/**
* 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.box.server.waveserver;
import org.waveprotocol.box.common.DeltaSequence;
import org.waveprotocol.wave.model.id.WaveletName;
import org.waveprotocol.wave.model.version.HashedVersion;
import org.waveprotocol.wave.model.wave.data.ReadableWaveletData;
/**
* Provides a subscription service for changes to wavelets.
*
* @author anorth@google.com (Alex North)
*/
public interface WaveBus {
/**
* Receives wave bus messages.
*/
interface Subscriber {
/**
* Notifies the subscriber of a wavelet update.
*
* @param wavelet the state of the wavelet after the deltas have
* been applied
* @param deltas deltas applied to the wavelet
*/
void waveletUpdate(ReadableWaveletData wavelet, DeltaSequence deltas);
/**
* Notifies the subscriber that a wavelet has been committed to persistent
* storage.
*
* @param waveletName name of wavelet
* @param version the version and hash of the wavelet as it was committed
*/
void waveletCommitted(WaveletName waveletName, HashedVersion version);
}
/**
* Subscribes to the bus, if the subscriber is not already subscribed.
*/
void subscribe(Subscriber s);
/**
* Unsubscribes from the bus, if the subscriber is currently subscribed.
*/
void unsubscribe(Subscriber s);
}