Modifier and Type	Class and Description
private static class	Util.BufferCache A simple cache of direct buffers.

Field Summary

Modifier and Type	Field and Description
private static final TerminatingThreadLocal<Util.BufferCache>	bufferCache
private static volatile Constructor<?>	directByteBufferConstructor
private static volatile Constructor<?>	directByteBufferRConstructor
private static final long	MAX_CACHED_BUFFER_SIZE
private static final JavaNioAccess	NIO_ACCESS
private static int	pageSize
private static final int	TEMP_BUF_POOL_SIZE
private static final Unsafe	unsafe

Constructor Summary

Access	Constructor and Description
public	Util()

Method Summary

Modifier and Type	Method and Description
private static byte	_get(long a)
private static void	_put(long a, byte b)
pack-priv static void	checkBufferPositionAligned(ByteBuffer bb, int pos, int alignment)
pack-priv static void	checkChannelPositionAligned(long position, int alignment)
pack-priv static void	checkRemainingBufferSizeAligned(int rem, int alignment)
pack-priv static void	erase(ByteBuffer bb)
private static void	free(ByteBuffer buf) Frees the memory for the given direct buffer
private static long	getMaxCachedBufferSize() Returns the max size allowed for a cached temp buffers, in bytes.
public static ByteBuffer	getTemporaryAlignedDirectBuffer(int size, int alignment) Returns a temporary buffer of at least the given size and aligned to the alignment
public static ByteBuffer	getTemporaryDirectBuffer(int size) Returns a temporary buffer of at least the given size
private static void	initDBBConstructor()
private static void	initDBBRConstructor()
private static boolean	isBufferTooLarge(int size) Returns true if a buffer of this size is too large to be added to the buffer cache, false otherwise.
private static boolean	isBufferTooLarge(ByteBuffer buf) Returns true if the buffer is too large to be added to the buffer cache, false otherwise.
pack-priv static MappedByteBuffer	newMappedByteBuffer(int size, long addr, FileDescriptor fd, Runnable unmapper, boolean isSync)
pack-priv static MappedByteBuffer	newMappedByteBufferR(int size, long addr, FileDescriptor fd, Runnable unmapper, boolean isSync)
pack-priv static void	offerFirstTemporaryDirectBuffer(ByteBuffer buf) Releases a temporary buffer by returning to the cache or freeing it.
pack-priv static void	offerLastTemporaryDirectBuffer(ByteBuffer buf) Releases a temporary buffer by returning to the cache or freeing it.
pack-priv static int	pageSize()
public static void	releaseTemporaryDirectBuffer(ByteBuffer buf) Releases a temporary buffer by returning to the cache or freeing it.
pack-priv static ByteBuffer[]	subsequence(ByteBuffer[] bs, int offset, int length)
pack-priv static <E> Set<E>	ungrowableSet(final Set<E> s)
pack-priv static Unsafe	unsafe()
private static ByteBuffer	unwrapIfAlignedSlice(ByteBuffer buf) Return the underling byte buffer if the given byte buffer is an aligned slice.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

bufferCache	back to summary
private static final TerminatingThreadLocal<Util.BufferCache> bufferCache

directByteBufferConstructor	back to summary
private static volatile Constructor<?> directByteBufferConstructor

directByteBufferRConstructor	back to summary
private static volatile Constructor<?> directByteBufferRConstructor

MAX_CACHED_BUFFER_SIZE	back to summary
private static final long MAX_CACHED_BUFFER_SIZE

NIO_ACCESS	back to summary
private static final JavaNioAccess NIO_ACCESS

pageSize	back to summary
private static int pageSize

TEMP_BUF_POOL_SIZE	back to summary
private static final int TEMP_BUF_POOL_SIZE

unsafe	back to summary
private static final Unsafe unsafe

Constructor Detail

Util	back to summary
public Util()

Method Detail

_get	back to summary
private static byte _get(long a)

_put	back to summary
private static void _put(long a, byte b)

checkBufferPositionAligned	back to summary
pack-priv static void checkBufferPositionAligned(ByteBuffer bb, int pos, int alignment) throws IOException

checkChannelPositionAligned	back to summary
pack-priv static void checkChannelPositionAligned(long position, int alignment) throws IOException

checkRemainingBufferSizeAligned	back to summary
pack-priv static void checkRemainingBufferSizeAligned(int rem, int alignment) throws IOException

erase	back to summary
pack-priv static void erase(ByteBuffer bb)

free	back to summary
private static void free(ByteBuffer buf) Frees the memory for the given direct buffer

getMaxCachedBufferSize	back to summary
private static long getMaxCachedBufferSize() Returns the max size allowed for a cached temp buffers, in bytes. It defaults to Long.MAX_VALUE. It can be set with the jdk.nio.maxCachedBufferSize property. Even though ByteBuffer.capacity() returns an int, we're using a long here for potential future-proofing.

