geode-core/src/main/java/org/apache/geode/cache/query/internal/index/IndexData.java

/*
 * 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.geode.cache.query.internal.index;

/**
 *
 *
 * Object of this class contains information of various attributes of Range Index for a filter
 * evaluatable condition , from the perspective of the query from clause. It identifies the match
 * level & the maping of Iterators of the Group to the index result fields.
 */
public class IndexData {

  /**
   * Index assosciated with the condition
   */
  IndexProtocol _index;
  /**
   * int idenifying the match level. A match level of zero means exact match. A match level greater
   * than 0 means the query from clauses have extra iterators as compared to Index resultset ( This
   * does not neccessarily mean that Index resultset is not having extra fields. It is just that the
   * criteria for match level is the absence or presence of extra iterators. The order of preference
   * will be 0 , <0 , > 0 for first cut.
   */
  int _matchLevel;
  /**
   * An int array of size equal to the number of Iterators present in the Group representing the
   * Iterators for that region. It identifies the index result field position which maps to the
   * RuntimeIterator for the Group. The mapping of index result field is 1 based ( not zero). For
   * example the second Iterator of the group ( 0 indxe based , hence 1 ) will map to the field
   * position in the Index Result given by the value maping[1]. If an iterator has no mapping , the
   * value will be 0. *
   *
   */
  int[] mapping = null;

  IndexData(IndexProtocol index, int matchLevel, int[] mapping) {
    this.mapping = mapping;
    _index = index;
    _matchLevel = matchLevel;
  }

  public IndexProtocol getIndex() {
    return this._index;
  }

  public int getMatchLevel() {
    return this._matchLevel;
  }

  public int[] getMapping() {
    return this.mapping;
  }
}