org.apache.parquet.bytes

Class ReusingByteBufferAllocator

java.lang.Object

org.apache.parquet.bytes.ReusingByteBufferAllocator

All Implemented Interfaces:

AutoCloseable, ByteBufferAllocator

public abstract class ReusingByteBufferAllocator
extends Object
implements ByteBufferAllocator, AutoCloseable

A special ByteBufferAllocator implementation that keeps one ByteBuffer object and reuses it at the next allocate(int) call. The close() shall be called when this allocator is not needed anymore to really release the one buffer.

Method Summary

Modifier and Type	Method and Description
ByteBuffer	allocate(int size)
void	close()
ByteBufferReleaser	getReleaser() A convenience method to get a ByteBufferReleaser instance already created for this allocator.
boolean	isDirect() Indicates if this allocator will produce ByteBuffers backed by direct memory.
void	release(ByteBuffer b) For RefCounted implementations using direct memory, the release method needs to be called to free references to the allocated memory.
static ReusingByteBufferAllocator	strict(ByteBufferAllocator allocator) Creates a new strict ReusingByteBufferAllocator object with the specified "parent" allocator to be used for allocating/releasing the one buffer.
static ReusingByteBufferAllocator	unsafe(ByteBufferAllocator allocator) Creates a new unsafe ReusingByteBufferAllocator object with the specified "parent" allocator to be used for allocating/releasing the one buffer.

Methods inherited from class java.lang.Object

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

Method Detail

strict

public static ReusingByteBufferAllocator strict(ByteBufferAllocator allocator)

Creates a new strict ReusingByteBufferAllocator object with the specified "parent" allocator to be used for allocating/releasing the one buffer.

Strict means it is enforced that release(ByteBuffer) is invoked before a new allocate(int) can be called.

Parameters:

allocator - the allocator to be used for allocating/releasing the one buffer

Returns:

a new strict ReusingByteBufferAllocator object

unsafe

public static ReusingByteBufferAllocator unsafe(ByteBufferAllocator allocator)

Creates a new unsafe ReusingByteBufferAllocator object with the specified "parent" allocator to be used for allocating/releasing the one buffer.

Unsafe means it is not enforced that release(ByteBuffer) is invoked before a new allocate(int) can be called, i.e. no exceptions will be thrown at allocate(int).

Parameters:

allocator - the allocator to be used for allocating/releasing the one buffer

Returns:

a new unsafe ReusingByteBufferAllocator object

getReleaser

public ByteBufferReleaser getReleaser()

A convenience method to get a ByteBufferReleaser instance already created for this allocator.

Returns:

a releaser for this allocator

allocate

public ByteBuffer allocate(int size)

Specified by:

allocate in interface ByteBufferAllocator

Throws:

IllegalStateException - if strict and the one buffer was not released yet

See Also:

strict(ByteBufferAllocator), unsafe(ByteBufferAllocator)

release

public void release(ByteBuffer b)

For RefCounted implementations using direct memory, the release method needs to be called to free references to the allocated memory.

Specified by:

release in interface ByteBufferAllocator

Parameters:

b - a ByteBuffer

Throws:

IllegalStateException - if the one buffer has already been released or never allocated

IllegalArgumentException - if the specified buffer is not the one allocated by this allocator

isDirect

public boolean isDirect()

Description copied from interface: ByteBufferAllocator

Indicates if this allocator will produce ByteBuffers backed by direct memory.

Specified by:

isDirect in interface ByteBufferAllocator

Returns:

true if direct memory backed buffers will be created by this allocator, else false

close

public void close()

Specified by:

close in interface AutoCloseable