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:

StreamChannel, java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable, java.nio.channels.Channel, java.nio.channels.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 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 close 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 java.nio.ByteBuffer	buffer
protected static int	MIN_BUFFER_SIZE Some minimum buffer size, particularly for longs and encoding UTF strings efficiently.

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

bytesWritten, channel

Constructor Summary

Constructors

Constructor and Description
ChannelBufferUnsafeOutputStream(java.nio.channels.WritableByteChannel channel)
ChannelBufferUnsafeOutputStream(java.nio.channels.WritableByteChannel channel, int bufferSize)

Method Summary

Modifier and Type	Method and Description
protected long	allocateBuffer(int bufferSize)
void	close()
void	closeChannel() Close the underlying channel in addition to flushing/clearing the buffer.
void	flush()
protected void	flushBufferBlocking(java.nio.ByteBuffer buffer)
java.nio.ByteBuffer	getInternalBuffer() Get handle to the underlying ByteBuffer.
boolean	isOpen()
int	position()
protected void	putByte(byte b)
protected static long	putInt(long addrPos, int v) Write an integer in big-endian format on given off-heap address.
protected void	releaseBuffer()
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(java.nio.ByteBuffer src)
void	write(int b)
void	writeInt(int v) Writes an int value, which is comprised of four bytes, to the output stream in big-endian format compatible with DataOutput.writeInt(int).

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

flushBufferNonBlockingBase, getBytesWritten, getParkedThread, getParkNanosMax, getUnderlyingChannel, isSocketToSameHost, setParkedThread, writeBuffer, writeBuffered, writeBufferNoWait

Methods inherited from class java.lang.Object

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

Field Detail

buffer

protected java.nio.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

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(java.nio.channels.WritableByteChannel channel)

ChannelBufferUnsafeOutputStream

public ChannelBufferUnsafeOutputStream(java.nio.channels.WritableByteChannel channel,
                                       int bufferSize)

Method Detail

getInternalBuffer

public java.nio.ByteBuffer getInternalBuffer()

Get handle to the underlying ByteBuffer. ONLY TO BE USED BY TESTS.

resetBufferPositions

protected final void resetBufferPositions()

allocateBuffer

protected long allocateBuffer(int bufferSize)

write

public final void write(int b)
                 throws java.io.IOException

Specified by:

write in class java.io.OutputStream

Throws:

java.io.IOException

write_

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

Throws:

java.io.IOException

write

public final void write(@Nonnull
                        byte[] b)
                 throws java.io.IOException

Overrides:

write in class java.io.OutputStream

Throws:

java.io.IOException

putByte

protected final void putByte(byte b)
                      throws java.io.IOException

Throws:

java.io.IOException

write

public final void write(@Nonnull
                        byte[] b,
                        int off,
                        int len)
                 throws java.io.IOException

Overrides:

write in class java.io.OutputStream

Throws:

java.io.IOException

write

public final int write(java.nio.ByteBuffer src)
                throws java.io.IOException

Specified by:

write in interface java.nio.channels.WritableByteChannel

Specified by:

write in class OutputStreamChannel

Throws:

java.io.IOException

writeInt

public final void writeInt(int v)
                    throws java.io.IOException

Writes an int value, which is comprised of four bytes, to the output stream in big-endian format compatible with DataOutput.writeInt(int).

Specified by:

writeInt in class OutputStreamChannel

Parameters:

v - the int value to be written.

Throws:

java.io.IOException - if an I/O error occurs.

See Also:

DataOutput.writeInt(int)

position

public final int position()

flush

public void flush()
           throws java.io.IOException

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.OutputStream

Throws:

java.io.IOException

isOpen

public final boolean isOpen()

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.nio.channels.Channel

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException

releaseBuffer

protected final void releaseBuffer()

closeChannel

public void closeChannel()
                  throws java.io.IOException

Close the underlying channel in addition to flushing/clearing the buffer.

Throws:

java.io.IOException

flushBufferBlocking

protected void flushBufferBlocking(java.nio.ByteBuffer buffer)
                            throws java.io.IOException

Throws:

java.io.IOException

putInt

protected static long putInt(long addrPos,
                             int v)

Write an integer in big-endian format on given off-heap address.