/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
package org.waveprotocol.wave.concurrencycontrol.client;
import org.waveprotocol.wave.model.document.operation.DocOp;
import org.waveprotocol.wave.model.document.operation.algorithm.Composer;
import org.waveprotocol.wave.model.operation.wave.BlipContentOperation;
import org.waveprotocol.wave.model.operation.wave.BlipOperation;
import org.waveprotocol.wave.model.operation.wave.WaveletBlipOperation;
import org.waveprotocol.wave.model.operation.wave.WaveletOperation;
import org.waveprotocol.wave.model.operation.wave.WaveletOperationContext;
import org.waveprotocol.wave.model.util.CollectionUtils;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.List;
/**
* A sequence of operations that composes adjacent operations when
* they can be safely merged together into a single operation.
*
* @author zdwang@google.com (David Wang)
*/
public class MergingSequence extends AbstractList<WaveletOperation> {
private final List<WaveletOperation> ops = CollectionUtils.newArrayList();
/**
* Constructs and empty operation sequence
*/
public MergingSequence() {
}
/**
* Constructs a delta from another delta's operations. Does not copy any
* version or signature information.
*/
public MergingSequence(Iterable<WaveletOperation> ops) {
for (WaveletOperation op : ops) {
add(op);
}
}
public void optimise() {
int startSize = size();
if (startSize == 1) {
return;
}
ArrayList<DocOp> docOps = CollectionUtils.newArrayList();
List<WaveletOperation> oldOperations = CollectionUtils.newArrayList(this);
String currentId = null;
WaveletOperationContext lastOperationContext = null;
this.clear();
for (WaveletOperation waveletOp : oldOperations) {
if (waveletOp instanceof WaveletBlipOperation) {
WaveletBlipOperation waveletBlipOp = ((WaveletBlipOperation) waveletOp);
String id = waveletBlipOp.getBlipId();
BlipOperation blipOp = waveletBlipOp.getBlipOp();
if (blipOp instanceof BlipContentOperation) {
if (!docOps.isEmpty() && !id.equals(currentId)) {
composeDocOps(this, currentId, lastOperationContext, docOps);
}
docOps.add(((BlipContentOperation) blipOp).getContentOp());
lastOperationContext = blipOp.getContext();
currentId = id;
continue;
}
}
if (!docOps.isEmpty()) {
composeDocOps(this, currentId, lastOperationContext, docOps);
}
add(waveletOp);
}
if (!docOps.isEmpty()) {
composeDocOps(this, currentId, lastOperationContext, docOps);
}
}
private static void composeDocOps(List<WaveletOperation> operations, String id,
WaveletOperationContext context, List<DocOp> docOps) {
operations.add(new WaveletBlipOperation(id,
new BlipContentOperation(context, Composer.compose(docOps))));
docOps.clear();
}
@Override
public WaveletOperation get(int index) {
return ops.get(index);
}
@Override
public int size() {
return ops.size();
}
@Override
public boolean add(WaveletOperation op) {
return ops.add(op);
}
@Override
public WaveletOperation remove(int index) {
return ops.remove(index);
}
}