Purge_groups_t Struct Reference

Public Types
using	GroupBy = std::unordered_map< table_id_t, std::size_t, std::hash< table_id_t >, std::equal_to< table_id_t >, mem_heap_allocator< std::pair< const table_id_t, std::size_t > > >
using	vec_alloc = mem_heap_allocator< purge_node_t::Recs * >
	Allocator used for the vector below. More...

Public Member Functions
	Purge_groups_t (std::size_t n_threads, mem_heap_t *heap)
void	init ()
std::size_t	find_smallest_group ()
void	distribute_if_needed ()
	Check the history list length and decide if distribution of workload between purge threads is needed or not. More...
std::ostream &	print (std::ostream &out) const
void	assign (que_thr_t **thrs)
bool	is_grouping_uniform () const
void	add (purge_node_t::rec_t &rec)

Public Attributes
GroupBy	m_grpid_umap
	Given a table_id obtain the group id to which it belongs. More...
std::vector< purge_node_t::Recs *, vec_alloc >	m_groups
	A vector of groups. More...
mem_heap_t *	m_heap
	Memory heap in which memory for unordered_map & vector is allocated. More...
std::size_t	m_total_rec
	Total number of undo records parsed and grouped. More...

Private Member Functions
void	distribute ()
	Redistribute the undo records across different groups. More...

Member Typedef Documentation

GroupBy

using Purge_groups_t::GroupBy = std::unordered_map< table_id_t, std::size_t, std::hash<table_id_t>, std::equal_to<table_id_t>, mem_heap_allocator<std::pair<const table_id_t, std::size_t> >>

vec_alloc

using Purge_groups_t::vec_alloc = mem_heap_allocator<purge_node_t::Recs *>

Allocator used for the vector below.

Constructor & Destructor Documentation

Purge_groups_t()

Purge_groups_t::Purge_groups_t ( std::size_t  n_threads, mem_heap_t *  heap  )

inline

Member Function Documentation

add()

void Purge_groups_t::add ( purge_node_t::rec_t &  rec )

inline

assign()

void Purge_groups_t::assign ( que_thr_t **  thrs )

inline

distribute()

void Purge_groups_t::distribute ( )

private

Redistribute the undo records across different groups.

If a group has more records than it should, move all the extra records to the next group. Maximum two passes might be needed.

distribute_if_needed()

void Purge_groups_t::distribute_if_needed

(

)

Check the history list length and decide if distribution of workload between purge threads is needed or not.

If needed, do the distribution, otherwise do nothing.

find_smallest_group()

std::size_t Purge_groups_t::find_smallest_group

(

)

init()

void Purge_groups_t::init ( void  )

inline

is_grouping_uniform()

bool Purge_groups_t::is_grouping_uniform

(

)

const

print()

std::ostream & Purge_groups_t::print

(

std::ostream &

out

)

const

Member Data Documentation

m_groups

std::vector<purge_node_t::Recs *, vec_alloc> Purge_groups_t::m_groups

A vector of groups.

The size of this vector is equal to the number of purge threads. Each undo record is assigned to one of the groups, based on its table_id. The index into this vector is the group_id.

m_grpid_umap

GroupBy Purge_groups_t::m_grpid_umap

Given a table_id obtain the group id to which it belongs.

m_heap

mem_heap_t* Purge_groups_t::m_heap

Memory heap in which memory for unordered_map & vector is allocated.

m_total_rec

std::size_t Purge_groups_t::m_total_rec

Total number of undo records parsed and grouped.

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

• storage/innobase/trx/trx0purge.cc