/**
* 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.apache.cassandra.db;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;
import org.apache.cassandra.db.filter.QueryPath;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.io.ICompactSerializer;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.service.IReadCommand;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.FBUtilities;
public abstract class ReadCommand implements IReadCommand
{
public static final byte CMD_TYPE_GET_SLICE_BY_NAMES = 1;
public static final byte CMD_TYPE_GET_SLICE = 2;
private static ReadCommandSerializer serializer = new ReadCommandSerializer();
public static ReadCommandSerializer serializer()
{
return serializer;
}
public Message makeReadMessage() throws IOException
{
ByteArrayOutputStream bos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(bos);
ReadCommand.serializer().serialize(this, dos);
return new Message(FBUtilities.getLocalAddress(), StorageService.Verb.READ, bos.toByteArray());
}
public final QueryPath queryPath;
public final String table;
public final ByteBuffer key;
private boolean isDigestQuery = false;
protected final byte commandType;
protected ReadCommand(String table, ByteBuffer key, QueryPath queryPath, byte cmdType)
{
this.table = table;
this.key = key;
this.queryPath = queryPath;
this.commandType = cmdType;
}
public boolean isDigestQuery()
{
return isDigestQuery;
}
public void setDigestQuery(boolean isDigestQuery)
{
this.isDigestQuery = isDigestQuery;
}
public String getColumnFamilyName()
{
return queryPath.columnFamilyName;
}
public abstract ReadCommand copy();
public abstract Row getRow(Table table) throws IOException;
protected AbstractType getComparator()
{
return ColumnFamily.getComparatorFor(table, getColumnFamilyName(), queryPath.superColumnName);
}
public String getKeyspace()
{
return table;
}
}
class ReadCommandSerializer implements ICompactSerializer<ReadCommand>
{
private static final Map<Byte, ReadCommandSerializer> CMD_SERIALIZER_MAP = new HashMap<Byte, ReadCommandSerializer>();
static
{
CMD_SERIALIZER_MAP.put(ReadCommand.CMD_TYPE_GET_SLICE_BY_NAMES, new SliceByNamesReadCommandSerializer());
CMD_SERIALIZER_MAP.put(ReadCommand.CMD_TYPE_GET_SLICE, new SliceFromReadCommandSerializer());
}
public void serialize(ReadCommand rm, DataOutputStream dos) throws IOException
{
dos.writeByte(rm.commandType);
ReadCommandSerializer ser = CMD_SERIALIZER_MAP.get(rm.commandType);
ser.serialize(rm, dos);
}
public ReadCommand deserialize(DataInputStream dis) throws IOException
{
byte msgType = dis.readByte();
return CMD_SERIALIZER_MAP.get(msgType).deserialize(dis);
}
}