore = $this->diff_cleanupSemanticScore($equality1, $edit) + $this->diff_cleanupSemanticScore($edit, $equality2);
|
|
while (isset($equality2[0]) && $edit[0] === $equality2[0]) {
|
|
$equality1 .= $edit[0];
|
|
$edit = mb_substr($edit, 1) . $equality2[0];
|
|
$equality2 = mb_substr($equality2, 1);
|
|
$score = $this->diff_cleanupSemanticScore($equality1, $edit) + $this->diff_cleanupSemanticScore($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 {
|
|
$zzz_diffs = array_splice($diffs, $pointer -1, 1);
|
|
$pointer--;
|
|
}
|
|
$diffs[$pointer][1] = $bestEdit;
|
|
if ($bestEquality2) {
|
|
$diffs[$pointer +1][1] = $bestEquality2;
|
|
} else {
|
|
$zzz_diffs = array_splice($diffs, $pointer +1, 1);
|
|
$pointer--;
|
|
}
|
|
}
|
|
}
|
|
$pointer++;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Given two strings, compute a score representing whether the internal
|
|
* boundary falls on logical boundaries.
|
|
* Scores range from 5 (best) to 0 (worst).
|
|
* Closure, makes reference to regex patterns defined above.
|
|
* @param {string} one First string
|
|
* @param {string} two Second string
|
|
* @return {number} The score.
|
|
*/
|
|
function diff_cleanupSemanticScore($one, $two) {
|
|
// Define some regex patterns for matching boundaries.
|
|
$punctuation = '/[^a-zA-Z0-9]/';
|
|
$whitespace = '/\s/';
|
|
$linebreak = '/[\r\n]/';
|
|
$blanklineEnd = '/\n\r?\n$/';
|
|
$blanklineStart = '/^\r?\n\r?\n/';
|
|
|
|
if (!$one || !$two) {
|
|
// Edges are the best.
|
|
return 5;
|
|
}
|
|
|
|
// 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.
|
|
$score = 0;
|
|
// One point for non-alphanumeric.
|
|
if (preg_match($punctuation, $one[mb_strlen($one) - 1]) || preg_match($punctuation, $two[0])) {
|
|
$score++;
|
|
// Two points for whitespace.
|
|
if (preg_match($whitespace, $one[mb_strlen($one) - 1] ) || preg_match($whitespace, $two[0])) {
|
|
$score++;
|
|
// Three points for line breaks.
|
|
if (preg_match($linebreak, $one[mb_strlen($one) - 1]) || preg_match($linebreak, $two[0])) {
|
|
$score++;
|
|
// Four points for blank lines.
|
|
if (preg_match($blanklineEnd, $one) || preg_match($blanklineStart, $two)) {
|
|
$score++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return $score;
|
|
}
|
|
|
|
/**
|
|
* Reduce the number of edits by eliminating operationally trivial equalities.
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
*/
|
|
function diff_cleanupEfficiency(&$diffs) {
|
|
$changes = false;
|
|
$equalities = array (); // Stack of indices where equalities are found.
|
|
$equalitiesLength = 0; // Keeping our own length var is faster in JS.
|
|
$lastequality = ''; // Always equal to equalities[equalitiesLength-1][1]
|
|
$pointer = 0; // Index of current position.
|
|
// Is there an insertion operation before the last equality.
|
|
$pre_ins = false;
|
|
// Is there a deletion operation before the last equality.
|
|
$pre_del = false;
|
|
// Is there an insertion operation after the last equality.
|
|
$post_ins = false;
|
|
// Is there a deletion operation after the last equality.
|
|
$post_del = false;
|
|
while ($pointer < count($diffs)) {
|
|
if ($diffs[$pointer][0] == DIFF_EQUAL) { // equality found
|
|
if (mb_strlen($diffs[$pointer][1]) < $this->Diff_EditCost && ($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 = '';
|
|
}
|
|
$post_ins = $post_del = false;
|
|
} else { // an insertion or deletion
|
|
if ($diffs[$pointer][0] == DIFF_DELETE) {
|
|
$post_del = true;
|
|
} else {
|
|
$post_ins = true;
|
|
}
|
|
/*
|
|
* Five types to be split:
|
|
* <ins>A</ins><del>B</del>XY<ins>C</ins><del>D</del>
|
|
* <ins>A</ins>X<ins>C</ins><del>D</del>
|
|
* <ins>A</ins><del>B</del>X<ins>C</ins>
|
|
* <ins>A</del>X<ins>C</ins><del>D</del>
|
|
* <ins>A</ins><del>B</del>X<del>C</del>
|
|
*/
|
|
if ($lastequality && (($pre_ins && $pre_del && $post_ins && $post_del) || ((mb_strlen($lastequality) < $this->Diff_EditCost / 2) && ($pre_ins + $pre_del + $post_ins + $post_del) == 3))) {
|
|
// Duplicate record
|
|
$zzz_diffs = array_splice($diffs, $equalities[$equalitiesLength -1], 0, array(array (
|
|
DIFF_DELETE,
|
|
$lastequality
|
|
)));
|
|
// Change second copy to insert.
|
|
$diffs[$equalities[$equalitiesLength -1] + 1][0] = DIFF_INSERT;
|
|
$equalitiesLength--; // Throw away the equality we just deleted;
|
|
$lastequality = '';
|
|
if ($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.<Array.<number|string>>} diffs Array of diff tuples.
|
|
*/
|
|
function diff_cleanupMerge(&$diffs) {
|
|
array_push($diffs, array ( DIFF_EQUAL, '' )); // Add a dummy entry at the end.
|
|
$pointer = 0;
|
|
$count_delete = 0;
|
|
$count_insert = 0;
|
|
$text_delete = '';
|
|
$text_insert = '';
|
|
$commonlength = null;
|
|
while ($pointer < count($diffs)) {
|
|
switch ($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 !== 0 || $count_insert !== 0) {
|
|
if ($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 - $count_insert -1][1] .= mb_substr($text_insert, 0, $commonlength);
|
|
} else {
|
|
array_splice($diffs, 0, 0, array(array (
|
|
DIFF_EQUAL,
|
|
mb_substr($text_insert, 0, $commonlength)
|
|
)));
|
|
$pointer++;
|
|
}
|
|
$text_insert = mb_substr($text_insert, $commonlength);
|
|
$text_delete = mb_substr($text_delete, $commonlength);
|
|
}
|
|
// Factor out any common suffixies.
|
|
$commonlength = $this->diff_commonSuffix($text_insert, $text_delete);
|
|
if ($commonlength !== 0) {
|
|
$diffs[$pointer][1] = mb_substr($text_insert, mb_strlen($text_insert) - $commonlength) . $diffs[$pointer][1];
|
|
$text_insert = mb_substr($text_insert, 0, mb_strlen($text_insert) - $commonlength);
|
|
$text_delete = mb_substr($text_delete, 0, mb_strlen($text_delete) - $commonlength);
|
|
}
|
|
}
|
|
// Delete the offending records and add the merged ones.
