/**
* 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 com.pinterest.secor.io.impl;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.hadoop.io.compress.CompressionCodec;
import com.google.common.io.CountingOutputStream;
import com.pinterest.secor.common.LogFilePath;
import com.pinterest.secor.io.FileReaderWriter;
import com.pinterest.secor.io.KeyValue;
/**
*
* Delimited Text File Reader Writer with Compression
*
* @author Praveen Murugesan (praveen@uber.com)
*
*/
public class DelimitedTextFileReaderWriter implements FileReaderWriter {
// delimiter used between messages
private static final byte DELIMITER = '\n';
private final CountingOutputStream mCountingStream;
private final BufferedOutputStream mWriter;
private final BufferedInputStream mReader;
private long mOffset;
// constructor
public DelimitedTextFileReaderWriter(LogFilePath path,
CompressionCodec codec, FileReaderWriter.Type type)
throws FileNotFoundException, IOException {
File logFile = new File(path.getLogFilePath());
logFile.getParentFile().mkdirs();
if (type == FileReaderWriter.Type.Reader) {
InputStream inputStream = new FileInputStream(new File(
path.getLogFilePath()));
this.mReader = (codec == null) ? new BufferedInputStream(inputStream)
: new BufferedInputStream(
codec.createInputStream(inputStream));
this.mOffset = path.getOffset();
this.mCountingStream = null;
this.mWriter = null;
} else if (type == FileReaderWriter.Type.Writer) {
this.mCountingStream = new CountingOutputStream(
new FileOutputStream(logFile));
this.mWriter = (codec == null) ? new BufferedOutputStream(
this.mCountingStream) : new BufferedOutputStream(
codec.createOutputStream(this.mCountingStream));
this.mReader = null;
} else {
throw new IllegalArgumentException("Undefined File Type: " + type);
}
}
@Override
public void close() throws IOException {
if (this.mWriter != null) {
this.mWriter.close();
}
if (this.mReader != null) {
this.mReader.close();
}
}
@Override
public long getLength() throws IOException {
assert this.mCountingStream != null;
return this.mCountingStream.getCount();
}
@Override
public void write(KeyValue keyValue) throws IOException {
assert this.mWriter != null;
this.mWriter.write(keyValue.getValue());
this.mWriter.write(DELIMITER);
}
@Override
public KeyValue next() throws IOException {
assert this.mReader != null;
ByteArrayOutputStream messageBuffer = new ByteArrayOutputStream();
int nextByte;
while ((nextByte = mReader.read()) != DELIMITER) {
if (nextByte == -1) { // end of stream?
if (messageBuffer.size() == 0) { // if no byte read
return null;
} else { // if bytes followed by end of stream: framing error
throw new EOFException(
"Non-empty message without delimiter");
}
}
messageBuffer.write(nextByte);
}
return new KeyValue(this.mOffset++, messageBuffer.toByteArray());
}
}