diff options
Diffstat (limited to 'infrastructure/ace/www/easysync2.js')
| -rw-r--r-- | infrastructure/ace/www/easysync2.js | 1968 |
1 files changed, 1968 insertions, 0 deletions
diff --git a/infrastructure/ace/www/easysync2.js b/infrastructure/ace/www/easysync2.js new file mode 100644 index 0000000..efc5b99 --- /dev/null +++ b/infrastructure/ace/www/easysync2.js @@ -0,0 +1,1968 @@ +// THIS FILE IS ALSO AN APPJET MODULE: etherpad.collab.ace.easysync2 +// %APPJET%: jimport("com.etherpad.Easysync2Support"); + +/** + * 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. + */ + +//var _opt = (this.Easysync2Support || null); +var _opt = null; // disable optimization for now + +function AttribPool() { + var p = {}; + p.numToAttrib = {}; // e.g. {0: ['foo','bar']} + p.attribToNum = {}; // e.g. {'foo,bar': 0} + p.nextNum = 0; + + p.putAttrib = function(attrib, dontAddIfAbsent) { + var str = String(attrib); + if (str in p.attribToNum) { + return p.attribToNum[str]; + } + if (dontAddIfAbsent) { + return -1; + } + var num = p.nextNum++; + p.attribToNum[str] = num; + p.numToAttrib[num] = [String(attrib[0]||''), + String(attrib[1]||'')]; + return num; + }; + + p.getAttrib = function(num) { + var pair = p.numToAttrib[num]; + if (! pair) return pair; + return [pair[0], pair[1]]; // return a mutable copy + }; + + p.getAttribKey = function(num) { + var pair = p.numToAttrib[num]; + if (! pair) return ''; + return pair[0]; + }; + + p.getAttribValue = function(num) { + var pair = p.numToAttrib[num]; + if (! pair) return ''; + return pair[1]; + }; + + p.eachAttrib = function(func) { + for(var n in p.numToAttrib) { + var pair = p.numToAttrib[n]; + func(pair[0], pair[1]); + } + }; + + p.toJsonable = function() { + return {numToAttrib: p.numToAttrib, nextNum: p.nextNum}; + }; + + p.fromJsonable = function(obj) { + p.numToAttrib = obj.numToAttrib; + p.nextNum = obj.nextNum; + p.attribToNum = {}; + for(var n in p.numToAttrib) { + p.attribToNum[String(p.numToAttrib[n])] = Number(n); + } + return p; + }; + + return p; +} + +var Changeset = {}; + +Changeset.error = function error(msg) { var e = new Error(msg); e.easysync = true; throw e; }; +Changeset.assert = function assert(b, msgParts) { + if (! b) { + var msg = Array.prototype.slice.call(arguments, 1).join(''); + Changeset.error("Changeset: "+msg); + } +}; + +Changeset.parseNum = function(str) { return parseInt(str, 36); }; +Changeset.numToString = function(num) { return num.toString(36).toLowerCase(); }; +Changeset.toBaseTen = function(cs) { + var dollarIndex = cs.indexOf('$'); + var beforeDollar = cs.substring(0, dollarIndex); + var fromDollar = cs.substring(dollarIndex); + return beforeDollar.replace(/[0-9a-z]+/g, function(s) { + return String(Changeset.parseNum(s)); }) + fromDollar; +}; + +Changeset.oldLen = function(cs) { + return Changeset.unpack(cs).oldLen; +}; +Changeset.newLen = function(cs) { + return Changeset.unpack(cs).newLen; +}; + +Changeset.opIterator = function(opsStr, optStartIndex) { + //print(opsStr); + var regex = /((?:\*[0-9a-z]+)*)(?:\|([0-9a-z]+))?([-+=])([0-9a-z]+)|\?|/g; + var startIndex = (optStartIndex || 0); + var curIndex = startIndex; + var prevIndex = curIndex; + function nextRegexMatch() { + prevIndex = curIndex; + var result; + if (_opt) { + result = _opt.nextOpInString(opsStr, curIndex); + if (result) { + if (result.opcode() == '?') { + Changeset.error("Hit error opcode in op stream"); + } + curIndex = result.lastIndex(); + } + } + else { + regex.lastIndex = curIndex; + result = regex.exec(opsStr); + curIndex = regex.lastIndex; + if (result[0] == '?') { + Changeset.error("Hit error opcode in op stream"); + } + } + return result; + } + var regexResult = nextRegexMatch(); + var obj = Changeset.newOp(); + function next(optObj) { + var op = (optObj || obj); + if (_opt && regexResult) { + op.attribs = regexResult.attribs(); + op.lines = regexResult.lines(); + op.chars = regexResult.chars(); + op.opcode = regexResult.opcode(); + regexResult = nextRegexMatch(); + } + else if ((! _opt) && regexResult[0]) { + op.attribs = regexResult[1]; + op.lines = Changeset.parseNum(regexResult[2] || 0); + op.opcode = regexResult[3]; + op.chars = Changeset.parseNum(regexResult[4]); + regexResult = nextRegexMatch(); + } + else { + Changeset.clearOp(op); + } + return op; + } + function hasNext() { return !! (_opt ? regexResult : regexResult[0]); } + function lastIndex() { return prevIndex; } + return {next: next, hasNext: hasNext, lastIndex: lastIndex}; +}; + +Changeset.clearOp = function(op) { + op.opcode = ''; + op.chars = 0; + op.lines = 0; + op.attribs = ''; +}; +Changeset.newOp = function(optOpcode) { + return {opcode:(optOpcode || ''), chars:0, lines:0, attribs:''}; +}; +Changeset.cloneOp = function(op) { + return {opcode: op.opcode, chars: op.chars, lines: op.lines, attribs: op.attribs}; +}; +Changeset.copyOp = function(op1, op2) { + op2.opcode = op1.opcode; + op2.chars = op1.chars; + op2.lines = op1.lines; + op2.attribs = op1.attribs; +}; +Changeset.opString = function(op) { + // just for debugging + if (! op.opcode) return 'null'; + var assem = Changeset.opAssembler(); + assem.append(op); + return assem.toString(); +}; +Changeset.stringOp = function(str) { + // just for debugging + return Changeset.opIterator(str).next(); +}; + +Changeset.checkRep = function(cs) { + // doesn't check things that require access to attrib pool (e.g. attribute order) + // or original string (e.g. newline positions) + var unpacked = Changeset.unpack(cs); + var oldLen = unpacked.oldLen; + var newLen = unpacked.newLen; + var ops = unpacked.ops; + var charBank = unpacked.charBank; + + var assem = Changeset.smartOpAssembler(); + var oldPos = 0; + var calcNewLen = 0; + var numInserted = 0; + var iter = Changeset.opIterator(ops); + while (iter.hasNext()) { + var o = iter.next(); + switch (o.opcode) { + case '=': oldPos += o.chars; calcNewLen += o.chars; break; + case '-': oldPos += o.chars; Changeset.assert(oldPos < oldLen, oldPos," >= ",oldLen," in ",cs); break; + case '+': { + calcNewLen += o.chars; numInserted += o.chars; + Changeset.assert(calcNewLen < newLen, calcNewLen," >= ",newLen," in ",cs); + break; + } + } + assem.append(o); + } + + calcNewLen += oldLen - oldPos; + charBank = charBank.substring(0, numInserted); + while (charBank.length < numInserted) { + charBank += "?"; + } + + assem.endDocument(); + var normalized = Changeset.pack(oldLen, calcNewLen, assem.toString(), charBank); + Changeset.assert(normalized == cs, normalized,' != ',cs); + + return cs; +} + +Changeset.smartOpAssembler = function() { + // Like opAssembler but able to produce conforming changesets + // from slightly looser input, at the cost of speed. + // Specifically: + // - merges consecutive operations that can be merged + // - strips final "=" + // - ignores 0-length changes + // - reorders consecutive + and - (which margingOpAssembler doesn't do) + + var minusAssem = Changeset.mergingOpAssembler(); + var plusAssem = Changeset.mergingOpAssembler(); + var keepAssem = Changeset.mergingOpAssembler(); + var assem = Changeset.stringAssembler(); + var lastOpcode = ''; + var lengthChange = 0; + + function flushKeeps() { + assem.append(keepAssem.toString()); + keepAssem.clear(); + } + + function flushPlusMinus() { + assem.append(minusAssem.toString()); + minusAssem.clear(); + assem.append(plusAssem.toString()); + plusAssem.clear(); + } + + function append(op) { + if (! op.opcode) return; + if (! op.chars) return; + + if (op.opcode == '-') { + if (lastOpcode == '=') { + flushKeeps(); + } + minusAssem.append(op); + lengthChange -= op.chars; + } + else if (op.opcode == '+') { + if (lastOpcode == '=') { + flushKeeps(); + } + plusAssem.append(op); + lengthChange += op.chars; + } + else if (op.opcode == '=') { + if (lastOpcode != '=') { + flushPlusMinus(); + } + keepAssem.append(op); + } + lastOpcode = op.opcode; + } + + function appendOpWithText(opcode, text, attribs, pool) { + var op = Changeset.newOp(opcode); + op.attribs = Changeset.makeAttribsString(opcode, attribs, pool); + var lastNewlinePos = text.lastIndexOf('\n'); + if (lastNewlinePos < 0) { + op.chars = text.length; + op.lines = 0; + append(op); + } + else { + op.chars = lastNewlinePos+1; + op.lines = text.match(/\n/g).length; + append(op); + op.chars = text.length - (lastNewlinePos+1); + op.lines = 0; + append(op); + } + } + + function toString() { + flushPlusMinus(); + flushKeeps(); + return assem.toString(); + } + + function clear() { + minusAssem.clear(); + plusAssem.clear(); + keepAssem.clear(); + assem.clear(); + lengthChange = 0; + } + + function endDocument() { + keepAssem.endDocument(); + } + + function getLengthChange() { + return lengthChange; + } + + return {append: append, toString: toString, clear: clear, endDocument: endDocument, + appendOpWithText: appendOpWithText, getLengthChange: getLengthChange }; +}; + +if (_opt) { + Changeset.mergingOpAssembler = function() { + var assem = _opt.mergingOpAssembler(); + + function append(op) { + assem.append(op.opcode, op.chars, op.lines, op.attribs); + } + function toString() { + return assem.toString(); + } + function clear() { + assem.clear(); + } + function endDocument() { + assem.endDocument(); + } + + return {append: append, toString: toString, clear: clear, endDocument: endDocument}; + }; +} +else { + Changeset.mergingOpAssembler = function() { + // This assembler can be used in production; it efficiently + // merges consecutive operations that are mergeable, ignores + // no-ops, and drops final pure "keeps". It does not re-order + // operations. + var assem = Changeset.opAssembler(); + var bufOp = Changeset.newOp(); + + // If we get, for example, insertions [xxx\n,yyy], those don't merge, + // but if we get [xxx\n,yyy,zzz\n], that merges to [xxx\nyyyzzz\n]. + // This variable stores the length of yyy and any other newline-less + // ops immediately after it. + var bufOpAdditionalCharsAfterNewline = 0; + + function flush(isEndDocument) { + if (bufOp.opcode) { + if (isEndDocument && bufOp.opcode == '=' && ! bufOp.attribs) { + // final merged keep, leave it implicit + } + else { + assem.append(bufOp); + if (bufOpAdditionalCharsAfterNewline) { + bufOp.chars = bufOpAdditionalCharsAfterNewline; + bufOp.lines = 0; + assem.append(bufOp); + bufOpAdditionalCharsAfterNewline = 0; + } + } + bufOp.opcode = ''; + } + } + function append(op) { + if (op.chars > 0) { + if (bufOp.opcode == op.opcode && bufOp.attribs == op.attribs) { + if (op.lines > 0) { + // bufOp and additional chars are all mergeable into a multi-line op + bufOp.chars += bufOpAdditionalCharsAfterNewline + op.chars; + bufOp.lines += op.lines; + bufOpAdditionalCharsAfterNewline = 0; + } + else if (bufOp.lines == 0) { + // both bufOp and op are in-line + bufOp.chars += op.chars; + } + else { + // append in-line text to multi-line bufOp + bufOpAdditionalCharsAfterNewline += op.chars; + } + } + else { + flush(); + Changeset.copyOp(op, bufOp); + } + } + } + function endDocument() { + flush(true); + } + function toString() { + flush(); + return assem.toString(); + } + function clear() { + assem.clear(); + Changeset.clearOp(bufOp); + } + return {append: append, toString: toString, clear: clear, endDocument: endDocument}; + }; +} + +if (_opt) { + Changeset.opAssembler = function() { + var assem = _opt.opAssembler(); + // this function allows op to be mutated later (doesn't keep a ref) + function append(op) { + assem.append(op.opcode, op.chars, op.lines, op.attribs); + } + function toString() { + return assem.toString(); + } + function clear() { + assem.clear(); + } + return {append: append, toString: toString, clear: clear}; + }; +} +else { + Changeset.opAssembler = function() { + var pieces = []; + // this function allows op to be mutated later (doesn't keep a ref) + function append(op) { + pieces.push(op.attribs); + if (op.lines) { + pieces.push('|', Changeset.numToString(op.lines)); + } + pieces.push(op.opcode); + pieces.push(Changeset.numToString(op.chars)); + } + function toString() { + return pieces.join(''); + } + function clear() { + pieces.length = 0; + } + return {append: append, toString: toString, clear: clear}; + }; +} + +Changeset.stringIterator = function(str) { + var curIndex = 0; + function assertRemaining(n) { + Changeset.assert(n <= remaining(), "!