org.waveprotocol.box.server.persistence.blocks.impl.SegmentOperationImpl.java Source code

Introduction

Here is the source code for org.waveprotocol.box.server.persistence.blocks.impl.SegmentOperationImpl.java

Source

/**
 * 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.blocks.impl;

import org.waveprotocol.wave.model.id.SegmentId;
import org.waveprotocol.wave.model.operation.wave.WaveletOperation;
import org.waveprotocol.wave.model.operation.wave.WaveletOperationContext;
import org.waveprotocol.wave.model.operation.OperationException;
import org.waveprotocol.wave.model.operation.ReversibleOperation;
import org.waveprotocol.wave.model.util.Preconditions;
import org.waveprotocol.wave.model.raw.RawOperation;
import org.waveprotocol.wave.model.raw.serialization.GsonSerializer;
import org.waveprotocol.wave.communication.Blob;

import org.waveprotocol.box.server.persistence.blocks.SegmentOperation;

import com.google.common.collect.ImmutableList;

/**
 * Wavelet operations on segment that change version.
 *
 * @author akaplanov@gmail.com (A. Kaplanov)
 */
public class SegmentOperationImpl implements SegmentOperation {

    private final RawOperation rawOperation;

    static SegmentOperationImpl deserialize(String buffer, SegmentId segmentId, WaveletOperationContext context) {
        RawOperation rawOperation = new RawOperation(GsonSerializer.OPERATION_SERIALIZER, new Blob(buffer),
                segmentId, context);
        return new SegmentOperationImpl(rawOperation);
    }

    public SegmentOperationImpl(RawOperation rawOperation) {
        this.rawOperation = rawOperation;
    }

    public SegmentOperationImpl(WaveletOperation... operations) {
        ImmutableList.Builder<WaveletOperation> operationsListBuilder = ImmutableList.builder();
        Preconditions.checkArgument(operations.length != 0, "No operations");
        for (WaveletOperation operation : operations) {
            operationsListBuilder.add(operation);
        }
        ImmutableList<WaveletOperation> operationsList = operationsListBuilder.build();
        rawOperation = new RawOperation(GsonSerializer.OPERATION_SERIALIZER, operationsList,
                operationsList.get(operationsList.size() - 1).getContext());
    }

    public SegmentOperationImpl(ImmutableList<? extends WaveletOperation> operations) {
        Preconditions.checkArgument(!operations.isEmpty(), "No operations");
        rawOperation = new RawOperation(GsonSerializer.OPERATION_SERIALIZER, operations,
                operations.get(operations.size() - 1).getContext());
    }

    @Override
    public ImmutableList<? extends WaveletOperation> getOperations() {
        return rawOperation.getOperations();
    }

    @Override
    public boolean isWorthy() {
        return rawOperation.isWorthy();
    }

    @Override
    public long getTargetVersion() {
        ImmutableList<? extends WaveletOperation> ops = rawOperation.getOperations();
        return ops.get(ops.size() - 1).getContext().getSegmentVersion();
    }

    @Override
    public long getTimestamp() {
        ImmutableList<? extends WaveletOperation> ops = rawOperation.getOperations();
        return ops.get(ops.size() - 1).getContext().getTimestamp();
    }

    /**
     * Returns reverted {@link SegmentOperation}.
     *
     * @param context the reversed context.
     */
    @Override
    public SegmentOperationImpl revert(WaveletOperationContext context) {
        ImmutableList<? extends WaveletOperation> ops = getOperations();
        ImmutableList.Builder<WaveletOperation> reverseOps = ImmutableList.builder();
        for (int i = ops.size() - 1; i >= 0; i--) {
            WaveletOperation operation = ops.get(i);
            try {
                Preconditions.checkArgument(operation instanceof ReversibleOperation, "Bad operation type");
                reverseOps.addAll(((ReversibleOperation) operation).reverse(context));
            } catch (OperationException ex) {
                throw new RuntimeException(ex);
            }
        }
        return new SegmentOperationImpl(reverseOps.build());
    }

    @Override
    public RawOperation getRawOperation() {
        return rawOperation;
    }

    @Override
    public Blob serialize() {
        return rawOperation.serialize();
    }

    @Override
    public String toString() {
        return rawOperation.toString();
    }
}