Module org.glassfish.grizzly

Package org.glassfish.grizzly.memory

Class ByteBufferManager

java.lang.Object

org.glassfish.grizzly.memory.AbstractMemoryManager<ByteBufferWrapper>

org.glassfish.grizzly.memory.ByteBufferManager

All Implemented Interfaces:

ByteBufferAware, MemoryManager<ByteBufferWrapper>, ThreadLocalPoolProvider, WrapperAware, MonitoringAware<MemoryProbe>

public class ByteBufferManager
extends AbstractMemoryManager<ByteBufferWrapper>
implements WrapperAware, ByteBufferAware

The simple Buffer manager implementation, which works as wrapper above ByteBuffers. It's possible to work either with direct or heap ByteBuffers.

Author:

Jean-Francois Arcand, Alexey Stashok

See Also:

• MemoryManager
• ByteBuffer

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected final class	ByteBufferManager.SmallByteBufferWrapper	ByteBufferWrapper implementation, which supports trimming.

Nested classes/interfaces inherited from class org.glassfish.grizzly.memory.AbstractMemoryManager

AbstractMemoryManager.TrimAware

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_SMALL_BUFFER_SIZE	TODO: Document
protected boolean	isDirect	Is direct ByteBuffer should be used?
protected final int	maxSmallBufferSize

Fields inherited from class org.glassfish.grizzly.memory.AbstractMemoryManager

DEFAULT_MAX_BUFFER_SIZE, maxBufferSize, monitoringConfig

Fields inherited from interface org.glassfish.grizzly.memory.MemoryManager

DEFAULT_MEMORY_MANAGER

Constructor Summary

Constructors

Constructor	Description
ByteBufferManager()
ByteBufferManager(boolean isDirect)
ByteBufferManager(boolean isDirect, int maxBufferSize, int maxSmallBufferSize)

Method Summary

Modifier and Type	Method	Description
ByteBufferWrapper	allocate(int size)	Allocated Buffer of the required size.
ByteBufferWrapper	allocateAtLeast(int size)	Allocated Buffer at least of the provided size.
ByteBuffer	allocateByteBuffer(int size)	Allocates ByteBuffer of required size.
protected final ByteBuffer	allocateByteBuffer0(int size)
ByteBuffer	allocateByteBufferAtLeast(int size)	Allocates ByteBuffer of required size.
protected Object	createJmxManagementObject()	Create the Memory Manager JMX management object.
protected ByteBufferManager.SmallByteBufferWrapper	createSmallBuffer()
ThreadLocalPool	createThreadLocalPool()
int	getMaxSmallBufferSize()
MonitoringConfig<MemoryProbe>	getMonitoringConfig()	Return the object associated MonitoringConfig.
boolean	isDirect()	Returns true, if ByteBufferManager works with direct ByteBuffers, or false otherwise.
ByteBufferWrapper	reallocate(ByteBufferWrapper oldBuffer, int newSize)	Reallocate Buffer to a required size.
ByteBuffer	reallocateByteBuffer(ByteBuffer oldByteBuffer, int newSize)
void	release(ByteBufferWrapper buffer)	Lets JVM Garbage collector to release buffer.
void	releaseByteBuffer(ByteBuffer byteBuffer)
void	setDirect(boolean isDirect)	Set true, if ByteBufferManager works with direct ByteBuffers, or false otherwise.
boolean	willAllocateDirect(int size)	Return true if next MemoryManager.allocate(int) or MemoryManager.allocateAtLeast(int) call, made in the current thread for the given memory size, going to return a Buffer based on direct ByteBuffer, or false otherwise.
ByteBufferWrapper	wrap(byte[] data)	Returns Buffer, which wraps the byte array.
ByteBufferWrapper	wrap(byte[] data, int offset, int length)	Returns Buffer, which wraps the part of byte array with specific offset and length.
ByteBufferWrapper	wrap(String s)	Returns Buffer, which wraps the String.
ByteBufferWrapper	wrap(String s, Charset charset)	Returns Buffer, which wraps the String with the specific Charset.
ByteBufferWrapper	wrap(ByteBuffer byteBuffer)	Returns Buffer, which wraps the ByteBuffer.

Methods inherited from class org.glassfish.grizzly.memory.AbstractMemoryManager

allocateFromPool, getMaxBufferSize, getReadyThreadBufferSize, getThreadLocalPool

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_SMALL_BUFFER_SIZE

public static final int DEFAULT_SMALL_BUFFER_SIZE

TODO: Document

See Also:

• Constant Field Values

isDirect

protected boolean isDirect

Is direct ByteBuffer should be used?

maxSmallBufferSize

protected final int maxSmallBufferSize

Constructor Details

ByteBufferManager

public ByteBufferManager()

ByteBufferManager

public ByteBufferManager(boolean isDirect)

ByteBufferManager

public ByteBufferManager(boolean isDirect,
 int maxBufferSize,
 int maxSmallBufferSize)

Method Details

getMaxSmallBufferSize

public int getMaxSmallBufferSize()

allocate

public ByteBufferWrapper allocate(int size)

Allocated Buffer of the required size.

Specified by:

allocate in interface MemoryManager<ByteBufferWrapper>

Parameters:

size - Buffer size to be allocated.

