diff options
Diffstat (limited to 'trunk/etherpad/src/etherpad/collab/ace/easysync1.js')
| -rw-r--r-- | trunk/etherpad/src/etherpad/collab/ace/easysync1.js | 923 |
1 files changed, 923 insertions, 0 deletions
diff --git a/trunk/etherpad/src/etherpad/collab/ace/easysync1.js b/trunk/etherpad/src/etherpad/collab/ace/easysync1.js new file mode 100644 index 0000000..4f40aa0 --- /dev/null +++ b/trunk/etherpad/src/etherpad/collab/ace/easysync1.js @@ -0,0 +1,923 @@ +// DO NOT EDIT THIS FILE, edit infrastructure/ace/www/easy_sync.js + +/** + * Copyright 2009 Google Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS-IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +function Changeset(arg) { + + var array; + if ((typeof arg) == "string") { + // constant + array = [Changeset.MAGIC, 0, arg.length, 0, 0, arg]; + } + else if ((typeof arg) == "number") { + var n = Math.round(arg); + // delete-all on n-length text (useful for making a "builder") + array = [Changeset.MAGIC, n, 0, 0, 0, ""]; + } + else if (! arg) { + // identity on 0-length text + array = [Changeset.MAGIC, 0, 0, 0, 0, ""]; + } + else if (arg.isChangeset) { + return arg; + } + else array = arg; + + array.isChangeset = true; + + // OOP style: attach generic methods to array object, hold no state in environment + + //function error(msg) { top.console.error(msg); top.console.trace(); } + function error(msg) { var e = new Error(msg); e.easysync = true; throw e; } + function assert(b, msg) { if (! b) error("Changeset: "+String(msg)); } + function min(x, y) { return (x < y) ? x : y; } + Changeset._assert = assert; + + array.isIdentity = function() { + return this.length == 6 && this[1] == this[2] && this[3] == 0 && + this[4] == this[1] && this[5] == ""; + } + + array.eachStrip = function(func, thisObj) { + // inside "func", the method receiver will be "this" by default, + // or you can pass an object. + for(var i=0;i<this.numStrips();i++) { + var ptr = 3 + i*3; + if (func.call(thisObj || this, this[ptr], this[ptr+1], this[ptr+2], i)) + return true; + } + return false; + } + + array.numStrips = function() { return (this.length-3)/3; }; + array.oldLen = function() { return this[1]; }; + array.newLen = function() { return this[2]; }; + + array.checkRep = function() { + assert(this[0] == Changeset.MAGIC, "bad magic"); + assert(this[1] >= 0, "bad old text length"); + assert(this[2] >= 0, "bad new text length"); + assert((this.length % 3) == 0, "bad array length"); + assert(this.length >= 6, "must be at least one strip"); + var numStrips = this.numStrips(); + var oldLen = this[1]; + var newLen = this[2]; + // iterate over the "text strips" + var actualNewLen = 0; + this.eachStrip(function(startIndex, numTaken, newText, i) { + var s = startIndex, t = numTaken, n = newText; + var isFirst = (i == 0); + var isLast = (i == numStrips-1); + assert(t >= 0, "can't take negative number of chars"); + assert(isFirst || t > 0, "all strips but first must take"); + assert((t > 0) || (s == 0), "if first strip doesn't take, must have 0 startIndex"); + assert(s >= 0 && s + t <= oldLen, "bad index: "+this.toString()); + assert(t > 0 || n.length > 0 || (isFirst && isLast), "empty strip must be first and only"); + if (! isLast) { + var s2 = this[3 + i*3 + 3]; // startIndex of following strip + var gap = s2 - (s + t); + assert(gap >= 0, "overlapping or out-of-order strips: "+this.toString()); + assert(gap > 0 || n.length > 0, "touching strips with no added text"); + } + actualNewLen += t + n.length; + }); + assert(newLen == actualNewLen, "calculated new text length doesn't match"); + } + + array.applyToText = function(text) { + assert(text.length == this.oldLen(), "mismatched apply: "+text.length+" / "+this.oldLen()); + var buf = []; + this.eachStrip(function (s, t, n) { + buf.push(text.substr(s, t), n); + }); + return buf.join(''); + } + + function _makeBuilder(oldLen, supportAuthors) { + var C = Changeset(oldLen); + if (supportAuthors) { + _ensureAuthors(C); + } + return