storm-client/src/jvm/org/apache/storm/tuple/Tuple.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.storm.tuple;

import org.apache.storm.generated.GlobalStreamId;
import org.apache.storm.task.GeneralTopologyContext;

/**
 * The tuple is the main data structure in Storm. A tuple is a named list of values, where each value can be any type. Tuples are
 * dynamically typed -- the types of the fields do not need to be declared. Tuples have helper methods like getInteger and getString to get
 * field values without having to cast the result.
 *
 * <p>Storm needs to know how to serialize all the values in a tuple. By default, Storm knows how to serialize the primitive types, strings,
 * and byte arrays. If you want to use another type, you'll need to implement and register a serializer for that type.
 *
 * @see <a href="http://storm.apache.org/documentation/Serialization.html">Serialization</a>
 */
public interface Tuple extends ITuple {

    /**
     * Returns the global stream id (component + stream) of this tuple.
     */
    public GlobalStreamId getSourceGlobalStreamId();

    /**
     * Gets the id of the component that created this tuple.
     */
    public String getSourceComponent();

    /**
     * Gets the id of the task that created this tuple.
     */
    public int getSourceTask();

    /**
     * Gets the id of the stream that this tuple was emitted to.
     */
    public String getSourceStreamId();

    /**
     * Gets the message id that associated with this tuple.
     */
    public MessageId getMessageId();

    /**
     * Gets the topology context associated with the tuple.
     */
    public GeneralTopologyContext getContext();
}