(",n," <= ",remaining(),")"); + } + function take(n) { + assertRemaining(n); + var s = str.substr(curIndex, n); + curIndex += n; + return s; + } + function peek(n) { + assertRemaining(n); + var s = str.substr(curIndex, n); + return s; + } + function skip(n) { + assertRemaining(n); + curIndex += n; + } + function remaining() { + return str.length - curIndex; + } + return {take:take, skip:skip, remaining:remaining, peek:peek}; +}; + +Changeset.stringAssembler = function() { + var pieces = []; + function append(x) { + pieces.push(String(x)); + } + function toString() { + return pieces.join(''); + } + return {append: append, toString: toString}; +}; + +// "lines" need not be an array as long as it supports certain calls (lines_foo inside). +Changeset.textLinesMutator = function(lines) { + // Mutates lines, an array of strings, in place. + // Mutation operations have the same constraints as changeset operations + // with respect to newlines, but not the other additional constraints + // (i.e. ins/del ordering, forbidden no-ops, non-mergeability, final newline). + // Can be used to mutate lists of strings where the last char of each string + // is not actually a newline, but for the purposes of N and L values, + // the caller should pretend it is, and for things to work right in that case, the input + // to insert() should be a single line with no newlines. + + var curSplice = [0,0]; + var inSplice = false; + // position in document after curSplice is applied: + var curLine = 0, curCol = 0; + // invariant: if (inSplice) then (curLine is in curSplice[0] + curSplice.length - {2,3}) && + // curLine >= curSplice[0] + // invariant: if (inSplice && (curLine >= curSplice[0] + curSplice.length - 2)) then + // curCol == 0 + + function lines_applySplice(s) { + lines.splice.apply(lines, s); + } + function lines_toSource() { + return lines.toSource(); + } + function lines_get(idx) { + if (lines.get) { + return lines.get(idx); + } + else { + return lines[idx]; + } + } + // can be unimplemented if removeLines's return value not needed + function lines_slice(start, end) { + if (lines.slice) { + return lines.slice(start, end); + } + else { + return []; + } + } + function lines_length() { + if ((typeof lines.length) == "number") { + return lines.length; + } + else { + return lines.length(); + } + } + + function enterSplice() { + curSplice[0] = curLine; + curSplice[1] = 0; + if (curCol > 0) { + putCurLineInSplice(); + } + inSplice = true; + } + function leaveSplice() { + lines_applySplice(curSplice); + curSplice.length = 2; + curSplice[0] = curSplice[1] = 0; + inSplice = false; + } + function isCurLineInSplice() { + return (curLine - curSplice[0] < (curSplice.length - 2)); + } + function debugPrint(typ) { + print(typ+": "+curSplice.toSource()+" / "+curLine+","+curCol+" / "+lines_toSource()); + } + function putCurLineInSplice() { + if (! isCurLineInSplice()) { + curSplice.push(lines_get(curSplice[0] + curSplice[1])); + curSplice[1]++; + } + return 2 + curLine - curSplice[0]; + } + + function skipLines(L, includeInSplice) { + if (L) { + if (includeInSplice) { + if (! inSplice) { + enterSplice(); + } + for(var i=0;i<L;i++) { + curCol = 0; + putCurLineInSplice(); + curLine++; + } + } + else { + if (inSplice) { + if (L > 1) { + leaveSplice(); + } + else { + putCurLineInSplice(); + } + } + curLine += L; + curCol = 0; + } + //print(inSplice+" / "+isCurLineInSplice()+" / "+curSplice[0]+" / "+curSplice[1]+" / "+lines.length); + /*if (inSplice && (! isCurLineInSplice()) && (curSplice[0] + curSplice[1] < lines.length)) { + print("BLAH"); + putCurLineInSplice(); + }*/ // tests case foo in remove(), which isn't otherwise covered in current impl + } + //debugPrint("skip"); + } + + function skip(N, L, includeInSplice) { + if (N) { + if (L) { + skipLines(L, includeInSplice); + } + else { + if (includeInSplice && ! inSplice) { + enterSplice(); + } + if (inSplice) { + putCurLineInSplice(); + } + curCol += N; + //debugPrint("skip"); + } + } + } + + function removeLines(L) { + var removed = ''; + if (L) { + if (! inSplice) { + enterSplice(); + } + function nextKLinesText(k) { + var m = curSplice[0] + curSplice[1]; + return lines_slice(m, m+k).join(''); + } + if (isCurLineInSplice()) { + //print(curCol); + if (curCol == 0) { + removed = curSplice[curSplice.length-1]; + // print("FOO"); // case foo + curSplice.length--; + removed += nextKLinesText(L-1); + curSplice[1] += L-1; + } + else { + removed = nextKLinesText(L-1); + curSplice[1] += L-1; + var sline = curSplice.length - 1; + removed = curSplice[sline].substring(curCol) + removed; + curSplice[sline] = curSplice[sline].substring(0, curCol) + + lines_get(curSplice[0] + curSplice[1]); + curSplice[1] += 1; + } + } + else { + removed = nextKLinesText(L); + curSplice[1] += L; + } + //debugPrint("remove"); + } + return removed; + } + + function remove(N, L) { + var removed = ''; + if (N) { + if (L) { + return removeLines(L); + } + else { + if (! inSplice) { + enterSplice(); + } + var sline = putCurLineInSplice(); + removed = curSplice[sline].substring(curCol, curCol+N); + curSplice[sline] = curSplice[sline].substring(0, curCol) + + curSplice[sline].substring(curCol+N); + //debugPrint("remove"); + } + } + return removed; + } + + function insert(text, L) { + if (text) { + if (! inSplice) { + enterSplice(); + } + if (L) { + var newLines = Changeset.splitTextLines(text); + if (isCurLineInSplice()) { + //if (curCol == 0) { + //curSplice.length--; + //curSplice[1]--; + //Array.prototype.push.apply(curSplice, newLines); + //curLine += newLines.length; + //} + //else { + var sline = curSplice.length - 1; + var theLine = curSplice[sline]; + var lineCol = curCol; + curSplice[sline] = theLine.substring(0, lineCol) + newLines[0]; + curLine++; + newLines.splice(0, 1); + Array.prototype.push.apply(curSplice, newLines); + curLine += newLines.length; + curSplice.push(theLine.substring(lineCol)); + curCol = 0; + //} + } + else { + Array.prototype.push.apply(curSplice, newLines); + curLine += newLines.length; + } + } + else { + var sline = putCurLineInSplice(); + curSplice[sline] = curSplice[sline].substring(0, curCol) + + text + curSplice[sline].substring(curCol); + curCol += text.length; + } + //debugPrint("insert"); + } + } + + function hasMore() { + //print(lines.length+" / "+inSplice+" / "+(curSplice.length - 2)+" / "+curSplice[1]); + var docLines = lines_length(); + if (inSplice) { + docLines += curSplice.length - 2 - curSplice[1]; + } + return curLine < docLines; + } + + function close() { + if (inSplice) { + leaveSplice(); + } + //debugPrint("close"); + } + + var self = {skip:skip, remove:remove, insert:insert, close:close, hasMore:hasMore, + removeLines:removeLines, skipLines: skipLines}; + return self; +}; + +Changeset.applyZip = function(in1, idx1, in2, idx2, func) { + var iter1 = Changeset.opIterator(in1, idx1); + var iter2 = Changeset.opIterator(in2, idx2); + var assem = Changeset.smartOpAssembler(); + var op1 = Changeset.newOp(); + var op2 = Changeset.newOp(); + var opOut = Changeset.newOp(); + while (op1.opcode || iter1.hasNext() || op2.opcode || iter2.hasNext()) { + if ((! op1.opcode) && iter1.hasNext()) iter1.next(op1); + if ((! op2.opcode) && iter2.hasNext()) iter2.next(op2); + func(op1, op2, opOut); + if (opOut.opcode) { + //print(opOut.toSource()); + assem.append(opOut); + opOut.opcode = ''; + } + } + assem.endDocument(); + return assem.toString(); +}; + +Changeset.unpack = function(cs) { + var headerRegex = /Z:([0-9a-z]+)([><])([0-9a-z]+)|/; + var headerMatch = headerRegex.exec(cs); + if ((! headerMatch) || (! headerMatch[0])) { + Changeset.error("Not a changeset: "+cs); + } + var oldLen = Changeset.parseNum(headerMatch[1]); + var changeSign = (headerMatch[2] == '>') ? 