package org.apache.lucene.util.fst;
/**
* 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.
*/
import java.io.IOException;
import org.apache.lucene.store.DataInput;
import org.apache.lucene.store.DataOutput;
/**
* Pairs up two outputs into one.
*
* @lucene.experimental
*/
public class PairOutputs<A,B> extends Outputs<PairOutputs.Pair<A,B>> {
private final Pair<A,B> NO_OUTPUT;
private final Outputs<A> outputs1;
private final Outputs<B> outputs2;
public static class Pair<A,B> {
public final A output1;
public final B output2;
public Pair(A output1, B output2) {
this.output1 = output1;
this.output2 = output2;
}
@Override @SuppressWarnings("rawtypes")
public boolean equals(Object other) {
if (other == this) {
return true;
} else if (other instanceof Pair) {
Pair pair = (Pair) other;
return output1.equals(pair.output1) && output2.equals(pair.output2);
} else {
return false;
}
}
@Override
public int hashCode() {
return output1.hashCode() + output2.hashCode();
}
};
public PairOutputs(Outputs<A> outputs1, Outputs<B> outputs2) {
this.outputs1 = outputs1;
this.outputs2 = outputs2;
NO_OUTPUT = new Pair<A,B>(outputs1.getNoOutput(), outputs2.getNoOutput());
}
public Pair<A,B> get(A output1, B output2) {
if (output1 == outputs1.getNoOutput() && output2 == outputs2.getNoOutput()) {
return NO_OUTPUT;
} else {
return new Pair<A,B>(output1, output2);
}
}
@Override
public Pair<A,B> common(Pair<A,B> pair1, Pair<A,B> pair2) {
return get(outputs1.common(pair1.output1, pair2.output1),
outputs2.common(pair1.output2, pair2.output2));
}
@Override
public Pair<A,B> subtract(Pair<A,B> output, Pair<A,B> inc) {
return get(outputs1.subtract(output.output1, inc.output1),
outputs2.subtract(output.output2, inc.output2));
}
@Override
public Pair<A,B> add(Pair<A,B> prefix, Pair<A,B> output) {
return get(outputs1.add(prefix.output1, output.output1),
outputs2.add(prefix.output2, output.output2));
}
@Override
public void write(Pair<A,B> output, DataOutput writer) throws IOException {
outputs1.write(output.output1, writer);
outputs2.write(output.output2, writer);
}
@Override
public Pair<A,B> read(DataInput in) throws IOException {
A output1 = outputs1.read(in);
B output2 = outputs2.read(in);
return get(output1, output2);
}
@Override
public Pair<A,B> getNoOutput() {
return NO_OUTPUT;
}
@Override
public String outputToString(Pair<A,B> output) {
return "<pair:" + outputs1.outputToString(output.output1) + "," + outputs2.outputToString(output.output2) + ">";
}
}