/*
* 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.pig.impl.streaming;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import org.apache.pig.LoadFunc;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.impl.PigContext;
import org.apache.pig.impl.io.BufferedPositionedInputStream;
import org.apache.pig.impl.streaming.StreamingCommand.HandleSpec;
/**
* FileOutputHandler handles the output from the Pig-Streaming
* executable in an asynchronous manner by reading it from
* an external file specified by the user.
*/
public class FileOutputHandler extends OutputHandler {
String fileName;
BufferedPositionedInputStream fileInStream;
public FileOutputHandler(HandleSpec handleSpec) throws ExecException {
fileName = handleSpec.name;
deserializer =
(LoadFunc) PigContext.instantiateFuncFromSpec(handleSpec.spec);
}
public OutputType getOutputType() {
return OutputType.ASYNCHRONOUS;
}
public void bindTo(String fileName, BufferedPositionedInputStream is,
long offset, long end) throws IOException {
// This is a trigger to start processing the output from the file ...
// ... however, we must ignore the input parameters and use ones
// provided during initialization
File file = new File(this.fileName);
this.fileInStream =
new BufferedPositionedInputStream(new FileInputStream(file));
super.bindTo(this.fileName, this.fileInStream, 0, file.length());
}
public synchronized void close() throws IOException {
if(!alreadyClosed) {
super.close();
fileInStream.close();
fileInStream = null;
alreadyClosed = true;
}
}
}