Java tutorial
/** * 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 com.bigdata.dastor.db; import java.io.ByteArrayOutputStream; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import org.apache.commons.lang.ArrayUtils; import com.bigdata.dastor.concurrent.StageManager; import com.bigdata.dastor.io.ICompactSerializer; import com.bigdata.dastor.net.Message; import com.bigdata.dastor.net.MessagingService; import com.bigdata.dastor.utils.FBUtilities; /* * The read response message is sent by the server when reading data * this encapsulates the tablename and the row that has been read. * The table name is needed so that we can use it to create repairs. */ public class ReadResponse { private static ICompactSerializer<ReadResponse> serializer_; static { serializer_ = new ReadResponseSerializer(); } public static ICompactSerializer<ReadResponse> serializer() { return serializer_; } private Row row_; private byte[] digest_ = ArrayUtils.EMPTY_BYTE_ARRAY; private boolean isDigestQuery_ = false; public ReadResponse(byte[] digest) { assert digest != null; digest_ = digest; } public ReadResponse(Row row) { row_ = row; } public Row row() { return row_; } public byte[] digest() { return digest_; } public boolean isDigestQuery() { return isDigestQuery_; } public void setIsDigestQuery(boolean isDigestQuery) { isDigestQuery_ = isDigestQuery; } } class ReadResponseSerializer implements ICompactSerializer<ReadResponse> { public void serialize(ReadResponse rm, DataOutputStream dos) throws IOException { dos.writeInt(rm.digest().length); dos.write(rm.digest()); dos.writeBoolean(rm.isDigestQuery()); if (!rm.isDigestQuery() && rm.row() != null) { Row.serializer().serialize(rm.row(), dos); } } public ReadResponse deserialize(DataInputStream dis) throws IOException { int digestSize = dis.readInt(); byte[] digest = new byte[digestSize]; dis.read(digest, 0, digestSize); boolean isDigest = dis.readBoolean(); Row row = null; if (!isDigest) { row = Row.serializer().deserialize(dis); } ReadResponse rmsg = isDigest ? new ReadResponse(digest) : new ReadResponse(row); rmsg.setIsDigestQuery(isDigest); return rmsg; } }