C.builder(); + } + + function _getNumInserted(C) { + var numChars = 0; + C.eachStrip(function(s,t,n) { + numChars += n.length; + }); + return numChars; + } + + function _ensureAuthors(C) { + if (! C.authors) { + C.setAuthor(); + } + return C; + } + + array.setAuthor = function(author) { + var C = this; + // authors array has even length >= 2; + // alternates [numChars1, author1, numChars2, author2]; + // all numChars > 0 unless there is exactly one, in which + // case it can be == 0. + C.authors = [_getNumInserted(C), author || '']; + return C; + } + + array.builder = function() { + // normal pattern is Changeset(oldLength).builder().appendOldText(...). ... + // builder methods mutate this! + var C = this; + // OOP style: state in environment + var self; + return self = { + appendNewText: function(str, author) { + C[C.length-1] += str; + C[2] += str.length; + + if (C.authors) { + var a = (author || ''); + var lastAuthorPtr = C.authors.length-1; + var lastAuthorLengthPtr = C.authors.length-2; + if ((!a) || a == C.authors[lastAuthorPtr]) { + C.authors[lastAuthorLengthPtr] += str.length; + } + else if (0 == C.authors[lastAuthorLengthPtr]) { + C.authors[lastAuthorLengthPtr] = str.length; + C.authors[lastAuthorPtr] = (a || C.authors[lastAuthorPtr]); + } + else { + C.authors.push(str.length, a); + } + } + + return self; + }, + appendOldText: function(startIndex, numTaken) { + if (numTaken == 0) return self; + // properties of last strip... + var s = C[C.length-3], t = C[C.length-2], n = C[C.length-1]; + if (t == 0 && n == "") { + // must be empty changeset, one strip that doesn't take old chars or add new ones + C[C.length-3] = startIndex; + C[C.length-2] = numTaken; + } + else if (n == "" && (s+t == startIndex)) { + C[C.length-2] += numTaken; // take more + } + else C.push(startIndex, numTaken, ""); // add a strip + C[2] += numTaken; + C.checkRep(); + return self; + }, + toChangeset: function() { return C; } + }; + } + + array.authorSlicer = function(outputBuilder) { + return _makeAuthorSlicer(this, outputBuilder); + } + + function _makeAuthorSlicer(changesetOrAuthorsIn, builderOut) { + // "builderOut" only needs to support appendNewText + var authors; // considered immutable + if (changesetOrAuthorsIn.isChangeset) { + authors = changesetOrAuthorsIn.authors; + } + else { + authors = changesetOrAuthorsIn; + } + + // OOP style: state in environment + var authorPtr = 0; + var charIndex = 0; + var charWithinAuthor = 0; // 0 <= charWithinAuthor <= authors[authorPtr]; max value iff atEnd + var atEnd = false; + function curAuthor() { return authors[authorPtr+1]; } + function curAuthorWidth() { return authors[authorPtr]; } + function assertNotAtEnd() { assert(! atEnd, "_authorSlicer: can't move past end"); } + function forwardInAuthor(numChars) { + charWithinAuthor += numChars; + charIndex += numChars; + } + function nextAuthor() { + assertNotAtEnd(); + assert(charWithinAuthor == curAuthorWidth(), "_authorSlicer: not at author end"); + charWithinAuthor = 0; + authorPtr += 2; + if (authorPtr == authors.length) { + atEnd = true; + } + } + + var self; + return self = { + skipChars: function(n) { + assert(n >= 0, "_authorSlicer: can't skip negative n"); + if (n == 0) return; + assertNotAtEnd(); + + var leftToSkip = n; + while (leftToSkip > 0) { + var leftInAuthor = curAuthorWidth() - charWithinAuthor; + if (leftToSkip >= leftInAuthor) { + forwardInAuthor(leftInAuthor); + leftToSkip -= leftInAuthor; + nextAuthor(); + } + else { + forwardInAuthor(leftToSkip); + leftToSkip = 0; + } + } + }, + takeChars: function(n, text) { + assert(n >= 0, "_authorSlicer: can't take negative n"); + if (n == 0) return; + assertNotAtEnd(); + assert(n == text.length, "_authorSlicer: bad text length"); + + var textLeft = text; + var leftToTake = n; + while (leftToTake > 0) { + if (curAuthorWidth() > 0 && charWithinAuthor < curAuthorWidth()) { + // at least one char to take from current