UpwardProtocol.java
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上传日期:2018-01-08
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文件大小:3k
- /**
- * 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.hadoop.mapred.pipes;
- import java.io.IOException;
- import org.apache.hadoop.io.Writable;
- import org.apache.hadoop.io.WritableComparable;
- /**
- * The interface for the messages that can come up from the child. All of these
- * calls are asynchronous and return before the message has been processed.
- */
- interface UpwardProtocol<K extends WritableComparable, V extends Writable> {
- /**
- * Output a record from the child.
- * @param key the record's key
- * @param value the record's value
- * @throws IOException
- */
- void output(K key, V value) throws IOException;
-
- /**
- * Map functions where the application has defined a partition function
- * output records along with their partition.
- * @param reduce the reduce to send this record to
- * @param key the record's key
- * @param value the record's value
- * @throws IOException
- */
- void partitionedOutput(int reduce, K key,
- V value) throws IOException;
-
- /**
- * Update the task's status message
- * @param msg the string to display to the user
- * @throws IOException
- */
- void status(String msg) throws IOException;
-
- /**
- * Report making progress (and the current progress)
- * @param progress the current progress (0.0 to 1.0)
- * @throws IOException
- */
- void progress(float progress) throws IOException;
-
- /**
- * Report that the application has finished processing all inputs
- * successfully.
- * @throws IOException
- */
- void done() throws IOException;
-
- /**
- * Report that the application or more likely communication failed.
- * @param e
- */
- void failed(Throwable e);
-
- /**
- * Register a counter with the given id and group/name.
- * @param group counter group
- * @param name counter name
- * @throws IOException
- */
- void registerCounter(int id, String group, String name) throws IOException;
-
- /**
- * Increment the value of a registered counter.
- * @param id counter id of the registered counter
- * @param amount increment for the counter value
- * @throws IOException
- */
- void incrementCounter(int id, long amount) throws IOException;
- }