|
|
if ($count_delete === 0) {
|
|
array_splice($diffs, $pointer-$count_delete-$count_insert, $count_delete+$count_insert, array(array(
|
|
DIFF_INSERT,
|
|
$text_insert
|
|
)));
|
|
} elseif ($count_insert === 0) {
|
|
array_splice($diffs, $pointer-$count_delete-$count_insert, $count_delete+$count_insert, array(array(
|
|
DIFF_DELETE,
|
|
$text_delete
|
|
)));
|
|
} else {
|
|
array_splice($diffs, $pointer-$count_delete-$count_insert, $count_delete+$count_insert, array(array(
|
|
DIFF_DELETE,
|
|
$text_delete
|
|
), array (
|
|
DIFF_INSERT,
|
|
$text_insert
|
|
)));
|
|
}
|
|
$pointer = $pointer - $count_delete - $count_insert + ($count_delete ? 1 : 0) + ($count_insert ? 1 : 0) + 1;
|
|
} elseif ($pointer !== 0 && $diffs[$pointer -1][0] == DIFF_EQUAL) {
|
|
// Merge this equality with the previous one.
|
|
$diffs[$pointer -1][1] .= $diffs[$pointer][1];
|
|
array_splice($diffs, $pointer, 1);
|
|
} else {
|
|
$pointer++;
|
|
}
|
|
$count_insert = 0;
|
|
$count_delete = 0;
|
|
$text_delete = '';
|
|
$text_insert = '';
|
|
break;
|
|
}
|
|
}
|
|
if ($diffs[count($diffs) - 1][1] === '') {
|
|
array_pop($diffs); // 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 < count($diffs) - 1) {
|
|
if ($diffs[$pointer-1][0] == DIFF_EQUAL && $diffs[$pointer+1][0] == DIFF_EQUAL) {
|
|
// This is a single edit surrounded by equalities.
|
|
if ( mb_substr($diffs[$pointer][1], mb_strlen($diffs[$pointer][1]) - mb_strlen($diffs[$pointer -1][1])) == $diffs[$pointer -1][1]) {
|
|
// Shift the edit over the previous equality.
|
|
$diffs[$pointer][1] = $diffs[$pointer -1][1] . mb_substr($diffs[$pointer][1], 0, mb_strlen($diffs[$pointer][1]) - mb_strlen($diffs[$pointer -1][1]));
|
|
$diffs[$pointer +1][1] = $diffs[$pointer -1][1] . $diffs[$pointer +1][1];
|
|
array_splice($diffs, $pointer -1, 1);
|
|
$changes = true;
|
|
} elseif (mb_substr($diffs[$pointer][1], 0, mb_strlen($diffs[$pointer +1][1])) == $diffs[$pointer +1][1]) {
|
|
// Shift the edit over the next equality.
|
|
$diffs[$pointer -1][1] .= $diffs[$pointer +1][1];
|
|
|
|
$diffs[$pointer][1] = mb_substr($diffs[$pointer][1], mb_strlen($diffs[$pointer +1][1])) . $diffs[$pointer +1][1];
|
|
array_splice($diffs, $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.<Array.<number|string>>} diffs Array of diff tuples.
|
|
* @param {number} loc Location within text1.
|
|
* @return {number} Location within text2.
|
|
*/
|
|
function diff_xIndex($diffs, $loc) {
|
|
$chars1 = 0;
|
|
$chars2 = 0;
|
|
$last_chars1 = 0;
|
|
$last_chars2 = 0;
|
|
for ($x = 0; $x < count($diffs); $x++) {
|
|
if ($diffs[$x][0] !== DIFF_INSERT) { // Equality or deletion.
|
|
$chars1 += mb_strlen($diffs[$x][1]);
|
|
}
|
|
if ($diffs[$x][0] !== DIFF_DELETE) { // Equality or insertion.
|
|
$chars2 += mb_strlen($diffs[$x][1]);
|
|
}
|
|
if ($chars1 > $loc) { // Overshot the location.
|
|
break;
|
|
}
|
|
$last_chars1 = $chars1;
|
|
$last_chars2 = $chars2;
|
|
}
|
|
// Was the location was deleted?
|
|
if (count($diffs) != $x && $diffs[$x][0] === DIFF_DELETE) {
|
|
return $last_chars2;
|
|
}
|
|
// Add the remaining character length.
|
|
return $last_chars2 + ($loc - $last_chars1);
|
|
}
|
|
|
|
/**
|
|
* Convert a diff array into a pretty HTML report.
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
* @return {string} HTML representation.
|
|
*/
|
|
function diff_prettyHtml($diffs) {
|
|
$html = array ();
|
|
$i = 0;
|
|
for ($x = 0; $x < count($diffs); $x++) {
|
|
$op = $diffs[$x][0]; // Operation (insert, delete, equal)
|
|
$data = $diffs[$x][1]; // Text of change.
|
|
$text = preg_replace(array (
|
|
'/&/',
|
|
'/</',
|
|
'/>/',
|
|
"/\n/"
|
|
), array (
|
|
'&',
|
|
'<',
|
|
'>',
|
|
'¶<BR>'
|
|
), $data);
|
|
|
|
switch ($op) {
|
|
case DIFF_INSERT :
|
|
$html[$x] = '<INS STYLE="background:#E6FFE6;" TITLE="i=' . $i . '">' . $text . '</INS>';
|
|
break;
|
|
case DIFF_DELETE :
|
|
$html[$x] = '<DEL STYLE="background:#FFE6E6;" TITLE="i=' . $i . '">' . $text . '</DEL>';
|
|
break;
|
|
case DIFF_EQUAL :
|
|
$html[$x] = '<SPAN TITLE="i=' . $i . '">' . $text . '</SPAN>';
|
|
break;
|
|
}
|
|
if ($op !== DIFF_DELETE) {
|
|
$i += mb_strlen($data);
|
|
}
|
|
}
|
|
return implode('',$html);
|
|
}
|
|
|
|
/**
|
|
* Compute and return the source text (all equalities and deletions).
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
* @return {string} Source text.
|
|
*/
|
|
function diff_text1($diffs) {
|
|
$text = array ();
|
|
for ($x = 0; $x < count($diffs); $x++) {
|
|
if ($diffs[$x][0] !== DIFF_INSERT) {
|
|
$text[$x] = $diffs[$x][1];
|
|
}
|
|
}
|
|
return implode('',$text);
|
|
}
|
|
|
|
/**
|
|
* Compute and return the destination text (all equalities and insertions).
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
* @return {string} Destination text.
|
|
*/
|
|
function diff_text2($diffs) {
|
|
$text = array ();
|
|
for ($x = 0; $x < count($diffs); $x++) {
|
|
if ($diffs[$x][0] !== DIFF_DELETE) {
|
|
$text[$x] = $diffs[$x][1];
|
|
}
|
|
}
|
|
return implode('',$text);
|
|
}
|
|
|
|
/**
|
|
* Compute the Levenshtein distance; the number of inserted, deleted or
|
|
* substituted characters.