Returns:

allocated Buffer.

allocateAtLeast

public ByteBufferWrapper allocateAtLeast(int size)

Allocated Buffer at least of the provided size. This could be useful for usecases like Socket.read(...), where we're not sure how many bytes are available, but want to read as much as possible.

Specified by:

allocateAtLeast in interface MemoryManager<ByteBufferWrapper>

Parameters:

size - the min Buffer size to be allocated.

Returns:

allocated Buffer.

reallocate

public ByteBufferWrapper reallocate(ByteBufferWrapper oldBuffer,
 int newSize)

Reallocate Buffer to a required size. Implementation may choose the way, how reallocation could be done, either by allocating new Buffer of required size and copying old Buffer content there, or perform more complex logic related to memory pooling etc.

Specified by:

reallocate in interface MemoryManager<ByteBufferWrapper>

Parameters:

oldBuffer - old Buffer to be reallocated.

newSize - new Buffer required size.

Returns:

reallocated Buffer.

release

public void release(ByteBufferWrapper buffer)

Lets JVM Garbage collector to release buffer.

Specified by:

release in interface MemoryManager<ByteBufferWrapper>

Parameters:

buffer - Buffer to be released.

isDirect

public boolean isDirect()

Returns true, if ByteBufferManager works with direct ByteBuffers, or false otherwise.

Returns:

true, if ByteBufferManager works with direct ByteBuffers, or false otherwise.

setDirect

public void setDirect(boolean isDirect)

Set true, if ByteBufferManager works with direct ByteBuffers, or false otherwise.

Parameters:

isDirect - true, if ByteBufferManager works with direct ByteBuffers, or false otherwise.

willAllocateDirect

public boolean willAllocateDirect(int size)

Return true if next MemoryManager.allocate(int) or MemoryManager.allocateAtLeast(int) call, made in the current thread for the given memory size, going to return a Buffer based on direct ByteBuffer, or false otherwise.

Specified by:

willAllocateDirect in interface MemoryManager<ByteBufferWrapper>

Returns:

wrap

public ByteBufferWrapper wrap(byte[] data)

Returns Buffer, which wraps the byte array.

Specified by:

wrap in interface WrapperAware

Parameters:

data - byte array to wrap

Returns:

Buffer wrapper on top of passed byte array.

wrap

public ByteBufferWrapper wrap(byte[] data,
 int offset,
 int length)

Returns Buffer, which wraps the part of byte array with specific offset and length.

Specified by:

wrap in interface WrapperAware

Parameters:

data - byte array to wrap

offset - byte buffer offset

length - byte buffer length

Returns:

Buffer wrapper on top of passed byte array.

wrap

public ByteBufferWrapper wrap(String s)

Returns Buffer, which wraps the String.

Specified by:

wrap in interface WrapperAware

Parameters:

s - String

Returns:

Buffer wrapper on top of passed String.

wrap

public ByteBufferWrapper wrap(String s,
 Charset charset)

Returns Buffer, which wraps the String with the specific Charset.

Specified by:

wrap in interface WrapperAware

Parameters:

s - String

charset - Charset, which will be used, when converting String to byte array.

Returns:

Buffer wrapper on top of passed String.

createThreadLocalPool

public ThreadLocalPool createThreadLocalPool()

Specified by:

createThreadLocalPool in interface ThreadLocalPoolProvider

Returns:

a new ThreadLocalPool implementation. This method must return a new ThreadLocalPool instance per invocation.

wrap

public ByteBufferWrapper wrap(ByteBuffer byteBuffer)

Returns Buffer, which wraps the ByteBuffer.

Specified by:

wrap in interface WrapperAware

Parameters:

byteBuffer - ByteBuffer to wrap

Returns:

Buffer wrapper on top of passed ByteBuffer.

allocateByteBuffer

public ByteBuffer allocateByteBuffer(int size)

Allocates ByteBuffer of required size.

Specified by:

allocateByteBuffer in interface ByteBufferAware

Parameters:

size - ByteBuffer size.

Returns:

allocated ByteBuffer.

allocateByteBufferAtLeast

public ByteBuffer allocateByteBufferAtLeast(int size)

Allocates ByteBuffer of required size.

Specified by:

allocateByteBufferAtLeast in interface ByteBufferAware

Parameters:

size - ByteBuffer size.

Returns:

allocated ByteBuffer.

reallocateByteBuffer

public ByteBuffer reallocateByteBuffer(ByteBuffer oldByteBuffer,
 int newSize)

Specified by:

reallocateByteBuffer in interface ByteBufferAware

releaseByteBuffer

public void releaseByteBuffer(ByteBuffer byteBuffer)

Specified by:

releaseByteBuffer in interface ByteBufferAware

createSmallBuffer

protected ByteBufferManager.SmallByteBufferWrapper createSmallBuffer()

getMonitoringConfig

public MonitoringConfig<MemoryProbe> getMonitoringConfig()

Description copied from interface: MonitoringAware

Return the object associated MonitoringConfig.

Specified by:

getMonitoringConfig in interface MonitoringAware<MemoryProbe>

Returns:

the object associated MonitoringConfig.

createJmxManagementObject

protected Object createJmxManagementObject()

Create the Memory Manager JMX management object.

Specified by:

createJmxManagementObject in class AbstractMemoryManager<ByteBufferWrapper>

Returns:

the Memory Manager JMX management object.

allocateByteBuffer0

protected final ByteBuffer allocateByteBuffer0(int size)