/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.api.java.record.io;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.util.Arrays;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import eu.stratosphere.configuration.Configuration;
import eu.stratosphere.types.Record;
import eu.stratosphere.types.StringValue;
/**
* Base implementation for an input format that returns each line as a separate record that contains
* only a single string, namely the line.
*/
public class TextInputFormat extends DelimitedInputFormat {
private static final long serialVersionUID = 1L;
public static final String CHARSET_NAME = "textformat.charset";
public static final String FIELD_POS = "textformat.pos";
public static final String DEFAULT_CHARSET_NAME = "UTF-8";
private static final Log LOG = LogFactory.getLog(TextInputFormat.class);
protected final StringValue theString = new StringValue();
// all fields below here are set in configure / open, so we do not serialze them
protected transient CharsetDecoder decoder;
protected transient ByteBuffer byteWrapper;
protected transient int pos;
protected transient boolean ascii;
/**
* Code of \r, used to remove \r from a line when the line ends with \r\n
*/
private static final byte CARRIAGE_RETURN = (byte) '\r';
/**
* Code of \n, used to identify if \n is used as delimiter
*/
private static final byte NEW_LINE = (byte) '\n';
// --------------------------------------------------------------------------------------------
@Override
public void configure(Configuration parameters) {
super.configure(parameters);
// get the charset for the decoding
String charsetName = parameters.getString(CHARSET_NAME, DEFAULT_CHARSET_NAME);
if (charsetName == null || !Charset.isSupported(charsetName)) {
throw new RuntimeException("Unsupported charset: " + charsetName);
}
if (charsetName.equals("ISO-8859-1") || charsetName.equalsIgnoreCase("ASCII")) {
this.ascii = true;
} else {
this.decoder = Charset.forName(charsetName).newDecoder();
this.byteWrapper = ByteBuffer.allocate(1);
}
// get the field position to write in the record
this.pos = parameters.getInteger(FIELD_POS, 0);
if (this.pos < 0) {
throw new RuntimeException("Illegal configuration value for the target position: " + this.pos);
}
}
// --------------------------------------------------------------------------------------------
public Record readRecord(Record reuse, byte[] bytes, int offset, int numBytes) {
StringValue str = this.theString;
//Check if \n is used as delimiter and the end of this line is a \r, then remove \r from the line
if (this.getDelimiter() != null && this.getDelimiter().length == 1
&& this.getDelimiter()[0] == NEW_LINE && offset+numBytes >= 1
&& bytes[offset+numBytes-1] == CARRIAGE_RETURN){
numBytes -= 1;
}
if (this.ascii) {
str.setValueAscii(bytes, offset, numBytes);
}
else {
ByteBuffer byteWrapper = this.byteWrapper;
if (bytes != byteWrapper.array()) {
byteWrapper = ByteBuffer.wrap(bytes, 0, bytes.length);
this.byteWrapper = byteWrapper;
}
byteWrapper.limit(offset + numBytes);
byteWrapper.position(offset);
try {
CharBuffer result = this.decoder.decode(byteWrapper);
str.setValue(result);
}
catch (CharacterCodingException e) {
byte[] copy = new byte[numBytes];
System.arraycopy(bytes, offset, copy, 0, numBytes);
LOG.warn("Line could not be encoded: " + Arrays.toString(copy), e);
return null;
}
}
reuse.clear();
reuse.setField(this.pos, str);
return reuse;
}
}