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
* @return {number} Number of changes.
|
|
*/
|
|
function diff_levenshtein($diffs) {
|
|
$levenshtein = 0;
|
|
$insertions = 0;
|
|
$deletions = 0;
|
|
for ($x = 0; $x < count($diffs); $x++) {
|
|
$op = $diffs[$x][0];
|
|
$data = $diffs[$x][1];
|
|
switch ($op) {
|
|
case DIFF_INSERT :
|
|
$insertions += mb_strlen($data);
|
|
break;
|
|
case DIFF_DELETE :
|
|
$deletions += mb_strlen($data);
|
|
break;
|
|
case DIFF_EQUAL :
|
|
// A deletion and an insertion is one substitution.
|
|
$levenshtein += max($insertions, $deletions);
|
|
$insertions = 0;
|
|
$deletions = 0;
|
|
break;
|
|
}
|
|
}
|
|
$levenshtein += max($insertions, $deletions);
|
|
return $levenshtein;
|
|
}
|
|
|
|
/**
|
|
* Crush the diff into an encoded string which describes the operations
|
|
* required to transform text1 into text2.
|
|
* E.g. =3\t-2\t+ing -> Keep 3 chars, delete 2 chars, insert 'ing'.
|
|
* Operations are tab-separated. Inserted text is escaped using %xx notation.
|
|
* @param {Array.<Array.<number|string>>} diffs Array of diff tuples.
|
|
* @return {string} Delta text.
|
|
*/
|
|
function diff_toDelta($diffs) {
|
|
$text = array ();
|
|
for ($x = 0; $x < count($diffs); $x++) {
|
|
switch ($diffs[$x][0]) {
|
|
case DIFF_INSERT :
|
|
$text[$x] = '+' .encodeURI($diffs[$x][1]);
|
|
break;
|
|
case DIFF_DELETE :
|
|
$text[$x] = '-' .mb_strlen($diffs[$x][1]);
|
|
break;
|
|
case DIFF_EQUAL :
|
|
$text[$x] = '=' .mb_strlen($diffs[$x][1]);
|
|
break;
|
|
}
|
|
}
|
|
return str_replace('%20', ' ', implode("\t", $text));
|
|
}
|
|
|
|
/**
|
|
* Given the original text1, and an encoded string which describes the
|
|
* operations required to transform text1 into text2, compute the full diff.
|
|
* @param {string} text1 Source string for the diff.
|
|
* @param {string} delta Delta text.
|
|
* @return {Array.<Array.<number|string>>} Array of diff tuples.
|
|
* @throws {Error} If invalid input.
|
|
*/
|
|
function diff_fromDelta($text1, $delta) {
|
|
$diffs = array ();
|
|
$diffsLength = 0; // Keeping our own length var is faster in JS.
|
|
$pointer = 0; // Cursor in text1
|
|
$tokens = preg_split("/\t/", $delta);
|
|
|
|
for ($x = 0; $x < count($tokens); $x++) {
|
|
// Each token begins with a one character parameter which specifies the
|
|
// operation of this token (delete, insert, equality).
|
|
$param = mb_substr($tokens[$x], 1);
|
|
switch ($tokens[$x][0]) {
|
|
case '+' :
|
|
try {
|
|
$diffs[$diffsLength++] = array (
|
|
DIFF_INSERT,
|
|
decodeURI($param)
|
|
);
|
|
} catch (Exception $ex) {
|
|
echo_Exception('Illegal escape in diff_fromDelta: ' . $param);
|
|
// Malformed URI sequence.
|
|
}
|
|
break;
|
|
case '-' :
|
|
// Fall through.
|
|
case '=' :
|
|
$n = (int) $param;
|
|
if ($n < 0) {
|
|
echo_Exception('Invalid number in diff_fromDelta: ' . $param);
|
|
}
|
|
$text = mb_substr($text1, $pointer, $n);
|
|
$pointer += $n;
|
|
if ($tokens[$x][0] == '=') {
|
|
$diffs[$diffsLength++] = array (
|
|
DIFF_EQUAL,
|
|
$text
|
|
);
|
|
} else {
|
|
$diffs[$diffsLength++] = array (
|
|
DIFF_DELETE,
|
|
$text
|
|
);
|
|
}
|
|
break;
|
|
default :
|
|
// Blank tokens are ok (from a trailing \t).
|
|
// Anything else is an error.
|
|
if ($tokens[$x]) {
|
|
echo_Exception('Invalid diff operation in diff_fromDelta: ' . $tokens[$x]);
|
|
}
|
|
}
|
|
}
|
|
if ($pointer != mb_strlen($text1)) {
|
|
// throw new Exception('Delta length (' . $pointer . ') does not equal source text length (' . mb_strlen($text1) . ').');
|
|
echo_Exception('Delta length (' . $pointer . ') does not equal source text length (' . mb_strlen($text1) . ').');
|
|
}
|
|
return $diffs;
|
|
}
|
|
|
|
// MATCH FUNCTIONS
|
|
|
|
/**
|
|
* Locate the best instance of 'pattern' in 'text' near 'loc'.
|
|
* @param {string} text The text to search.
|
|
* @param {string} pattern The pattern to search for.
|
|
* @param {number} loc The location to search around.
|
|
* @return {number} Best match index or -1.
|
|
*/
|
|
function match_main($text, $pattern, $loc) {
|
|
$loc = max(0, min($loc, mb_strlen($text)));
|
|
if ($text == $pattern) {
|
|
// Shortcut (potentially not guaranteed by the algorithm)
|
|
return 0;
|
|
}
|
|
elseif (!mb_strlen($text)) {
|
|
// Nothing to match.
|
|
return -1;
|
|
}
|
|
elseif (mb_substr($text, $loc, mb_strlen($pattern)) == $pattern) {
|
|
// Perfect match at the perfect spot! (Includes case of null pattern)
|
|
return $loc;
|
|
} else {
|
|
// Do a fuzzy compare.
|
|
return $this->match_bitap($text, $pattern, $loc);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Locate the best instance of 'pattern' in 'text' near 'loc' using the
|
|
* Bitap algorithm.
|
|
* @param {string} text The text to search.
|
|
* @param {string} pattern The pattern to search for.
|
|
* @param {number} loc The location to search around.
|
|
* @return {number} Best match index or -1.
|
|
* @private
|
|
*/
|
|
function match_bitap($text, $pattern, $loc) {
|
|
if (mb_strlen($pattern) > Match_MaxBits) {
|
|
echo_Exception('Pattern too long for this browser.');
|
|
}
|
|
|
|
// Initialise the alphabet.
|
|
$s = $this->match_alphabet($pattern);
|
|
|
|
// Highest score beyond which we give up.
