An implementation of a very simple block allocator. More...

Inheritance diagram for SimpleAllocator:

Public Member Functions
	__init__ (unsigned int max_size, Mutex lock)
SimpleAllocatorBlock	alloc (unsigned int size)
	Allocates a new block.
unsigned int	getContiguous ()
	Returns an upper-bound estimate of the size of the largest contiguous block that may be allocated.
SimpleAllocatorBlock	getFirstBlock ()
	Returns a pointer to the first allocated block, or NULL if there are no allocated blocks.
unsigned int	getMaxSize ()
	Returns the available space for allocated objects.
unsigned int	getTotalSize ()
	Returns the total size of allocated objects.
bool	isEmpty ()
	Returns true if there are no blocks allocated on this page, or false if there is at least one.
	output (ostream out)
	setMaxSize (unsigned int max_size)
	Changes the available space for allocated objects.
	write (ostream out)

Detailed Description

An implementation of a very simple block allocator.

This class can allocate ranges of nonnegative integers within a specified upper limit; it uses a simple first-fit algorithm to find the next available space.

Member Function Documentation

__init__	(	unsigned int	max_size,
		Mutex	lock
	)

SimpleAllocatorBlock alloc ( unsigned int size )

Allocates a new block.

Returns NULL if a block of the requested size cannot be allocated.

To free the allocated block, call block->free(), or simply delete the block pointer.

Reimplemented in VertexDataPage.

unsigned int getContiguous ( )

Returns an upper-bound estimate of the size of the largest contiguous block that may be allocated.

It is guaranteed that an attempt to allocate a block larger than this will fail, though it is not guaranteed that an attempt to allocate a block this size or smaller will succeed.

SimpleAllocatorBlock getFirstBlock ( )

Returns a pointer to the first allocated block, or NULL if there are no allocated blocks.

Reimplemented in VertexDataPage.

unsigned int getMaxSize ( )

Returns the available space for allocated objects.

unsigned int getTotalSize ( )

Returns the total size of allocated objects.

bool isEmpty ( )

Returns true if there are no blocks allocated on this page, or false if there is at least one.

output ( ostream out )

Reimplemented in VertexDataPage.

setMaxSize ( unsigned int max_size )

Changes the available space for allocated objects.

This will not affect any already-allocated objects, but will have an effect on future calls to alloc().

write ( ostream out )

Public Member Functions

Detailed Description

Member Function Documentation