com.gemstone.gemfire.internal.shared.unsafe

Class ChannelBufferUnsafeOutputStream

java.lang.Object

java.io.OutputStream

com.gemstone.gemfire.internal.shared.OutputStreamChannel

com.gemstone.gemfire.internal.shared.unsafe.ChannelBufferUnsafeOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, Channel, WritableByteChannel

Direct Known Subclasses:

ChannelBufferUnsafeDataOutputStream

public class ChannelBufferUnsafeOutputStream
extends OutputStreamChannel

A somewhat more efficient implementation of ChannelBufferOutputStream using internal unsafe class (~30% in raw single byte write calls). Use this only when UnsafeHolder.getDirectByteBufferAddressMethod() returns non-null. Alternatively use UnsafeHolder.newChannelBufferOutputStream(java.nio.channels.WritableByteChannel, int) method to create either this or ChannelBufferOutputStream depending on availability.

NOTE: THIS CLASS IS NOT THREAD-SAFE BY DESIGN. IF IT IS USED CONCURRENTLY BY MULTIPLE THREADS THEN BAD THINGS CAN HAPPEN DUE TO UNSAFE MEMORY WRITES.

Note that the close() method of this class does not closing the underlying channel.

Since:

gfxd 1.1

Field Summary

Fields

Modifier and Type	Field and Description
protected long	addrLimit
protected long	addrPosition Actual buffer position (+baseAddress) accounting is done by this.
protected long	baseAddress
protected ByteBuffer	buffer
protected static int	MIN_BUFFER_SIZE Some minimum buffer size, particularly for longs and encoding UTF strings efficiently.
protected static sun.misc.Unsafe	unsafe

Fields inherited from class com.gemstone.gemfire.internal.shared.OutputStreamChannel

channel, PARK_NANOS, PARK_NANOS_MAX, parkedThread

Constructor Summary

Constructors

Constructor and Description
ChannelBufferUnsafeOutputStream(WritableByteChannel channel)
ChannelBufferUnsafeOutputStream(WritableByteChannel channel, int bufferSize)

Method Summary

Methods

Modifier and Type	Method and Description
protected ByteBuffer	allocateBuffer(int bufferSize)
void	close()
void	flush()
protected void	flushBufferBlocking(ByteBuffer buffer)
protected boolean	flushBufferNonBlocking(ByteBuffer buffer, boolean isChannelBuffer)
boolean	isOpen()
protected void	resetBufferPositions()
protected void	write_(byte[] b, int off, int len)
void	write(byte[] b)
void	write(byte[] b, int off, int len)
int	write(ByteBuffer src)
void	write(int b)

Methods inherited from class com.gemstone.gemfire.internal.shared.OutputStreamChannel

getParkedThread, getUnderlyingChannel, writeBuffer, writeBuffered, writeBufferNonBlocking

Methods inherited from class java.lang.Object

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

Field Detail

buffer

protected final ByteBuffer buffer

baseAddress

protected final long baseAddress

addrPosition

protected long addrPosition

Actual buffer position (+baseAddress) accounting is done by this. Buffer position is adjusted during refill and other places where required using this.

addrLimit

protected long addrLimit

unsafe

protected static final sun.misc.Unsafe unsafe

MIN_BUFFER_SIZE

protected static final int MIN_BUFFER_SIZE

Some minimum buffer size, particularly for longs and encoding UTF strings efficiently. If reducing this, then consider the logic in ChannelBufferUnsafeDataOutputStream.writeUTF(String) carefully.

See Also:

Constant Field Values

Constructor Detail

ChannelBufferUnsafeOutputStream

public ChannelBufferUnsafeOutputStream(WritableByteChannel channel)
                                throws IOException

Throws:

IOException

ChannelBufferUnsafeOutputStream

public ChannelBufferUnsafeOutputStream(WritableByteChannel channel,
                               int bufferSize)
                                throws IOException

Throws:

IOException

Method Detail

resetBufferPositions

protected final void resetBufferPositions()

allocateBuffer

protected ByteBuffer allocateBuffer(int bufferSize)

write

public final void write(int b)
                 throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write_

protected final void write_(byte[] b,
          int off,
          int len)
                     throws IOException

Throws:

IOException

write

public final void write(byte[] b)
                 throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

write

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

Overrides:

write in class OutputStream

Throws:

IOException

write

public final int write(ByteBuffer src)
                throws IOException

Specified by:

write in interface WritableByteChannel

Specified by:

write in class OutputStreamChannel

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException

isOpen

public final boolean isOpen()

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Overrides:

close in class OutputStream

Throws:

IOException

flushBufferBlocking

protected void flushBufferBlocking(ByteBuffer buffer)
                            throws IOException

Throws:

IOException

flushBufferNonBlocking

protected boolean flushBufferNonBlocking(ByteBuffer buffer,
                             boolean isChannelBuffer)
                                  throws IOException

Overrides:

flushBufferNonBlocking in class OutputStreamChannel

Throws:

IOException