|
|
$score_threshold = $this->Match_Threshold;
|
|
|
|
// Is there a nearby exact match? (speedup)
|
|
$best_loc = mb_strpos($text, $pattern, $loc);
|
|
if ($best_loc !== false) {
|
|
$score_threshold = min($this->match_bitapScore(0, $best_loc, $pattern, $loc), $score_threshold);
|
|
}
|
|
|
|
// What about in the other direction? (speedup)
|
|
$best_loc = mb_strrpos( $text, $pattern, min($loc + mb_strlen($pattern), mb_strlen($text)) );
|
|
if ($best_loc !== false) {
|
|
$score_threshold = min($this->match_bitapScore(0, $best_loc, $pattern, $loc), $score_threshold);
|
|
}
|
|
|
|
// Initialise the bit arrays.
|
|
$matchmask = 1 << (mb_strlen($pattern) - 1);
|
|
$best_loc = -1;
|
|
|
|
$bin_min = null;
|
|
$bin_mid = null;
|
|
$bin_max = mb_strlen($pattern) + mb_strlen($text);
|
|
$last_rd = null;
|
|
for ($d = 0; $d < mb_strlen($pattern); $d++) {
|
|
// Scan for the best match; each iteration allows for one more error.
|
|
// Run a binary search to determine how far from 'loc' we can stray at this
|
|
// error level.
|
|
$bin_min = 0;
|
|
$bin_mid = $bin_max;
|
|
while ($bin_min < $bin_mid) {
|
|
if ($this->match_bitapScore($d, $loc + $bin_mid, $pattern, $loc) <= $score_threshold) {
|
|
$bin_min = $bin_mid;
|
|
} else {
|
|
$bin_max = $bin_mid;
|
|
}
|
|
$bin_mid = floor(($bin_max - $bin_min) / 2 + $bin_min);
|
|
}
|
|
// Use the result from this iteration as the maximum for the next.
|
|
$bin_max = $bin_mid;
|
|
$start = max(1, $loc - $bin_mid +1);
|
|
$finish = min($loc + $bin_mid, mb_strlen($text)) + mb_strlen($pattern);
|
|
|
|
$rd = Array (
|
|
$finish +2
|
|
);
|
|
$rd[$finish +1] = (1 << $d) - 1;
|
|
for ($j = $finish; $j >= $start; $j--) {
|
|
// The alphabet (s) is a sparse hash, so the following line generates
|
|
// warnings.
|
|
@ $charMatch = $s[ $text[$j -1] ];
|
|
if ($d === 0) { // First pass: exact match.
|
|
$rd[$j] = (($rd[$j +1] << 1) | 1) & $charMatch;
|
|
} else { // Subsequent passes: fuzzy match.
|
|
$rd[$j] = (($rd[$j +1] << 1) | 1) & $charMatch | ((($last_rd[$j +1] | $last_rd[$j]) << 1) | 1) | $last_rd[$j +1];
|
|
}
|
|
if ($rd[$j] & $matchmask) {
|
|
$score = $this->match_bitapScore($d, $j -1, $pattern, $loc);
|
|
// This match will almost certainly be better than any existing match.
|
|
// But check anyway.
|
|
if ($score <= $score_threshold) {
|
|
// Told you so.
|
|
$score_threshold = $score;
|
|
$best_loc = $j -1;
|
|
if ($best_loc > $loc) {
|
|
// When passing loc, don't exceed our current distance from loc.
|
|
$start = max(1, 2 * $loc - $best_loc);
|
|
} else {
|
|
// Already passed loc, downhill from here on in.
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// No hope for a (better) match at greater error levels.
|
|
if ($this->match_bitapScore($d +1, $loc, $pattern, $loc) > $score_threshold) {
|
|
break;
|
|
}
|
|
$last_rd = $rd;
|
|
}
|
|
return (int)$best_loc;
|
|
}
|
|
|
|
/**
|
|
* Compute and return the score for a match with e errors and x location.
|
|
* Accesses loc and pattern through being a closure.
|
|
* @param {number} e Number of errors in match.
|
|
* @param {number} x Location of match.
|
|
* @return {number} Overall score for match (0.0 = good, 1.0 = bad).
|
|
* @private
|
|
*/
|
|
function match_bitapScore($e, $x, $pattern, $loc) {
|
|
$accuracy = $e / mb_strlen($pattern);
|
|
$proximity = abs($loc - $x);
|
|
if (!$this->Match_Distance) {
|
|
// Dodge divide by zero error.
|
|
return $proximity ? 1.0 : $accuracy;
|
|
}
|
|
return $accuracy + ($proximity / $this->Match_Distance);
|
|
}
|
|
|
|
/**
|
|
* Initialise the alphabet for the Bitap algorithm.
|
|
* @param {string} pattern The text to encode.
|
|
* @return {Object} Hash of character locations.
|
|
* @private
|
|
*/
|
|
function match_alphabet($pattern) {
|
|
$s = array ();
|
|
for ($i = 0; $i < mb_strlen($pattern); $i++) {
|
|
$s[ $pattern[$i] ] = 0;
|
|
}
|
|
for ($i = 0; $i < mb_strlen($pattern); $i++) {
|
|
$s[ $pattern[$i] ] |= 1 << (mb_strlen($pattern) - $i - 1);
|
|
}
|
|
return $s;
|
|
}
|
|
|
|
// PATCH FUNCTIONS
|
|
|
|
/**
|
|
* Increase the context until it is unique,
|
|
* but don't let the pattern expand beyond Match_MaxBits.
|
|
* @param {patch_obj} patch The patch to grow.
|
|
* @param {string} text Source text.
|
|
* @private
|
|
*/
|
|
function patch_addContext($patch, $text) {
|
|
$pattern = mb_substr($text, $patch->start2, $patch->length1 );
|
|
$previousPattern = null;
|
|
$padding = 0;
|
|
$i = 0;
|
|
while (
|
|
( mb_strlen($pattern) === 0 // Javascript's indexOf/lastIndexOd return 0/strlen respectively if pattern = ''
|
|
|| mb_strpos($text, $pattern) !== mb_strrpos($text, $pattern)
|
|
)
|
|
&& $pattern !== $previousPattern // avoid infinte loop
|
|
&& mb_strlen($pattern) < Match_MaxBits - $this->Patch_Margin - $this->Patch_Margin ) {
|
|
$padding += $this->Patch_Margin;
|
|
$previousPattern = $pattern;
|
|
$pattern = mb_substr($text, max($patch->start2 - $padding,0), ($patch->start2 + $patch->length1 + $padding) - max($patch->start2 - $padding,0) );
|
|
}
|
|
// Add one chunk for good luck.
|
|
$padding += $this->Patch_Margin;
|
|
// Add the prefix.
|
|
$prefix = mb_substr($text, max($patch->start2 - $padding,0), $patch->start2 - max($patch->start2 - $padding,0) );
|
|
if ($prefix!=='') {
|
|
array_unshift($patch->diffs, array (
|
|
DIFF_EQUAL,
|
|
$prefix
|
|
));
|
|
}
|
|
// Add the suffix.
|
|
$suffix = mb_substr($text, $patch->start2 + $patch->length1, ($patch->start2 + $patch->length1 + $padding) - ($patch->start2 + $patch->length1) );
|
|
if ($suffix!=='') {
|
|
array_push($patch->diffs, array (
|
|
DIFF_EQUAL,
|
|
$suffix
|
|
));
|
|
}
|
|
|
|
// Roll back the start points.
