Snapshot based on duration

[CourchesneA]

Description

There was a recent addition of the snapshot feature that allows a circular buffer of fixed size. In our case, it is not possible to specify a buffer zise, but we would like to specify a duration. It would be great to be able to trigger a snapshot for X seconds in the past and Y seconds in the future.

Related Issues

#663

Completion Criteria

• Able to trigger a snapshot based on time instead of memory

Testing Notes / Suggestions

Extra goals would be support for multiple overlapping snapshots

[AntoineHX]

Are their plans to integrate this to Foxy-future ?
I believe https://github.com/gaia-platform/rosbag2_snapshot, now, has this feature. But it seems only compatible with Galactic or above.

[MichaelOrlov]

@AntoineHX There are no plans or scheduled effort for backporting rosbag2_snapshot feature to the https://github.com/ros2/rosbag2/tree/foxy-future branch.
As always PRs are welcome.

[Stefan-working]

Are there any plans to implement this enhancement to the rosbag2?
If I am reading the doc and source of the https://github.com/gaia-platform/rosbag2_snapshot correctly this still misses the feature to also further record Y seconds into the future and rosbag2_snapshot seems to have no license.
I really would appreciate it if this feature would be part of the rosbag2 core, as we really like to use this feature for recording only specific scenarios and use cases.

[CourchesneA]

@Stefan-working In the end we ended up using the GAIA's implementation (which I believe is not unmaintained). We were able to implement "record Y seconds into the future" manually with a simple sleep(Y).

[MichaelOrlov]

@Stefan-working As regards to the license.
I found this line
https://github.com/gaia-platform/rosbag2_snapshot/blob/333ae57b9f606c3e69da7b968d0e8ba44ccc5374/rosbag2_snapshot/package.xml#L8

[Stefan-working]

Thank you @CourchesneA and @MichaelOrlov with this license we may be able to use it and adapt it with the sleep.

[tonynajjar]

Reviving this issue, this would be quite useful to me as well!

[MichaelOrlov]

Sorry, don't have capacity for this feature for a while. It is supposed to be structural changes and not straightforward to implement.

[tonynajjar]

Sorry, don't have capacity for this feature for a while. It is supposed to be structural changes and not straightforward to implement.

It's the issue with the most "thumbs up" though, or how is work prioritized in this repo?

[MichaelOrlov]

Priority is assigned according to the importance and feasibility.
Priority is low because there exists a workaround (one can estimate data stream size and specify buffer size in bytes) and also exists a third-party solution. Another reason why the priority is low is because potential implementation is not straightforward and requires structural changes in the core of the rosbag2 on multiple layers.

I personally was planning to get back to this issue/feature somewhere in the June-July when dust after the Jazzy release will settle down.