Detailed Description

An API for constructing LV2 atoms.

Data Structures
struct	LV2_Atom_Forge_Frame

struct	LV2_Atom_Forge

Typedefs
typedef void *	LV2_Atom_Forge_Sink_Handle

typedef intptr_t	LV2_Atom_Forge_Ref

typedef LV2_Atom_Forge_Ref(*	LV2_Atom_Forge_Sink) (LV2_Atom_Forge_Sink_Handle handle, const void *buf, uint32_t size)

typedef LV2_Atom (	LV2_Atom_Forge_Deref_Func) (LV2_Atom_Forge_Sink_Handle handle, LV2_Atom_Forge_Ref ref)

Functions
static void	lv2_atom_forge_init (LV2_Atom_Forge forge, LV2_URID_Map map)

static LV2_Atom *	lv2_atom_forge_deref (LV2_Atom_Forge *forge, LV2_Atom_Forge_Ref ref)

Output Configuration
static void	lv2_atom_forge_set_buffer (LV2_Atom_Forge forge, uint8_t buf, size_t size)

static void	lv2_atom_forge_set_sink (LV2_Atom_Forge *forge, LV2_Atom_Forge_Sink sink, LV2_Atom_Forge_Deref_Func deref, LV2_Atom_Forge_Sink_Handle handle)

Object Stack
static LV2_Atom_Forge_Ref	lv2_atom_forge_push (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame, LV2_Atom_Forge_Ref ref)

static void	lv2_atom_forge_pop (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame)

static bool	lv2_atom_forge_top_is (LV2_Atom_Forge *forge, uint32_t type)

static bool	lv2_atom_forge_is_object_type (const LV2_Atom_Forge *forge, uint32_t type)

static bool	lv2_atom_forge_is_blank (const LV2_Atom_Forge forge, uint32_t type, const LV2_Atom_Object_Body body)

Low Level Output
static LV2_Atom_Forge_Ref	lv2_atom_forge_raw (LV2_Atom_Forge forge, const void data, uint32_t size)

static void	lv2_atom_forge_pad (LV2_Atom_Forge *forge, uint32_t written)

static LV2_Atom_Forge_Ref	lv2_atom_forge_write (LV2_Atom_Forge forge, const void data, uint32_t size)

static LV2_Atom_Forge_Ref	lv2_atom_forge_string_body (LV2_Atom_Forge forge, const char str, uint32_t len)

Atom Output
static LV2_Atom_Forge_Ref	lv2_atom_forge_atom (LV2_Atom_Forge *forge, uint32_t size, uint32_t type)

static LV2_Atom_Forge_Ref	lv2_atom_forge_primitive (LV2_Atom_Forge forge, const LV2_Atom a)

static LV2_Atom_Forge_Ref	lv2_atom_forge_int (LV2_Atom_Forge *forge, int32_t val)

static LV2_Atom_Forge_Ref	lv2_atom_forge_long (LV2_Atom_Forge *forge, int64_t val)

static LV2_Atom_Forge_Ref	lv2_atom_forge_float (LV2_Atom_Forge *forge, float val)

static LV2_Atom_Forge_Ref	lv2_atom_forge_double (LV2_Atom_Forge *forge, double val)

static LV2_Atom_Forge_Ref	lv2_atom_forge_bool (LV2_Atom_Forge *forge, bool val)

static LV2_Atom_Forge_Ref	lv2_atom_forge_urid (LV2_Atom_Forge *forge, LV2_URID id)

static LV2_Atom_Forge_Ref	lv2_atom_forge_typed_string (LV2_Atom_Forge forge, uint32_t type, const char str, uint32_t len)

static LV2_Atom_Forge_Ref	lv2_atom_forge_string (LV2_Atom_Forge forge, const char str, uint32_t len)

static LV2_Atom_Forge_Ref	lv2_atom_forge_uri (LV2_Atom_Forge forge, const char uri, uint32_t len)

static LV2_Atom_Forge_Ref	lv2_atom_forge_path (LV2_Atom_Forge forge, const char path, uint32_t len)

static LV2_Atom_Forge_Ref	lv2_atom_forge_literal (LV2_Atom_Forge forge, const char str, uint32_t len, uint32_t datatype, uint32_t lang)

static LV2_Atom_Forge_Ref	lv2_atom_forge_vector_head (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame, uint32_t child_size, uint32_t child_type)

static LV2_Atom_Forge_Ref	lv2_atom_forge_vector (LV2_Atom_Forge forge, uint32_t child_size, uint32_t child_type, uint32_t n_elems, const void elems)

