com.datatorrent.lib.io.fs.FileSplitterBase.java Source code

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Here is the source code for com.datatorrent.lib.io.fs.FileSplitterBase.java

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/**
 * 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 com.datatorrent.lib.io.fs;

import java.io.IOException;
import java.util.LinkedList;

import javax.validation.constraints.NotNull;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

import com.google.common.base.Preconditions;

import com.datatorrent.api.Context;
import com.datatorrent.api.DefaultInputPort;
import com.datatorrent.api.Operator;

/**
 * A file splitter that receives its input from an upstream operator.
 *
 * @since 3.2.0
 */
public class FileSplitterBase extends AbstractFileSplitter implements Operator.IdleTimeHandler {
    @NotNull
    protected String file;
    protected transient FileSystem fs;

    protected final LinkedList<FileInfo> fileInfos;
    protected transient int sleepTimeMillis;

    public FileSplitterBase() {
        fileInfos = new LinkedList<>();
    }

    public final transient DefaultInputPort<FileInfo> input = new DefaultInputPort<FileInfo>() {
        @Override
        public void process(FileInfo fileInfo) {
            fileInfos.add(fileInfo);
            FileSplitterBase.this.process();
        }
    };

    @Override
    public void setup(Context.OperatorContext context) {
        sleepTimeMillis = context.getValue(Context.OperatorContext.SPIN_MILLIS);
        try {
            fs = getFSInstance();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        super.setup(context);
    }

    protected FileSystem getFSInstance() throws IOException {
        return FileSystem.newInstance(new Path(file).toUri(), new Configuration());
    }

    @Override
    protected FileInfo getFileInfo() {
        if (fileInfos.size() > 0) {
            return fileInfos.remove();
        }
        return null;
    }

    @Override
    public void handleIdleTime() {
        if (blockCount < blocksThreshold && (blockMetadataIterator != null || fileInfos.size() > 0)) {
            process();
        } else {
            /* nothing to do here, so sleep for a while to avoid busy loop */
            try {
                Thread.sleep(sleepTimeMillis);
            } catch (InterruptedException ie) {
                throw new RuntimeException(ie);
            }
        }
    }

    @Override
    public void teardown() {
        super.teardown();
        try {
            fs.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    protected long getDefaultBlockSize() {
        return fs.getDefaultBlockSize(new Path(file));
    }

    @Override
    protected FileStatus getFileStatus(Path path) throws IOException {
        return fs.getFileStatus(path);
    }

    /**
     * File path from which the File System is inferred.
     *
     * @param file files
     */
    public void setFile(@NotNull String file) {
        this.file = Preconditions.checkNotNull(file, "file path");
    }

    /**
     * @return file path from which the File System is inferred.
     */
    public String getFile() {
        return file;
    }
}