Detailed Description

Helper methods to read and write signals within a stream

Typedefs
typedef struct ed247_internal_stream_assistant_t *	ed247_stream_assistant_t
	An assistant to help building stream samples.

Functions
LIBED247_EXPORT ed247_status_t	ed247_stream_assistant_get_stream (ed247_stream_assistant_t assistant, ed247_stream_t *stream)
	Get the stream associated to the assistant. More...

LIBED247_EXPORT ed247_status_t	ed247_stream_assistant_write_signal (ed247_stream_assistant_t assistant, ed247_signal_t signal, const void *signal_sample_data, uint32_t signal_sample_size)
	Write a signal into the assistant sample buffer. More...

LIBED247_EXPORT bool	ed247_stream_assistant_was_written (ed247_stream_assistant_t assistant)
	Return true if a signal has been written since last ed247_stream_assistant_push_sample().

LIBED247_EXPORT ed247_status_t	ed247_stream_assistant_read_signal (ed247_stream_assistant_t assistant, ed247_signal_t signal, const void *signal_sample_data, uint32_t signal_sample_size)
	Read a signal sample from the assistant sample buffer. More...

LIBED247_EXPORT ed247_status_t	ed247_stream_assistant_push_sample (ed247_stream_assistant_t assistant, const ed247_timestamp_t data_timestamp, bool full)
	Push the assistant sample buffer on the stream stack. More...

LIBED247_EXPORT ed247_status_t	ed247_stream_assistants_written_push_samples (ed247_context_t context, const ed247_timestamp_t *data_timestamp)
	Push all stream assistants whose signals have been written since last push_sample() More...

LIBED247_EXPORT ed247_status_t	ed247_stream_assistant_pop_sample (ed247_stream_assistant_t assistant, const ed247_timestamp_t data_timestamp, const ed247_timestamp_t recv_timestamp, const ed247_sample_details_t *sample_details, bool empty)
	Pop a sample from stream samples stack. More...

LIBED247_EXPORT ed247_status_t	stream_assistants_pop_samples (ed247_context_t context)
	Pop all samples of all input stream assistants. aka 'update all signals'. More...

Function Documentation

LIBED247_EXPORT ed247_status_t ed247_stream_assistant_get_stream	(	ed247_stream_assistant_t	assistant,
		ed247_stream_t *	stream
	)

Get the stream associated to the assistant.

Parameters

[in]	assistant	Assistant identifier
[out]	stream	Stream identifier pointer

Return values

ED247_STATUS_SUCCESS
ED247_STATUS_FAILURE

LIBED247_EXPORT ed247_status_t ed247_stream_assistant_write_signal	(	ed247_stream_assistant_t	assistant,
		ed247_signal_t	signal,
		const void *	signal_sample_data,
		uint32_t	signal_sample_size
	)

Write a signal into the assistant sample buffer.

This function manage endianness (analogue, NAD, VNAD).

The signal_sample_size shall be set to:

1 for DISCRETE,
4 for ANALOGUE (float),
nad_type_size * dimensions for NAD,
a multiple of nad_type_size for VNAD.

Once signals are written, call ed247_stream_assistant_push_sample() to push the sample on the stream stack.
if a non-VNAD signal is not wrotten before the push, the previous value will be sent (0 if never wrote).
if a VNAD signal is not wrotten before the push, it will not be part of the payload.
See also ed247_stream_assistants_written_push_samples().

Parameters

[in]	assistant	Assistant identifier
[in]	signal	Signal identifier
[in]	signal_sample_data	Retrieve pointer of allocated memory
[in]	signal_sample_size	Retrieve size of allocated memory

Return values

ED247_STATUS_SUCCESS
ED247_STATUS_FAILURE

LIBED247_EXPORT ed247_status_t ed247_stream_assistant_read_signal	(	ed247_stream_assistant_t	assistant,
		ed247_signal_t	signal,
		const void **	signal_sample_data,
		uint32_t *	signal_sample_size
	)

Read a signal sample from the assistant sample buffer.

/!\ The assistant sample buffer is updated by ed247_stream_assistant_pop_sample() or stream_assistants_pop_samples().

