[lttng-dev] [barectf] Support for empty payload ?

[Simon Marchi]

On 2016-03-25 10:14, Jean-François Monestier wrote:
> Hello Tracers,
> 
> Does anyone know whether barectf supports some sort of empty payloads
> for events specified in the .yaml configuration file ?
> 
> Something such as the well-known lttng_ust_statedump:start event :
> 
> event {
>         name = "lttng_ust_statedump:start";
>         id = 0;
>         stream_id = 0;
>         loglevel = 13;
>         fields := struct {
>         };
> };
> 
> I can't figure out the yaml syntax for such an event, your help would
> be welcome.
> 
> I must confess I'm still stuck to barectf v2.0.2
> 
> 
> Thanks in advance,

Hi Jean-François,

I don't believe barectf allows specifying empty payloads as of now.  
Trying to specify an empty fields dict, such as:

simple_uint32:
   log-level: CRIT
   payload-type:
     class: struct
     fields: {}

yields:

Error:
   cannot create configuration from YAML file "config.yaml":
   metadata error:
   invalid event in stream "default":
   event payload type must have at least one field for event 
"simple_uint32"

See: 
https://github.com/efficios/barectf/blob/master/barectf/config.py#L1119

The maintainers will be able to confirm/infirm, and say whether it's in 
the plans to add support for that.

Simon