/**
* 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.box.server.persistence.mongodb;
import com.mongodb.BasicDBObject;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.WriteConcern;
import org.waveprotocol.box.server.persistence.PersistenceException;
import org.waveprotocol.box.server.waveserver.ByteStringMessage;
import org.waveprotocol.box.server.waveserver.DeltaStore;
import org.waveprotocol.box.server.waveserver.WaveletDeltaRecord;
import org.waveprotocol.wave.federation.Proto.ProtocolAppliedWaveletDelta;
import org.waveprotocol.wave.model.id.WaveletName;
import org.waveprotocol.wave.model.operation.wave.TransformedWaveletDelta;
import org.waveprotocol.wave.model.version.HashedVersion;
import java.io.IOException;
import java.util.Collection;
/**
* A MongoDB based Delta Access implementation using a simple <b>deltas</b>
* collection, storing a delta record per each MongoDb document.
*
* @author pablojan@gmail.com (Pablo Ojanguren)
*
*/
public class MongoDbDeltaCollection implements DeltaStore.DeltasAccess {
/** Wavelet name to work with. */
private final WaveletName waveletName;
/** MongoDB Collection object for delta storage */
private final DBCollection deltaDbCollection;
/**
* Construct a new Delta Access object for the wavelet
*
* @param waveletName The wavelet name.
* @param deltaDbCollection The MongoDB deltas collection
*/
public MongoDbDeltaCollection(WaveletName waveletName, DBCollection deltaDbCollection) {
this.waveletName = waveletName;
this.deltaDbCollection = deltaDbCollection;
}
@Override
public WaveletName getWaveletName() {
return waveletName;
}
/**
* Create a new DBObject for a common query to select this wavelet
*
* @return DBObject query
*/
protected DBObject createWaveletDBQuery() {
DBObject query = new BasicDBObject();
query.put(MongoDbDeltaStoreUtil.FIELD_WAVE_ID, waveletName.waveId.serialise());
query.put(MongoDbDeltaStoreUtil.FIELD_WAVELET_ID, waveletName.waveletId.serialise());
return query;
}
@Override
public boolean isEmpty() {
return deltaDbCollection.count(createWaveletDBQuery()) == 0;
}
@Override
public HashedVersion getEndVersion() {
// Search the max of delta.getTransformedDelta().getResultingVersion()
DBObject query = createWaveletDBQuery();
DBObject sort = new BasicDBObject();
sort.put(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED_RESULTINGVERSION_VERSION, -1); // Descending
DBObject field = new BasicDBObject();
field.put(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED_RESULTINGVERSION, 1);
DBObject result = deltaDbCollection.findOne(query, field, sort);
return result != null ? MongoDbDeltaStoreUtil
.deserializeHashedVersion((DBObject) ((DBObject) result
.get(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED))
.get(MongoDbDeltaStoreUtil.FIELD_RESULTINGVERSION)) : null;
}
@Override
public WaveletDeltaRecord getDelta(long version) throws IOException {
DBObject query = createWaveletDBQuery();
query.put(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED_APPLIEDATVERSION, version);
DBObject result = deltaDbCollection.findOne(query);
WaveletDeltaRecord waveletDelta = null;
if (result != null) try {
waveletDelta = MongoDbDeltaStoreUtil.deserializeWaveletDeltaRecord(result);
} catch (PersistenceException e) {
throw new IOException(e);
}
return waveletDelta;
}
@Override
public WaveletDeltaRecord getDeltaByEndVersion(long version) throws IOException {
DBObject query = createWaveletDBQuery();
query.put(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED_RESULTINGVERSION_VERSION, version);
DBObject result = deltaDbCollection.findOne(query);
WaveletDeltaRecord waveletDelta = null;
if (result != null)
try {
MongoDbDeltaStoreUtil.deserializeWaveletDeltaRecord(result);
} catch (PersistenceException e) {
throw new IOException(e);
}
return waveletDelta;
}
@Override
public HashedVersion getAppliedAtVersion(long version) throws IOException {
DBObject query = createWaveletDBQuery();
query.put(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED_APPLIEDATVERSION, version);
DBObject result = deltaDbCollection.findOne(query);
if (result != null)
return MongoDbDeltaStoreUtil.deserializeHashedVersion((DBObject) result
.get(MongoDbDeltaStoreUtil.FIELD_APPLIEDATVERSION));
return null;
}
@Override
public HashedVersion getResultingVersion(long version) throws IOException {
DBObject query = createWaveletDBQuery();
query.put(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED_APPLIEDATVERSION, version);
DBObject result = deltaDbCollection.findOne(query);
if (result != null)
return MongoDbDeltaStoreUtil.deserializeHashedVersion((DBObject) result
.get(MongoDbDeltaStoreUtil.FIELD_TRANSFORMED_RESULTINGVERSION));
return null;
}
@Override
public ByteStringMessage<ProtocolAppliedWaveletDelta> getAppliedDelta(long version)
throws IOException {
WaveletDeltaRecord delta = getDelta(version);
return (delta != null) ? delta.getAppliedDelta() : null;
}
@Override
public TransformedWaveletDelta getTransformedDelta(long version) throws IOException {
WaveletDeltaRecord delta = getDelta(version);
return (delta != null) ? delta.getTransformedDelta() : null;
}
@Override
public void close() throws IOException {
// Does nothing.
}
@Override
public void append(Collection<WaveletDeltaRecord> newDeltas) throws PersistenceException {
for (WaveletDeltaRecord delta : newDeltas) {
// Using Journaled Write Concern
// (http://docs.mongodb.org/manual/core/write-concern/#journaled)
deltaDbCollection.insert(MongoDbDeltaStoreUtil.serialize(delta,
waveletName.waveId.serialise(), waveletName.waveletId.serialise()),
WriteConcern.JOURNALED);
}
}
}