static LV2_Atom_Forge_Ref	lv2_atom_forge_tuple (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame)

static LV2_Atom_Forge_Ref	lv2_atom_forge_object (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame, LV2_URID id, LV2_URID otype)

static LV2_DEPRECATED LV2_Atom_Forge_Ref	lv2_atom_forge_resource (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame, LV2_URID id, LV2_URID otype)

static LV2_DEPRECATED LV2_Atom_Forge_Ref	lv2_atom_forge_blank (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame, uint32_t id, LV2_URID otype)

static LV2_Atom_Forge_Ref	lv2_atom_forge_key (LV2_Atom_Forge *forge, LV2_URID key)

static LV2_Atom_Forge_Ref	lv2_atom_forge_property_head (LV2_Atom_Forge *forge, LV2_URID key, LV2_URID context)

static LV2_Atom_Forge_Ref	lv2_atom_forge_sequence_head (LV2_Atom_Forge forge, LV2_Atom_Forge_Frame frame, uint32_t unit)

static LV2_Atom_Forge_Ref	lv2_atom_forge_frame_time (LV2_Atom_Forge *forge, int64_t frames)

static LV2_Atom_Forge_Ref	lv2_atom_forge_beat_time (LV2_Atom_Forge *forge, double beats)

Data Structure Documentation

◆ LV2_Atom_Forge_Frame

struct LV2_Atom_Forge_Frame

A stack frame used for keeping track of nested Atom containers.

Data Fields
struct LV2_Atom_Forge_Frame *	parent
LV2_Atom_Forge_Ref	ref

◆ LV2_Atom_Forge

struct LV2_Atom_Forge

A "forge" for creating atoms by appending to a buffer.

Data Fields
uint8_t *	buf
uint32_t	offset
uint32_t	size
LV2_Atom_Forge_Sink	sink
LV2_Atom_Forge_Deref_Func	deref
LV2_Atom_Forge_Sink_Handle	handle
LV2_Atom_Forge_Frame *	stack
LV2_URID Blank	LV2_DEPRECATED
LV2_URID	Bool
LV2_URID	Chunk
LV2_URID	Double
LV2_URID	Float
LV2_URID	Int
LV2_URID	Long
LV2_URID	Literal
LV2_URID	Object
LV2_URID	Path
LV2_URID	Property
LV2_URID Resource	LV2_DEPRECATED
LV2_URID	Sequence
LV2_URID	String
LV2_URID	Tuple
LV2_URID	URI
LV2_URID	URID
LV2_URID	Vector

Typedef Documentation

◆ LV2_Atom_Forge_Sink_Handle

typedef void* LV2_Atom_Forge_Sink_Handle

Handle for LV2_Atom_Forge_Sink.

◆ LV2_Atom_Forge_Ref

typedef intptr_t LV2_Atom_Forge_Ref

A reference to a chunk of written output.

◆ LV2_Atom_Forge_Sink

typedef LV2_Atom_Forge_Ref(* LV2_Atom_Forge_Sink) (LV2_Atom_Forge_Sink_Handle handle, const void *buf, uint32_t size)

Sink function for writing output.

See lv2_atom_forge_set_sink().

◆ LV2_Atom_Forge_Deref_Func

typedef LV2_Atom *(* LV2_Atom_Forge_Deref_Func) (LV2_Atom_Forge_Sink_Handle handle, LV2_Atom_Forge_Ref ref)

Function for resolving a reference.

See lv2_atom_forge_set_sink().

Function Documentation

◆ lv2_atom_forge_set_buffer()

static void lv2_atom_forge_set_buffer	(	LV2_Atom_Forge *	forge,
		uint8_t *	buf,
		size_t	size
	)

inlinestatic

Set the output buffer where forge will write atoms.

◆ lv2_atom_forge_init()

static void lv2_atom_forge_init	(	LV2_Atom_Forge *	forge,
		LV2_URID_Map *	map
	)

inlinestatic

Initialise forge.

URIs will be mapped using map and stored, a reference to map itself is not held.

◆ lv2_atom_forge_deref()

static LV2_Atom * lv2_atom_forge_deref	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Ref	ref
	)

inlinestatic

Access the Atom pointed to by a reference.

◆ lv2_atom_forge_push()

static LV2_Atom_Forge_Ref lv2_atom_forge_push	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame,
		LV2_Atom_Forge_Ref	ref
	)

inlinestatic

Push a stack frame.