author + var leftInAuthor = (curAuthorWidth() - charWithinAuthor); + assert(leftInAuthor > 0, "_authorSlicer: should have leftInAuthor > 0"); + var toTake = min(leftInAuthor, leftToTake); + assert(toTake > 0, "_authorSlicer: should have toTake > 0"); + builderOut.appendNewText(textLeft.substring(0, toTake), curAuthor()); + forwardInAuthor(toTake); + leftToTake -= toTake; + textLeft = textLeft.substring(toTake); + } + assert(charWithinAuthor <= curAuthorWidth(), "_authorSlicer: past end of author"); + if (charWithinAuthor == curAuthorWidth()) { + nextAuthor(); + } + } + }, + setBuilder: function(builder) { + builderOut = builder; + } + }; + } + + function _makeSlicer(C, output) { + // C: Changeset, output: builder from _makeBuilder + // C is considered immutable, won't change or be changed + + // OOP style: state in environment + var charIndex = 0; // 0 <= charIndex <= C.newLen(); maximum value iff atEnd + var stripIndex = 0; // 0 <= stripIndex <= C.numStrips(); maximum value iff atEnd + var charWithinStrip = 0; // 0 <= charWithinStrip < curStripWidth() + var atEnd = false; + + var authorSlicer; + if (C.authors) { + authorSlicer = _makeAuthorSlicer(C.authors, output); + } + + var ptr = 3; + function curStartIndex() { return C[ptr]; } + function curNumTaken() { return C[ptr+1]; } + function curNewText() { return C[ptr+2]; } + function curStripWidth() { return curNumTaken() + curNewText().length; } + function assertNotAtEnd() { assert(! atEnd, "_slicer: can't move past changeset end"); } + function forwardInStrip(numChars) { + charWithinStrip += numChars; + charIndex += numChars; + } + function nextStrip() { + assertNotAtEnd(); + assert(charWithinStrip == curStripWidth(), "_slicer: not at strip end"); + charWithinStrip = 0; + stripIndex++; + ptr += 3; + if (stripIndex == C.numStrips()) { + atEnd = true; + } + } + function curNumNewCharsInRange(start, end) { + // takes two indices into the current strip's combined "taken" and "new" + // chars, and returns how many "new" chars are included in the range + assert(start <= end, "_slicer: curNumNewCharsInRange given out-of-order indices"); + var nt = curNumTaken(); + var nn = curNewText().length; + var s = nt; + var e = nt+nn; + if (s < start) s = start; + if (e > end) e = end; + if (e < s) return 0; + return e-s; + } + + var self; + return self = { + skipChars: function (n) { + assert(n >= 0, "_slicer: can't skip negative n"); + if (n == 0) return; + assertNotAtEnd(); + + var leftToSkip = n; + while (leftToSkip > 0) { + var leftInStrip = curStripWidth() - charWithinStrip; + if (leftToSkip >= leftInStrip) { + forwardInStrip(leftInStrip); + + if (authorSlicer) + authorSlicer.skipChars(curNumNewCharsInRange(charWithinStrip, + charWithinStrip + leftInStrip)); + + leftToSkip -= leftInStrip; + nextStrip(); + } + else { + if (authorSlicer) + authorSlicer.skipChars(curNumNewCharsInRange(charWithinStrip, + charWithinStrip + leftToSkip)); + + forwardInStrip(leftToSkip); + leftToSkip = 0; + } + } + }, + takeChars: function (n) { + assert(n >= 0, "_slicer: can't take negative n"); + if (n == 0) return; + assertNotAtEnd(); + + var leftToTake = n; + while (leftToTake > 0) { + if (curNumTaken() > 0 && charWithinStrip < curNumTaken()) { + // at least one char to take from current strip's numTaken + var leftInTaken = (curNumTaken() - charWithinStrip); + assert(leftInTaken > 0, "_slicer: should have leftInTaken > 0"); + var toTake = min(leftInTaken, leftToTake); + assert(toTake > 0, "_slicer: should have toTake > 0"); + output.appendOldText(curStartIndex() + charWithinStrip, toTake); + forwardInStrip(toTake); + leftToTake -= toTake; + } + if (leftToTake > 0 && curNewText().length > 0 && charWithinStrip >= curNumTaken() && + charWithinStrip < curStripWidth()) { + // at least one char to take from current strip's newText + var leftInNewText = (curStripWidth() - charWithinStrip); + assert(leftInNewText > 0, "_slicer: should have leftInNewText > 0"); + var