getTemporaryAlignedDirectBuffer	back to summary
public static ByteBuffer getTemporaryAlignedDirectBuffer(int size, int alignment) Returns a temporary buffer of at least the given size and aligned to the alignment

getTemporaryDirectBuffer	back to summary
public static ByteBuffer getTemporaryDirectBuffer(int size) Returns a temporary buffer of at least the given size

initDBBConstructor	back to summary
private static void initDBBConstructor()

initDBBRConstructor	back to summary
private static void initDBBRConstructor()

isBufferTooLarge	back to summary
private static boolean isBufferTooLarge(int size) Returns true if a buffer of this size is too large to be added to the buffer cache, false otherwise.

isBufferTooLarge	back to summary
private static boolean isBufferTooLarge(ByteBuffer buf) Returns true if the buffer is too large to be added to the buffer cache, false otherwise.

newMappedByteBuffer	back to summary
pack-priv static MappedByteBuffer newMappedByteBuffer(int size, long addr, FileDescriptor fd, Runnable unmapper, boolean isSync)

newMappedByteBufferR	back to summary
pack-priv static MappedByteBuffer newMappedByteBufferR(int size, long addr, FileDescriptor fd, Runnable unmapper, boolean isSync)

offerFirstTemporaryDirectBuffer	back to summary
pack-priv static void offerFirstTemporaryDirectBuffer(ByteBuffer buf) Releases a temporary buffer by returning to the cache or freeing it. If returning to the cache then insert it at the start so that it is likely to be returned by a subsequent call to getTemporaryDirectBuffer.

offerLastTemporaryDirectBuffer	back to summary
pack-priv static void offerLastTemporaryDirectBuffer(ByteBuffer buf) Releases a temporary buffer by returning to the cache or freeing it. If returning to the cache then insert it at the end. This makes it suitable for scatter/gather operations where the buffers are returned to cache in same order that they were obtained.

pageSize	back to summary
pack-priv static int pageSize()

releaseTemporaryDirectBuffer	back to summary
public static void releaseTemporaryDirectBuffer(ByteBuffer buf) Releases a temporary buffer by returning to the cache or freeing it.

subsequence	back to summary
pack-priv static ByteBuffer[] subsequence(ByteBuffer[] bs, int offset, int length)

ungrowableSet	back to summary
pack-priv static <E> Set<E> ungrowableSet(final Set<E> s)

unsafe	back to summary
pack-priv static Unsafe unsafe()

unwrapIfAlignedSlice	back to summary
private static ByteBuffer unwrapIfAlignedSlice(ByteBuffer buf) Return the underling byte buffer if the given byte buffer is an aligned slice.

sun.nio.ch back to summary

private Class Util.BufferCache

Class Inheritance

extends Object

java.lang.Object
sun.nio.ch.Util.BufferCache

A simple cache of direct buffers.

Field Summary

Modifier and Type	Field and Description
private final ByteBuffer[]	buffers
private int	count
private int	start

Constructor Summary

Access	Constructor and Description
pack-priv	BufferCache()

Method Summary

Modifier and Type	Method and Description
pack-priv ByteBuffer	get(int size) Removes and returns a buffer from the cache of at least the given size (or null if no suitable buffer is found).
pack-priv boolean	isEmpty()
private int	next(int i)
pack-priv boolean	offerFirst(ByteBuffer buf)
pack-priv boolean	offerLast(ByteBuffer buf)
pack-priv ByteBuffer	removeFirst()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

buffers	back to summary
private final ByteBuffer[] buffers

count	back to summary
private int count

start	back to summary
private int start

Constructor Detail

BufferCache	back to summary
pack-priv BufferCache()

Method Detail

get	back to summary
pack-priv ByteBuffer get(int size) Removes and returns a buffer from the cache of at least the given size (or null if no suitable buffer is found).

isEmpty	back to summary
pack-priv boolean isEmpty()

next	back to summary
private int next(int i)

offerFirst	back to summary
pack-priv boolean offerFirst(ByteBuffer buf)

offerLast	back to summary
pack-priv boolean offerLast(ByteBuffer buf)

removeFirst	back to summary
pack-priv ByteBuffer removeFirst()

public Class Util

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class Util.BufferCache

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail