Utilities

Detailed Description

Utilities for working with atoms.

Data Structures
struct	LV2_Atom_Object_Query

Functions
static uint32_t	lv2_atom_pad_size (uint32_t size)
static uint32_t	lv2_atom_total_size (const LV2_Atom *atom)
static bool	lv2_atom_is_null (const LV2_Atom *atom)
static bool	lv2_atom_equals (const LV2_Atom *a, const LV2_Atom *b)

Object Query
static const LV2_Atom_Object_Query	LV2_ATOM_OBJECT_QUERY_END = {0, NULL}
static int	lv2_atom_object_query (const LV2_Atom_Object *object, LV2_Atom_Object_Query *query)
static int	lv2_atom_object_body_get (uint32_t size, const LV2_Atom_Object_Body *body,...)
static int	lv2_atom_object_get (const LV2_Atom_Object *object,...)
static int	lv2_atom_object_get_typed (const LV2_Atom_Object *object,...)

Sequence Iterator
static LV2_Atom_Event *	lv2_atom_sequence_begin (const LV2_Atom_Sequence_Body *body)
static LV2_Atom_Event *	lv2_atom_sequence_end (const LV2_Atom_Sequence_Body *body, uint32_t size)
static bool	lv2_atom_sequence_is_end (const LV2_Atom_Sequence_Body *body, uint32_t size, const LV2_Atom_Event *i)
static LV2_Atom_Event *	lv2_atom_sequence_next (const LV2_Atom_Event *i)
#define	LV2_ATOM_SEQUENCE_FOREACH(seq, iter)
#define	LV2_ATOM_SEQUENCE_BODY_FOREACH(body, size, iter)

Sequence Utilities
static void	lv2_atom_sequence_clear (LV2_Atom_Sequence *seq)
static LV2_Atom_Event *	lv2_atom_sequence_append_event (LV2_Atom_Sequence *seq, uint32_t capacity, const LV2_Atom_Event *event)

Tuple Iterator
static LV2_Atom *	lv2_atom_tuple_begin (const LV2_Atom_Tuple *tup)
static bool	lv2_atom_tuple_is_end (const void *body, uint32_t size, const LV2_Atom *i)
static LV2_Atom *	lv2_atom_tuple_next (const LV2_Atom *i)
#define	LV2_ATOM_TUPLE_FOREACH(tuple, iter)
#define	LV2_ATOM_TUPLE_BODY_FOREACH(body, size, iter)

Object Iterator
static LV2_Atom_Property_Body *	lv2_atom_object_begin (const LV2_Atom_Object_Body *body)
static bool	lv2_atom_object_is_end (const LV2_Atom_Object_Body *body, uint32_t size, const LV2_Atom_Property_Body *i)
static LV2_Atom_Property_Body *	lv2_atom_object_next (const LV2_Atom_Property_Body *i)
#define	LV2_ATOM_OBJECT_FOREACH(obj, iter)
#define	LV2_ATOM_OBJECT_BODY_FOREACH(body, size, iter)

---

Data Structure Documentation

LV2_Atom_Object_Query

struct LV2_Atom_Object_Query

A single entry in an Object query.

Data Fields
uint32_t	key	Key to query (input set by user)
const LV2_Atom **	value	Found value (output set by query function)

Macro Definition Documentation

LV2_ATOM_SEQUENCE_FOREACH

#define LV2_ATOM_SEQUENCE_FOREACH	(		seq,
			iter
	)

Value:

  for (LV2_Atom_Event * iter = lv2_atom_sequence_begin(&(seq)->body);   \
       !lv2_atom_sequence_is_end(&(seq)->body, (seq)->atom.size, (iter)); \
       (iter) = lv2_atom_sequence_next(iter))

A macro for iterating over all events in a Sequence.

Parameters

seq	The sequence to iterate over
iter	The name of the iterator

This macro is used similarly to a for loop (which it expands to), for example:

LV2_ATOM_SEQUENCE_FOREACH(sequence, ev) {
    // Do something with ev (an LV2_Atom_Event*) here...
}

LV2_ATOM_SEQUENCE_BODY_FOREACH

#define LV2_ATOM_SEQUENCE_BODY_FOREACH	(		body,
			size,
			iter
	)

Value:

  for (LV2_Atom_Event * iter = lv2_atom_sequence_begin(body); \
       !lv2_atom_sequence_is_end(body, size, (iter));           \
       (iter) = lv2_atom_sequence_next(iter))

Like LV2_ATOM_SEQUENCE_FOREACH but for a headerless sequence body.

