CandidateExploder.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.lens.cube.parse;

import java.util.Set;

import org.apache.lens.server.api.error.LensException;

import com.google.common.collect.Sets;

/**
 * Created on 21/04/17.
 */
public class CandidateExploder implements ContextRewriter {
  /**
   * Replacing all candidates with their exploded versions in cubeql.getCandidates()
   * @param cubeql CubeQueryContext
   * @throws LensException propagated exception
   */
  @Override
  public void rewriteContext(CubeQueryContext cubeql) throws LensException {
    Set<Candidate> candidateSet = Sets.newHashSet();
    for (Candidate candidate : cubeql.getCandidates()) {
      candidateSet.add(candidate.explode());
    }
    cubeql.getCandidates().clear();
    cubeql.getCandidates().addAll(candidateSet);
  }
}