001    /*
002     * Copyright (c) 2007-2015 Concurrent, Inc. All Rights Reserved.
003     *
004     * Project and contact information: http://www.cascading.org/
005     *
006     * This file is part of the Cascading project.
007     *
008     * Licensed under the Apache License, Version 2.0 (the "License");
009     * you may not use this file except in compliance with the License.
010     * You may obtain a copy of the License at
011     *
012     *     http://www.apache.org/licenses/LICENSE-2.0
013     *
014     * Unless required by applicable law or agreed to in writing, software
015     * distributed under the License is distributed on an "AS IS" BASIS,
016     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017     * See the License for the specific language governing permissions and
018     * limitations under the License.
019     */
020    
021    package cascading.tap.type;
022    
023    import java.io.IOException;
024    
025    /** Interface FileType marks specific platform {@link cascading.tap.Tap} classes as representing a file like interface. */
026    public interface FileType<Config>
027      {
028      /**
029       * Method isDirectory returns true if the underlying resource represents a directory or folder instead
030       * of an individual file.
031       *
032       * @param conf of JobConf
033       * @return boolean
034       * @throws java.io.IOException
035       */
036      boolean isDirectory( Config conf ) throws IOException;
037    
038      /**
039       * Method getChildIdentifiers returns an array of child identifiers if this resource is a directory.
040       * <p/>
041       * This method will skip Hadoop log directories ({@code _log}).
042       *
043       * @param conf of JobConf
044       * @return String[]
045       * @throws java.io.IOException
046       */
047      String[] getChildIdentifiers( Config conf ) throws IOException;
048    
049      String[] getChildIdentifiers( Config conf, int depth, boolean fullyQualified ) throws IOException;
050    
051      /**
052       * Method getSize returns the size of the file referenced by this tap.
053       *
054       * @param conf of type Config
055       * @return The size of the file reference by this tap.
056       * @throws java.io.IOException
057       */
058      long getSize( Config conf ) throws IOException;
059      }