Package de.undercouch.bson4jackson.io

Class StaticBuffers

java.lang.Object

de.undercouch.bson4jackson.io.StaticBuffers

public class StaticBuffers
extends Object

Keeps thread-local re-usable buffers. Each buffer is identified by a key. This class is a singleton, whereas the reference to the instance is held in a SoftReference so buffers can be freed when they are not needed anymore.

See Also:

• BufferRecycler

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	StaticBuffers.Key	Possible buffer keys

Field Summary

Fields

Modifier and Type	Field	Description
protected ByteBuffer[]	_byteBuffers	Maps of already allocated re-usable buffers
protected CharBuffer[]	_charBuffers
protected static final ThreadLocal<SoftReference<StaticBuffers>>	_instance	A thread-local soft reference to the singleton instance of this class
static final int	GLOBAL_MIN_SIZE	All buffers have a minimum size of 64 kb

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	StaticBuffers()	Hidden constructor

Method Summary

Modifier and Type	Method	Description
ByteBuffer	byteBuffer(StaticBuffers.Key key, int minSize)	Creates or re-uses a ByteBuffer that has a minimum size.
CharBuffer	charBuffer(StaticBuffers.Key key, int minSize)	Creates or re-uses a CharBuffer that has a minimum size.
static StaticBuffers	getInstance()
void	releaseByteBuffer(StaticBuffers.Key key, ByteBuffer buf)	Marks a buffer a being re-usable.
void	releaseCharBuffer(StaticBuffers.Key key, CharBuffer buf)	Marks a buffer a being re-usable.

Methods inherited from class java.lang.Object

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

Field Details

GLOBAL_MIN_SIZE

public static final int GLOBAL_MIN_SIZE

All buffers have a minimum size of 64 kb

See Also:

• Constant Field Values

_instance

protected static final ThreadLocal<SoftReference<StaticBuffers>> _instance

A thread-local soft reference to the singleton instance of this class

_byteBuffers

protected ByteBuffer[] _byteBuffers

Maps of already allocated re-usable buffers

_charBuffers

protected CharBuffer[] _charBuffers

Constructor Details

StaticBuffers

protected StaticBuffers()

Hidden constructor

Method Details

getInstance

public static StaticBuffers getInstance()

Returns:

a thread-local singleton instance of this class

charBuffer

public CharBuffer charBuffer(StaticBuffers.Key key,
 int minSize)

Creates or re-uses a CharBuffer that has a minimum size. Calling this method multiple times with the same key will always return the same buffer, as long as it has the minimum size and is marked to be re-used. Buffers that are allowed to be re-used should be released using releaseCharBuffer(Key, CharBuffer).

Parameters:

key - the buffer's identifier

minSize - the minimum size

Returns:

the CharBuffer instance

See Also:

• byteBuffer(Key, int)

releaseCharBuffer

public void releaseCharBuffer(StaticBuffers.Key key,
 CharBuffer buf)

Marks a buffer a being re-usable.

Parameters:

key - the buffer's key

buf - the buffer

See Also:

• releaseByteBuffer(Key, ByteBuffer)

byteBuffer

public ByteBuffer byteBuffer(StaticBuffers.Key key,
 int minSize)

Creates or re-uses a ByteBuffer that has a minimum size. Calling this method multiple times with the same key will always return the same buffer, as long as it has the minimum size and is marked to be re-used. Buffers that are allowed to be re-used should be released using releaseByteBuffer(Key, ByteBuffer).

Parameters:

key - the buffer's identifier

minSize - the minimum size

Returns:

the ByteBuffer instance

See Also:

• charBuffer(Key, int)

releaseByteBuffer

public void releaseByteBuffer(StaticBuffers.Key key,
 ByteBuffer buf)

Marks a buffer a being re-usable.

Parameters:

key - the buffer's key

buf - the buffer

See Also:

• releaseCharBuffer(Key, CharBuffer)