| /* |
| * 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.reef.driver.context; |
| |
| import org.apache.reef.annotations.Provided; |
| import org.apache.reef.annotations.audience.DriverSide; |
| import org.apache.reef.annotations.audience.Public; |
| import org.apache.reef.io.Message; |
| import org.apache.reef.io.Numberable; |
| import org.apache.reef.io.naming.Identifiable; |
| |
| /** |
| * Driver-side representation of a message sent by a Context to the Driver. |
| */ |
| @Public |
| @DriverSide |
| @Provided |
| public interface ContextMessage extends Message, Identifiable, Numberable { |
| |
| /** |
| * @return the message sent by the Context. |
| */ |
| @Override |
| byte[] get(); |
| |
| /** |
| * @return the ID of the sending Context. |
| */ |
| @Override |
| String getId(); |
| |
| /** |
| * @return the ID of the ContextMessageSource that sent the message on the Context. |
| */ |
| String getMessageSourceID(); |
| |
| /** |
| * @return the sequence number of the message |
| * |
| * Terminology: a source sends a message to a target. |
| * Example sources are Tasks or Contexts. Example targets are Drivers. |
| * |
| * The method guarantees that sequence numbers increase strictly monotonically per message source. |
| * So numbers of messages from different sources should not be compared to each other. |
| * |
| * Clients of this method must not assume any particular method implementation |
| * because it may change in the future. |
| * |
| * The current implementation returns the timestamp of a heartbeat that contained the message. |
| * A heartbeat may contain several messages; all such message will get the same sequence number. |
| * A source can attach only one message to a single heartbeat, so the strict sequence number monotonicity |
| * per source is guaranteed. |
| * |
| */ |
| @Override |
| long getSequenceNumber(); |
| |
| } |