core/src/main/java/org/apache/carbondata/core/scan/executor/QueryExecutor.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.carbondata.core.scan.executor;

import java.io.IOException;

import org.apache.carbondata.common.CarbonIterator;
import org.apache.carbondata.core.scan.executor.exception.QueryExecutionException;
import org.apache.carbondata.core.scan.model.QueryModel;

/**
 * Interface for carbon query executor.
 * Will be used to execute the query based on the query model
 * and will return the iterator over query result
 */
public interface QueryExecutor<E> {

  /**
   * Below method will be used to execute the query based on query model passed from driver
   *
   * @param queryModel query details
   * @return query result iterator
   * @throws IOException if fail to read files
   */
  CarbonIterator<E> execute(QueryModel queryModel) throws IOException;

  /**
   * Below method will be used for cleanup
   *
   * @throws QueryExecutionException
   */
  void finish() throws QueryExecutionException;
}