/***********************************************************************************************************************
*
* 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.common.typeutils.base;
import java.io.IOException;
import eu.stratosphere.core.memory.DataInputView;
import eu.stratosphere.core.memory.MemorySegment;
public final class CharComparator extends BasicTypeComparator<Character> {
private static final long serialVersionUID = 1L;
public CharComparator(boolean ascending) {
super(ascending);
}
@Override
public int compare(DataInputView firstSource, DataInputView secondSource) throws IOException {
char c1 = firstSource.readChar();
char c2 = secondSource.readChar();
int comp = (c1 < c2 ? -1 : (c1 == c2 ? 0 : 1));
return ascendingComparison ? comp : -comp;
}
@Override
public boolean supportsNormalizedKey() {
return true;
}
@Override
public int getNormalizeKeyLen() {
return 2;
}
@Override
public boolean isNormalizedKeyPrefixOnly(int keyBytes) {
return keyBytes < 2;
}
@Override
public void putNormalizedKey(Character value, MemorySegment target, int offset, int numBytes) {
// note that the char is an unsigned data type in java and consequently needs
// no code that transforms the signed representation to an offsetted representation
// that is equivalent to unsigned, when compared byte by byte
if (numBytes == 2) {
// default case, full normalized key
target.put(offset, (byte) ((value >>> 8) & 0xff));
target.put(offset + 1, (byte) ((value ) & 0xff));
}
else if (numBytes <= 0) {
}
else if (numBytes == 1) {
target.put(offset, (byte) ((value >>> 8) & 0xff));
}
else {
target.put(offset, (byte) ((value >>> 8) & 0xff));
target.put(offset + 1, (byte) ((value ) & 0xff));
for (int i = 2; i < numBytes; i++) {
target.put(offset + i, (byte) 0);
}
}
}
@Override
public CharComparator duplicate() {
return new CharComparator(ascendingComparison);
}
}