This function manage endianness (analogue, NAD, VNAD).

The signal_sample_size will be be set to:

1 for DISCRETE,
4 for ANALOGUE (float),
nad_type_size * dimensions for NAD,
a multiple of nad_type_size for VNAD (including 0).

Parameters

[in]	assistant	Assistant identifier
[in]	signal	Signal identifier
[in]	signal_sample_data	Retrieve pointer of the stream sample allocated in memory
[in]	signal_sample_size	Retrieve size of the stream sample allocated in memory

Return values

ED247_STATUS_SUCCESS
ED247_STATUS_FAILURE

LIBED247_EXPORT ed247_status_t ed247_stream_assistant_push_sample	(	ed247_stream_assistant_t	assistant,
		const ed247_timestamp_t *	data_timestamp,
		bool *	full
	)

Push the assistant sample buffer on the stream stack.

Data will be effectively sent by ed247_send_pushed_samples().
If internal stack is full, the oldest sample will be silently dropped. This is not an error.

Signals shall have been wrotten by ed247_stream_assistant_write_signal().
if a non-VNAD signal is not wrotten before the push, the previous value will be sent (0 if never wrote).
if a VNAD signal is not wrotten before the push, it will not be part of the payload.
See also ed247_stream_assistants_written_push_samples().

Parameters

[in]	assistant	Assistant identifier
[in]	data_timestamp	either NULL or define the data timestamp associated with the sample.
[out]	full	set to true if the internal stack is full after the push. Set to NULL if not desired

Return values

ED247_STATUS_SUCCESS
ED247_STATUS_FAILURE

LIBED247_EXPORT ed247_status_t ed247_stream_assistants_written_push_samples	(	ed247_context_t	context,
		const ed247_timestamp_t *	data_timestamp
	)

Push all stream assistants whose signals have been written since last push_sample()

This function will check, for each output stream assistant, if some signals have been written (call to ed247_stream_assistant_was_written()). It will push all the assistants that match. (call to ed247_stream_assistant_push_sample()). The stream will be effectively send by calling ed247_send_pushed_samples().

Parameters

[in]	context	Context
[in]	data_timestamp	either NULL or define the data timestamp associated with the sample.

Return values

ED247_STATUS_SUCCESS
ED247_STATUS_FAILURE

LIBED247_EXPORT ed247_status_t ed247_stream_assistant_pop_sample	(	ed247_stream_assistant_t	assistant,
		const ed247_timestamp_t **	data_timestamp,
		const ed247_timestamp_t **	recv_timestamp,
		const ed247_sample_details_t **	sample_details,
		bool *	empty
	)

Pop a sample from stream samples stack.

This function will fill assistant sample buffer that can be readed with ed247_stream_assistant_read_signal().

Argument empty, if not NULL, will be set to false if the stream stack is empty after the pop.
Return value will be ED247_STATUS_NODATA if the stream stack is empty before the pop.

Parameters

[in]	assistant	Assistant identifier
[out]	data_timestamp	if not NULL, filed with the data timestamp associated with the sample.
[out]	recv_timestamp	if not NULL, filed with the receive timestamp. See ed247_get_receive_timestamp().
[out]	sample_details	Stream sample details
[out]	empty	set to true if the internal stack is empty after the pop.

Return values

ED247_STATUS_SUCCESS
ED247_STATUS_NODATA	Receive stack is empty before the pop.
ED247_STATUS_FAILURE

LIBED247_EXPORT ed247_status_t stream_assistants_pop_samples ( ed247_context_t context )

Pop all samples of all input stream assistants. aka 'update all signals'.

After this call, all stream assistants will provide the last received signals value throught ed247_stream_assistant_read_signal(). If a singal has never been received, its value will be 0. This function is equivalent to call ed247_stream_assistant_pop_sample() on all stream assistants until all fifos are empties.

Parameters

[in] context Context

Returns: ED247_STATUS_FAILURE on fatal error, else ED247_STATUS_SUCCESS.

Detailed Description

Typedefs

Functions

Function Documentation