/*
* 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 org.apache.flink.api.java.typeutils.runtime;
import java.io.IOException;
import org.apache.flink.api.common.typeutils.TypeComparator;
import org.apache.flink.core.memory.DataInputView;
import org.apache.flink.core.memory.DataOutputView;
import org.apache.flink.core.memory.MemorySegment;
import org.apache.flink.types.NormalizableKey;
import org.apache.flink.util.InstantiationUtil;
import org.apache.hadoop.io.Writable;
import com.esotericsoftware.kryo.Kryo;
public class WritableComparator<T extends Writable & Comparable<T>> extends TypeComparator<T> {
private static final long serialVersionUID = 1L;
private Class<T> type;
private final boolean ascendingComparison;
private transient T reference;
private transient T tempReference;
private transient Kryo kryo;
@SuppressWarnings("rawtypes")
private final TypeComparator[] comparators = new TypeComparator[] {this};
public WritableComparator(boolean ascending, Class<T> type) {
this.type = type;
this.ascendingComparison = ascending;
}
@Override
public int hash(T record) {
return record.hashCode();
}
@Override
public void setReference(T toCompare) {
checkKryoInitialized();
reference = this.kryo.copy(toCompare);
}
@Override
public boolean equalToReference(T candidate) {
return candidate.equals(reference);
}
@Override
public int compareToReference(TypeComparator<T> referencedComparator) {
T otherRef = ((WritableComparator<T>) referencedComparator).reference;
int comp = otherRef.compareTo(reference);
return ascendingComparison ? comp : -comp;
}
@Override
public int compare(T first, T second) {
int comp = first.compareTo(second);
return ascendingComparison ? comp : -comp;
}
@Override
public int compareSerialized(DataInputView firstSource, DataInputView secondSource) throws IOException {
ensureReferenceInstantiated();
ensureTempReferenceInstantiated();
reference.readFields(firstSource);
tempReference.readFields(secondSource);
int comp = reference.compareTo(tempReference);
return ascendingComparison ? comp : -comp;
}
@Override
public boolean supportsNormalizedKey() {
return NormalizableKey.class.isAssignableFrom(type);
}
@Override
public int getNormalizeKeyLen() {
ensureReferenceInstantiated();
NormalizableKey<?> key = (NormalizableKey<?>) reference;
return key.getMaxNormalizedKeyLen();
}
@Override
public boolean isNormalizedKeyPrefixOnly(int keyBytes) {
return keyBytes < getNormalizeKeyLen();
}
@Override
public void putNormalizedKey(T record, MemorySegment target, int offset, int numBytes) {
NormalizableKey<?> key = (NormalizableKey<?>) record;
key.copyNormalizedKey(target, offset, numBytes);
}
@Override
public boolean invertNormalizedKey() {
return !ascendingComparison;
}
@Override
public TypeComparator<T> duplicate() {
return new WritableComparator<T>(ascendingComparison, type);
}
@Override
public int extractKeys(Object record, Object[] target, int index) {
target[index] = record;
return 1;
}
@SuppressWarnings("rawtypes")
@Override public TypeComparator[] getFlatComparators() {
return comparators;
}
// --------------------------------------------------------------------------------------------
// unsupported normalization
// --------------------------------------------------------------------------------------------
@Override
public boolean supportsSerializationWithKeyNormalization() {
return false;
}
@Override
public void writeWithKeyNormalization(T record, DataOutputView target) throws IOException {
throw new UnsupportedOperationException();
}
@Override
public T readWithKeyDenormalization(T reuse, DataInputView source) throws IOException {
throw new UnsupportedOperationException();
}
// --------------------------------------------------------------------------------------------
private void checkKryoInitialized() {
if (this.kryo == null) {
this.kryo = new Kryo();
this.kryo.setAsmEnabled(true);
this.kryo.register(type);
}
}
private void ensureReferenceInstantiated() {
if (reference == null) {
reference = InstantiationUtil.instantiate(type, Writable.class);
}
}
private void ensureTempReferenceInstantiated() {
if (tempReference == null) {
tempReference = InstantiationUtil.instantiate(type, Writable.class);
}
}
}