toTake = min(leftInNewText, leftToTake); + assert(toTake > 0, "_slicer: should have toTake > 0"); + var newText = curNewText().substr(charWithinStrip - curNumTaken(), toTake); + if (authorSlicer) { + authorSlicer.takeChars(newText.length, newText); + } + else { + output.appendNewText(newText); + } + forwardInStrip(toTake); + leftToTake -= toTake; + } + assert(charWithinStrip <= curStripWidth(), "_slicer: past end of strip"); + if (charWithinStrip == curStripWidth()) { + nextStrip(); + } + } + }, + skipTo: function(n) { + self.skipChars(n - charIndex); + } + }; + } + + array.slicer = function(outputBuilder) { + return _makeSlicer(this, outputBuilder); + } + + array.compose = function(next) { + assert(next.oldLen() == this.newLen(), "mismatched composition"); + + var builder = _makeBuilder(this.oldLen(), !!(this.authors || next.authors)); + var slicer = _makeSlicer(this, builder); + + var authorSlicer; + if (next.authors) { + authorSlicer = _makeAuthorSlicer(next.authors, builder); + } + + next.eachStrip(function(s, t, n) { + slicer.skipTo(s); + slicer.takeChars(t); + if (authorSlicer) { + authorSlicer.takeChars(n.length, n); + } + else { + builder.appendNewText(n); + } + }, this); + + return builder.toChangeset(); + }; + + array.traverser = function() { + return _makeTraverser(this); + } + + function _makeTraverser(C) { + var s = C[3], t = C[4], n = C[5]; + var nextIndex = 6; + var indexIntoNewText = 0; + + var authorSlicer; + if (C.authors) { + authorSlicer = _makeAuthorSlicer(C.authors, null); + } + + function advanceIfPossible() { + if (t == 0 && n == "" && nextIndex < C.length) { + s = C[nextIndex]; + t = C[nextIndex+1]; + n = C[nextIndex+2]; + nextIndex += 3; + } + } + + var self; + return self = { + numTakenChars: function() { + // if starts with taken characters, then how many, else 0 + return (t > 0) ? t : 0; + }, + numNewChars: function() { + // if starts with new characters, then how many, else 0 + return (t == 0 && n.length > 0) ? n.length : 0; + }, + takenCharsStart: function() { + return (self.numTakenChars() > 0) ? s : 0; + }, + hasMore: function() { + return self.numTakenChars() > 0 || self.numNewChars() > 0; + }, + curIndex: function() { + return indexIntoNewText; + }, + consumeTakenChars: function (x) { + assert(self.numTakenChars() > 0, "_traverser: no taken chars"); + assert(x >= 0 && x <= self.numTakenChars(), "_traverser: bad number of taken chars"); + if (x == 0) return; + if (t == x) { s = 0; t = 0; } + else { s += x; t -= x; } + indexIntoNewText += x; + advanceIfPossible(); + }, + consumeNewChars: function(x) { + return self.appendNewChars(x, null); + }, + appendNewChars: function(x, builder) { + assert(self.numNewChars() > 0, "_traverser: no new chars"); + assert(x >= 0 && x <= self.numNewChars(), "_traverser: bad number of new chars"); + if (x == 0) return ""; + var str = n.substring(0, x); + n = n.substring(x); + indexIntoNewText += x; + advanceIfPossible(); + + if (builder) { + if (authorSlicer) { + authorSlicer.setBuilder(builder); + authorSlicer.takeChars(x, str); + } + else { + builder.appendNewText(str); + } + } + else { + if (authorSlicer) authorSlicer.skipChars(x); + return str; + } + }, + consumeAvailableTakenChars: function() { + return self.consumeTakenChars(self.numTakenChars()); + }, + consumeAvailableNewChars: function() { + return self.consumeNewChars(self.numNewChars()); + }, + appendAvailableNewChars: function(builder) { + return self.appendNewChars(self.numNewChars(), builder); + } + }; + } + + array.follow = function(prev, reverseInsertOrder) { + // prev: Changeset, reverseInsertOrder: boolean + + // A.compose(B.follow(A)) is the merging of Changesets A and B, which operate on the same old text. + // It is always the same as B.compose(A.follow(B, true)). + + assert(prev.oldLen() == this.oldLen(), "mismatched follow: "+prev.oldLen()+"/"+this.oldLen()); + var builder = _makeBuilder(prev.newLen(), !! this.authors); + var a = _makeTraverser(prev); + var b = _makeTraverser(this); + while (a.hasMore() || b.hasMore()) { + if (a.numNewChars() > 0 && ! reverseInsertOrder) { + builder.appendOldText(a.curIndex(), a.numNewChars()); + a.consumeAvailableNewChars(); + } + else if (b.numNewChars() > 0) { + b.appendAvailableNewChars(builder); + } + else if (a.numNewChars() > 0 && reverseInsertOrder) { + builder.appendOldText(a.curIndex(), a.numNewChars()); + a.consumeAvailableNewChars(); + } + else if (! b.hasMore()) a.consumeAvailableTakenChars(); + else if (! a.hasMore()) b.consumeAvailableTakenChars(); + else { + var x = a.takenCharsStart(); + var y = b.takenCharsStart(); + if (x < y) a.consumeTakenChars(min(a.numTakenChars(), y-x)); + else if (y < x) b.consumeTakenChars(min(b.numTakenChars(), x-y)); + else { + var takenByBoth = min(a.numTakenChars(), b.numTakenChars()); + builder.appendOldText(a.curIndex(), takenByBoth); + a.consumeTakenChars(takenByBoth); + b.consumeTakenChars(takenByBoth); + } + } + } + return builder.toChangeset(); + } + + array.encodeToString = function(asBinary) { + var stringDataArray = []; + var numsArray = []; + if (! asBinary) numsArray.push(this[0]); + numsArray.push(this[1], this[2]); + this.eachStrip(function(s, t, n) { + numsArray.push(s, t, n.length); + stringDataArray.push(n); + }, this); + if (! asBinary) { + return numsArray.join(',')+'|'+stringDataArray.join(''); + } + else { + return "A" + Changeset.numberArrayToString(numsArray) + +escapeCrazyUnicode(stringDataArray.join('')); + } + } + + function escapeCrazyUnicode(str) { + return str.replace(/\\/g, '\\\\').replace(/[\ud800-\udfff]/g, function (c) { + return "\\u"+("0000"+c.charCodeAt(0).toString(16)).slice(-4); + }); + } + + array.applyToAttributedText = Changeset.applyToAttributedText; + + function splicesFromChanges(c) { + var splices = []; + // get a list of splices, [startChar, endChar, newText] + var traverser = c.traverser(); + var oldTextLength = c.oldLen(); + var indexIntoOldText = 0; + while (traverser.hasMore() || indexIntoOldText < oldTextLength) { + var newText = ""; + var startChar = indexIntoOldText; + var endChar = indexIntoOldText; + if (traverser.numNewChars() > 0) { + newText = traverser.consumeAvailableNewChars(); + } + if (traverser.hasMore()) { + endChar = traverser.takenCharsStart(); + indexIntoOldText = endChar + traverser.numTakenChars(); + traverser.consumeAvailableTakenChars(); + } + else { + endChar = oldTextLength; + indexIntoOldText = endChar; + } + if (endChar != startChar || newText.length > 0) { + splices.push([startChar, endChar, newText]); + } + } + return splices; + } + + array.toSplices = function() { + return splicesFromChanges(this); + } + + array.characterRangeFollowThis = function(selStartChar, selEndChar, insertionsAfter) { + var changeset = this; + // represent the selection as a changeset that replaces the selection with some finite string. + // Because insertions indicate intention, it doesn't matter what this string is, and even + // if the selectionChangeset is made to "follow" other changes it will still be the only + // insertion. + var selectionChangeset = + Changeset(changeset.oldLen()).builder().appendOldText(0, selStartChar).appendNewText( + "X").appendOldText(selEndChar, changeset.oldLen() - selEndChar).toChangeset(); + var newSelectionChangeset = selectionChangeset.follow(changeset, insertionsAfter); + var selectionSplices = newSelectionChangeset.toSplices(); + function includeChar(i) { + if (! includeChar.calledYet) { + selStartChar = i; + selEndChar = i; + includeChar.calledYet = true; + } + else { + if (i < selStartChar) selStartChar = i; + if (i > selEndChar) selEndChar = i; + } + } + for(var i=0; i<selectionSplices.length; i++) { + var s = selectionSplices[i]; + includeChar(s[0]); + includeChar(s[1]); + } + return [selStartChar, selEndChar]; + } + + return array; +} + +Changeset.MAGIC = "Changeset"; +Changeset.makeSplice = function(oldLength, spliceStart, numRemoved, stringInserted) { + oldLength = (oldLength || 0); + spliceStart = (spliceStart || 0); + numRemoved = (numRemoved || 0); + stringInserted = String(stringInserted || ""); + + var builder = Changeset(oldLength).builder(); + builder.appendOldText(0, spliceStart); + builder.appendNewText(stringInserted); + builder.appendOldText(spliceStart + numRemoved, oldLength - numRemoved - spliceStart); + return builder.toChangeset(); +}; +Changeset.identity = function(len) { + return Changeset(len).builder().appendOldText(0, len).toChangeset(); +}; +Changeset.decodeFromString = function(str) { + function error(msg) { var e = new Error(msg); e.easysync = true; throw e; } + function toHex(str) { + var a = []; + a.push("length["+str.length+"]:"); + var TRUNC=20; + for(var i=0;i<str.substring(0,TRUNC).length;i++) { + a.push(("000"+str.charCodeAt(i).toString(16)).slice(-4)); + } + if (str.length > TRUNC) a.push("..."); + return a.join(' '); + } + function unescapeCrazyUnicode(str) { + return str.replace(/\\(u....|\\)/g, function(seq) { + if (seq == "\\\\") return "\\"; + return String.fromCharCode(Number("0x"+seq.substring(2))); + }); + } + + var numData, stringData; + var binary = false; + var typ = str.charAt(0); + if (typ == "B" || typ == "A") { + var result = Changeset.numberArrayFromString(str, 1); + numData = result[0]; + stringData = result[1]; + if (typ == "A") { + stringData = unescapeCrazyUnicode(stringData); + } + binary = true; + } + else if (typ == "C") { + var barPosition = str.indexOf('|'); + numData = str.substring(0, barPosition).split(','); + stringData = str.substring(barPosition+1); + } + else { + error("Not a changeset: "+toHex(str)); + } + var stringDataOffset = 0; + var array = []; + var ptr; + if (binary) { + array.push("Changeset", numData[0], numData[1]); + var ptr = 2; + } + else { + array.push(numData[0], Number(numData[1]), Number(numData[2])); + var ptr = 3; + } + while (ptr < numData.length) { + array.push(Number(numData[ptr++]), Number(numData[ptr++])); + var newTextLength = Number(numData[ptr++]); + array.push(stringData.substr(stringDataOffset, newTextLength)); + stringDataOffset += newTextLength; + } + if (stringDataOffset != stringData.length) { + error("Extra character data beyond end of encoded string ("+toHex(str)+")"); + } + return Changeset(array); +}; + +Changeset.numberArrayToString = function(nums) { + var array = []; + function writeNum(n) { + // does not support negative numbers + var twentyEightBit = (n & 0xfffffff); + if (twentyEightBit <= 0x7fff) { + array.push(String.fromCharCode(twentyEightBit)); + } + else { + array.push(String.fromCharCode(0xa000 | (twentyEightBit >> 15), + twentyEightBit & 0x7fff)); + } + } + writeNum(nums.length); + var len = nums.length; + for(var i=0;i<len;i++) { + writeNum(nums[i]); + } + return array.join(''); +}; + +Changeset.numberArrayFromString = function(str, startIndex) { + // returns [numberArray, remainingString] + var nums = []; + var strIndex = (startIndex || 0); + function readNum() { + var n = str.charCodeAt(strIndex++); + if (n > 0x7fff) { + if (n >= 0xa000) { + n = (((n & 0x1fff) << 15) | str.charCodeAt(strIndex++)); + } + else { + // legacy format + n = (((n & 0x1fff) << 16) | str.charCodeAt(strIndex++)); + } + } + return n; + } + var len = readNum(); + for(var i=0;i<len;i++) { + nums.push(readNum()); + } + return [nums, str.substring(strIndex)]; +}; + +(function() { + function repeatString(str, times) { + if (times <= 0) return ""; + var s = repeatString(str, times >> 1); + s += s; + if (times & 1) s += str; + return s; + } + function chr(n) { return String.fromCharCode(n+48); } + function ord(c) { return c.charCodeAt(0)-48; } + function runMatcher(c) { + // Takes "A" and returns /\u0041+/g . + // Avoid creating new objects unnecessarily by caching matchers + // as properties of this function. + var re = runMatcher[c]; + if (re) return re; + re = runMatcher[c] = new