How to use

getCurrentBuf

method

in

org.apache.hadoop.hdfs.server.namenode.EditsDoubleBuffer

/**
 * Create empty edits logs file.
 */
@Override
public void create(int layoutVersion) throws IOException {
 fc.truncate(0);
 fc.position(0);
 writeHeader(layoutVersion, doubleBuf.getCurrentBuf());
 setReadyToFlush();
 flush();
}

/**
 * Create empty edits logs file.
 */
@Override
public void create(int layoutVersion) throws IOException {
 fc.truncate(0);
 fc.position(0);
 writeHeader(layoutVersion, doubleBuf.getCurrentBuf());
 setReadyToFlush();
 flush();
}

/**
 * Create empty edits logs file.
 */
@Override
public void create() throws IOException {
 fc.truncate(0);
 fc.position(0);
 doubleBuf.getCurrentBuf().writeInt(FSConstants.LAYOUT_VERSION);
 setReadyToFlush();
 flush();
}

/**
 * Create empty edits logs file.
 */
@Override
public void create(int layoutVersion) throws IOException {
 fc.truncate(0);
 fc.position(0);
 writeHeader(layoutVersion, doubleBuf.getCurrentBuf());
 setReadyToFlush();
 flush();
}

/**
 * All data that has been written to the stream so far will be flushed. New
 * data can be still written to the stream while flushing is performed.
 */
@Override
public void setReadyToFlush() throws IOException {
 doubleBuf.getCurrentBuf().write(FSEditLogOpCodes.OP_INVALID.getOpCode()); // insert eof marker
 doubleBuf.setReadyToFlush();
}