org.xerial.snappy.pool

Class CachingBufferPool

java.lang.Object

org.xerial.snappy.pool.CachingBufferPool

All Implemented Interfaces:

BufferPool

public final class CachingBufferPool
extends java.lang.Object
implements BufferPool

A BufferPool implementation which caches values at fixed sizes.

Pooled instances are held as SoftReference to allow GC if necessary.

The current fixed sizes are calculated as follows:

• Values < 4KB return 4KB
• 4KB - 32KB to 2KB
• 32KB - 512KB to 16KB
• 512KB - 2MB to 128KB
• 2MB - 16MB to 512KB
• 16MB - 128MB to 4MB
• 128MB - 512MB to 16MB
• 512MB - 1.5 GB to 128MB
• Values > 1.5GB return Integer.MAX_VALUE

Method Summary

Modifier and Type	Method and Description
byte[]	allocateArray(int size) Returns a byte[] of size or greater length.
java.nio.ByteBuffer	allocateDirect(int size) Returns a direct ByteBuffer of size or greater capacity.
static BufferPool	getInstance() Returns instance of CachingBufferPool for using cached buffers.
void	releaseArray(byte[] buffer) Returns instance to pool for potential future reuse.
void	releaseDirect(java.nio.ByteBuffer buffer) Returns instance to pool for potential future reuse.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static BufferPool getInstance()

Returns instance of CachingBufferPool for using cached buffers.

Returns:

instance of CachingBufferPool for using cached buffers.

allocateArray

public byte[] allocateArray(int size)

Returns a byte[] of size or greater length.

Specified by:

allocateArray in interface BufferPool

Parameters:

size - The minimum size array required. Must be >= 0.

Returns:

A byte[] with length of at least size.

See Also:

BufferPool.releaseArray(byte[])

releaseArray

public void releaseArray(byte[] buffer)

Returns instance to pool for potential future reuse.

Must not be returned more than 1 time. Must not be used by caller after return.

Specified by:

releaseArray in interface BufferPool

Parameters:

buffer - Instance to return to pool. Must not be null. Must not be returned more than 1 time. Must not be used by caller after return.

allocateDirect

public java.nio.ByteBuffer allocateDirect(int size)

Returns a direct ByteBuffer of size or greater capacity.

Specified by:

allocateDirect in interface BufferPool

Parameters:

size - The minimum size buffer required. Must be >= 0.

Returns:

A ByteBuffer of size or greater capacity.

See Also:

BufferPool.releaseDirect(ByteBuffer), ByteBuffer.allocateDirect(int)

releaseDirect

public void releaseDirect(java.nio.ByteBuffer buffer)

Returns instance to pool for potential future reuse.

Must not be returned more than 1 time. Must not be used by caller after return.

Specified by:

releaseDirect in interface BufferPool

Parameters:

buffer - Instance to return to pool. Must not be null. Must not be returned more than 1 time. Must not be used by caller after return.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object