[lttng-dev] CTF2-PROP-1.0: Proposal for a major revision of the Common Trace Format, version 1.8

[Jérémie Galarneau]

On 11 December 2016 at 12:49, Philippe Proulx <pproulx at efficios.com> wrote:
> ----- Original Message -----
>> From: "Jérémie Galarneau" <jeremie.galarneau at efficios.com>
>> To: "Philippe Proulx" <pproulx at efficios.com>
>> Cc: "diamon-discuss" <diamon-discuss at lists.linuxfoundation.org>, "lttng-dev" <lttng-dev at lists.lttng.org>,
>> "tracecompass-dev" <tracecompass-dev at eclipse.org>, "etienne bergeron" <etienne.bergeron at gmail.com>, "francois doray"
>> <francois.doray at gmail.com>
>> Sent: Sunday, 11 December, 2016 06:13:09
>> Subject: Re: [lttng-dev] CTF2-PROP-1.0: Proposal for a major revision of the Common Trace Format, version 1.8
>>
>> May I propose the addition of packet-begin and packet-end attributes,
>> analogous to the current "timestamp_begin" and "timestamp_end" fields?
>>
>> These fields greatly facilitate the job of readers that need to index
>> and seek within a CTF stream (time-wise) if clocks are used. Moreover,
>> the attributes could be re-used shall the index format currently
>> produced by LTTng become part of the official specification in one
>> form or another.
>>
>> Thoughts?
>
> Isn't it enough to tag the `timestamp_begin` field with
> `update-data-stream-clock-now` and the `timestamp_end` field with
> `update-data-stream-clock-after-packet`?
>

Ah, I completely missed "update-data-stream-clock-after-packet". Seems
like my grep-fu failed me as some tag tables in the document use "Tag
name" and others simply "Name".

As for 'update-data-stream-clock-now", I hadn't thought of using it
this way, but it certainly makes sense.

Thanks for the reply!
Jérémie

> If you need to seek, read the packet header and context, then
> look at the current values of the data stream clocks and at their
> projected values (after packet).
>
> Philippe Proulx
> EfficiOS Inc.
> http://www.efficios.com/
>
>> Jérémie



-- 
Jérémie Galarneau
EfficiOS Inc.
http://www.efficios.com