/**
* 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.server.persistence.PersistenceException;
import java.io.Closeable;
import java.util.Collection;
/**
* Stores wavelet deltas.
*
* @author soren@google.com (Soren Lassen)
*/
public interface DeltaStore extends WaveletStore<DeltaStore.DeltasAccess> {
/**
* Accesses the delta history for a wavelet.
* Permits reading historical deltas and appending deltas to the history.
*/
interface DeltasAccess extends WaveletDeltaRecordReader, Closeable {
/**
* Blocking call to append deltas to the end of the delta history.
* If the call returns normally (doesn't throw an exception), then
* the deltas have been successfully and "durably" stored, that is,
* the method forces the data to disk.
*
* @param deltas contiguous deltas, beginning from the DeltaAccess object's
* end version. It is the caller's responsibility to ensure that
* everything matches up (applied and transformed deltas in the
* records match, that the hashes are correctly computed, etc).
* @throws PersistenceException if anything goes wrong with the underlying
* storage.
*/
void append(Collection<WaveletDeltaRecord> deltas) throws PersistenceException;
}
}