128 lines
4 KiB
JavaScript
128 lines
4 KiB
JavaScript
/**
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* This code is mostly from the old Etherpad. Please help us to comment this code.
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* This helps other people to understand this code better and helps them to improve it.
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* TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
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*/
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/**
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* Copyright 2009 Google Inc.
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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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// revision info is a skip list whos entries represent a particular revision
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// of the document. These revisions are connected together by various
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// changesets, or deltas, between any two revisions.
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function loadBroadcastRevisionsJS()
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{
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function Revision(revNum)
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{
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this.rev = revNum;
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this.changesets = [];
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}
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Revision.prototype.addChangeset = function(destIndex, changeset, timeDelta)
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{
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var changesetWrapper = {
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deltaRev: destIndex - this.rev,
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deltaTime: timeDelta,
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getValue: function()
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{
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return changeset;
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}
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};
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this.changesets.push(changesetWrapper);
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this.changesets.sort(function(a, b)
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{
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return (b.deltaRev - a.deltaRev)
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});
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}
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revisionInfo = {};
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revisionInfo.addChangeset = function(fromIndex, toIndex, changeset, backChangeset, timeDelta)
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{
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var startRevision = revisionInfo[fromIndex] || revisionInfo.createNew(fromIndex);
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var endRevision = revisionInfo[toIndex] || revisionInfo.createNew(toIndex);
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startRevision.addChangeset(toIndex, changeset, timeDelta);
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endRevision.addChangeset(fromIndex, backChangeset, -1 * timeDelta);
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}
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revisionInfo.latest = clientVars.totalRevs || -1;
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revisionInfo.createNew = function(index)
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{
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revisionInfo[index] = new Revision(index);
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if (index > revisionInfo.latest)
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{
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revisionInfo.latest = index;
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}
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return revisionInfo[index];
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}
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// assuming that there is a path from fromIndex to toIndex, and that the links
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// are laid out in a skip-list format
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revisionInfo.getPath = function(fromIndex, toIndex)
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{
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var changesets = [];
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var spans = [];
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var times = [];
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var elem = revisionInfo[fromIndex] || revisionInfo.createNew(fromIndex);
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if (elem.changesets.length != 0 && fromIndex != toIndex)
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{
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var reverse = !(fromIndex < toIndex)
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while (((elem.rev < toIndex) && !reverse) || ((elem.rev > toIndex) && reverse))
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{
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var couldNotContinue = false;
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var oldRev = elem.rev;
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for (var i = reverse ? elem.changesets.length - 1 : 0;
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reverse ? i >= 0 : i < elem.changesets.length;
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i += reverse ? -1 : 1)
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{
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if (((elem.changesets[i].deltaRev < 0) && !reverse) || ((elem.changesets[i].deltaRev > 0) && reverse))
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{
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couldNotContinue = true;
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break;
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}
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if (((elem.rev + elem.changesets[i].deltaRev <= toIndex) && !reverse) || ((elem.rev + elem.changesets[i].deltaRev >= toIndex) && reverse))
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{
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var topush = elem.changesets[i];
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changesets.push(topush.getValue());
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spans.push(elem.changesets[i].deltaRev);
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times.push(topush.deltaTime);
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elem = revisionInfo[elem.rev + elem.changesets[i].deltaRev];
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break;
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}
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}
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if (couldNotContinue || oldRev == elem.rev) break;
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}
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}
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var status = 'partial';
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if (elem.rev == toIndex) status = 'complete';
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return {
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'fromRev': fromIndex,
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'rev': elem.rev,
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'status': status,
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'changesets': changesets,
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'spans': spans,
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'times': times
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};
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}
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}
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exports.loadBroadcastRevisionsJS = loadBroadcastRevisionsJS;
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