core/src/main/java/org/apache/mrql/MRQLFileInputFormat.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.mrql;

import java.io.*;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.io.*;


/** An interface for all MRQL FileInputFormats */
public interface MRQLFileInputFormat {
    /** materialize the input file into a memory Bag */
    public Bag materialize ( final Path path ) throws IOException;

    /** materialize the entire dataset into a Bag
     * @param x the DataSet in HDFS to collect values from
     * @param strip is not used in MapReduce mode
     * @return the Bag that contains the collected values
     */
    public Bag collect ( final DataSet x, boolean strip ) throws Exception;
}