src/java/org/apache/cassandra/db/SliceByNamesReadCommand.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.apache.cassandra.db;

import java.io.*;
import java.nio.ByteBuffer;

import com.google.common.base.Objects;

import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.db.filter.*;
import org.apache.cassandra.io.IVersionedSerializer;
import org.apache.cassandra.io.util.DataOutputPlus;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.ByteBufferUtil;

public class SliceByNamesReadCommand extends ReadCommand
{
    static final SliceByNamesReadCommandSerializer serializer = new SliceByNamesReadCommandSerializer();

    public final NamesQueryFilter filter;

    public SliceByNamesReadCommand(String keyspaceName, ByteBuffer key, String cfName, long timestamp, NamesQueryFilter filter)
    {
        super(keyspaceName, key, cfName, timestamp, Type.GET_BY_NAMES);
        this.filter = filter;
    }

    public ReadCommand copy()
    {
        return new SliceByNamesReadCommand(ksName, key, cfName, timestamp, filter).setIsDigestQuery(isDigestQuery());
    }

    public Row getRow(Keyspace keyspace)
    {
        DecoratedKey dk = StorageService.getPartitioner().decorateKey(key);
        return keyspace.getRow(new QueryFilter(dk, cfName, filter, timestamp));
    }

    @Override
    public String toString()
    {
        return Objects.toStringHelper(this)
                      .add("ksName", ksName)
                      .add("cfName", cfName)
                      .add("key", ByteBufferUtil.bytesToHex(key))
                      .add("filter", filter)
                      .add("timestamp", timestamp)
                      .toString();
    }

    public IDiskAtomFilter filter()
    {
        return filter;
    }
}

class SliceByNamesReadCommandSerializer implements IVersionedSerializer<ReadCommand>
{
    public void serialize(ReadCommand cmd, DataOutputPlus out, int version) throws IOException
    {
        SliceByNamesReadCommand command = (SliceByNamesReadCommand) cmd;
        out.writeBoolean(command.isDigestQuery());
        out.writeUTF(command.ksName);
        ByteBufferUtil.writeWithShortLength(command.key, out);
        out.writeUTF(command.cfName);
        out.writeLong(cmd.timestamp);

        CFMetaData metadata = Schema.instance.getCFMetaData(cmd.ksName, cmd.cfName);
        metadata.comparator.namesQueryFilterSerializer().serialize(command.filter, out, version);
    }

    public ReadCommand deserialize(DataInput in, int version) throws IOException
    {
        boolean isDigest = in.readBoolean();
        String keyspaceName = in.readUTF();
        ByteBuffer key = ByteBufferUtil.readWithShortLength(in);
        String cfName = in.readUTF();
        long timestamp = in.readLong();
        CFMetaData metadata = Schema.instance.getCFMetaData(keyspaceName, cfName);
        if (metadata == null)
        {
            String message = String.format("Got slice command for nonexistent table %s.%s.  If the table was just " +
                    "created, this is likely due to the schema not being fully propagated.  Please wait for schema " +
                    "agreement on table creation.", keyspaceName, cfName);
            throw new UnknownColumnFamilyException(message, null);
        }
        NamesQueryFilter filter = metadata.comparator.namesQueryFilterSerializer().deserialize(in, version);
        return new SliceByNamesReadCommand(keyspaceName, key, cfName, timestamp, filter).setIsDigestQuery(isDigest);
    }

    public long serializedSize(ReadCommand cmd, int version)
    {
        TypeSizes sizes = TypeSizes.NATIVE;
        SliceByNamesReadCommand command = (SliceByNamesReadCommand) cmd;
        int size = sizes.sizeof(command.isDigestQuery());
        int keySize = command.key.remaining();

        CFMetaData metadata = Schema.instance.getCFMetaData(cmd.ksName, cmd.cfName);

        size += sizes.sizeof(command.ksName);
        size += sizes.sizeof((short)keySize) + keySize;
        size += sizes.sizeof(command.cfName);
        size += sizes.sizeof(cmd.timestamp);
        size += metadata.comparator.namesQueryFilterSerializer().serializedSize(command.filter, version);

        return size;
    }
}