RegExp("\\u"+("0000"+c.charCodeAt(0).toString(16)).slice(-4)+"+", 'g'); + return re; + } + function runLength(str, idx, c) { + var re = runMatcher(c); + re.lastIndex = idx; + var result = re.exec(str); + if (result && result[0]) { + return result[0].length; + } + return 0; + } + + // emptyObj may be a StorableObject + Changeset.initAttributedText = function(emptyObj, initialString, initialAuthor) { + var obj = emptyObj; + obj.authorMap = { 1: (initialAuthor || '') }; + obj.text = (initialString || ''); + obj.attribs = repeatString(chr(1), obj.text.length); + return obj; + }; + Changeset.gcAttributedText = function(atObj) { + // "garbage collect" the list of authors + var removedAuthors = []; + for(var a in atObj.authorMap) { + if (atObj.attribs.indexOf(chr(Number(a))) < 0) { + removedAuthors.push(atObj.authorMap[a]); + delete atObj.authorMap[a]; + } + } + return removedAuthors; + }; + Changeset.cloneAttributedText = function(emptyObj, atObj) { + var obj = emptyObj; + obj.text = atObj.text; // string + if (atObj.attribs) obj.attribs = atObj.attribs; // string + if (atObj.attribs_c) obj.attribs_c = atObj.attribs_c; // string + obj.authorMap = {}; + for(var a in atObj.authorMap) { + obj.authorMap[a] = atObj.authorMap[a]; + } + return obj; + }; + Changeset.applyToAttributedText = function(atObj, C) { + C = (C || this); + var oldText = atObj.text; + var oldAttribs = atObj.attribs; + Changeset._assert(C.isChangeset, "applyToAttributedText: 'this' is not a changeset"); + Changeset._assert(oldText.length == C.oldLen(), + "applyToAttributedText: mismatch "+oldText.length+" / "+C.oldLen()); + var textBuf = []; + var attribsBuf = []; + var authorMap = atObj.authorMap; + function authorId(author) { + for(var a in authorMap) { + if (authorMap[Number(a)] === author) { + return Number(a); + } + } + for(var i=1;i<=60000;i++) { + // don't use "in" because it's currently broken on StorableObjects + if (authorMap[i] === undefined) { + authorMap[i] = author; + return i; + } + } + } + var myBuilder = { appendNewText: function(txt, author) { + // object that acts as a "builder" in that it receives requests from + // authorSlicer to append text attributed to different authors + attribsBuf.push(repeatString(chr(authorId(author)), txt.length)); + } }; + var authorSlicer; + if (C.authors) { + authorSlicer = C.authorSlicer(myBuilder); + } + C.eachStrip(function (s, t, n) { + textBuf.push(oldText.substr(s, t), n); + attribsBuf.push(oldAttribs.substr(s, t)); + if (authorSlicer) { + authorSlicer.takeChars(n.length, n); + } + else { + myBuilder.appendNewText(n, ''); + } + }); + atObj.text = textBuf.join(''); + atObj.attribs = attribsBuf.join(''); + return atObj; + }; + Changeset.getAttributedTextCharAuthor = function(atObj, idx) { + return atObj.authorMap[ord(atObj.attribs.charAt(idx))]; + }; + Changeset.getAttributedTextCharRunLength = function(atObj, idx) { + var c = atObj.attribs.charAt(idx); + return runLength(atObj.attribs, idx, c); + }; + Changeset.eachAuthorInAttributedText = function(atObj, func) { + // call func(author, authorNum) + for(var a in atObj.authorMap) { + if (func(atObj.authorMap[a], Number(a))) break; + } + }; + Changeset.getAttributedTextAuthorByNum = function(atObj, n) { + return atObj.authorMap[n]; + }; + // Compressed attributed text can be cloned, but nothing else until uncompressed!! + Changeset.compressAttributedText = function(atObj) { + // idempotent, mutates the object, returns it + if (atObj.attribs) { + atObj.attribs_c = atObj.attribs.replace(/([\s\S])\1{0,63}/g, function(run) { + return run.charAt(0)+chr(run.length);; + }); + delete atObj.attribs; + } + return atObj; + }; + Changeset.decompressAttributedText = function(atObj) { + // idempotent, mutates the object, returns it + if (atObj.attribs_c) { + atObj.attribs = atObj.attribs_c.replace(/[\s\S][\s\S]/g, function(run) { + return repeatString(run.charAt(0), ord(run.charAt(1))); + }); + delete atObj.attribs_c; + } + return atObj; + }; +})(); |