1 : -1; + var changeMag = Changeset.parseNum(headerMatch[3]); + var newLen = oldLen + changeSign*changeMag; + var opsStart = headerMatch[0].length; + var opsEnd = cs.indexOf("$"); + if (opsEnd < 0) opsEnd = cs.length; + return {oldLen: oldLen, newLen: newLen, ops: cs.substring(opsStart, opsEnd), + charBank: cs.substring(opsEnd+1)}; +}; + +Changeset.pack = function(oldLen, newLen, opsStr, bank) { + var lenDiff = newLen - oldLen; + var lenDiffStr = (lenDiff >= 0 ? + '>'+Changeset.numToString(lenDiff) : + '<'+Changeset.numToString(-lenDiff)); + var a = []; + a.push('Z:', Changeset.numToString(oldLen), lenDiffStr, opsStr, '$', bank); + return a.join(''); +}; + +Changeset.applyToText = function(cs, str) { + var unpacked = Changeset.unpack(cs); + Changeset.assert(str.length == unpacked.oldLen, + "mismatched apply: ",str.length," / ",unpacked.oldLen); + var csIter = Changeset.opIterator(unpacked.ops); + var bankIter = Changeset.stringIterator(unpacked.charBank); + var strIter = Changeset.stringIterator(str); + var assem = Changeset.stringAssembler(); + while (csIter.hasNext()) { + var op = csIter.next(); + switch(op.opcode) { + case '+': assem.append(bankIter.take(op.chars)); break; + case '-': strIter.skip(op.chars); break; + case '=': assem.append(strIter.take(op.chars)); break; + } + } + assem.append(strIter.take(strIter.remaining())); + return assem.toString(); +}; + +Changeset.mutateTextLines = function(cs, lines) { + var unpacked = Changeset.unpack(cs); + var csIter = Changeset.opIterator(unpacked.ops); + var bankIter = Changeset.stringIterator(unpacked.charBank); + var mut = Changeset.textLinesMutator(lines); + while (csIter.hasNext()) { + var op = csIter.next(); + switch(op.opcode) { + case '+': mut.insert(bankIter.take(op.chars), op.lines); break; + case '-': mut.remove(op.chars, op.lines); break; + case '=': mut.skip(op.chars, op.lines, (!! op.attribs)); break; + } + } + mut.close(); +}; + +Changeset.composeAttributes = function(att1, att2, resultIsMutation, pool) { + // att1 and att2 are strings like "*3*f*1c", asMutation is a boolean. + + // Sometimes attribute (key,value) pairs are treated as attribute presence + // information, while other times they are treated as operations that + // mutate a set of attributes, and this affects whether an empty value + // is a deletion or a change. + // Examples, of the form (att1Items, att2Items, resultIsMutation) -> result + // ([], [(bold, )], true) -> [(bold, )] + // ([], [(bold, )], false) -> [] + // ([], [(bold, true)], true) -> [(bold, true)] + // ([], [(bold, true)], false) -> [(bold, true)] + // ([(bold, true)], [(bold, )], true) -> [(bold, )] + // ([(bold, true)], [(bold, )], false) -> [] + + // pool can be null if att2 has no attributes. + + if ((! att1) && resultIsMutation) { + // In the case of a mutation (i.e. composing two changesets), + // an att2 composed with an empy att1 is just att2. If att1 + // is part of an attribution string, then att2 may remove + // attributes that are already gone, so don't do this optimization. + return att2; + } + if (! att2) return att1; + var atts = []; + att1.replace(/\*([0-9a-z]+)/g, function(_, a) { + atts.push(pool.getAttrib(Changeset.parseNum(a))); + return ''; + }); + att2.replace(/\*([0-9a-z]+)/g, function(_, a) { + var pair = pool.getAttrib(Changeset.parseNum(a)); + var found = false; + for(var i=0;i<atts.length;i++) { + var oldPair = atts[i]; + if (oldPair[0] == pair[0]) { + if (pair[1] || resultIsMutation) { + oldPair[1] = pair[1]; + } + else { + atts.splice(i, 1); + } + found = true; + break; + } + } + if ((! found) && (pair[1] || resultIsMutation)) { + atts.push(pair); + } + return ''; + }); + atts.sort(); + var buf = Changeset.stringAssembler(); + for(var i=0;i<atts.length;i++) { + buf.append('*'); + buf.append(Changeset.numToString(pool.putAttrib(atts[i]))); + } + //print(att1+" / "+att2+" / "+buf.toString()); + return buf.toString(); +}; + +Changeset._slicerZipperFunc = function(attOp, csOp, opOut, pool) { + // attOp is the op from the sequence that is being operated on, either an + // attribution string or the earlier of two changesets being composed. + // pool can be null if definitely not needed. + + //print(csOp.toSource()+" "+attOp.toSource()+" "+opOut.toSource()); + if (attOp.opcode == '-') { + Changeset.copyOp(attOp, opOut); + attOp.opcode = ''; + } + else if (! attOp.opcode) { + Changeset.copyOp(csOp, opOut); + csOp.opcode = ''; + } + else { + switch (csOp.opcode) { + case '-': { + if (csOp.chars <= attOp.chars) { + // delete or delete part + if (attOp.opcode == '=') { + opOut.opcode = '-'; + opOut.chars = csOp.chars; + opOut.lines = csOp.lines; + opOut.attribs = ''; + } + attOp.chars -= csOp.chars; + attOp.lines -= csOp.lines; + csOp.opcode = ''; + if (! attOp.chars) { + attOp.opcode = ''; + } + } + else { + // delete and keep going + if (attOp.opcode == '=') { + opOut.opcode = '-'; + opOut.chars = attOp.chars; + opOut.lines = attOp.lines; + opOut.attribs = ''; + } + csOp.chars -= attOp.chars; + csOp.lines -= attOp.lines; + attOp.opcode = ''; + } + break; + } + case '+': { + // insert + Changeset.copyOp(csOp, opOut); + csOp.opcode = ''; + break; + } + case '=': { + if (csOp.chars <= attOp.chars) { + // keep or keep part + opOut.opcode = attOp.opcode; + opOut.chars = csOp.chars; + opOut.lines = csOp.lines; + opOut.attribs = Changeset.composeAttributes(attOp.attribs, csOp.attribs, + attOp.opcode == '=', pool); + csOp.opcode = ''; + attOp.chars -= csOp.chars; + attOp.lines -= csOp.lines; + if (! attOp.chars) { + attOp.opcode = ''; + } + } + else { + // keep and keep going + opOut.opcode = attOp.opcode; + opOut.chars = attOp.chars; + opOut.lines = attOp.lines; + opOut.attribs = Changeset.composeAttributes(attOp.attribs, csOp.attribs, + attOp.opcode == '=', pool); + attOp.opcode = ''; + csOp.chars -= attOp.chars; + csOp.lines -= attOp.lines; + } + break; + } + case '': { + Changeset.copyOp(attOp, opOut); + attOp.opcode = ''; + break; + } + } + } +}; + +Changeset.applyToAttribution = function(cs, astr, pool) { + var unpacked = Changeset.unpack(cs); + + return Changeset.applyZip(astr, 0, unpacked.ops, 0, function(op1, op2, opOut) { + return Changeset._slicerZipperFunc(op1, op2, opOut, pool); + }); +}; + +/*Changeset.oneInsertedLineAtATimeOpIterator = function(opsStr, optStartIndex, charBank) { + var iter = Changeset.opIterator(opsStr, optStartIndex); + var bankIndex = 0; + +};*/ + +Changeset.mutateAttributionLines = function(cs, lines, pool) { + //dmesg(cs); + //dmesg(lines.toSource()+" ->"); + + var unpacked = Changeset.unpack(cs); + var csIter = Changeset.opIterator(unpacked.ops); + var csBank = unpacked.charBank; + var csBankIndex = 0; + // treat the attribution lines as text lines, mutating a line at a time + var mut = Changeset.textLinesMutator(lines); + + var lineIter = null; + function isNextMutOp() { + return (lineIter && lineIter.hasNext()) || mut.hasMore(); + } + function nextMutOp(destOp) { + if ((!(lineIter && lineIter.hasNext())) && mut.hasMore()) { + var line = mut.removeLines(1); + lineIter = Changeset.opIterator(line); + } + if (lineIter && lineIter.hasNext()) { + lineIter.next(destOp); + } + else { + destOp.opcode = ''; + } + } + var lineAssem = null; + function outputMutOp(op) { + //print("outputMutOp: "+op.toSource()); + if (! lineAssem) { + lineAssem = Changeset.mergingOpAssembler(); + } + lineAssem.append(op); + if (op.lines > 0) { + Changeset.assert(op.lines == 1, "Can't have op.lines of ",op.lines," in attribution lines"); + // ship it to the mut + mut.insert(lineAssem.toString(), 1); + lineAssem = null; + } + } + + var csOp = Changeset.newOp(); + var attOp = Changeset.newOp(); + var opOut = Changeset.newOp(); + while (csOp.opcode || csIter.hasNext() || attOp.opcode || isNextMutOp()) { + if ((! csOp.opcode) && csIter.hasNext()) { + csIter.next(csOp); + } + //print(csOp.toSource()+" "+attOp.toSource()+" "+opOut.toSource()); + //print(csOp.opcode+"/"+csOp.lines+"/"+csOp.attribs+"/"+lineAssem+"/"+lineIter+"/"+(lineIter?lineIter.hasNext():null)); + //print("csOp: "+csOp.toSource()); + if ((! csOp.opcode) && (! attOp.opcode) && + (! lineAssem) && (! (lineIter && lineIter.hasNext()))) { + break; // done + } + else if (csOp.opcode == '=' && csOp.lines > 0 && (! csOp.attribs) && (! attOp.opcode) && + (! lineAssem) && (! (lineIter && lineIter.hasNext()))) { + // skip multiple lines; this is what makes small changes not order of the document size + mut.skipLines(csOp.lines); + //print("skipped: "+csOp.lines); + csOp.opcode = ''; + } + else if (csOp.opcode == '+') { + if (csOp.lines > 1) { + var firstLineLen = csBank.indexOf('\n', csBankIndex) + 1 - csBankIndex; + Changeset.copyOp(csOp, opOut); + csOp.chars -= firstLineLen; + csOp.lines--; + opOut.lines = 1; + opOut.chars = firstLineLen; + } + else { + Changeset.copyOp(csOp, opOut); + csOp.opcode = ''; + } + outputMutOp(opOut); + csBankIndex += opOut.chars; + opOut.opcode = ''; + } + else { + if ((! attOp.opcode) && isNextMutOp()) { + nextMutOp(attOp); + } + //print("attOp: "+attOp.toSource()); + Changeset._slicerZipperFunc(attOp, csOp, opOut, pool); + if (opOut.opcode) { + outputMutOp(opOut); + opOut.opcode = ''; + } + } + } + + Changeset.assert(! lineAssem, "line assembler not finished"); + mut.close(); + + //dmesg("-> "+lines.toSource()); +}; + +Changeset.joinAttributionLines = function(theAlines) { + var assem = Changeset.mergingOpAssembler(); + for(var i=0;i<theAlines.length;i++) { + var aline = theAlines[i]; + var iter = Changeset.opIterator(aline); + while (iter.hasNext()) { + assem.append(iter.next()); + } + } + return assem.toString(); +}; + +Changeset.splitAttributionLines = function(attrOps, text) { + var iter = Changeset.opIterator(attrOps); + var assem = Changeset.mergingOpAssembler(); + var lines = []; + var pos = 0; + + function appendOp(op) { + assem.append(op); + if (op.lines > 0) { + lines.push(assem.toString()); + assem.clear(); + } + pos += op.chars; + } + + while (iter.hasNext()) { + var op = iter.next(); + var numChars = op.chars; + var numLines = op.lines; + while (numLines > 1) { + var newlineEnd = text.indexOf('\n', pos)+1; + Changeset.assert(newlineEnd > 0, "newlineEnd <= 0 in splitAttributionLines"); + op.chars = newlineEnd - pos; + op.lines = 1; + appendOp(op); + numChars -= op.chars; + numLines -= op.lines; + } + if (numLines == 1) { + op.chars = numChars; + op.lines = 1; + } + appendOp(op); + } + + return lines; +}; + +Changeset.splitTextLines = function(text) { + return text.match(/[^\n]*(?:\n|[^\n]$)/g); +}; + +Changeset.compose = function(cs1, cs2, pool) { + var unpacked1 = Changeset.unpack(cs1); + var unpacked2 = Changeset.unpack(cs2); + var len1 = unpacked1.oldLen; + var len2 = unpacked1.newLen; + Changeset.assert(len2 == unpacked2.oldLen, "mismatched composition"); + var len3 = unpacked2.newLen; + var bankIter1 = Changeset.stringIterator(unpacked1.charBank); + var bankIter2 = Changeset.stringIterator(unpacked2.charBank); + var bankAssem = Changeset.stringAssembler(); + + var newOps = Changeset.applyZip(unpacked1.ops, 0, unpacked2.ops, 0, function(op1, op2, opOut) { + //var debugBuilder = Changeset.stringAssembler(); + //debugBuilder.append(Changeset.opString(op1)); + //debugBuilder.append(','); + //debugBuilder.append(Changeset.opString(op2)); + //debugBuilder.append(' / '); + + var op1code = op1.opcode; + var op2code = op2.opcode; + if (op1code == '+' && op2code == '-') { + bankIter1.skip(Math.min(op1.chars, op2.chars)); + } + Changeset._slicerZipperFunc(op1, op2, opOut, pool); + if (opOut.opcode == '+') { + if (op2code == '+') { + bankAssem.append(bankIter2.take(opOut.chars)); + } + else { + bankAssem.append(bankIter1.take(opOut.chars)); + } + } + + //debugBuilder.append(Changeset.opString(op1)); + //debugBuilder.append(','); + //debugBuilder.append(Changeset.opString(op2)); + //debugBuilder.append(' -> '); + //debugBuilder.append(Changeset.opString(opOut)); + //print(debugBuilder.toString()); + }); + + return Changeset.pack(len1, len3, newOps, bankAssem.toString()); +}; + +Changeset.attributeTester = function(attribPair, pool) { + // returns a function that tests if a string of attributes + // (e.g. *3*4) contains a given attribute key,value that + // is already present in the pool. + if (! pool) { + return never; + } + var attribNum = pool.putAttrib(attribPair, true); + if (attribNum < 0) { + return never; + } + else { + var re = new RegExp('\\*'+Changeset.numToString(attribNum)+ + '(?!