This is done automatically by container functions (which take a stack frame pointer), but may be called by the user to push the top level container when writing to an existing Atom.

◆ lv2_atom_forge_pop()

static void lv2_atom_forge_pop	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame
	)

inlinestatic

Pop a stack frame.

This must be called when a container is finished.

◆ lv2_atom_forge_top_is()

static bool lv2_atom_forge_top_is	(	LV2_Atom_Forge *	forge,
		uint32_t	type
	)

inlinestatic

Return true iff the top of the stack has the given type.

◆ lv2_atom_forge_is_object_type()

static bool lv2_atom_forge_is_object_type	(	const LV2_Atom_Forge *	forge,
		uint32_t	type
	)

inlinestatic

Return true iff type is an atom:Object.

◆ lv2_atom_forge_is_blank()

static bool lv2_atom_forge_is_blank	(	const LV2_Atom_Forge *	forge,
		uint32_t	type,
		const LV2_Atom_Object_Body *	body
	)

inlinestatic

Return true iff type is an atom:Object with a blank ID.

◆ lv2_atom_forge_set_sink()

static void lv2_atom_forge_set_sink	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Sink	sink,
		LV2_Atom_Forge_Deref_Func	deref,
		LV2_Atom_Forge_Sink_Handle	handle
	)

inlinestatic

Set the sink function where forge will write output.

The return value of forge functions is an LV2_Atom_Forge_Ref which is an integer type safe to use as a pointer but is otherwise opaque. The sink function must return a ref that can be dereferenced to access as least sizeof(LV2_Atom) bytes of the written data, so sizes can be updated. For ringbuffers, this should be possible as long as the size of the buffer is a multiple of sizeof(LV2_Atom), since atoms are always aligned.

Note that 0 is an invalid reference, so if you are using a buffer offset be sure to offset it such that 0 is never a valid reference. You will get confusing errors otherwise.

◆ lv2_atom_forge_raw()

static LV2_Atom_Forge_Ref lv2_atom_forge_raw	(	LV2_Atom_Forge *	forge,
		const void *	data,
		uint32_t	size
	)

inlinestatic

Write raw output.

This is used internally, but is also useful for writing atom types not explicitly supported by the forge API. Note the caller is responsible for ensuring the output is appropriately padded.

◆ lv2_atom_forge_pad()

static void lv2_atom_forge_pad	(	LV2_Atom_Forge *	forge,
		uint32_t	written
	)

inlinestatic

Pad output accordingly so next write is 64-bit aligned.

◆ lv2_atom_forge_write()

static LV2_Atom_Forge_Ref lv2_atom_forge_write	(	LV2_Atom_Forge *	forge,
		const void *	data,
		uint32_t	size
	)

inlinestatic

Write raw output, padding to 64-bits as necessary.

◆ lv2_atom_forge_string_body()

static LV2_Atom_Forge_Ref lv2_atom_forge_string_body	(	LV2_Atom_Forge *	forge,
		const char *	str,
		uint32_t	len
	)

inlinestatic

Write a null-terminated string body.

◆ lv2_atom_forge_atom()

static LV2_Atom_Forge_Ref lv2_atom_forge_atom	(	LV2_Atom_Forge *	forge,
		uint32_t	size,
		uint32_t	type
	)

inlinestatic

Write an atom:Atom header.

◆ lv2_atom_forge_primitive()

static LV2_Atom_Forge_Ref lv2_atom_forge_primitive	(	LV2_Atom_Forge *	forge,
		const LV2_Atom *	a
	)

inlinestatic

Write a primitive (fixed-size) atom.

◆ lv2_atom_forge_int()

static LV2_Atom_Forge_Ref lv2_atom_forge_int	(	LV2_Atom_Forge *	forge,
		int32_t	val
	)

inlinestatic

Write an atom:Int.

◆ lv2_atom_forge_long()

static LV2_Atom_Forge_Ref lv2_atom_forge_long	(	LV2_Atom_Forge *	forge,
		int64_t	val
	)

inlinestatic

Write an atom:Long.

◆ lv2_atom_forge_float()

static LV2_Atom_Forge_Ref lv2_atom_forge_float	(	LV2_Atom_Forge *	forge,
		float	val
	)

inlinestatic

Write an atom:Float.

◆ lv2_atom_forge_double()

static LV2_Atom_Forge_Ref lv2_atom_forge_double	(	LV2_Atom_Forge *	forge,
		double	val
	)

inlinestatic

Write an atom:Double.

