buf_stat_per_index_t Class Reference

Per index buffer pool statistics. More...

#include <buf0stats.h>

Public Member Functions
	buf_stat_per_index_t ()
	Constructor. More...
	~buf_stat_per_index_t ()
	Destructor. More...
void	inc (const index_id_t &id)
	Increment the number of pages for a given index with 1. More...
void	reset (const index_id_t &id)
	Set the count for given id to 0. More...
void	dec (const index_id_t &id)
	Decrement the number of pages for a given index with 1. More...
void	dec_if_tracked_page (const page_t *frame)
	Decrement the page count if a frame currently satisfies the accounting predicate. More...
void	inc_if_tracked_page (const page_t *frame)
	Increment the page count if a frame currently satisfies the accounting predicate. More...
bool	is_tracked_page (const page_t *frame)
	Check whether a frame currently satisfies the accounting predicate. More...
uint64_t	get (const index_id_t &id)
	Get the number of pages in the buffer pool for a given index. More...

Private Member Functions
void	change_if_tracked_page (const page_t *frame, bool increment)
	Change the page count if a frame currently satisfies the accounting predicate. More...
bool	should_skip (const index_id_t &id)
	Assess if we should skip a page from accounting. More...

Static Private Member Functions
static space_id_t	get_space_id (const page_t *frame)
	Gets the space id from a page image. More...

Private Attributes
ut_lock_free_hash_t *	m_store
	(key, value) storage. More...

Detailed Description

Per index buffer pool statistics.

This tracks the number of logical buffer pool file pages that currently satisfy all of these predicates:

1. the page is present in the buffer pool page hash, not on the free list,
2. the FIL page type is FIL_PAGE_INDEX or FIL_PAGE_RTREE,
3. PAGE_LEVEL is 0, i.e. page_is_leaf() is true,
4. the page id's space id and PAGE_INDEX_ID identify the tracked index.

For compressed tables, the compressed image and the uncompressed frame are two possible in-memory representations of the same buffer pool page. They are counted once while the page id remains cached. Discarding only the uncompressed frame must not decrement the count if the compressed descriptor remains cached.

This is a key,value store where the key is a packed index_id_t and the value is the number of cached leaf pages that belong to the index.

Constructor & Destructor Documentation

buf_stat_per_index_t()

buf_stat_per_index_t::buf_stat_per_index_t ( )

inline

Constructor.

~buf_stat_per_index_t()

buf_stat_per_index_t::~buf_stat_per_index_t ( )

inline

Destructor.

Member Function Documentation

change_if_tracked_page()

void buf_stat_per_index_t::change_if_tracked_page ( const page_t *  frame, bool  increment  )

inlineprivate

Change the page count if a frame currently satisfies the accounting predicate.

Parameters

[in]	frame	buffer frame
[in]	increment	true to increment, false to decrement

dec()

void buf_stat_per_index_t::dec ( const index_id_t &  id )

inline

Decrement the number of pages for a given index with 1.

Parameters

[in]

id

id of the index whose count to decrement

dec_if_tracked_page()

void buf_stat_per_index_t::dec_if_tracked_page ( const page_t *  frame )

inline

Decrement the page count if a frame currently satisfies the accounting predicate.

Parameters

[in]

frame

buffer frame

get()

uint64_t buf_stat_per_index_t::get ( const index_id_t &  id )

inline

Get the number of pages in the buffer pool for a given index.

Parameters

[in]

id

id of the index whose pages to peek

Returns

number of pages

get_space_id()

static space_id_t buf_stat_per_index_t::get_space_id ( const page_t *  frame )

inlinestaticprivate

Gets the space id from a page image.

Do not use page_get_space_id() here: it asserts that the frame is page-aligned, but compressed page images are allocated by the buddy allocator and need not satisfy that assertion.

Parameters

[in]

frame

page image

Returns

tablespace identifier from the FIL header

inc()

void buf_stat_per_index_t::inc ( const index_id_t &  id )

inline

Increment the number of pages for a given index with 1.

Parameters

[in]

id

id of the index whose count to increment

inc_if_tracked_page()

void buf_stat_per_index_t::inc_if_tracked_page ( const page_t *  frame )

inline

Increment the page count if a frame currently satisfies the accounting predicate.

Parameters

[in]

frame

buffer frame

is_tracked_page()

bool buf_stat_per_index_t::is_tracked_page ( const page_t *  frame )

inline

Check whether a frame currently satisfies the accounting predicate.

Parameters

[in]

frame

buffer frame

Returns

true if the frame is counted by this structure

reset()

void buf_stat_per_index_t::reset ( const index_id_t &  id )

inline

Set the count for given id to 0.

Parameters

[in]

id

id of the index whose count will be reset

should_skip()

bool buf_stat_per_index_t::should_skip ( const index_id_t &  id )

inlineprivate

Assess if we should skip a page from accounting.

Parameters

[in]

id

index_id of the page

Returns

true if it should not be accounted

Member Data Documentation

m_store

ut_lock_free_hash_t* buf_stat_per_index_t::m_store

private

(key, value) storage.

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The documentation for this class was generated from the following file:

• storage/innobase/include/buf0stats.h