public class DirectChannelBufferFactory extends AbstractChannelBufferFactory
ChannelBufferFactory which pre-allocates a large chunk of direct
buffer and returns its slice on demand. Direct buffers are reclaimed via
ReferenceQueue in most JDK implementations, and therefore they are
deallocated less efficiently than an ordinary heap buffer. Consequently,
a user will get OutOfMemoryError when one tries to allocate small
direct buffers more often than the GC throughput of direct buffers, which
is much lower than the GC throughput of heap buffers. This factory avoids
this problem by allocating a large chunk of pre-allocated direct buffer and
reducing the number of the garbage collected internal direct buffer objects.| Modifier and Type | Field and Description |
|---|---|
private java.lang.Object |
bigEndianLock |
private static DirectChannelBufferFactory |
INSTANCE_BE |
private static DirectChannelBufferFactory |
INSTANCE_LE |
private java.lang.Object |
littleEndianLock |
private ChannelBuffer |
preallocatedBEBuf |
private int |
preallocatedBEBufPos |
private int |
preallocatedBufCapacity |
private ChannelBuffer |
preallocatedLEBuf |
private int |
preallocatedLEBufPos |
| Constructor and Description |
|---|
DirectChannelBufferFactory()
Creates a new factory whose default
ByteOrder is
ByteOrder.BIG_ENDIAN. |
DirectChannelBufferFactory(java.nio.ByteOrder defaultOrder)
Creates a new factory with the specified default
ByteOrder. |
DirectChannelBufferFactory(java.nio.ByteOrder defaultOrder,
int preallocatedBufferCapacity)
Creates a new factory with the specified default
ByteOrder. |
DirectChannelBufferFactory(int preallocatedBufferCapacity)
Creates a new factory whose default
ByteOrder is
ByteOrder.BIG_ENDIAN. |
| Modifier and Type | Method and Description |
|---|---|
private ChannelBuffer |
allocateBigEndianBuffer(int capacity) |
private ChannelBuffer |
allocateLittleEndianBuffer(int capacity) |
ChannelBuffer |
getBuffer(java.nio.ByteBuffer nioBuffer)
Returns a
ChannelBuffer whose content is equal to the sub-region
of the specified nioBuffer. |
ChannelBuffer |
getBuffer(java.nio.ByteOrder order,
byte[] array,
int offset,
int length)
Returns a
ChannelBuffer whose content is equal to the sub-region
of the specified array. |
ChannelBuffer |
getBuffer(java.nio.ByteOrder order,
int capacity)
|
static ChannelBufferFactory |
getInstance() |
static ChannelBufferFactory |
getInstance(java.nio.ByteOrder defaultEndianness) |
getBuffer, getBuffer, getDefaultOrderprivate static final DirectChannelBufferFactory INSTANCE_BE
private static final DirectChannelBufferFactory INSTANCE_LE
private final java.lang.Object bigEndianLock
private final java.lang.Object littleEndianLock
private final int preallocatedBufCapacity
private ChannelBuffer preallocatedBEBuf
private int preallocatedBEBufPos
private ChannelBuffer preallocatedLEBuf
private int preallocatedLEBufPos
public DirectChannelBufferFactory()
ByteOrder is
ByteOrder.BIG_ENDIAN.public DirectChannelBufferFactory(int preallocatedBufferCapacity)
ByteOrder is
ByteOrder.BIG_ENDIAN.public DirectChannelBufferFactory(java.nio.ByteOrder defaultOrder)
ByteOrder.defaultOrder - the default ByteOrder of this factorypublic DirectChannelBufferFactory(java.nio.ByteOrder defaultOrder,
int preallocatedBufferCapacity)
ByteOrder.defaultOrder - the default ByteOrder of this factorypublic static ChannelBufferFactory getInstance()
public static ChannelBufferFactory getInstance(java.nio.ByteOrder defaultEndianness)
public ChannelBuffer getBuffer(java.nio.ByteOrder order, int capacity)
ChannelBufferFactoryorder - the endianness of the returned ChannelBuffercapacity - the capacity of the returned ChannelBufferChannelBuffer with the specified endianness and
capacity, whose readerIndex and writerIndex
are 0public ChannelBuffer getBuffer(java.nio.ByteOrder order, byte[] array, int offset, int length)
ChannelBufferFactoryChannelBuffer whose content is equal to the sub-region
of the specified array. Depending on the factory implementation,
the returned buffer could wrap the array or create a new copy of
the array.order - the endianness of the returned ChannelBufferarray - the byte arrayoffset - the offset of the byte arraylength - the length of the byte arrayChannelBuffer with the specified content,
whose readerIndex and writerIndex
are 0 and (length - offset) respectivelypublic ChannelBuffer getBuffer(java.nio.ByteBuffer nioBuffer)
ChannelBufferFactoryChannelBuffer whose content is equal to the sub-region
of the specified nioBuffer. Depending on the factory
implementation, the returned buffer could wrap the nioBuffer or
create a new copy of the nioBuffer.nioBuffer - the NIO ByteBufferChannelBuffer with the specified content,
whose readerIndex and writerIndex
are 0 and nioBuffer.remaining() respectivelyprivate ChannelBuffer allocateBigEndianBuffer(int capacity)
private ChannelBuffer allocateLittleEndianBuffer(int capacity)