◆ lv2_atom_forge_bool()

static LV2_Atom_Forge_Ref lv2_atom_forge_bool	(	LV2_Atom_Forge *	forge,
		bool	val
	)

inlinestatic

Write an atom:Bool.

◆ lv2_atom_forge_urid()

static LV2_Atom_Forge_Ref lv2_atom_forge_urid	(	LV2_Atom_Forge *	forge,
		LV2_URID	id
	)

inlinestatic

Write an atom:URID.

◆ lv2_atom_forge_typed_string()

static LV2_Atom_Forge_Ref lv2_atom_forge_typed_string	(	LV2_Atom_Forge *	forge,
		uint32_t	type,
		const char *	str,
		uint32_t	len
	)

inlinestatic

Write an atom compatible with atom:String.

Used internally.

◆ lv2_atom_forge_string()

static LV2_Atom_Forge_Ref lv2_atom_forge_string	(	LV2_Atom_Forge *	forge,
		const char *	str,
		uint32_t	len
	)

inlinestatic

Write an atom:String.

Note that str need not be NULL terminated.

◆ lv2_atom_forge_uri()

static LV2_Atom_Forge_Ref lv2_atom_forge_uri	(	LV2_Atom_Forge *	forge,
		const char *	uri,
		uint32_t	len
	)

inlinestatic

Write an atom:URI.

Note that uri need not be NULL terminated. This does not map the URI, but writes the complete URI string. To write a mapped URI, use lv2_atom_forge_urid().

◆ lv2_atom_forge_path()

static LV2_Atom_Forge_Ref lv2_atom_forge_path	(	LV2_Atom_Forge *	forge,
		const char *	path,
		uint32_t	len
	)

inlinestatic

Write an atom:Path.

Note that path need not be NULL terminated.

◆ lv2_atom_forge_literal()

static LV2_Atom_Forge_Ref lv2_atom_forge_literal	(	LV2_Atom_Forge *	forge,
		const char *	str,
		uint32_t	len,
		uint32_t	datatype,
		uint32_t	lang
	)

inlinestatic

Write an atom:Literal.

◆ lv2_atom_forge_vector_head()

static LV2_Atom_Forge_Ref lv2_atom_forge_vector_head	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame,
		uint32_t	child_size,
		uint32_t	child_type
	)

inlinestatic

Start an atom:Vector.

◆ lv2_atom_forge_vector()

static LV2_Atom_Forge_Ref lv2_atom_forge_vector	(	LV2_Atom_Forge *	forge,
		uint32_t	child_size,
		uint32_t	child_type,
		uint32_t	n_elems,
		const void *	elems
	)

inlinestatic

Write a complete atom:Vector.

◆ lv2_atom_forge_tuple()

static LV2_Atom_Forge_Ref lv2_atom_forge_tuple	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame
	)

inlinestatic

Write the header of an atom:Tuple.

The passed frame will be initialised to represent this tuple. To complete the tuple, write a sequence of atoms, then pop the frame with lv2_atom_forge_pop().

For example:

// Write tuple (1, 2.0)
LV2_Atom_Forge_Frame frame;
LV2_Atom* tup = (LV2_Atom*)lv2_atom_forge_tuple(forge, &frame);
lv2_atom_forge_int(forge, 1);
lv2_atom_forge_float(forge, 2.0);
lv2_atom_forge_pop(forge, &frame);

◆ lv2_atom_forge_object()

static LV2_Atom_Forge_Ref lv2_atom_forge_object	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame,
		LV2_URID	id,
		LV2_URID	otype
	)

inlinestatic

Write the header of an atom:Object.

The passed frame will be initialised to represent this object. To complete the object, write a sequence of properties, then pop the frame with lv2_atom_forge_pop().

For example:

LV2_URID eg_Cat  = map("http://example.org/Cat");
LV2_URID eg_name = map("http://example.org/name");
 
// Start object with type eg_Cat and blank ID
LV2_Atom_Forge_Frame frame;
lv2_atom_forge_object(forge, &frame, 0, eg_Cat);
 
// Append property eg:name = "Hobbes"
lv2_atom_forge_key(forge, eg_name);
lv2_atom_forge_string(forge, "Hobbes", strlen("Hobbes"));
 
// Finish object
lv2_atom_forge_pop(forge, &frame);

◆ lv2_atom_forge_resource()

static LV2_DEPRECATED LV2_Atom_Forge_Ref lv2_atom_forge_resource	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame,
		LV2_URID	id,
		LV2_URID	otype
	)

inlinestatic

The same as lv2_atom_forge_object(), but for object:Resource.