|
|
$patch->start1 -= mb_strlen($prefix);
|
|
$patch->start2 -= mb_strlen($prefix);
|
|
// Extend the lengths.
|
|
$patch->length1 += mb_strlen($prefix) + mb_strlen($suffix);
|
|
$patch->length2 += mb_strlen($prefix) + mb_strlen($suffix);
|
|
}
|
|
|
|
/**
|
|
* Compute a list of patches to turn text1 into text2.
|
|
* Use diffs if provided, otherwise compute it ourselves.
|
|
* There are four ways to call this function, depending on what data is
|
|
* available to the caller:
|
|
* Method 1:
|
|
* a = text1, b = text2
|
|
* Method 2:
|
|
* a = diffs
|
|
* Method 3 (optimal):
|
|
* a = text1, b = diffs
|
|
* Method 4 (deprecated, use method 3):
|
|
* a = text1, b = text2, c = diffs
|
|
*
|
|
* @param {string|Array.<Array.<number|string>>} a text1 (methods 1,3,4) or
|
|
* Array of diff tuples for text1 to text2 (method 2).
|
|
* @param {string|Array.<Array.<number|string>>} opt_b text2 (methods 1,4) or
|
|
* Array of diff tuples for text1 to text2 (method 3) or undefined (method 2).
|
|
* @param {string|Array.<Array.<number|string>>} opt_c Array of diff tuples for
|
|
* text1 to text2 (method 4) or undefined (methods 1,2,3).
|
|
* @return {Array.<patch_obj>} Array of patch objects.
|
|
*/
|
|
function patch_make($a, $opt_b = null, $opt_c = null ) {
|
|
if (is_string($a) && is_string($opt_b) && $opt_c === null ) {
|
|
// Method 1: text1, text2
|
|
// Compute diffs from text1 and text2.
|
|
$text1 = $a;
|
|
$diffs = $this->diff_main($text1, $opt_b, true);
|
|
if ( count($diffs) > 2) {
|
|
$this->diff_cleanupSemantic($diffs);
|
|
$this->diff_cleanupEfficiency($diffs);
|
|
}
|
|
} elseif ( is_array($a) && $opt_b === null && $opt_c === null) {
|
|
// Method 2: diffs
|
|
// Compute text1 from diffs.
|
|
$diffs = $a;
|
|
$text1 = $this->diff_text1($diffs);
|
|
} elseif ( is_string($a) && is_array($opt_b) && $opt_c === null) {
|
|
// Method 3: text1, diffs
|
|
$text1 = $a;
|
|
$diffs = $opt_b;
|
|
} elseif ( is_string($a) && is_string($opt_b) && is_array($opt_c) ) {
|
|
// Method 4: text1, text2, diffs
|
|
// text2 is not used.
|
|
$text1 = $a;
|
|
$diffs = $opt_c;
|
|
} else {
|
|
echo_Exception('Unknown call format to patch_make.');
|
|
}
|
|
|
|
if ( count($diffs) === 0) {
|
|
return array(); // Get rid of the null case.
|
|
}
|
|
$patches = array();
|
|
$patch = new patch_obj();
|
|
$patchDiffLength = 0; // Keeping our own length var is faster in JS.
|
|
$char_count1 = 0; // Number of characters into the text1 string.
|
|
$char_count2 = 0; // Number of characters into the text2 string.
|
|
// Start with text1 (prepatch_text) and apply the diffs until we arrive at
|
|
// text2 (postpatch_text). We recreate the patches one by one to determine
|
|
// context info.
|
|
$prepatch_text = $text1;
|
|
$postpatch_text = $text1;
|
|
for ($x = 0; $x < count($diffs); $x++) {
|
|
$diff_type = $diffs[$x][0];
|
|
$diff_text = $diffs[$x][1];
|
|
|
|
if (!$patchDiffLength && $diff_type !== DIFF_EQUAL) {
|
|
// A new patch starts here.
|
|
$patch->start1 = $char_count1;
|
|
$patch->start2 = $char_count2;
|
|
}
|
|
|
|
switch ($diff_type) {
|
|
case DIFF_INSERT :
|
|
$patch->diffs[$patchDiffLength++] = $diffs[$x];
|
|
$patch->length2 += mb_strlen($diff_text);
|
|
$postpatch_text = mb_substr($postpatch_text, 0, $char_count2) . $diff_text . mb_substr($postpatch_text,$char_count2);
|
|
break;
|
|
case DIFF_DELETE :
|
|
$patch->length1 += mb_strlen($diff_text);
|
|
$patch->diffs[$patchDiffLength++] = $diffs[$x];
|
|
$postpatch_text = mb_substr($postpatch_text, 0, $char_count2) . mb_substr($postpatch_text, $char_count2 + mb_strlen($diff_text) );
|
|
break;
|
|
case DIFF_EQUAL :
|
|
if ( mb_strlen($diff_text) <= 2 * $this->Patch_Margin && $patchDiffLength && count($diffs) != $x + 1) {
|
|
// Small equality inside a patch.
|
|
$patch->diffs[$patchDiffLength++] = $diffs[$x];
|
|
$patch->length1 += mb_strlen($diff_text);
|
|
$patch->length2 += mb_strlen($diff_text);
|
|
} elseif ( mb_strlen($diff_text) >= 2 * $this->Patch_Margin ) {
|
|
// Time for a new patch.
|
|
if ($patchDiffLength) {
|
|
$this->patch_addContext($patch, $prepatch_text);
|
|
array_push($patches,$patch);
|
|
$patch = new patch_obj();
|
|
$patchDiffLength = 0;
|
|
// Unlike Unidiff, our patch lists have a rolling context.
|
|
// http://code.google.com/p/google-diff-match-patch/wiki/Unidiff
|
|
// Update prepatch text & pos to reflect the application of the
|
|
// just completed patch.
|
|
$prepatch_text = $postpatch_text;
|
|
$char_count1 = $char_count2;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
// Update the current character count.
|
|
if ($diff_type !== DIFF_INSERT) {
|
|
$char_count1 += mb_strlen($diff_text);
|
|
}
|
|
if ($diff_type !== DIFF_DELETE) {
|
|
$char_count2 += mb_strlen($diff_text);
|
|
}
|
|
}
|
|
// Pick up the leftover patch if not empty.
|
|
if ($patchDiffLength) {
|
|
$this->patch_addContext($patch, $prepatch_text);
|
|
array_push($patches, $patch);
|
|
}
|
|
|
|
return $patches;
|
|
}
|
|
|
|
/**
|
|
* Given an array of patches, return another array that is identical.
|
|
* @param {Array.<patch_obj>} patches Array of patch objects.
|
|
* @return {Array.<patch_obj>} Array of patch objects.
|
|
*/
|
|
function patch_deepCopy($patches) {
|
|
// Making deep copies is hard in JavaScript.
