content: /*
   * 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.arrow.algorithm.sort;
  
  import org.apache.arrow.vector.ValueVector;
  
  /**
   * A composite vector comparator compares a number of vectors by a number of inner comparators.
   *
   * <p>It works by first using the first comparator, if a non-zero value is returned, it simply
   * returns it. Otherwise, it uses the second comparator, and so on, until a non-zero value is
   * produced, or all inner comparators have been used.
   */
  public class CompositeVectorComparator extends VectorValueComparator<ValueVector> {
  
    private final VectorValueComparator[] innerComparators;
  
    public CompositeVectorComparator(VectorValueComparator[] innerComparators) {
      this.innerComparators = innerComparators;
    }
  
    @Override
    public int compareNotNull(int index1, int index2) {
      // short-cut for scenarios when the caller can be sure that the vectors are non-nullable.
      for (int i = 0; i < innerComparators.length; i++) {
        int result = innerComparators[i].compareNotNull(index1, index2);
        if (result != 0) {
          return result;
        }
      }
      return 0;
    }
  
    @Override
    public int compare(int index1, int index2) {
      for (int i = 0; i < innerComparators.length; i++) {
        int result = innerComparators[i].compare(index1, index2);
        if (result != 0) {
          return result;
        }
      }
      return 0;
    }
  
    @Override
    public VectorValueComparator<ValueVector> createNew() {
      VectorValueComparator[] newInnerComparators =
          new VectorValueComparator[innerComparators.length];
      for (int i = 0; i < innerComparators.length; i++) {
        newInnerComparators[i] = innerComparators[i].createNew();
      }
      return new CompositeVectorComparator(newInnerComparators);
    }
  }
  