Package com.orientechnologies.common.directmemory

Class OByteBufferPool

java.lang.Object

com.orientechnologies.common.directmemory.OByteBufferPool

All Implemented Interfaces:

OByteBufferPoolMXBean

public final class OByteBufferPool
extends Object
implements OByteBufferPoolMXBean

Object of this class works at the same time as factory for DirectByteBuffer objects and pool for DirectByteBuffer objects which were used and now are free to be reused by other parts of the code. All DirectByteBuffer objects have the same size which is specified in objects constructor as "page size".

See Also:

• ODirectMemoryAllocator

Constructor Summary

Constructors

Constructor	Description
OByteBufferPool(int pageSize)
OByteBufferPool(int pageSize, ODirectMemoryAllocator allocator, int poolSize)

Method Summary

Modifier and Type	Method	Description
final OPointer	acquireDirect(boolean clear, MemTrace intention)	Acquires direct memory buffer with native byte order.
void	checkMemoryLeaks()	Checks whether there are not released buffers in the pool
void	clear()	Clears pool and dealocates memory.
final int	getPoolSize()
static OByteBufferPool	instance(OContextConfiguration contextConfiguration)
final void	release(OPointer pointer)	Put buffer which is not used any more back to the pool or frees direct memory if pool is full.

Methods inherited from class java.lang.Object

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

Constructor Details

OByteBufferPool

public OByteBufferPool(int pageSize)

Parameters:

pageSize - Size of single page (instance of DirectByteBuffer) returned by pool.

OByteBufferPool

public OByteBufferPool(int pageSize,
 ODirectMemoryAllocator allocator,
 int poolSize)

Parameters:

allocator - Direct memory allocator to use.

pageSize - Size of single page (instance of DirectByteBuffer) returned by pool.

poolSize - Size of the page pool

Method Details

instance

public static OByteBufferPool instance(OContextConfiguration contextConfiguration)

Returns:

Singleton instance

acquireDirect

public final OPointer acquireDirect(boolean clear,
 MemTrace intention)

Acquires direct memory buffer with native byte order. If there is free (already released) direct memory page we reuse it, otherwise new memory chunk is allocated from direct memory.

Parameters:

clear - Whether returned buffer should be filled with zeros before return.

intention - Why this memory is allocated. This parameter is used for memory profiling.

Returns:

Direct memory buffer instance.

release

public final void release(OPointer pointer)

Put buffer which is not used any more back to the pool or frees direct memory if pool is full.

Parameters:

pointer - Not used instance of buffer.

See Also:

• OGlobalConfiguration.DIRECT_MEMORY_POOL_LIMIT

getPoolSize

public final int getPoolSize()

Specified by:

getPoolSize in interface OByteBufferPoolMXBean

Returns:

Current size of the memory pool

checkMemoryLeaks

public void checkMemoryLeaks()

Checks whether there are not released buffers in the pool

clear

public void clear()

Clears pool and dealocates memory.