|
|
$patchesCopy = array();
|
|
for ($x = 0; $x < count($patches); $x++) {
|
|
$patch = $patches[$x];
|
|
$patchCopy = new patch_obj();
|
|
for ($y = 0; $y < count($patch->diffs); $y++) {
|
|
$patchCopy->diffs[$y] = $patch->diffs[$y]; // ?? . slice();
|
|
}
|
|
$patchCopy->start1 = $patch->start1;
|
|
$patchCopy->start2 = $patch->start2;
|
|
$patchCopy->length1 = $patch->length1;
|
|
$patchCopy->length2 = $patch->length2;
|
|
$patchesCopy[$x] = $patchCopy;
|
|
}
|
|
return $patchesCopy;
|
|
}
|
|
|
|
/**
|
|
* Merge a set of patches onto the text. Return a patched text, as well
|
|
* as a list of true/false values indicating which patches were applied.
|
|
* @param {Array.<patch_obj>} patches Array of patch objects.
|
|
* @param {string} text Old text.
|
|
* @return {Array.<string|Array.<boolean>>} Two element Array, containing the
|
|
* new text and an array of boolean values.
|
|
*/
|
|
function patch_apply($patches, $text) {
|
|
if ( count($patches) == 0) {
|
|
return array($text,array());
|
|
}
|
|
|
|
// Deep copy the patches so that no changes are made to originals.
|
|
$patches = $this->patch_deepCopy($patches);
|
|
|
|
$nullPadding = $this->patch_addPadding($patches);
|
|
$text = $nullPadding . $text . $nullPadding;
|
|
|
|
$this->patch_splitMax($patches);
|
|
// delta keeps track of the offset between the expected and actual location
|
|
// of the previous patch. If there are patches expected at positions 10 and
|
|
// 20, but the first patch was found at 12, delta is 2 and the second patch
|
|
// has an effective expected position of 22.
|
|
$delta = 0;
|
|
$results = array();
|
|
for ($x = 0; $x < count($patches) ; $x++) {
|
|
$expected_loc = $patches[$x]->start2 + $delta;
|
|
$text1 = $this->diff_text1($patches[$x]->diffs);
|
|
$start_loc = null;
|
|
$end_loc = -1;
|
|
if (mb_strlen($text1) > Match_MaxBits) {
|
|
// patch_splitMax will only provide an oversized pattern in the case of
|
|
// a monster delete.
|
|
$start_loc = $this->match_main($text, mb_substr($text1, 0, Match_MaxBits ), $expected_loc);
|
|
if ($start_loc != -1) {
|
|
$end_loc = $this->match_main($text, mb_substr($text1,mb_strlen($text1) - Match_MaxBits), $expected_loc + mb_strlen($text1) - Match_MaxBits);
|
|
if ($end_loc == -1 || $start_loc >= $end_loc) {
|
|
// Can't find valid trailing context. Drop this patch.
|
|
$start_loc = -1;
|
|
}
|
|
}
|
|
} else {
|
|
$start_loc = $this->match_main($text, $text1, $expected_loc);
|
|
}
|
|
if ($start_loc == -1) {
|
|
// No match found. :(
|
|
$results[$x] = false;
|
|
// Subtract the delta for this failed patch from subsequent patches.
|
|
$delta -= $patches[$x]->length2 - $patches[$x]->length1;
|
|
} else {
|
|
// Found a match. :)
|
|
$results[$x] = true;
|
|
$delta = $start_loc - $expected_loc;
|
|
$text2 = null;
|
|
if ($end_loc == -1) {
|
|
$text2 = mb_substr($text, $start_loc, mb_strlen($text1) );
|
|
} else {
|
|
$text2 = mb_substr($text, $start_loc, $end_loc + Match_MaxBits - $start_loc);
|
|
}
|
|
if ($text1 == $text2) {
|
|
// Perfect match, just shove the replacement text in.
|
|
$text = mb_substr($text, 0, $start_loc) . $this->diff_text2($patches[$x]->diffs) . mb_substr($text,$start_loc + mb_strlen($text1) );
|
|
} else {
|
|
// Imperfect match. Run a diff to get a framework of equivalent
|
|
// indices.
|
|
$diffs = $this->diff_main($text1, $text2, false);
|
|
if ( mb_strlen($text1) > Match_MaxBits && $this->diff_levenshtein($diffs) / mb_strlen($text1) > $this->Patch_DeleteThreshold) {
|
|
// The end points match, but the content is unacceptably bad.
|
|
$results[$x] = false;
|
|
} else {
|
|
$this->diff_cleanupSemanticLossless($diffs);
|
|
$index1 = 0;
|
|
$index2 = NULL;
|
|
for ($y = 0; $y < count($patches[$x]->diffs); $y++) {
|
|
$mod = $patches[$x]->diffs[$y];
|
|
if ($mod[0] !== DIFF_EQUAL) {
|
|
$index2 = $this->diff_xIndex($diffs, $index1);
|
|
}
|
|
if ($mod[0] === DIFF_INSERT) { // Insertion
|
|
$text = mb_substr($text, 0, $start_loc + $index2) . $mod[1] . mb_substr($text, $start_loc + $index2);
|
|
} elseif ($mod[0] === DIFF_DELETE) { // Deletion
|
|
$text = mb_substr($text, 0, $start_loc + $index2) . mb_substr($text,$start_loc + $this->diff_xIndex($diffs, $index1 + mb_strlen($mod[1]) ));
|
|
}
|
|
if ($mod[0] !== DIFF_DELETE) {
|
|
$index1 += mb_strlen($mod[1]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// Strip the padding off.
|
|
$text = mb_substr($text, mb_strlen($nullPadding), mb_strlen($text) - 2*mb_strlen($nullPadding) );
|
|
return array($text, $results);
|
|
}
|
|
|
|
/**
|
|
* Add some padding on text start and end so that edges can match something.
|
|
* Intended to be called only from within patch_apply.
|
|
* @param {Array.<patch_obj>} patches Array of patch objects.
|
|
* @return {string} The padding string added to each side.
|
|
*/
|
|
function patch_addPadding(&$patches){
|
|
$paddingLength = $this->Patch_Margin;
|
|
$nullPadding = '';
|
|
for ($x = 1; $x <= $paddingLength; $x++) {
|
|
$nullPadding .= mb_chr($x);
|
|
}
|
|
|
|
// Bump all the patches forward.
|
|
for ($x = 0; $x < count($patches); $x++) {
|
|
$patches[$x]->start1 += $paddingLength;
|
|
$patches[$x]->start2 += $paddingLength;
|
|
}
|
|
|
|
// Add some padding on start of first diff.
|
|
$patch = &$patches[0];
|
|
$diffs = &$patch->diffs;
|
|
if (count($diffs) == 0 || $diffs[0][0] != DIFF_EQUAL) {
|
|
// Add nullPadding equality.
|
|
array_unshift($diffs, array(DIFF_EQUAL, $nullPadding));
|
|
$patch->start1 -= $paddingLength; // Should be 0.
|
|
$patch->start2 -= $paddingLength; // Should be 0.
|
|
$patch->length1 += $paddingLength;
|
|
$patch->length2 += $paddingLength;
|
|
} elseif ($paddingLength > mb_strlen($diffs[0][1]) ) {
|
|
// Grow first equality.
|
|
$extraLength = $paddingLength - mb_strlen($diffs[0][1]);
|
|
$diffs[0][1] = mb_substr( $nullPadding , mb_strlen($diffs[0][1]) ) . $diffs[0][1];
|
|
$patch->start1 -= $extraLength;
|
|
$patch->start2 -= $extraLength;
|
|
$patch->length1 += $extraLength;
|
|
$patch->length2 += $extraLength;
|
|
}
|
|
|
|
// Add some padding on end of last diff.
|
|
$patch = &$patches[count($patches) - 1];
|
|
$diffs = &$patch->diffs;
|
|
if ( count($diffs) == 0 || $diffs[ count($diffs) - 1][0] != DIFF_EQUAL) {
|
|
// Add nullPadding equality.
|
|
array_push($diffs, array(DIFF_EQUAL, $nullPadding) );
|
|
$patch->length1 += $paddingLength;
|
|
$patch->length2 += $paddingLength;
|
|
} elseif ($paddingLength > mb_strlen( $diffs[count($diffs)-1][1] ) ) {
|
|
// Grow last equality.
|
|
$extraLength = $paddingLength - mb_strlen( $diffs[count($diffs)-1][1] );
|
|
$diffs[ count($diffs)-1][1] .= mb_substr($nullPadding,0,$extraLength);
|
|
$patch->length1 += $extraLength;
|
|
$patch->length2 += $extraLength;
|
|
}
|
|
|
|
return $nullPadding;
|
|
}
|
|
|
|
/**
|
|
* Look through the patches and break up any which are longer than the maximum
|
|
* limit of the match algorithm.
|
|
* @param {Array.<patch_obj>} patches Array of patch objects.
|
|
*/
|
|
function patch_splitMax(&$patches) {
|
|
for ($x = 0; $x < count($patches); $x++) {
|
|
if ( $patches[$x]->length1 > Match_MaxBits) {
|
|
$bigpatch = $patches[$x];
|
|
// Remove the big old patch.
|
|
array_splice($patches,$x--,1);
|
|
$patch_size = Match_MaxBits;
|
|
$start1 = $bigpatch->start1;
|
|
$start2 = $bigpatch->start2;
|
|
$precontext = '';
|
|
while ( count($bigpatch->diffs) !== 0) {
|
|
// Create one of several smaller patches.
|
|
$patch = new patch_obj();
|
|
$empty = true;
|
|
$patch->start1 = $start1 - mb_strlen($precontext);
|
|
$patch->start2 = $start2 - mb_strlen($precontext);
|
|
if ($precontext !== '') {
|
|
$patch->length1 = $patch->length2 = mb_strlen($precontext);
|
|
array_push($patch->diffs, array(DIFF_EQUAL, $precontext) );
|
|
}
|
|
while ( count($bigpatch->diffs) !== 0 && $patch->length1 < $patch_size - $this->Patch_Margin) {
|
|
$diff_type = $bigpatch->diffs[0][0];
|
|
$diff_text = $bigpatch->diffs[0][1];
|
|
if ($diff_type === DIFF_INSERT) {
|
|
// Insertions are harmless.
|
|
$patch->length2 += mb_strlen($diff_text);
|
|
$start2 += mb_strlen($diff_text);
|
|
array_push($patch->diffs, array_shift($bigpatch->diffs) );
|
|
$empty = false;
|
|
} else
|
|
if ($diff_type === DIFF_DELETE && count($patch->diffs) == 1 && $patch->diffs[0][0] == DIFF_EQUAL && (mb_strlen($diff_text) > 2 * $patch_size) ) {
|
|
// This is a large deletion. Let it pass in one chunk.
|
|
$patch->length1 += mb_strlen($diff_text);
|
|
$start1 += mb_strlen($diff_text);
|
|
$empty = false;
|
|
array_push( $patch->diffs, array($diff_type, $diff_text) );
|
|
array_shift($bigpatch->diffs);
|
|
} else {
|
|
// Deletion or equality. Only take as much as we can stomach.
|
|
$diff_text = mb_substr($diff_text, 0, $patch_size - $patch->length1 - $this->Patch_Margin);
|
|
$patch->length1 += mb_strlen($diff_text);
|
|
$start1 += mb_strlen($diff_text);
|
|
if ($diff_type === DIFF_EQUAL) {
|
|
$patch->length2 += mb_strlen($diff_text);
|
|
$start2 += mb_strlen($diff_text);
|
|
} else {
|
|
$empty = false;
|
|
}
|
|
array_push($patch->diffs, array($diff_type, $diff_text) );
|
|
if ($diff_text == $bigpatch->diffs[0][1]) {
|
|
array_shift($bigpatch->diffs);
|
|
} else {
|
|
$bigpatch->diffs[0][1] = mb_substr( $bigpatch->diffs[0][1],mb_strlen($diff_text) );
|
|
}
|
|
}
|
|
}
|
|
// Compute the head context for the next patch.
|
|
$precontext = $this->diff_text2($patch->diffs);
|
|
$precontext = mb_substr($precontext, mb_strlen($precontext)-$this->Patch_Margin);
|
|
// Append the end context for this patch.
|
|
$postcontext = mb_substr( $this->diff_text1($bigpatch->diffs), 0, $this->Patch_Margin );
|
|
if ($postcontext !== '') {
|
|
$patch->length1 += mb_strlen($postcontext);
|
|
$patch->length2 += mb_strlen($postcontext);
|
|
if ( count($patch->diffs) !== 0 && $patch->diffs[ count($patch->diffs) - 1][0] === DIFF_EQUAL) {
|
|
$patch->diffs[ count($patch->diffs) - 1][1] .= $postcontext;
|
|
} else {
|
|
array_push($patch->diffs, array(DIFF_EQUAL, $postcontext));
|
|
}
|
|
}
|
|
if (!$empty) {
|
|
array_splice($patches, ++$x, 0, array($patch));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Take a list of patches and return a textual representation.
|
|
* @param {Array.<patch_obj>} patches Array of patch objects.
|
|
* @return {string} Text representation of patches.
|
|
*/
|
|
function patch_toText($patches) {
|
|
$text = array();
|
|
for ($x = 0; $x < count($patches) ; $x++) {
|
|
$text[$x] = $patches[$x];
|
|
}
|
|
return implode('',$text);
|
|
}
|
|
|
|
/**
|
|
* Parse a textual representation of patches and return a list of patch objects.
|
|
* @param {string} textline Text representation of patches.
|
|
* @return {Array.<patch_obj>} Array of patch objects.
|
|
* @throws {Error} If invalid input.
