carta::TilePool Struct Reference

This struct stores the memory allocated for cached tile data. More...

#include <TilePool.h>

Inheritance diagram for carta::TilePool:

Collaboration diagram for carta::TilePool:

Classes
struct	TilePtrDeleter
	The custom deleter which allows discarded tiles to be returned to the pool. More...

Public Member Functions
	TilePool ()
	Constructor.
void	Grow (int size)
	Grow the capacity of the pool.
TilePtr	Pull ()
	Request a tile object from the pool.
void	Push (std::unique_ptr< std::vector< float > > &unique_tile) noexcept
	Return a tile object to the pool.
bool	Full ()
	Check if the pool is full.

Private Member Functions
TilePtr	Create ()
	Allocate a new tile object.

Private Attributes
std::mutex	_tile_pool_mutex
	The mutex used by functions which modify the stack.
std::stack< TilePtr >	_stack
	The stack where reusable tile objects are stored.
int	_capacity
	The maximum number of items which may be stored in the stack.

Detailed Description

This struct stores the memory allocated for cached tile data.

Instead of repeatedly allocating and freeing memory for cached tile data, which has a significant performance cost, we keep a pool of allocated tile objects which are reused as tiles are read and discarded (up to a given capacity). The capacity of the pool should be 4 more than the capacity of the cache, so that we can always load a chunk before evicting anything.

Constructor & Destructor Documentation

TilePool()

carta::TilePool::TilePool ( )

inline

Constructor.

Member Function Documentation

Create()

TilePtr TilePool::Create ( )

private

Allocate a new tile object.

Returns

A tile object.

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Full()

bool TilePool::Full

(

)

Check if the pool is full.

Returns

Whether the pool has reached capacity.

This function is called from the custom deleter which is attached to tile objects obtained from this pool.

Grow()

void TilePool::Grow

(

int

size

)

Grow the capacity of the pool.

Parameters

size	the size increment to be added

Pull()

TilePtr TilePool::Pull

(

)

Request a tile object from the pool.

Returns

A tile object.

If the pool is empty, a new tile object will be created.

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Push()

void TilePool::Push ( std::unique_ptr< std::vector< float > > &  unique_tile )

noexcept

Return a tile object to the pool.

Parameters

unique_tile

a unique pointer to a tile object

This function is called from the custom deleter which is attached to tile objects obtained from this pool.

Member Data Documentation

_capacity

int carta::TilePool::_capacity

private

The maximum number of items which may be stored in the stack.

When capacity is reached, discarded tile objects are really deleted instead of being returned to the pool.

_stack

std::stack<TilePtr> carta::TilePool::_stack

private

The stack where reusable tile objects are stored.

_tile_pool_mutex

std::mutex carta::TilePool::_tile_pool_mutex

private

The mutex used by functions which modify the stack.

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The documentation for this struct was generated from the following files:

• TilePool.h
• TilePool.cc