Condition

Functions to create and use S4 search conditions. More...

Functions
s4_condition_t *	s4_cond_new_combiner (s4_combine_type_t type)
	Creates a new combiner. More...
s4_condition_t *	s4_cond_new_custom_combiner (combine_function_t func)
	Creates a new combiner with a user specified combiner function. More...
void	s4_cond_add_operand (s4_condition_t *cond, s4_condition_t *operand)
	Adds and references an operand to a combiner condition. More...
s4_condition_t *	s4_cond_get_operand (s4_condition_t *cond, int operand)
	Gets an operand from a combiner condition. More...
s4_condition_t *	s4_cond_new_filter (s4_filter_type_t type, const char *key, const s4_val_t *value, s4_sourcepref_t *sourcepref, s4_cmp_mode_t cmp_mode, int flags)
	Creates a new filter condition. More...
s4_condition_t *	s4_cond_new_custom_filter (filter_function_t func, void *userdata, free_func_t free, const char *key, s4_sourcepref_t *sourcepref, s4_cmp_mode_t cmp_mode, int monotonic, int flags)
	Creates a new filter condition with a user specified filter function. More...
int	s4_cond_is_filter (s4_condition_t *cond)
	Checks if this condition is a filter condition. More...
int	s4_cond_is_combiner (s4_condition_t *cond)
	Checks if this condition is a combiner condition. More...
s4_filter_type_t	s4_cond_get_filter_type (s4_condition_t *cond)
s4_combine_type_t	s4_cond_get_combiner_type (s4_condition_t *cond)
int	s4_cond_get_flags (s4_condition_t *cond)
	Gets the flags for a condition. More...
const char *	s4_cond_get_key (s4_condition_t *cond)
	Gets the key for a condition. More...
s4_sourcepref_t *	s4_cond_get_sourcepref (s4_condition_t *cond)
	Gets the source preference that should be used. More...
void *	s4_cond_get_funcdata (s4_condition_t *cond)
	Returns the data that should be fed to the filter function. More...
void	s4_cond_free (s4_condition_t *cond)
	Frees a condition and operands recursively. More...
s4_condition_t *	s4_cond_ref (s4_condition_t *cond)
	Increments the reference count of a condition. More...
void	s4_cond_unref (s4_condition_t *cond)
	Decrements the reference count of a condition. More...
filter_function_t	s4_cond_get_filter_function (s4_condition_t *cond)
	Gets the filter function for the condition. More...
combine_function_t	s4_cond_get_combine_function (s4_condition_t *cond)
	Gets the combine function for the condition. More...
int	s4_cond_is_monotonic (s4_condition_t *cond)
	Checks if the condition is a monotonic filter. More...
int	s4_cond_get_cmp_mode (s4_condition_t *cond)
	Gets the comparison mode used by the filter condition. More...
void	s4_cond_update_key (s4_condition_t *cond, s4_t *s4)
	Change the key with a constant key for faster checking. More...

Detailed Description

Functions to create and use S4 search conditions.

Function Documentation

void s4_cond_add_operand	(	s4_condition_t *	cond,
		s4_condition_t *	operand
	)

Adds and references an operand to a combiner condition.

Parameters

cond	The condition to add to
operand	The operand to add

Referenced by CASE().

void s4_cond_free

(

s4_condition_t *

cond

)

Frees a condition and operands recursively.

Parameters

cond	The condition to free

Referenced by CASE(), s4_cond_unref(), xmms_medialib_query_recurs(), and xmms_medialib_session_property_set().

int s4_cond_get_cmp_mode

(

s4_condition_t *

cond

)

Gets the comparison mode used by the filter condition.

Parameters

cond	The condition to check

Returns

The comparison mode used

combine_function_t s4_cond_get_combine_function

(

s4_condition_t *

cond

)

Gets the combine function for the condition.

This function does not check if the condition is actually a combine condition, if it's called on a condition that is not a combiner it will return bogus data

Parameters

cond	The condition to get the combine function of

Returns

The combine function

s4_combine_type_t s4_cond_get_combiner_type

(

s4_condition_t *

cond

)

Referenced by print_cond().

filter_function_t s4_cond_get_filter_function

(

s4_condition_t *

cond

)

Gets the filter function for the condition.

This function does not check if the condition is actually a filter condition, if it is called on a condition that is not a filter it will return bogus data

Parameters

cond	The condition to get the filter function of

Returns

The filter function

Referenced by _s4_query(), and CASE().

s4_filter_type_t s4_cond_get_filter_type

(

s4_condition_t *

cond

)

Referenced by print_cond().

int s4_cond_get_flags

(

s4_condition_t *

cond

)

Gets the flags for a condition.

