    001/*
    002 * Copyright (c) 2007-2016 Concurrent, Inc. All Rights Reserved.
    003 *
    004 * Project and contact information: http://www.cascading.org/
    005 *
    006 * This file is part of the Cascading project.
    007 *
    008 * Licensed under the Apache License, Version 2.0 (the "License");
    009 * you may not use this file except in compliance with the License.
    010 * You may obtain a copy of the License at
    011 *
    012 *     http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing, software
    015 * distributed under the License is distributed on an "AS IS" BASIS,
    016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    017 * See the License for the specific language governing permissions and
    018 * limitations under the License.
    019 */
    020
    021package cascading.operation.filter;
    022
    023import java.beans.ConstructorProperties;
    024
    025import cascading.flow.FlowProcess;
    026import cascading.operation.Filter;
    027import cascading.operation.FilterCall;
    028import cascading.tuple.Fields;
    029import cascading.tuple.TupleEntry;
    030
    031/**
    032 * Class Xor is a {@link Filter} class that will logically 'xor' (exclusive or) the results of the
    033 * constructor provided Filter instances.
    034 * <p/>
    035 * Logically, if {@link Filter#isRemove(cascading.flow.FlowProcess, cascading.operation.FilterCall)} returns {@code true} for all given instances,
    036 * or returns {@code false} for all given instances, this filter will return {@code false}.
    037 * <p/>
    038 * Note that Xor can only be applied to two values.
    039 *
    040 * @see And
    041 * @see Or
    042 * @see Not
    043 */
    044public class Xor extends Logic
    045  {
    046  /**
    047   * Constructor Xor creates a new Xor instance where all Filter instances receive all arguments.
    048   *
    049   * @param filters of type Filter...
    050   */
    051  @ConstructorProperties({"filters"})
    052  public Xor( Filter... filters )
    053    {
    054    super( filters );
    055    }
    056
    057  /**
    058   * Constructor Xor creates a new Xor instance.
    059   *
    060   * @param lhsArgumentSelector of type Fields
    061   * @param lhsFilter           of type Filter
    062   * @param rhsArgumentSelector of type Fields
    063   * @param rhsFilter           of type Filter
    064   */
    065  @ConstructorProperties({"lhsArgumentsSelector", "lhsFilter", "rhsArgumentSelector", "rhsFilter"})
    066  public Xor( Fields lhsArgumentSelector, Filter lhsFilter, Fields rhsArgumentSelector, Filter rhsFilter )
    067    {
    068    super( lhsArgumentSelector, lhsFilter, rhsArgumentSelector, rhsFilter );
    069    }
    070
    071  @Override
    072  public boolean isRemove( FlowProcess flowProcess, FilterCall filterCall )
    073    {
    074    Context context = (Logic.Context) filterCall.getContext();
    075
    076    TupleEntry lhsEntry = context.argumentEntries[ 0 ];
    077    TupleEntry rhsEntry = context.argumentEntries[ 1 ];
    078
    079    lhsEntry.setTuple( filterCall.getArguments().selectTuple( argumentSelectors[ 0 ] ) );
    080    rhsEntry.setTuple( filterCall.getArguments().selectTuple( argumentSelectors[ 1 ] ) );
    081
    082    boolean lhsResult = filters[ 0 ].isRemove( flowProcess, context.calls[ 0 ] );
    083    boolean rhsResult = filters[ 1 ].isRemove( flowProcess, context.calls[ 1 ] );
    084
    085    return lhsResult != rhsResult;
    086    }
    087  }