/***********************************************************************************************************************
* 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.types.parser;
import eu.stratosphere.types.StringValue;
/**
* Converts a variable length field of a byte array into a {@link StringValue}. The byte contents between
* delimiters is interpreted as an ASCII string. The string may be quoted in double quotes. For quoted
* strings, whitespaces (space and tab) leading and trailing before and after the quotes are removed.
*
* @see StringValue
*/
public class VarLengthStringParser extends FieldParser<StringValue> {
private static final byte WHITESPACE_SPACE = (byte) ' ';
private static final byte WHITESPACE_TAB = (byte) '\t';
private static final byte QUOTE_DOUBLE = (byte) '"';
private StringValue result;
@Override
public int parseField(byte[] bytes, int startPos, int length, char delim, StringValue reusable) {
this.result = reusable;
int i = startPos;
final byte delByte = (byte) delim;
byte current;
// count initial whitespace lines
while (i < length && ((current = bytes[i]) == WHITESPACE_SPACE || current == WHITESPACE_TAB)) {
i++;
}
// first none whitespace character
if (i < length && bytes[i] == QUOTE_DOUBLE) {
// quoted string
i++; // the quote
// we count only from after the quote
int quoteStart = i;
while (i < length && bytes[i] != QUOTE_DOUBLE) {
i++;
}
if (i < length) {
// end of the string
reusable.setValueAscii(bytes, quoteStart, i-quoteStart);
i++; // the quote
// skip trailing whitespace characters
while (i < length && (current = bytes[i]) != delByte) {
if (current == WHITESPACE_SPACE || current == WHITESPACE_TAB) {
i++;
}
else {
setErrorState(ParseErrorState.UNQUOTED_CHARS_AFTER_QUOTED_STRING);
return -1; // illegal case of non-whitespace characters trailing
}
}
return (i == length ? length : i+1);
} else {
// exited due to line end without quote termination
setErrorState(ParseErrorState.UNTERMINATED_QUOTED_STRING);
return -1;
}
}
else {
// unquoted string
while (i < length && bytes[i] != delByte) {
i++;
}
// set from the beginning. unquoted strings include the leading whitespaces
reusable.setValueAscii(bytes, startPos, i-startPos);
return (i == length ? length : i+1);
}
}
@Override
public StringValue createValue() {
return new StringValue();
}
@Override
public StringValue getLastResult() {
return this.result;
}
}