geode-core/src/main/java/org/apache/geode/cache/query/internal/index/IndexCreationHelper.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.
 */
/*
 * AbstractIndexCreationHelper.java
 *
 * Created on March 20, 2005, 8:26 PM
 */
package org.apache.geode.cache.query.internal.index;

import java.util.List;

import org.apache.geode.cache.Region;
import org.apache.geode.cache.query.IndexInvalidException;
import org.apache.geode.cache.query.internal.CompiledValue;
import org.apache.geode.cache.query.internal.QCompiler;
import org.apache.geode.internal.cache.InternalCache;

public abstract class IndexCreationHelper {

  public static final int INDEX_QUERY_SCOPE_ID = -2;

  /**
   * Canonicalized attributes. The value in these fields is set during the execution of
   * prepareFromClause function While the value of fromClause is reset in execution of
   * prepareFromClause, to canonicalized from clause
   */
  String fromClause;

  String indexedExpression;

  String projectionAttributes;

  // use the same compiler for each query string to use
  QCompiler compiler;

  InternalCache cache;

  /**
   * The array containing the canonicalized iterator names which will get reused.
   * <p>
   * TODO: How to make it final so that the invokers do not end up modifying it
   */
  String[] canonicalizedIteratorNames = null;

  /**
   * Array containing canonicalized iterator definitions
   * <p>
   * TODO: How to make it final so that the invokers do not end up modifying it
   */
  String[] canonicalizedIteratorDefinitions = null;

  IndexCreationHelper(String fromClause, String projectionAttributes, InternalCache cache)
      throws IndexInvalidException {
    this.cache = cache;
    // The fromClause,indexedExpression & projectionAttributes
    // will get modified with the canonicalized value , once the
    // constructor of derived class is over.
    this.fromClause = fromClause;
    this.projectionAttributes = projectionAttributes;
    this.compiler = new QCompiler(true);
  }

  public String getCanonicalizedProjectionAttributes() {
    return this.projectionAttributes;
  }

  public String getCanonicalizedIndexedExpression() {
    return this.indexedExpression;
  }

  public String getCanonicalizedFromClause() {
    return this.fromClause;
  }

  public InternalCache getCache() {
    return this.cache;
  }

  /**
   * This function returns the canonicalized Iterator Definitions of the from clauses used in Index
   * creation
   */
  String[] getCanonicalizedIteratorDefinitions() {
    return this.canonicalizedIteratorDefinitions;
  }

  boolean isMapTypeIndex() {
    return false;
  }

  public abstract List getIterators();

  abstract CompiledValue getCompiledIndexedExpression();

  abstract Region getRegion();
}