Package org.apache.druid.frame.allocation

Class HeapMemoryAllocator

java.lang.Object

org.apache.druid.frame.allocation.HeapMemoryAllocator

All Implemented Interfaces:

MemoryAllocator

public class HeapMemoryAllocator
extends Object
implements MemoryAllocator

Allocator that uses ByteBuffer.allocate(int) to create chunks in the JVM heap.

Method Summary

Modifier and Type	Method	Description
Optional<ResourceHolder<org.apache.datasketches.memory.WritableMemory>>	allocate(long size)	Allocates a block of memory of capacity {@param size}.
long	available()	Returns the number of bytes available for allocations.
long	capacity()	Returns the number of bytes managed by this allocator.
static HeapMemoryAllocator	unlimited()	Create an allocator that is "unlimited", which, of course, means it is limited only by available JVM heap.

Methods inherited from class java.lang.Object

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

Method Detail

unlimited

public static HeapMemoryAllocator unlimited()

Create an allocator that is "unlimited", which, of course, means it is limited only by available JVM heap.

allocate

public Optional<ResourceHolder<org.apache.datasketches.memory.WritableMemory>> allocate(long size)

Description copied from interface: MemoryAllocator

Allocates a block of memory of capacity {@param size}. Returns empty if no more memory is available. The memory can be freed by closing the returned ResourceHolder. The returned WritableMemory object will use little-endian byte order.

Specified by:

allocate in interface MemoryAllocator

available

public long available()

Description copied from interface: MemoryAllocator

Returns the number of bytes available for allocations. May return Long.MAX_VALUE if there is no inherent limit. This generally does not mean you can actually allocate 9 exabytes.

Specified by:

available in interface MemoryAllocator

capacity

public long capacity()

Description copied from interface: MemoryAllocator

Returns the number of bytes managed by this allocator. When no memory has been allocated yet, this is identical to MemoryAllocator.available(). May return Long.MAX_VALUE if there is no inherent limit. This generally does not mean you can actually allocate 9 exabytes.

Specified by:

capacity in interface MemoryAllocator