com.idvp.platform.hdfs.HDFSDataStream.java Source code

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Here is the source code for com.idvp.platform.hdfs.HDFSDataStream.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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.idvp.platform.hdfs;

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

import java.io.IOException;

public class HDFSDataStream extends AbstractHDFSWriter {

    private FSDataOutputStream outStream;
    private EventSerializer serializer;

    public HDFSDataStream() {
    }

    protected FileSystem getDfs(Configuration conf, Path dstPath) throws IOException {
        return dstPath.getFileSystem(conf);
    }

    protected void doOpen(Configuration conf, Path dstPath, FileSystem hdfs) throws IOException {

        boolean appending = false;
        if (conf.getBoolean("hdfs.append.support", false) == true && hdfs.isFile(dstPath)) {
            outStream = hdfs.append(dstPath);
            appending = true;
        } else {
            outStream = hdfs.create(dstPath);
        }

        serializer = new BodyTextEventSerializer.Builder().build(outStream);
        if (appending && !serializer.supportsReopen()) {
            outStream.close();
            serializer = null;
            throw new IOException("serializer (" + "TEXT" + ") does not support append");
        }

        // must call superclass to check for replication issues
        registerCurrentStream(outStream, hdfs, dstPath);

        if (appending) {
            serializer.afterReopen();
        } else {
            serializer.afterCreate();
        }
    }

    @Override
    public void open(String filePath) throws IOException {
        Configuration conf = new Configuration();
        Path dstPath = new Path(filePath);
        FileSystem hdfs = getDfs(conf, dstPath);
        doOpen(conf, dstPath, hdfs);
    }

    @Override
    public void append(byte[] data) throws IOException {
        serializer.write(data);
    }

    @Override
    public void sync() throws IOException {
        serializer.flush();
        outStream.flush();
        hflushOrSync(outStream);
    }

    @Override
    public void close() throws IOException {
        serializer.flush();
        serializer.beforeClose();
        outStream.flush();
        hflushOrSync(outStream);
        outStream.close();

        unregisterCurrentStream();
    }

}