Parameters

cond	The condition to get the flags of

Returns

The flags

Referenced by _s4_query().

void* s4_cond_get_funcdata

(

s4_condition_t *

cond

)

Returns the data that should be fed to the filter function.

Parameters

cond	The condition to get the function data of

Returns

The function data

Referenced by print_cond().

const char* s4_cond_get_key

(

s4_condition_t *

cond

)

Gets the key for a condition.

Parameters

cond	The condition to get the key of

Returns

The key

Referenced by _s4_query(), and print_cond().

s4_condition_t* s4_cond_get_operand	(	s4_condition_t *	cond,
		int	operand
	)

Gets an operand from a combiner condition.

Parameters

cond	The condition to get the operand from
operand	The index of the operand to get

Returns

The operand, or NULL if the index is out of bounds or cond is not a combiner condition. The reference is still held by cond, so you must not call s4_cond_unref on the returned condition.

Referenced by print_cond().

s4_sourcepref_t* s4_cond_get_sourcepref

(

s4_condition_t *

cond

)

Gets the source preference that should be used.

Parameters

cond	The condition to get the source preference of

Returns

The source preference

int s4_cond_is_combiner

(

s4_condition_t *

cond

)

Checks if this condition is a combiner condition.

Parameters

cond	The condition to check

Returns

non-zero if the condition is a combiner, 0 otherwise

int s4_cond_is_filter

(

s4_condition_t *

cond

)

Checks if this condition is a filter condition.

Parameters

cond	The condition to check

Returns

non-zero if the condition is a filter, 0 otherwise

Referenced by _s4_query(), and print_cond().

int s4_cond_is_monotonic

(

s4_condition_t *

cond

)

Checks if the condition is a monotonic filter.

A monotonic filter is a filter that preserves the order, and it can thus be used to search in an index.

Parameters

cond	The condition to check

Returns

non-zero if the condition is monotonic, 0 otherwise

Referenced by _s4_query().

s4_condition_t* s4_cond_new_combiner

(

s4_combine_type_t

type

)

Creates a new combiner.

Parameters

type	The combiner type

Returns

A new combiner

s4_condition_t* s4_cond_new_custom_combiner

(

combine_function_t

func

)

Creates a new combiner with a user specified combiner function.

Parameters

func	The combiner function to use

Returns

A new custom combiner

Referenced by CASE().

s4_condition_t* s4_cond_new_custom_filter	(	filter_function_t	func,
		void *	userdata,
		free_func_t	free,
		const char *	key,
		s4_sourcepref_t *	sourcepref,
		s4_cmp_mode_t	cmp_mode,
		int	monotonic,
		int	flags
	)

Creates a new filter condition with a user specified filter function.

The filter function should return 0 if the value meets the condition, non-zero otherwise.

Parameters

func	The filter function to use
userdata	The data that will be passed to the function along with the value to check
free	The function that should be called to free userdata
key	The key the condition should check
sourcepref	The source preference
cmp_mode	The comparison mode to use
flags	Condition flags, or 0

Returns

A new custom filter condition

Referenced by CASE().

s4_condition_t* s4_cond_new_filter	(	s4_filter_type_t	type,
		const char *	key,
		const s4_val_t *	value,
		s4_sourcepref_t *	sourcepref,
		s4_cmp_mode_t	cmp_mode,
		int	flags
	)

Creates a new filter condition.

Parameters

type	The type of the filter
key	The key the condition should check
value	The value to check against
sourcepref	The source preference
cmp_mode	The comparison mode to use
flags	Condition flags, or 0

Returns

A new filter condition

Referenced by CASE(), and xmms_medialib_session_property_set().

s4_condition_t* s4_cond_ref

(

s4_condition_t *

cond

)

Increments the reference count of a condition.

Parameters

cond	The condition to reference

Returns

The condition given

Referenced by s4_cond_add_operand().

void s4_cond_unref

(

s4_condition_t *

cond

)

Decrements the reference count of a condition.

If the reference count is 0 after this, the condition is freed.

Parameters

cond	The condition to decrement the count of

Referenced by CASE(), s4_cond_new_combiner(), and s4_cond_new_custom_combiner().

void s4_cond_update_key	(	s4_condition_t *	cond,
		s4_t *	s4
	)

Change the key with a constant key for faster checking.

Parameters

s4	The database to optimize for
cond	The condition to update

Referenced by _s4_query().