\\w)'); + return function(attribs) { + return re.test(attribs); + }; + } + function never(attribs) { return false; } +}; + +Changeset.identity = function(N) { + return Changeset.pack(N, N, "", ""); +}; + +Changeset.makeSplice = function(oldFullText, spliceStart, numRemoved, newText, optNewTextAPairs, pool) { + var oldLen = oldFullText.length; + + if (spliceStart >= oldLen) { + spliceStart = oldLen - 1; + } + if (numRemoved > oldFullText.length - spliceStart - 1) { + numRemoved = oldFullText.length - spliceStart - 1; + } + var oldText = oldFullText.substring(spliceStart, spliceStart+numRemoved); + var newLen = oldLen + newText.length - oldText.length; + + var assem = Changeset.smartOpAssembler(); + assem.appendOpWithText('=', oldFullText.substring(0, spliceStart)); + assem.appendOpWithText('-', oldText); + assem.appendOpWithText('+', newText, optNewTextAPairs, pool); + assem.endDocument(); + return Changeset.pack(oldLen, newLen, assem.toString(), newText); +}; + +Changeset.toSplices = function(cs) { + // get a list of splices, [startChar, endChar, newText] + + var unpacked = Changeset.unpack(cs); + var splices = []; + + var oldPos = 0; + var iter = Changeset.opIterator(unpacked.ops); + var charIter = Changeset.stringIterator(unpacked.charBank); + var inSplice = false; + while (iter.hasNext()) { + var op = iter.next(); + if (op.opcode == '=') { + oldPos += op.chars; + inSplice = false; + } + else { + if (! inSplice) { + splices.push([oldPos, oldPos, ""]); + inSplice = true; + } + if (op.opcode == '-') { + oldPos += op.chars; + splices[splices.length-1][1] += op.chars; + } + else if (op.opcode == '+') { + splices[splices.length-1][2] += charIter.take(op.chars); + } + } + } + + return splices; +}; + +Changeset.characterRangeFollow = function(cs, startChar, endChar, insertionsAfter) { + var newStartChar = startChar; + var newEndChar = endChar; + var splices = Changeset.toSplices(cs); + var lengthChangeSoFar = 0; + for(var i=0;i<splices.length;i++) { + var splice = splices[i]; + var spliceStart = splice[0] + lengthChangeSoFar; + var spliceEnd = splice[1] + lengthChangeSoFar; + var newTextLength = splice[2].length; + var thisLengthChange = newTextLength - (spliceEnd - spliceStart); + + if (spliceStart <= newStartChar && spliceEnd >= newEndChar) { + // splice fully replaces/deletes range + // (also case that handles insertion at a collapsed selection) + if (insertionsAfter) { + newStartChar = newEndChar = spliceStart; + } + else { + newStartChar = newEndChar = spliceStart + newTextLength; + } + } + else if (spliceEnd <= newStartChar) { + // splice is before range + newStartChar += thisLengthChange; + newEndChar += thisLengthChange; + } + else if (spliceStart >= newEndChar) { + // splice is after range + } + else if (spliceStart >= newStartChar && spliceEnd <= newEndChar) { + // splice is inside range + newEndChar += thisLengthChange; + } + else if (spliceEnd < newEndChar) { + // splice overlaps beginning of range + newStartChar = spliceStart + newTextLength; + newEndChar += thisLengthChange; + } + else { + // splice overlaps end of range + newEndChar = spliceStart; + } + + lengthChangeSoFar += thisLengthChange; + } + + return [newStartChar, newEndChar]; +}; + +Changeset.moveOpsToNewPool = function(cs, oldPool, newPool) { + // works on changeset or attribution string + var dollarPos = cs.indexOf('$'); + if (dollarPos < 0) { + dollarPos = cs.length; + } + var upToDollar = cs.substring(0, dollarPos); + var fromDollar = cs.substring(dollarPos); + // order of attribs stays the same + return upToDollar.replace(/\*([0-9a-z]+)/g, function(_, a) { + var oldNum = Changeset.parseNum(a); + var pair = oldPool.getAttrib(oldNum); + var newNum = newPool.putAttrib(pair); + return '*'+Changeset.numToString(newNum); + }) + fromDollar; +}; + +Changeset.makeAttribution = function(text) { + var assem = Changeset.smartOpAssembler(); + assem.appendOpWithText('+', text); + return assem.toString(); +}; + +// callable on a changeset, attribution string, or attribs property of an op +Changeset.eachAttribNumber = function(cs, func) { + var dollarPos = cs.indexOf('$'); + if (dollarPos < 0) { + dollarPos = cs.length; + } + var upToDollar = cs.substring(0, dollarPos); + + upToDollar.replace(/\*([0-9a-z]+)/g, function(_, a) { + func(Changeset.parseNum(a)); + return ''; + }); +}; + +// callable on a changeset, attribution string, or attribs property of an op, +// though it may easily create adjacent ops that can be merged. +Changeset.filterAttribNumbers = function(cs, filter) { + return Changeset.mapAttribNumbers(cs, filter); +}; + +Changeset.mapAttribNumbers = function(cs, func) { + var dollarPos = cs.indexOf('$'); + if (dollarPos < 0) { + dollarPos = cs.length; + } + var upToDollar = cs.substring(0, dollarPos); + + var newUpToDollar = upToDollar.replace(/\*([0-9a-z]+)/g, function(s, a) { + var n = func(Changeset.parseNum(a)); + if (n === true) { + return s; + } + else if ((typeof n) === "number") { + return '*'+Changeset.numToString(n); + } + else { + return ''; + } + }); + + return newUpToDollar + cs.substring(dollarPos); +}; + +Changeset.makeAText = function(text, attribs) { + return { text: text, attribs: (attribs || Changeset.makeAttribution(text)) }; +}; + +Changeset.applyToAText = function(cs, atext, pool) { + return { text: Changeset.applyToText(cs, atext.text), + attribs: Changeset.applyToAttribution(cs, atext.attribs, pool) }; +}; + +Changeset.cloneAText = function(atext) { + return { text: atext.text, attribs: atext.attribs }; +}; + +Changeset.copyAText = function(atext1, atext2) { + atext2.text = atext1.text; + atext2.attribs = atext1.attribs; +}; + +Changeset.appendATextToAssembler = function(atext, assem) { + // intentionally skips last newline char of atext + var iter = Changeset.opIterator(atext.attribs); + var op = Changeset.newOp(); + while (iter.hasNext()) { + iter.next(op); + if (! iter.hasNext()) { + // last op, exclude final newline + if (op.lines <= 1) { + op.lines = 0; + op.chars--; + if (op.chars) { + assem.append(op); + } + } + else { + var nextToLastNewlineEnd = + atext.text.lastIndexOf('\n', atext.text.length-2) + 1; + var lastLineLength = atext.text.length - nextToLastNewlineEnd - 1; + op.lines--; + op.chars -= (lastLineLength + 1); + assem.append(op); + op.lines = 0; + op.chars = lastLineLength; + if (op.chars) { + assem.append(op); + } + } + } + else { + assem.append(op); + } + } +}; + +Changeset.prepareForWire = function(cs, pool) { + var newPool = new AttribPool(); + var newCs = Changeset.moveOpsToNewPool(cs, pool, newPool); + return {translated: newCs, pool: newPool}; +}; + +Changeset.isIdentity = function(cs) { + var unpacked = Changeset.unpack(cs); + return unpacked.ops == "" && unpacked.oldLen == unpacked.newLen; +}; + +Changeset.opAttributeValue = function(op, key, pool) { + return Changeset.attribsAttributeValue(op.attribs, key, pool); +}; + +Changeset.attribsAttributeValue = function(attribs, key, pool) { + var value = ''; + if (attribs) { + Changeset.eachAttribNumber(attribs, function(n) { + if (pool.getAttribKey(n) == key) { + value = pool.getAttribValue(n); + } + }); + } + return value; +}; + +Changeset.builder = function(oldLen) { + var assem = Changeset.smartOpAssembler(); + var o = Changeset.newOp(); + var charBank = Changeset.stringAssembler(); + + var self = { + // attribs are [[key1,value1],[key2,value2],...] or '*0*1...' (no pool needed in latter case) + keep: function(N, L, attribs, pool) { + o.opcode = '='; + o.attribs = (attribs && + Changeset.makeAttribsString('=', attribs, pool)) || ''; + o.chars = N; + o.lines = (L || 0); + assem.append(o); + return self; + }, + keepText: function(text, attribs, pool) { + assem.appendOpWithText('=', text, attribs, pool); + return self; + }, + insert: function(text, attribs, pool) { + assem.appendOpWithText('+', text, attribs, pool); + charBank.append(text); + return self; + }, + remove: function(N, L) { + o.opcode = '-'; + o.attribs = ''; + o.chars = N; + o.lines = (L || 0); + assem.append(o); + return self; + }, + toString: function() { + assem.endDocument(); + var newLen = oldLen + assem.getLengthChange(); + return Changeset.pack(oldLen, newLen, assem.toString(), + charBank.toString()); + } + }; + + return self; +}; + +Changeset.makeAttribsString = function(opcode, attribs, pool) { + // makeAttribsString(opcode, '*3') or makeAttribsString(opcode, [['foo','bar']], myPool) work + if (! attribs) { + return ''; + } + else if ((typeof attribs) == "string") { + return attribs; + } + else if (pool && attribs && attribs.length) { + if (attribs.length > 1) { + attribs = attribs.slice(); + attribs.sort(); + } + var result = []; + for(var i=0;i<attribs.length;i++) { + var pair = attribs[i]; + if (opcode == '=' || (opcode == '+' && pair[1])) { + result.push('*'+Changeset.numToString(pool.putAttrib(pair))); + } + } + return result.join(''); + } +}; + +// like "substring" but on a single-line attribution string +Changeset.subattribution = function(astr, start, optEnd) { + var iter = Changeset.opIterator(astr, 0); + var assem = Changeset.smartOpAssembler(); + var attOp = Changeset.newOp(); + var csOp = Changeset.newOp(); + var opOut = Changeset.newOp(); + + function doCsOp() { + if (csOp.chars) { + while (csOp.opcode && (attOp.opcode || iter.hasNext())) { + if (! attOp.opcode) iter.next(attOp); + + if (csOp.opcode && attOp.opcode && csOp.chars >= attOp.chars && + attOp.lines > 0 && csOp.lines <= 0) { + csOp.lines++; + } + + Changeset._slicerZipperFunc(attOp, csOp, opOut, null); + if (opOut.opcode) { + assem.append(opOut); + opOut.opcode = ''; + } + } + } + } + + csOp.opcode = '-'; + csOp.chars = start; + + doCsOp(); + + if (optEnd === undefined) { + if (attOp.opcode) { + assem.append(attOp); + } + while (iter.hasNext()) { + iter.next(attOp); + assem.append(attOp); + } + } + else { + csOp.opcode = '='; + csOp.chars = optEnd - start; + doCsOp(); + } + + return assem.toString(); +}; + +Changeset.inverse = function(cs, lines, alines, pool) { + // lines and alines are what the changeset is meant to apply to. + // They may be arrays or objects with .get(i) and .length methods. + // They include final newlines on lines. + function lines_get(idx) { + if (lines.get) { + return lines.get(idx); + } + else { + return lines[idx]; + } + } + function lines_length() { + if ((typeof lines.length) == "number") { + return lines.length; + } + else { + return lines.length(); + } + } + function alines_get(idx) { + if (alines.get) { + return alines.get(idx); + } + else { + return alines[idx]; + } + } + function alines_length() { + if ((typeof alines.length) == "number") { + return alines.length; + } + else { + return alines.length(); + } + } + + var curLine = 0; + var curChar = 0; + var curLineOpIter = null; + var curLineOpIterLine; + var curLineNextOp = Changeset.newOp('+'); + + var unpacked = Changeset.unpack(cs); + var csIter = Changeset.opIterator(unpacked.ops); + var builder = Changeset.builder(unpacked.newLen); + + function consumeAttribRuns(numChars, func/*(len, attribs, endsLine)*/) { + + if ((! curLineOpIter) || (curLineOpIterLine != curLine)) { + // create curLineOpIter and advance it to curChar + curLineOpIter = Changeset.opIterator(alines_get(curLine)); + curLineOpIterLine = curLine; + var indexIntoLine = 0; + var done = false; + while (! done) { + curLineOpIter.next(curLineNextOp); + if (indexIntoLine + curLineNextOp.chars >= curChar) { + curLineNextOp.chars -= (curChar - indexIntoLine); + done = true; + } + else { + indexIntoLine += curLineNextOp.chars; + } + } + } + + while (numChars > 0) { + if ((! curLineNextOp.chars) && (! curLineOpIter.hasNext())) { + curLine++; + curChar = 0; + curLineOpIterLine = curLine; + curLineNextOp.chars = 0; + curLineOpIter = Changeset.opIterator(alines_get(curLine)); + } + if (! curLineNextOp.chars) { + curLineOpIter.next(curLineNextOp); + } + var charsToUse = Math.min(numChars, curLineNextOp.chars); + func(charsToUse, curLineNextOp.attribs, + charsToUse == curLineNextOp.chars && curLineNextOp.lines > 0); + numChars -= charsToUse; + curLineNextOp.chars -= charsToUse; + curChar += charsToUse; + } + + if ((! curLineNextOp.chars) && (! curLineOpIter.hasNext())) { + curLine++; + curChar = 0; + } + } + + function skip(N, L) { + if (L) { + curLine += L; + curChar = 0; + } + else { + if (curLineOpIter && curLineOpIterLine == curLine) { + consumeAttribRuns(N, function() {}); + } + else { + curChar += N; + } + } + } + + function nextText(numChars) { + var len = 0; + var assem = Changeset.stringAssembler(); + var firstString = lines_get(curLine).substring(curChar); + len += firstString.length; + assem.append(firstString); + + var lineNum = curLine+1; + while (len < numChars) { + var nextString = lines_get(lineNum); + len += nextString.length; + assem.append(nextString); + lineNum++; + } + + return assem.toString().substring(0, numChars); + } + + function cachedStrFunc(func) { + var cache = {}; + return function(s) { + if (! cache[s]) { + cache[s] = func(s); + } + return cache[s]; + }; + } + + var attribKeys = []; + var attribValues = []; + while (csIter.hasNext()) { + var csOp = csIter.next(); + if (csOp.opcode == '=') { + if (csOp.attribs) { + attribKeys.length = 0; + attribValues.length = 0; + Changeset.eachAttribNumber(csOp.attribs, function(n) { + attribKeys.push(pool.getAttribKey(n)); + attribValues.push(pool.getAttribValue(n)); + }); + var undoBackToAttribs = cachedStrFunc(function(attribs) { + var backAttribs = []; + for(var i=0;i<attribKeys.length;i++) { + var appliedKey = attribKeys[i]; + var appliedValue = attribValues[i]; + var oldValue = Changeset.attribsAttributeValue(attribs, appliedKey, pool); + if (appliedValue != oldValue) { + backAttribs.push([appliedKey, oldValue]); + } + } + return Changeset.makeAttribsString('=', backAttribs, pool); + }); + consumeAttribRuns(csOp.chars, function(len, attribs, endsLine) { + builder.keep(len, endsLine ? 1 : 0, undoBackToAttribs(attribs)); + }); + } + else { + skip(csOp.chars, csOp.lines); + builder.keep(csOp.chars, csOp.lines); + } + } + else if (csOp.opcode == '+') { + builder.remove(csOp.chars, csOp.lines); + } + else if (csOp.opcode == '-') { + var textBank = nextText(csOp.chars); + var textBankIndex = 0; + consumeAttribRuns(csOp.chars, function(len, attribs, endsLine) { + builder.insert(textBank.substr(textBankIndex, len), attribs); + textBankIndex += len; + }); + } + } + + return Changeset.checkRep(builder.toString()); +}; + +// %CLIENT FILE ENDS HERE% + +Changeset.follow = function(cs1, cs2, reverseInsertOrder, pool) { + var unpacked1 = Changeset.unpack(cs1); + var unpacked2 = Changeset.unpack(cs2); + var len1 = unpacked1.oldLen; + var len2 = unpacked2.oldLen; + Changeset.assert(len1 == len2, "mismatched follow"); + var chars1 = Changeset.stringIterator(unpacked1.charBank); + var chars2 = Changeset.stringIterator(unpacked2.charBank); + + var oldLen = unpacked1.newLen; + var oldPos = 0; + var newLen = 0; + + var hasInsertFirst = Changeset.attributeTester(['insertorder','first'], + pool); + + var newOps = Changeset.applyZip(unpacked1.ops, 0, unpacked2.ops, 0, function(op1, op2, opOut) { + if (op1.opcode == '+' || op2.opcode == '+') { + var whichToDo; + if (op2.opcode != '+') { + whichToDo = 1; + } + else if (op1.opcode != '+') { + whichToDo = 2; + } + else { + // both + + var firstChar1 = chars1.peek(1); + var firstChar2 = chars2.peek(1); + var insertFirst1 = hasInsertFirst(op1.attribs); + var insertFirst2 = hasInsertFirst(op2.attribs); + if (insertFirst1 && ! insertFirst2) { + whichToDo = 1; + } + else if (insertFirst2 && ! insertFirst1) { + whichToDo = 2; + } + // insert string that doesn't start with a newline first so as not to break up lines + else if (firstChar1 == '\n' && firstChar2 != '\n') { + whichToDo = 2; + } + else if (firstChar1 != '\n' && firstChar2 == '\n') { + whichToDo = 1; + } + // break symmetry: + else if (reverseInsertOrder) { + whichToDo = 2; + } + else { + whichToDo = 1; + } + } + if (whichToDo == 1) { + chars1.skip(op1.chars); + opOut.opcode = '='; + opOut.lines = op1.lines; + opOut.chars = op1.chars; + opOut.attribs = ''; + op1.opcode = ''; + } + else { + // whichToDo == 2 + chars2.skip(op2.chars); + Changeset.copyOp(op2, opOut); + op2.opcode = ''; + } + } + else if (op1.opcode == '-') { + if (! op2.opcode) { + op1.opcode = ''; + } + else { + if (op1.chars <= op2.chars) { + op2.chars -= op1.chars; + op2.lines -= op1.lines; + op1.opcode = ''; + if (! op2.chars) { + op2.opcode = ''; + } + } + else { + op1.chars -= op2.chars; + op1.lines -= op2.lines; + op2.opcode = ''; + } + } + } + else if (op2.opcode == '-') { + Changeset.copyOp(op2, opOut); + if (! op1.opcode) { + op2.opcode = ''; + } + else if (op2.chars <= op1.chars) { + // delete part or all of a keep + op1.chars -= op2.chars; + op1.lines -= op2.lines; + op2.opcode = ''; + if (! op1.chars) { + op1.opcode = ''; + } + } + else { + // delete all of a keep, and keep going + opOut.lines = op1.lines; + opOut.chars = op1.chars; + op2.lines -= op1.lines; + op2.chars -= op1.chars; + op1.opcode = ''; + } + } + else if (! op1.opcode) { + Changeset.copyOp(op2, opOut); + op2.opcode = ''; + } + else if (! op2.opcode) { + Changeset.copyOp(op1, opOut); + op1.opcode = ''; + } + else { + // both keeps + opOut.opcode = '='; + opOut.attribs = Changeset.followAttributes(op1.attribs, op2.attribs, pool); + if (op1.chars <= op2.chars) { + opOut.chars = op1.chars; + opOut.lines = op1.lines; + op2.chars -= op1.chars; + op2.lines -= op1.lines; + op1.opcode = ''; + if (! op2.chars) { + op2.opcode = ''; + } + } + else { + opOut.chars = op2.chars; + opOut.lines = op2.lines; + op1.chars -= op2.chars; + op1.lines -= op2.lines; + op2.opcode = ''; + } + } + switch (opOut.opcode) { + case '=': oldPos += opOut.chars; newLen += opOut.chars; break; + case '-': oldPos += opOut.chars; break; + case '+': newLen += opOut.chars; break; + } + }); + newLen += oldLen - oldPos; + + return Changeset.pack(oldLen, newLen, newOps, unpacked2.charBank); +}; + +Changeset.followAttributes = function(att1, att2, pool) { + // The merge of two sets of attribute changes to the same text + // takes the lexically-earlier value if there are two values + // for the same key. Otherwise, all key/value changes from + // both attribute sets are taken. This operation is the "follow", + // so a set of changes is produced that can be applied to att1 + // to produce the merged set. + if ((! att2) || (! pool)) return ''; + if (! att1) return att2; + var atts = []; + att2.replace(/\*([0-9a-z]+)/g, function(_, a) { + atts.push(pool.getAttrib(Changeset.parseNum(a))); + return ''; + }); + att1.replace(/\*([0-9a-z]+)/g, function(_, a) { + var pair1 = pool.getAttrib(Changeset.parseNum(a)); + for(var i=0;i<atts.length;i++) { + var pair2 = atts[i]; + if (pair1[0] == pair2[0]) { + if (pair1[1] <= pair2[1]) { + // winner of merge is pair1, delete this attribute + atts.splice(i, 1); + } + break; + } + } + return ''; + }); + // we've only removed attributes, so they're already sorted + var buf = Changeset.stringAssembler(); + for(var i=0;i<atts.length;i++) { + buf.append('*'); + buf.append(Changeset.numToString(pool.putAttrib(atts[i]))); + } + return buf.toString(); +}; |