Implements dynamically resizable prefetching pool. More...

#include <prefetch_pool.h>

Inherits noncopyable.

Public Types
typedef BlockType	block_type
typedef block_type::bid_type	bid_type
Public Member Functions
	prefetch_pool (unsigned_type init_size=1)
	Constructs pool.
void	swap (prefetch_pool &obj)
virtual	~prefetch_pool ()
	Waits for completion of all ongoing read requests and frees memory.
unsigned_type	size () const
	Returns number of owned blocks.
bool	hint (bid_type bid)
	Gives a hint for prefetching a block.
bool	hint (bid_type bid, write_pool< block_type > &w_pool)
bool	invalidate (bid_type bid)
bool	in_prefetching (bid_type bid)
request_ptr	read (block_type *&block, bid_type bid)
	Reads block. If this block is cached block is not read but passed from the cache.
request_ptr	read (block_type *&block, bid_type bid, write_pool< block_type > &w_pool)
unsigned_type	resize (unsigned_type new_size)
	Resizes size of the pool.
Protected Types
typedef std::pair< block_type *, request_ptr >	busy_entry
typedef compat_hash_map < bid_type, busy_entry, bid_hash >::result	hash_map_type
typedef std::list< block_type * > ::iterator	free_blocks_iterator
typedef hash_map_type::iterator	busy_blocks_iterator
Protected Attributes
std::list< block_type * >	free_blocks
hash_map_type	busy_blocks
unsigned_type	free_blocks_size

Detailed Description

template<class BlockType>
class prefetch_pool< BlockType >

Implements dynamically resizable prefetching pool.

Constructor & Destructor Documentation

template<class BlockType>

prefetch_pool< BlockType >::prefetch_pool ( unsigned_type init_size = 1 ) [inline, explicit]

Constructs pool.

Parameters:

init_size

initial number of blocks in the pool

template<class BlockType>

virtual prefetch_pool< BlockType >::~prefetch_pool ( ) [inline, virtual]

Waits for completion of all ongoing read requests and frees memory.

Member Function Documentation

template<class BlockType>

bool prefetch_pool< BlockType >::hint ( bid_type bid ) [inline]

Gives a hint for prefetching a block.

Parameters:

bid

address of a block to be prefetched

Returns:: true if there was a free block to do prefetch and prefetching was scheduled, false otherwise

Note:: If there are no free blocks available (all blocks are already in reading or read but not retrieved by user calling read method) calling hint function has no effect

Referenced by read_write_pool< BlockType >::hint(), and read_write_pool< BlockType >::write().

template<class BlockType>

request_ptr prefetch_pool< BlockType >::read	(	block_type *&	block,
		bid_type	bid
	)			`[inline]`

Reads block. If this block is cached block is not read but passed from the cache.

Parameters:

	block	block object, where data to be read to. If block was cached `block` 's ownership goes to the pool and block from cache is returned in `block` value.
	bid	address of the block

Warning:: block parameter must be allocated dynamically using new .

Returns:: request pointer object of read operation

Referenced by read_write_pool< BlockType >::read().

template<class BlockType>

unsigned_type prefetch_pool< BlockType >::resize ( unsigned_type new_size ) [inline]

Resizes size of the pool.

Parameters:

new_size

desired size of the pool. If some blocks are used for prefetching, these blocks can't be freed. Only free blocks (not in prefetching) can be freed by reducing the size of the pool calling this method.