This function is deprecated and should not be used in new code. Use lv2_atom_forge_object() directly instead.

◆ lv2_atom_forge_blank()

static LV2_DEPRECATED LV2_Atom_Forge_Ref lv2_atom_forge_blank	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame,
		uint32_t	id,
		LV2_URID	otype
	)

inlinestatic

The same as lv2_atom_forge_object(), but for object:Blank.

This function is deprecated and should not be used in new code. Use lv2_atom_forge_object() directly instead.

◆ lv2_atom_forge_key()

static LV2_Atom_Forge_Ref lv2_atom_forge_key	(	LV2_Atom_Forge *	forge,
		LV2_URID	key
	)

inlinestatic

Write a property key in an Object, to be followed by the value.

See lv2_atom_forge_object() documentation for an example.

◆ lv2_atom_forge_property_head()

static LV2_Atom_Forge_Ref lv2_atom_forge_property_head	(	LV2_Atom_Forge *	forge,
		LV2_URID	key,
		LV2_URID	context
	)

inlinestatic

Write the header for a property body in an object, with context.

If you do not need the context, which is almost certainly the case, use the simpler lv2_atom_forge_key() instead.

◆ lv2_atom_forge_sequence_head()

static LV2_Atom_Forge_Ref lv2_atom_forge_sequence_head	(	LV2_Atom_Forge *	forge,
		LV2_Atom_Forge_Frame *	frame,
		uint32_t	unit
	)

inlinestatic

Write the header for a Sequence.

◆ lv2_atom_forge_frame_time()

static LV2_Atom_Forge_Ref lv2_atom_forge_frame_time	(	LV2_Atom_Forge *	forge,
		int64_t	frames
	)

inlinestatic

Write the time stamp header of an Event (in a Sequence) in audio frames.

After this, call the appropriate forge method(s) to write the body. Note the returned reference is to an LV2_Event which is NOT an Atom.

◆ lv2_atom_forge_beat_time()

static LV2_Atom_Forge_Ref lv2_atom_forge_beat_time	(	LV2_Atom_Forge *	forge,
		double	beats
	)

inlinestatic

Write the time stamp header of an Event (in a Sequence) in beats.

After this, call the appropriate forge method(s) to write the body. Note the returned reference is to an LV2_Event which is NOT an Atom.

LV2

Detailed Description

Data Structures

Typedefs

Functions

Output Configuration

Object Stack

Low Level Output

Atom Output

Data Structure Documentation

◆ LV2_Atom_Forge_Frame

◆ LV2_Atom_Forge

Typedef Documentation

◆ LV2_Atom_Forge_Sink_Handle

◆ LV2_Atom_Forge_Ref

◆ LV2_Atom_Forge_Sink

◆ LV2_Atom_Forge_Deref_Func

Function Documentation

◆ lv2_atom_forge_set_buffer()

◆ lv2_atom_forge_init()

◆ lv2_atom_forge_deref()

◆ lv2_atom_forge_push()

◆ lv2_atom_forge_pop()

◆ lv2_atom_forge_top_is()

◆ lv2_atom_forge_is_object_type()

◆ lv2_atom_forge_is_blank()

◆ lv2_atom_forge_set_sink()

◆ lv2_atom_forge_raw()

◆ lv2_atom_forge_pad()

◆ lv2_atom_forge_write()

◆ lv2_atom_forge_string_body()

◆ lv2_atom_forge_atom()

◆ lv2_atom_forge_primitive()

◆ lv2_atom_forge_int()

◆ lv2_atom_forge_long()

◆ lv2_atom_forge_float()

◆ lv2_atom_forge_double()

◆ lv2_atom_forge_bool()

◆ lv2_atom_forge_urid()

◆ lv2_atom_forge_typed_string()

◆ lv2_atom_forge_string()

◆ lv2_atom_forge_uri()

◆ lv2_atom_forge_path()

◆ lv2_atom_forge_literal()

◆ lv2_atom_forge_vector_head()

◆ lv2_atom_forge_vector()

◆ lv2_atom_forge_tuple()

◆ lv2_atom_forge_object()

◆ lv2_atom_forge_resource()

◆ lv2_atom_forge_blank()

◆ lv2_atom_forge_key()

◆ lv2_atom_forge_property_head()

◆ lv2_atom_forge_sequence_head()

◆ lv2_atom_forge_frame_time()

◆ lv2_atom_forge_beat_time()