|
|
*/
|
|
function patch_fromText($textline) {
|
|
$patches = array();
|
|
if ($textline === '') {
|
|
return $patches;
|
|
}
|
|
$text = explode("\n",$textline);
|
|
foreach($text as $i=>$t){ if($t===''){ unset($text[$i]); } }
|
|
$textPointer = 0;
|
|
while ($textPointer < count($text) ) {
|
|
$m = null;
|
|
preg_match('/^@@ -(\d+),?(\d*) \+(\d+),?(\d*) @@$/',$text[$textPointer],$m);
|
|
if (!$m) {
|
|
echo_Exception('Invalid patch string: ' . $text[$textPointer]);
|
|
}
|
|
$patch = new patch_obj();
|
|
array_push($patches, $patch);
|
|
@$patch->start1 = (int)$m[1];
|
|
if (@$m[2] === '') {
|
|
$patch->start1--;
|
|
$patch->length1 = 1;
|
|
} elseif ( @$m[2] == '0') {
|
|
$patch->length1 = 0;
|
|
} else {
|
|
$patch->start1--;
|
|
@$patch->length1 = (int)$m[2];
|
|
}
|
|
|
|
@$patch->start2 = (int)$m[3];
|
|
if (@$m[4] === '') {
|
|
$patch->start2--;
|
|
$patch->length2 = 1;
|
|
} elseif ( @$m[4] == '0') {
|
|
$patch->length2 = 0;
|
|
} else {
|
|
$patch->start2--;
|
|
@$patch->length2 = (int)$m[4];
|
|
}
|
|
$textPointer++;
|
|
|
|
while ($textPointer < count($text) ) {
|
|
$sign = $text[$textPointer][0];
|
|
try {
|
|
$line = decodeURI( mb_substr($text[$textPointer],1) );
|
|
} catch (Exception $ex) {
|
|
// Malformed URI sequence.
|
|
throw new Exception('Illegal escape in patch_fromText: ' . $line);
|
|
}
|
|
if ($sign == '-') {
|
|
// Deletion.
|
|
array_push( $patch->diffs, array(DIFF_DELETE, $line) );
|
|
} elseif ($sign == '+') {
|
|
// Insertion.
|
|
array_push($patch->diffs, array(DIFF_INSERT, $line) );
|
|
} elseif ($sign == ' ') {
|
|
// Minor equality.
|
|
array_push($patch->diffs, array(DIFF_EQUAL, $line) );
|
|
} elseif ($sign == '@') {
|
|
// Start of next patch.
|
|
break;
|
|
} elseif ($sign === '') {
|
|
// Blank line? Whatever.
|
|
} else {
|
|
// WTF?
|
|
echo_Exception('Invalid patch mode "' . $sign . '" in: ' . $line);
|
|
}
|
|
$textPointer++;
|
|
}
|
|
}
|
|
return $patches;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Class representing one patch operation.
|
|
* @constructor
|
|
*/
|
|
class patch_obj {
|
|
/** @type {Array.<Array.<number|string>>} */
|
|
public $diffs = array();
|
|
/** @type {number?} */
|
|
public $start1 = null;
|
|
/** @type {number?} */
|
|
public $start2 = null;
|
|
/** @type {number} */
|
|
public $length1 = 0;
|
|
/** @type {number} */
|
|
public $length2 = 0;
|
|
|
|
/**
|
|
* Emmulate GNU diff's format.
|
|
* Header: @@ -382,8 +481,9 @@
|
|
* Indicies are printed as 1-based, not 0-based.
|
|
* @return {string} The GNU diff string.
|
|
*/
|
|
function toString() {
|
|
if ($this->length1 === 0) {
|
|
$coords1 = $this->start1 . ',0';
|
|
} elseif ($this->length1 == 1) {
|
|
$coords1 = $this->start1 + 1;
|
|
} else {
|
|
$coords1 = ($this->start1 + 1) . ',' . $this->length1;
|
|
}
|
|
if ($this->length2 === 0) {
|
|
$coords2 = $this->start2 . ',0';
|
|
} elseif ($this->length2 == 1) {
|
|
$coords2 = $this->start2 + 1;
|
|
} else {
|
|
$coords2 = ($this->start2 + 1) . ',' . $this->length2;
|
|
}
|
|
$text = array ( '@@ -' . $coords1 . ' +' . $coords2 . " @@\n" );
|
|
|
|
// Escape the body of the patch with %xx notation.
|
|
for ($x = 0; $x < count($this->diffs); $x++) {
|
|
switch ($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[$x][1]) . "\n";
|
|
}
|
|
return str_replace('%20', ' ', implode('',$text));
|
|
}
|
|
function __toString(){
|
|
return $this->toString();
|
|
}
|
|
}
|
|
|
|
define('DIFF_DELETE', -1);
|
|
define('DIFF_INSERT', 1);
|
|
define('DIFF_EQUAL', 0);
|
|
|
|
define('Match_MaxBits', PHP_INT_SIZE * 8);
|
|
|
|
|
|
function charCodeAt($str, $pos) {
|
|
return mb_ord(mb_substr($str, $pos, 1));
|
|
}
|
|
function mb_ord($v) {
|
|
$k = mb_convert_encoding($v, 'UCS-2LE', 'UTF-8');
|
|
$k1 = ord(substr($k, 0, 1));
|
|
$k2 = ord(substr($k, 1, 1));
|
|
return $k2 * 256 + $k1;
|
|
}
|
|
function mb_chr($num){
|
|
return mb_convert_encoding('&#'.intval($num).';', 'UTF-8', 'HTML-ENTITIES');
|
|
}
|
|
|
|
/**
|
|
* as in javascript encodeURI() following the MDN description
|
|
*
|
|
* @link https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/encodeURI
|
|
* @param $url
|
|
* @return string
|
|
*/
|
|
function encodeURI($url) {
|
|
return strtr(rawurlencode($url), array (
|
|
'%3B' => ';', '%2C' => ',', '%2F' => '/', '%3F' => '?', '%3A' => ':', '%40' => '@', '%26' => '&', '%3D' => '=',
|
|
'%2B' => '+', '%24' => '$', '%21' => '!', '%2A' => '*', '%27' => '\'', '%28' => '(', '%29' => ')', '%23' => '#',
|
|
));
|
|
}
|
|
|
|
function decodeURI($encoded) {
|
|
static $dontDecode;
|
|
if (!$dontDecode) {
|
|
$table = array (
|
|
'%3B' => ';', '%2C' => ',', '%2F' => '/', '%3F' => '?', '%3A' => ':', '%40' => '@', '%26' => '&', '%3D' => '=',
|
|
'%2B' => '+', '%24' => '$', '%21' => '!', '%2A' => '*', '%27' => '\'', '%28' => '(', '%29' => ')', '%23' => '#',
|
|
);
|
|
$dontDecode = array();
|
|
foreach ($table as $k => $v) {
|
|
$dontDecode[$k] = encodeURI($k);
|
|
}
|
|
}
|
|
return rawurldecode(strtr($encoded, $dontDecode));
|
|
}
|
|
|
|
function echo_Exception($str){
|
|
global $lastException;
|
|
$lastException = $str;
|
|
echo $str;
|
|
}
|
|
//mb_internal_encoding("UTF-8");
|
|
|
|
?>
|