Package org.apache.hadoop.hbase.io

Class ByteBufferWriterOutputStream

java.lang.Object

java.io.OutputStream

org.apache.hadoop.hbase.io.ByteBufferWriterOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, ByteBufferWriter

@Private
public class ByteBufferWriterOutputStream
extends OutputStream
implements ByteBufferWriter

When deal with OutputStream which is not ByteBufferWriter type, wrap it with this class. We will have to write offheap ByteBuffer (DBB) data into the OS. This class is having a temp byte array to which we can copy the DBB data for writing to the OS.
This is used while writing Cell data to WAL. In case of AsyncWAL, the OS created there is ByteBufferWriter. But in case of FSHLog, the OS passed by DFS client, is not of type ByteBufferWriter. We will need this temp solution until DFS client supports writing ByteBuffer directly to the OS it creates.
Note: This class is not thread safe.

Field Summary

Fields

Modifier and Type	Field	Description
private byte[]	buf
private final int	bufSize
private static final int	DEFAULT_BUFFER_SIZE
private final OutputStream	os

Constructor Summary

Constructors

Constructor	Description
ByteBufferWriterOutputStream(OutputStream os)
ByteBufferWriterOutputStream(OutputStream os, int size)

Method Summary

Modifier and Type	Method	Description
void	close()
void	flush()
void	write(byte[] b, int off, int len)
void	write(int b)
void	write(ByteBuffer b, int off, int len)	Writes len bytes from the specified ByteBuffer starting at offset off to this OutputStream.
void	writeInt(int i)	Writes an int to the underlying output stream as four bytes, high byte first.

Methods inherited from class java.io.OutputStream

nullOutputStream, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_BUFFER_SIZE

private static final int DEFAULT_BUFFER_SIZE

See Also:

• Constant Field Values

os

private final OutputStream os

bufSize

private final int bufSize

buf

private byte[] buf

Constructor Details

ByteBufferWriterOutputStream

public ByteBufferWriterOutputStream(OutputStream os)

ByteBufferWriterOutputStream

public ByteBufferWriterOutputStream(OutputStream os,
 int size)

Method Details

write

public void write(ByteBuffer b,
 int off,
 int len)
           throws IOException

Writes len bytes from the specified ByteBuffer starting at offset off to this OutputStream. If off is negative or larger than the ByteBuffer then an ArrayIndexOutOfBoundsException is thrown. If len is greater than the length of the ByteBuffer, then an ArrayIndexOutOfBoundsException is thrown. This method does not change the position of the ByteBuffer.

Specified by:

write in interface ByteBufferWriter

Parameters:

b - the ByteBuffer

off - the start offset in the data

len - the number of bytes to write

Throws:

IOException - if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed.

NullPointerException - if b is null

writeInt

public void writeInt(int i)
              throws IOException

Description copied from interface: ByteBufferWriter

Writes an int to the underlying output stream as four bytes, high byte first.

Specified by:

writeInt in interface ByteBufferWriter

Parameters:

i - the int to write

Throws:

IOException - if an I/O error occurs.

write

public void write(int b)
           throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write

public void write(byte[] b,
 int off,
 int len)
           throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException