com.gemstone.gemfire.internal.shared.unsafe

Class ChannelBufferUnsafeInputStream

java.lang.Object

java.io.InputStream

com.gemstone.gemfire.internal.shared.InputStreamChannel

com.gemstone.gemfire.internal.shared.unsafe.ChannelBufferUnsafeInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, Channel, ReadableByteChannel

Direct Known Subclasses:

ChannelBufferUnsafeDataInputStream

public class ChannelBufferUnsafeInputStream
extends InputStreamChannel

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

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 sun.misc.Unsafe	unsafe

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

channel, PARK_NANOS, PARK_NANOS_MAX, parkedThread

Constructor Summary

Constructors

Constructor and Description
ChannelBufferUnsafeInputStream(ReadableByteChannel channel)
ChannelBufferUnsafeInputStream(ReadableByteChannel channel, int bufferSize)

Method Summary

Methods

Modifier and Type	Method and Description
protected ByteBuffer	allocateBuffer(int bufferSize)
int	available()
void	close()
protected int	getInt(long addrPos)
boolean	isOpen()
int	read()
int	read(byte[] buf)
int	read(byte[] buf, int off, int len) /**
int	read(ByteBuffer dst)
int	readInt() Reads four input bytes and returns an int value.
protected int	refillBuffer(ByteBuffer channelBuffer, int tryReadBytes, String eofMessage)
protected void	resetBufferPositions()

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

getParkedThread, getUnderlyingChannel, readBuffered, readFrame, readFrameFragment, readIntoBuffer, readIntoBufferNonBlocking, resetAndCopyLeftOverBytes

Methods inherited from class java.io.InputStream

mark, markSupported, reset, skip

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

Constructor Detail

ChannelBufferUnsafeInputStream

public ChannelBufferUnsafeInputStream(ReadableByteChannel channel)
                               throws IOException

Throws:

IOException

ChannelBufferUnsafeInputStream

public ChannelBufferUnsafeInputStream(ReadableByteChannel channel,
                              int bufferSize)
                               throws IOException

Throws:

IOException

Method Detail

resetBufferPositions

protected final void resetBufferPositions()

allocateBuffer

protected ByteBuffer allocateBuffer(int bufferSize)

read

public final int read()
               throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public final int read(byte[] buf)
               throws IOException

Overrides:

read in class InputStream

Throws:

IOException

read

public final int read(ByteBuffer dst)
               throws IOException

Specified by:

read in interface ReadableByteChannel

Specified by:

read in class InputStreamChannel

Throws:

IOException

read

public final int read(byte[] buf,
       int off,
       int len)
               throws IOException

/**

Overrides:

read in class InputStream

Throws:

IOException

readInt

public final int readInt()
                  throws IOException

Reads four input bytes and returns an int value. Let a-d be the first through fourth bytes read. The value returned is:

 
 (((a & 0xff) << 24) | ((b & 0xff) << 16) |
  ((c & 0xff) << 8) | (d & 0xff))
 
 

This method is suitable for reading bytes written by the writeInt method of interface DataOutput.

Specified by:

readInt in class InputStreamChannel

Returns:

the int value read.

Throws:

EOFException - if this stream reaches the end before reading all the bytes.

IOException - if an I/O error occurs.

getInt

protected final int getInt(long addrPos)

available

public final int available()
                    throws IOException

Overrides:

available in class InputStream

Throws:

IOException

refillBuffer

protected int refillBuffer(ByteBuffer channelBuffer,
               int tryReadBytes,
               String eofMessage)
                    throws IOException

Overrides:

refillBuffer in class InputStreamChannel

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 InputStream

Throws:

IOException