/**
* Copyright 2010 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.
*
*/
package org.waveprotocol.wave.client.concurrencycontrol;
import org.waveprotocol.wave.client.wave.WaveDocuments;
import org.waveprotocol.wave.concurrencycontrol.channel.OperationChannel;
import org.waveprotocol.wave.concurrencycontrol.common.ChannelException;
import org.waveprotocol.wave.concurrencycontrol.wave.CcDocument;
import org.waveprotocol.wave.concurrencycontrol.wave.FlushingOperationSink;
import org.waveprotocol.wave.concurrencycontrol.wave.OperationSucker;
import org.waveprotocol.wave.model.operation.SilentOperationSink;
import org.waveprotocol.wave.model.operation.wave.WaveletBlipOperation;
import org.waveprotocol.wave.model.operation.wave.WaveletOperation;
import org.waveprotocol.wave.model.util.Pair;
/**
* Binds a wave's wavelets with supplied operation channels.
*
* @author hearnden@google.com (David Hearnden)
*/
public final class StaticChannelBinder {
private final WaveletOperationalizer operationalizer;
private final WaveDocuments<? extends CcDocument> docRegistry;
/**
* Creates a binder for a wave.
*
* @param operationalizer operationalizer of the wave
* @param docRegistry document registry of the wave
*/
public StaticChannelBinder(
WaveletOperationalizer operationalizer, WaveDocuments<? extends CcDocument> docRegistry) {
this.operationalizer = operationalizer;
this.docRegistry = docRegistry;
}
/**
* Connects a wavelet's operation sinks with an operation channel.
*
* @param id id of the wavelet to bind
* @param channel channel to bind
*/
public void bind(String id, OperationChannel channel) {
Pair<SilentOperationSink<WaveletOperation>, ProxyOperationSink<WaveletOperation>> sinks =
operationalizer.getSinks(id);
// Bind the two ends together.
OperationSucker.start(channel, asFlushing(id, sinks.first));
sinks.second.setTarget(asOpSink(channel));
}
/**
* Adapts a regular operation sink as a flushing sink.
*/
private FlushingOperationSink<WaveletOperation> asFlushing(
final String waveletId, final SilentOperationSink<WaveletOperation> target) {
return new FlushingOperationSink<WaveletOperation>() {
@Override
public void consume(WaveletOperation op) {
target.consume(op);
}
@Override
public boolean flush(WaveletOperation op, Runnable c) {
if (op instanceof WaveletBlipOperation) {
CcDocument doc =
docRegistry.getBlipDocument(waveletId, ((WaveletBlipOperation) op).getBlipId());
if (doc != null) {
return doc.flush(c);
}
}
return true;
}
};
}
/**
* Adapts an operation channel, making it look like an operation sink. The
* only reason a channel is not already a sink is because it has a more
* general acceptor that takes a varargs parameter.
*/
private static SilentOperationSink<WaveletOperation> asOpSink(final OperationChannel target) {
return new SilentOperationSink<WaveletOperation>() {
@Override
public void consume(WaveletOperation op) {
try {
target.send(op);
} catch (ChannelException e) {
throw new RuntimeException("Send failed, channel is broken", e);
}
}
};
}
}