com.devexperts.io

Class ChunkPool

java.lang.Object

com.devexperts.io.ChunkPool

public class ChunkPool
extends Object

Pool for Chunk and ChunkList instances.

See Also:

Chunk, ChunkList

Field Summary

Fields

Modifier and Type	Field and Description
static ChunkPool	DEFAULT Default pool instance with default parameters.

Constructor Summary

Constructors

Constructor and Description
ChunkPool(String poolName, int threadLocalCapacity, int chunkPoolCapacity, int chunkListPoolCapacity, int chunkSize, int recyclableChunkListCapacity) Constructs new pool with specified parameters.

Method Summary

Modifier and Type	Method and Description
ChunkList	copyToChunkList(byte[] bytes, int offset, int length, Object owner) Extracts a ChunkList from the pool for specified owner and fills it with data from specified byte array.
protected Chunk	createNewChunk(Object owner) Constructs new Chunk instance for specified owner.
protected ChunkList	createNewChunkList(Object owner) Constructs a new ChunkList of specified owner.
Chunk	getChunk(Object owner) Extracts a Chunk from the pool (or creates new one if the pool is empty).
ChunkList	getChunkList(Object owner) Extracts a ChunkList from the pool (or creates new one if the pool is empty).
int	getChunkSize() Returns chunk size of this pool.
protected void	recycleChunk(Chunk chunk, Object owner) Returns the specified Chunk into the pool.
protected void	recycleChunkList(ChunkList chunkList, Object owner) Returns the specified ChunkList into the pool.
String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT

public static final ChunkPool DEFAULT

Default pool instance with default parameters. Default parameters can be configured with the following JVM system properties:

• com.devexperts.io.Chunk.threadLocalCapacity — the capacity of thread-local pool of chunks (3 by default);
• com.devexperts.io.Chunk.poolCapacity — the capacity of global pool of chunks (4096 by default);
• com.devexperts.io.ChunkList.threadLocalCapacity — the capacity of thread-local pool of chunk lists (3 by default);
• com.devexperts.io.ChunkList.poolCapacity — the capacity of global pool of chunk lists (1024 by default);
• com.devexperts.io.chunkSize — the size of a chunks (8192 by default);
• com.devexperts.io.recyclableChunkListCapacity — the maximum capacity of ChunkList that is kept in the pool (1024 by default).

Constructor Detail

ChunkPool

public ChunkPool(String poolName,
                 int threadLocalCapacity,
                 int chunkPoolCapacity,
                 int chunkListPoolCapacity,
                 int chunkSize,
                 int recyclableChunkListCapacity)

Constructs new pool with specified parameters.

Parameters:

poolName - the base name of the pool.

threadLocalCapacity - the capacity of thread-local pool, e.g. how many objects are pooled per thread.

chunkPoolCapacity - maximum number of chunks to pool.

chunkListPoolCapacity - maximum number of chunk lists to pool.

chunkSize - size of the chunk.

recyclableChunkListCapacity - maximum allowed chunk list capacity.

Method Detail

getChunkSize

public int getChunkSize()

Returns chunk size of this pool.

getChunk

public Chunk getChunk(Object owner)

Extracts a Chunk from the pool (or creates new one if the pool is empty). The returned chunk is not read-only, has non-zero length and belongs to specified owner.

The default implementation returns Chunk with zero offset and length equal to underlying byte array length, however subclasses' behaviour may differ.

Parameters:

owner - owner for the chunk

Returns:

a chunk extracted from the pool (or created if the pool was empty)

getChunkList

public ChunkList getChunkList(Object owner)

Extracts a ChunkList from the pool (or creates new one if the pool is empty). The returned chunk list is empty, not read-only and belongs to specified owner.

Parameters:

owner - owner for the chunk list

Returns:

a chunk list extracted from the pool (or created if the pool was empty)

copyToChunkList

public ChunkList copyToChunkList(byte[] bytes,
                                 int offset,
                                 int length,
                                 Object owner)

Extracts a ChunkList from the pool for specified owner and fills it with data from specified byte array.

Parameters:

bytes - byte array to take data from

offset - offset of data within the array

length - length of data

owner - owner for the chunk list

Returns:

a chunk list extracted from the pool of specified owner that contains specified data.

createNewChunk

protected Chunk createNewChunk(Object owner)

Constructs new Chunk instance for specified owner.

Parameters:

owner - owner for the chunk

Returns:

constructed chunk

createNewChunkList

protected ChunkList createNewChunkList(Object owner)

Constructs a new ChunkList of specified owner.

Parameters:

owner - owner for the chunk list

Returns:

constructed chunk list

recycleChunk

protected void recycleChunk(Chunk chunk,
                            Object owner)

Returns the specified Chunk into the pool. This method is invoked by Chunk.recycle(Object) method.

Parameters:

chunk - a chunk to recycle

owner - current owner of the chunk

Throws:

IllegalStateException - if the chunk's owner differs from the one specified or if the chunk is read-only

IllegalArgumentException - if the chunk does not belong to this pool or has invalid length

recycleChunkList

protected void recycleChunkList(ChunkList chunkList,
                                Object owner)

Returns the specified ChunkList into the pool. This method is invoked from ChunkList.recycle(Object) method.

Parameters:

chunkList - a chunk list to recycle

owner - current owner of the chunk list

Throws:

IllegalStateException - if the chunk's owner differs from the one specified or if the chunk is read-only

IllegalArgumentException - if the chunk list does not belong to this pool or is not empty

toString

public String toString()

Returns a string representation of the object.

Overrides:

toString in class Object

Returns:

a string representation of the object.