ImportDeltasService.java

/**
 * 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.robots.operations;

import com.google.common.collect.Maps;
import com.google.wave.api.InvalidRequestException;
import com.google.wave.api.OperationRequest;
import com.google.inject.Inject;
import com.google.inject.name.Named;
import com.google.protobuf.ByteString;
import com.google.protobuf.InvalidProtocolBufferException;
import com.google.wave.api.ApiIdSerializer;
import com.google.wave.api.JsonRpcConstant.ParamsProperty;

import org.waveprotocol.box.server.CoreSettingsNames;
import org.waveprotocol.box.server.robots.OperationContext;
import org.waveprotocol.box.server.frontend.CommittedWaveletSnapshot;
import org.waveprotocol.box.server.waveserver.WaveServerException;
import org.waveprotocol.box.server.waveserver.WaveletProvider;
import org.waveprotocol.box.server.robots.util.OperationUtil;
import org.waveprotocol.wave.model.version.HashedVersion;
import org.waveprotocol.wave.model.wave.InvalidParticipantAddress;
import org.waveprotocol.wave.util.logging.Log;
import org.waveprotocol.wave.federation.Proto.ProtocolHashedVersion;
import org.waveprotocol.wave.federation.Proto.ProtocolWaveletDelta;
import org.waveprotocol.wave.model.id.*;
import org.waveprotocol.wave.model.version.HashedVersionFactory;
import org.waveprotocol.wave.model.version.HashedVersionFactoryImpl;
import org.waveprotocol.wave.model.wave.ParticipantId;
import org.waveprotocol.wave.util.escapers.jvm.JavaUrlCodec;

import java.util.Map;
import java.util.List;

/**
 * {@link OperationService} for the "importDeltas" operation.
 * @author akaplanov@gmail.com (Andrew Kaplanov)
 */
public class ImportDeltasService implements OperationService {
  private static final Log LOG = Log.get(ImportDeltasService.class);
  private static final IdURIEncoderDecoder URI_CODEC = new IdURIEncoderDecoder(new JavaUrlCodec());
  private static final HashedVersionFactory HASH_FACTORY = new HashedVersionFactoryImpl(URI_CODEC);
  private final WaveletProvider waveletProvider;
  private final String waveDomain;

  @Inject
  public ImportDeltasService(WaveletProvider waveletProvider,
      @Named(CoreSettingsNames.WAVE_SERVER_DOMAIN) final String waveDomain) {
    this.waveletProvider = waveletProvider;
    this.waveDomain = waveDomain;
  }

  @Override
  public void execute(OperationRequest operation, OperationContext context, ParticipantId participant)
      throws InvalidRequestException {
    WaveId waveId;
    WaveletId waveletId;
    try {
      waveId = ApiIdSerializer.instance().deserialiseWaveId(
          OperationUtil.<String>getRequiredParameter(operation, ParamsProperty.WAVE_ID));
      waveletId = ApiIdSerializer.instance().deserialiseWaveletId(
          OperationUtil.<String>getRequiredParameter(operation, ParamsProperty.WAVELET_ID));
    } catch (InvalidIdException ex) {
      throw new InvalidRequestException("Invalid id", operation, ex);
    }
    waveId = WaveId.of(waveDomain, waveId.getId());
    waveletId = WaveletId.of(waveDomain, waveletId.getId());
    List<byte[]> history =
        OperationUtil.getRequiredParameter(operation, ParamsProperty.RAW_DELTAS);
    WaveletName waveletName = WaveletName.of(waveId, waveletId);
    long importedFromVersion = -1;
    if (!history.isEmpty()) {
      CommittedWaveletSnapshot waveletSnapshot;
      try {
        waveletSnapshot = waveletProvider.getSnapshot(waveletName);
      } catch (WaveServerException ex) {
        LOG.info("Get wavelet snapshot", ex);
        context.constructErrorResponse(operation, ex.toString());
        return;
      }
      for (byte[] deltaBytes : history) {
        ProtocolWaveletDelta delta;
        try {
          delta = ProtocolWaveletDelta.parseFrom(deltaBytes);
        } catch (InvalidProtocolBufferException ex) {
          throw new InvalidRequestException("Parse delta", operation, ex);
        }
        long currentVersion = 0;
        if (waveletSnapshot != null) {
          currentVersion = waveletSnapshot.snapshot.getVersion();
        }
        if (currentVersion == delta.getHashedVersion().getVersion()) {
          if (importedFromVersion == -1) {
            importedFromVersion = currentVersion;
          }
          ProtocolWaveletDelta newDelta;
          try {
            newDelta = setVersionHash(delta, waveletSnapshot, waveletName);
          } catch (InvalidParticipantAddress ex) {
            throw new InvalidRequestException("Convert delta", operation, ex);
          }
          final StringBuffer error = new StringBuffer();
          waveletProvider.submitRequest(waveletName, newDelta,
              new WaveletProvider.SubmitRequestListener() {

                @Override
                public void onSuccess(int operationsApplied, HashedVersion hashedVersionAfterApplication,
                    long applicationTimestamp) {
                }

                @Override
                public void onFailure(String errorMessage) {
                  error.append(errorMessage);
                }
              });
          if (error.length() != 0) {
            context.constructErrorResponse(operation, error.toString());
            return;
          }
          if (waveletSnapshot == null) {
            try {
              waveletSnapshot = waveletProvider.getSnapshot(waveletName);
            } catch (WaveServerException ex) {
              LOG.info("Get wavelet snapshot", ex);
              context.constructErrorResponse(operation, ex.toString());
              return;
            }
          }
        } else if (importedFromVersion != -1) {
          context.constructErrorResponse(operation, "Expected wavelet version "
              + delta.getHashedVersion().getVersion() + ", but current version is " + currentVersion + "."
              + "Possibly wavelet is modified during import.");
          return;
        }
      }
    }
    Map<ParamsProperty, Object> response = Maps.<ParamsProperty, Object> newHashMap();
    response.put(ParamsProperty.IMPORTED_FROM_VERSION, importedFromVersion);
    context.constructResponse(operation, response);
  }

  /**
   * Sets correct version hash to delta.
   *
   * @param delta the source delta.
   * @param waveletSnapshot to append delta.
   * @param waveletName name of wavelet.
   * @return the delta to import.
   * @throws InvalidParticipantAddress deserialize of participant error.
   */
  ProtocolWaveletDelta setVersionHash(ProtocolWaveletDelta delta,
      CommittedWaveletSnapshot waveletSnapshot, WaveletName waveletName) throws InvalidParticipantAddress {
    ProtocolWaveletDelta.Builder newDelta = ProtocolWaveletDelta.newBuilder(delta);
    if (waveletSnapshot == null) {
      ProtocolHashedVersion ver = ProtocolHashedVersion.newBuilder(delta.getHashedVersion()).
          setHistoryHash(ByteString.copyFrom(HASH_FACTORY.createVersionZero(waveletName).getHistoryHash())).
          build();
      newDelta.setHashedVersion(ver);
    } else {
      ProtocolHashedVersion ver = ProtocolHashedVersion.newBuilder(delta.getHashedVersion()).
          setHistoryHash(ByteString.copyFrom(waveletSnapshot.snapshot.getHashedVersion().getHistoryHash())).
          build();
      newDelta.setHashedVersion(ver);
    }
    return newDelta.build();
  }
}