/*********************************************************************************************************************** * * 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); } }