index.c File Reference

#include "s4_priv.h"
#include <stdlib.h>
#include <string.h>

Functions
s4_index_data_t *	_index_create_data ()
void	_index_free_data (s4_index_data_t *data)
s4_index_t *	_index_get_a (s4_t *s4, const char *key, int create)
	Gets the a-index associated with key.
s4_index_t *	_index_get_b (s4_t *s4, const char *key)
	Gets the b-index associated with key.
GList *	_index_get_all_a (s4_t *s4)
	Gets all a-indexes.
GList *	_index_get_all_b (s4_t *s4)
	Gets all b-indexes.
s4_index_t *	_index_create ()
	Creates a new index.
int	_index_add (s4_t *s4, const char *key, s4_index_t *index)
	Adds an index to a database.
int	_index_insert (s4_index_t *index, const s4_val_t *val, void *new_data)
	Inserts a new value-data pair into the index.
int	_index_delete (s4_index_t *index, const s4_val_t *val, void *data)
	Removes a value-data pair from the index.
GList *	_index_search (s4_index_t *index, index_function_t func, void *func_data)
	Searches an index.
GList *	_index_lsearch (s4_index_t *index, index_function_t func, void *func_data)
	Searches an index using a linear search.
void	_index_free (s4_index_t *index)
	Frees an index.
int	_index_lock_shared (s4_index_t *index, s4_transaction_t *trans)
int	_index_lock_exclusive (s4_index_t *index, s4_transaction_t *trans)

Function Documentation

_index_add()

int _index_add	(	s4_t *	s4,
		const char *	key,
		s4_index_t *	index )

Adds an index to a database.

Parameters

s4	The database to add the index to
key	The key to associate the index with
index	The index to insert

Returns

0 if the key already has an index, non-zero otherwise

Referenced by _index_add(), and s4_open().

_index_create()

s4_index_t * _index_create

(

void

)

Creates a new index.

Returns

A new index

Referenced by _index_create(), _index_get_a(), and s4_open().

_index_create_data()

s4_index_data_t * _index_create_data

(

void

)

Referenced by _index_create_data(), and _reread_file().

_index_delete()

int _index_delete	(	s4_index_t *	index,
		const s4_val_t *	val,
		void *	data )

Removes a value-data pair from the index.

Parameters

index	The index to remove from
val	The value to remove
data	The data to remove

Returns

0 if the value-data pair is not found, 1 otherwise

Referenced by _index_delete(), and _s4_del().

_index_free()

void _index_free

(

s4_index_t *

index

)

Frees an index.

The values and data is NOT freed

Parameters

index

The index to free

Referenced by _index_create_data(), and _index_free().

_index_free_data()

void _index_free_data

(

s4_index_data_t *

data

)

Referenced by _index_free_data(), and _reread_file().

_index_get_a()

s4_index_t * _index_get_a	(	s4_t *	s4,
		const char *	key,
		int	create )

Gets the a-index associated with key.

A a-index is used to lookup entries by the a-value. If an index has not yet been created for this key and create is non-zero, one will be created and returned.

Parameters

s4	The database to look for the index in
key	The key the index should be indexing
create	Creates the index if it does not exist

Returns

The index, or NULL if it does not exist and create is 0.

Referenced by _index_get_a(), _s4_add(), _s4_add_internal(), _s4_del(), and _s4_query().

_index_get_all_a()

GList * _index_get_all_a

(

s4_t *

s4

)

Gets all a-indexes.

Parameters

s4	The database to get the index of.

Returns

A list of indexes.

Referenced by _free_relations(), _index_get_all_a(), and _s4_query().

_index_get_all_b()

GList * _index_get_all_b

(

s4_t *

s4

)

Gets all b-indexes.

Parameters

s4	The database to get the index of.

Returns

A list of indexes.

Referenced by _index_get_all_b().

_index_get_b()

s4_index_t * _index_get_b	(	s4_t *	s4,
		const char *	key )

Gets the b-index associated with key.

A b-index is used to lookup entries by the b-value.

Parameters

s4	The database to look for the index in
key	The key the index should be indexing

Returns

The index, or NULL if it is not found

Referenced by _index_get_b(), _s4_add(), _s4_add_internal(), _s4_del(), and _s4_query().

_index_insert()

int _index_insert	(	s4_index_t *	index,
		const s4_val_t *	val,
		void *	new_data )

Inserts a new value-data pair into the index.

Parameters

index	The index to insert into
val	The value to associate the data with
new_data	The data

Returns

1

Referenced by _index_insert(), _s4_add(), and _s4_add_internal().

_index_lock_exclusive()

int _index_lock_exclusive	(	s4_index_t *	index,
		s4_transaction_t *	trans )

Referenced by _index_lock_exclusive(), _s4_add(), and _s4_del().

_index_lock_shared()

int _index_lock_shared	(	s4_index_t *	index,
		s4_transaction_t *	trans )

Referenced by _index_lock_shared(), _s4_add(), _s4_del(), and _s4_query().

_index_lsearch()

GList * _index_lsearch	(	s4_index_t *	index,
		index_function_t	func,
		void *	func_data )

Searches an index using a linear search.

Parameters

index	The index to search
func	The function to use when searching. It should return 0 if the value matches, -1 if the value is too small and 1 if the value is too big,
func_data	Data passed as the second argument to func

Returns

A GList where list->data is the data found matching

Referenced by _index_lsearch(), and _s4_query().

_index_search()

GList * _index_search	(	s4_index_t *	index,
		index_function_t	func,
		void *	func_data )

Searches an index.

Parameters

index	The index to search
func	The function to use when searching. It must be monotonic, It should return 0 if the value matches, -1 if the value is too small and 1 if the value is too big,
func_data	Data passed as the second argument to func

Returns

A GList where list->data is the data found matching

Referenced by _free_relations(), _index_search(), _s4_add(), _s4_add_internal(), _s4_del(), and _s4_query().