LV2_ATOM_TUPLE_FOREACH

#define LV2_ATOM_TUPLE_FOREACH	(		tuple,
			iter
	)

Value:

  for (LV2_Atom * iter = lv2_atom_tuple_begin(tuple);     \
       !lv2_atom_tuple_is_end(                              \
         LV2_ATOM_BODY(tuple), (tuple)->atom.size, (iter)); \
       (iter) = lv2_atom_tuple_next(iter))

A macro for iterating over all properties of a Tuple.

Parameters

tuple	The tuple to iterate over
iter	The name of the iterator

This macro is used similarly to a for loop (which it expands to), for example:

LV2_ATOM_TUPLE_FOREACH(tuple, elem) {
    // Do something with elem (an LV2_Atom*) here...
}

LV2_ATOM_TUPLE_BODY_FOREACH

#define LV2_ATOM_TUPLE_BODY_FOREACH	(		body,
			size,
			iter
	)

Value:

  for (LV2_Atom * iter = (LV2_Atom*)(body);         \
       !lv2_atom_tuple_is_end(body, size, (iter));    \
       (iter) = lv2_atom_tuple_next(iter))

Like LV2_ATOM_TUPLE_FOREACH but for a headerless tuple body.

LV2_ATOM_OBJECT_FOREACH

#define LV2_ATOM_OBJECT_FOREACH	(		obj,
			iter
	)

Value:

  for (LV2_Atom_Property_Body * iter = lv2_atom_object_begin(&(obj)->body); \
       !lv2_atom_object_is_end(&(obj)->body, (obj)->atom.size, (iter));       \
       (iter) = lv2_atom_object_next(iter))

A macro for iterating over all properties of an Object.

Parameters

obj	The object to iterate over
iter	The name of the iterator

This macro is used similarly to a for loop (which it expands to), for example:

LV2_ATOM_OBJECT_FOREACH(object, i) {
    // Do something with i (an LV2_Atom_Property_Body*) here...
}

LV2_ATOM_OBJECT_BODY_FOREACH

#define LV2_ATOM_OBJECT_BODY_FOREACH	(		body,
			size,
			iter
	)

Value:

  for (LV2_Atom_Property_Body * iter = lv2_atom_object_begin(body); \
       !lv2_atom_object_is_end(body, size, (iter));                   \
       (iter) = lv2_atom_object_next(iter))

Like LV2_ATOM_OBJECT_FOREACH but for a headerless object body.

Function Documentation

lv2_atom_pad_size()

static uint32_t lv2_atom_pad_size ( uint32_t  size )

inlinestatic

Pad a size to 64 bits.

lv2_atom_total_size()

static uint32_t lv2_atom_total_size ( const LV2_Atom *  atom )

inlinestatic

Return the total size of atom, including the header.

lv2_atom_is_null()

static bool lv2_atom_is_null ( const LV2_Atom *  atom )

inlinestatic

Return true iff atom is null.

lv2_atom_equals()

static bool lv2_atom_equals ( const LV2_Atom *  a, const LV2_Atom *  b  )

inlinestatic

Return true iff a is equal to b.

lv2_atom_sequence_begin()

static LV2_Atom_Event * lv2_atom_sequence_begin ( const LV2_Atom_Sequence_Body *  body )

inlinestatic

Get an iterator pointing to the first event in a Sequence body.

lv2_atom_sequence_end()

static LV2_Atom_Event * lv2_atom_sequence_end ( const LV2_Atom_Sequence_Body *  body, uint32_t  size  )

inlinestatic

Get an iterator pointing to the end of a Sequence body.

lv2_atom_sequence_is_end()

static bool lv2_atom_sequence_is_end ( const LV2_Atom_Sequence_Body *  body, uint32_t  size, const LV2_Atom_Event *  i  )

inlinestatic

Return true iff i has reached the end of body.

lv2_atom_sequence_next()

static LV2_Atom_Event * lv2_atom_sequence_next ( const LV2_Atom_Event *  i )

inlinestatic

Return an iterator to the element following i.

lv2_atom_sequence_clear()

static void lv2_atom_sequence_clear ( LV2_Atom_Sequence *  seq )

inlinestatic

Clear all events from sequence.

This simply resets the size field, the other fields are left untouched.

lv2_atom_sequence_append_event()

static LV2_Atom_Event * lv2_atom_sequence_append_event ( LV2_Atom_Sequence *  seq, uint32_t  capacity, const LV2_Atom_Event *  event  )

inlinestatic

Append an event at the end of sequence.

Parameters

seq	Sequence to append to.
capacity	Total capacity of the sequence atom (as set by the host for sequence output ports).
event	Event to write.

Returns

A pointer to the newly written event in seq, or NULL on failure (insufficient space).

lv2_atom_tuple_begin()

static LV2_Atom * lv2_atom_tuple_begin ( const LV2_Atom_Tuple *  tup )

inlinestatic

Get an iterator pointing to the first element in tup.

lv2_atom_tuple_is_end()

static bool lv2_atom_tuple_is_end ( const void *  body, uint32_t  size, const LV2_Atom *  i  )

inlinestatic

Return true iff i has reached the end of body.

lv2_atom_tuple_next()

static LV2_Atom * lv2_atom_tuple_next ( const LV2_Atom *  i )

inlinestatic

Return an iterator to the element following i.

lv2_atom_object_begin()

static LV2_Atom_Property_Body * lv2_atom_object_begin ( const LV2_Atom_Object_Body *  body )

inlinestatic

Return a pointer to the first property in body.

lv2_atom_object_is_end()

static bool lv2_atom_object_is_end ( const LV2_Atom_Object_Body *  body, uint32_t  size, const LV2_Atom_Property_Body *  i  )

inlinestatic

Return true iff i has reached the end of obj.

lv2_atom_object_next()

static LV2_Atom_Property_Body * lv2_atom_object_next ( const LV2_Atom_Property_Body *  i )

inlinestatic

Return an iterator to the property following i.

lv2_atom_object_query()

static int lv2_atom_object_query ( const LV2_Atom_Object *  object, LV2_Atom_Object_Query *  query  )

inlinestatic

Get an object's values for various keys.

The value pointer of each item in query will be set to the location of the corresponding value in object. Every value pointer in query MUST be initialised to NULL. This function reads object in a single linear sweep. By allocating query on the stack, objects can be "queried" quickly without allocating any memory. This function is realtime safe.

This function can only do "flat" queries, it is not smart enough to match variables in nested objects.

For example:

const LV2_Atom* name = NULL;
const LV2_Atom* age  = NULL;
LV2_Atom_Object_Query q[] = {
    { urids.eg_name, &name },
    { urids.eg_age,  &age },
    LV2_ATOM_OBJECT_QUERY_END
};
lv2_atom_object_query(obj, q);
// name and age are now set to the appropriate values in obj, or NULL.

lv2_atom_object_body_get()

static int lv2_atom_object_body_get ( uint32_t  size, const LV2_Atom_Object_Body *  body,   ...  )

inlinestatic

Body only version of lv2_atom_object_get().

lv2_atom_object_get()

static int lv2_atom_object_get ( const LV2_Atom_Object *  object,   ...  )

inlinestatic

Variable argument version of lv2_atom_object_query().

This is nicer-looking in code, but a bit more error-prone since it is not type safe and the argument list must be terminated.

The arguments should be a series of uint32_t key and const LV2_Atom** value pairs, terminated by a zero key. The value pointers MUST be initialized to NULL. For example:

const LV2_Atom* name = NULL;
const LV2_Atom* age  = NULL;
lv2_atom_object_get(obj,
                    uris.name_key, &name,
                    uris.age_key,  &age,
                    0);

lv2_atom_object_get_typed()

static int lv2_atom_object_get_typed ( const LV2_Atom_Object *  object,   ...  )

inlinestatic

Variable argument version of lv2_atom_object_query() with types.

This is like lv2_atom_object_get(), but each entry has an additional parameter to specify the required type. Only atoms with a matching type will be selected.

The arguments should be a series of uint32_t key, const LV2_Atom**, uint32_t type triples, terminated by a zero key. The value pointers MUST be initialized to NULL. For example:

const LV2_Atom_String* name = NULL;
const LV2_Atom_Int*    age  = NULL;
lv2_atom_object_get(obj,
                    uris.name_key, &name, uris.atom_String,
                    uris.age_key,  &age, uris.atom_Int
                    0);

Variable Documentation

LV2_ATOM_OBJECT_QUERY_END

const LV2_Atom_Object_Query LV2_ATOM_OBJECT_QUERY_END = {0, NULL}

static

Sentinel for lv2_atom_object_query().