ha0ha.cc File Reference

The hash table with external chains. More...

#include "ha0ha.h"
#include <sys/types.h>
#include "buf0buf.h"
#include "btr0sea.h"
#include "page0page.h"

Macros
#define	PRINT_USED_CELLS

Functions
hash_table_t *	ib_create (size_t n, latch_id_t id, size_t n_sync_obj, uint32_t type)
	Creates a hash table with at least n array cells. More...
void	ha_clear (hash_table_t *table)
	Empties a hash table and frees the memory heaps. More...
static void	ha_btr_search_latch_x_locked (const hash_table_t *table)
	Verify if latch corresponding to the hash table is x-latched. More...
bool	ha_insert_for_hash_func (hash_table_t *table, uint64_t hash_value, buf_block_t *block, const rec_t *data)
	Inserts an entry into a hash table. More...
void	ha_delete_hash_node (hash_table_t *table, ha_node_t *del_node)
	Deletes a hash node. More...
bool	ha_search_and_update_if_found_func (hash_table_t *table, uint64_t hash_value, const rec_t *data, buf_block_t *new_block, const rec_t *new_data)
	Looks for an element when we know the pointer to the data and updates the pointer to data if found. More...
void	ha_remove_a_node_to_page (hash_table_t *table, uint64_t hash_value, const page_t *page)
	Removes from the chain determined by hash value a single node whose data pointer points to the page given. More...
bool	ha_validate (hash_table_t *table, uint64_t start_index, uint64_t end_index)
	Validates a given range of the cells in hash table. More...
void	ha_print_info (FILE *file, hash_table_t *table)
	Prints info of a hash table. More...

Detailed Description

The hash table with external chains.

Created 8/22/1994 Heikki Tuuri

Macro Definition Documentation

PRINT_USED_CELLS

#define PRINT_USED_CELLS

Function Documentation

ha_btr_search_latch_x_locked()

static void ha_btr_search_latch_x_locked ( const hash_table_t *  table )

static

Verify if latch corresponding to the hash table is x-latched.

Parameters

[in]

table

hash table

ha_clear()

void ha_clear

(

hash_table_t *

table

)

Empties a hash table and frees the memory heaps.

in, own: hash table

Parameters

table

in, own: hash table

ha_delete_hash_node()

void ha_delete_hash_node	(	hash_table_t *	table,
		ha_node_t *	del_node
	)

Deletes a hash node.

in: node to be deleted

Parameters

table	in: hash table
del_node	in: node to be deleted

ha_insert_for_hash_func()

bool ha_insert_for_hash_func	(	hash_table_t *	table,
		uint64_t	hash_value,
		buf_block_t *	block,
		const rec_t *	data
	)

Inserts an entry into a hash table.

If an entry with the same hash number is found, its node is updated to point to the new data, and no new node is inserted. If btr_search_enabled is set to false, we will only allow updating existing nodes, but no new node is allowed to be added.

Parameters

[in]	table	hash table
[in]	hash_value	hashed value of data; if a node with the same hash value already exists, it is updated to point to the same data, and no new node is created!
[in]	block	buffer block containing the data
[in]	data	data, must not be NULL

Returns

true if succeeded, false if no more memory could be allocated

ha_print_info()

void ha_print_info	(	FILE *	file,
		hash_table_t *	table
	)

Prints info of a hash table.

Parameters

[in]	file	File where to print
[in]	table	Hash table

ha_remove_a_node_to_page()

void ha_remove_a_node_to_page	(	hash_table_t *	table,
		uint64_t	hash_value,
		const page_t *	page
	)

Removes from the chain determined by hash value a single node whose data pointer points to the page given.

Note that the node deleted can have a different hash value.

Parameters

[in]	table	Hash table
[in]	hash_value	Hash value
[in]	page	Buffer page

ha_search_and_update_if_found_func()

bool ha_search_and_update_if_found_func	(	hash_table_t *	table,
		uint64_t	hash_value,
		const rec_t *	data,
		buf_block_t *	new_block,
		const rec_t *	new_data
	)

Looks for an element when we know the pointer to the data and updates the pointer to data if found.

Parameters

[in,out]	table	hash table
[in]	hash_value	hashed value of the searched data
[in]	data	pointer to the data
[in]	new_block	block containing new data
[in]	new_data	new pointer to the data

Returns

true if found

ha_validate()

bool ha_validate	(	hash_table_t *	table,
		uint64_t	start_index,
		uint64_t	end_index
	)

Validates a given range of the cells in hash table.

Parameters

[in]	table	Hash table
[in]	start_index	Start index
[in]	end_index	End index

Returns

true if ok

ib_create()

hash_table_t * ib_create	(	size_t	n,
		latch_id_t	id,
		size_t	n_sync_obj,
		uint32_t	type
	)

Creates a hash table with at least n array cells.

The actual number of cells is chosen to be a prime number slightly bigger than n.

Parameters

[in]	n	number of array cells
[in]	id	latch ID
[in]	n_sync_obj	Number of sync objects protecting the hash table. Must be a power of 2, or 0.
[in]	type	type of datastructure for which the memory heap is going to be used: MEM_HEAP_FOR_BTR_SEARCH or MEM_HEAP_FOR_PAGE_HASH

Returns

own: created table