org.apache.carbondata.core.writer.ThriftWriter.java Source code

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Here is the source code for org.apache.carbondata.core.writer.ThriftWriter.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 org.apache.carbondata.core.writer;

import java.io.DataOutputStream;
import java.io.IOException;

import org.apache.carbondata.core.datastore.impl.FileFactory;
import org.apache.carbondata.core.util.CarbonUtil;

import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.thrift.TBase;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TCompactProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TIOStreamTransport;

/**
 * Simple class that makes it easy to write Thrift objects to disk.
 */
public class ThriftWriter {

    /**
     * buffer size
     */
    private static final int bufferSize = 2048;

    /**
     * File to write to.
     */
    private String fileName;

    /**
     * For writing to the file.
     */
    private DataOutputStream dataOutputStream;

    /**
     * For binary serialization of objects.
     */
    private TProtocol binaryOut;

    /**
     * flag to append to existing file
     */
    private boolean append;

    /**
     * Constructor.
     */
    public ThriftWriter(String fileName, boolean append) {
        this.fileName = fileName;
        this.append = append;
    }

    /**
     * Open the file for writing.
     */
    public void open() throws IOException {
        FileFactory.FileType fileType = FileFactory.getFileType(fileName);
        dataOutputStream = FileFactory.getDataOutputStream(fileName, fileType, bufferSize, append);
        binaryOut = new TCompactProtocol(new TIOStreamTransport(dataOutputStream));
    }

    /**
     * This will check whether stream and binary out is open or not.
     * @return
     */
    public boolean isOpen() {
        if (null != binaryOut && null != dataOutputStream) {
            return true;
        }
        return false;
    }

    /**
     * Write the object to disk.
     */
    public void write(TBase t) throws IOException {
        try {
            t.write(binaryOut);
            dataOutputStream.flush();
        } catch (TException e) {
            throw new IOException(e);
        }
    }

    /**
     * Write the offset to the file
     *
     * @param offset
     * @throws IOException
     */
    public void writeOffset(long offset) throws IOException {
        dataOutputStream.writeLong(offset);
    }

    /**
     * Close the file stream.
     */
    public void close() {
        CarbonUtil.closeStreams(dataOutputStream);
    }

    /**
     * Flush data to HDFS file
     */
    public void sync() throws IOException {
        if (dataOutputStream instanceof FSDataOutputStream) {
            ((FSDataOutputStream) dataOutputStream).hsync();
        }
    }
}