New log file format design #9
Conversation
Signed-off-by: Nate Koenig <nate@openrobotics.org>
Signed-off-by: Nate Koenig <nate@openrobotics.org>
Signed-off-by: Nate Koenig <nate@openrobotics.org>
| 1. Support random access to logged data | ||
| 1. Low barrier to entry | ||
| 1. A user of the current log format needs to re-implement the Gazebo ECS. | ||
| 1. Efficient |
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Support being "interrupted" in that the log file won't be corrputed/destroyed in the case that Gazebo is shut down incorrectly or has a segmentation fault.
Since user systems run directly in the executable, there is always a chance of segfaults and we should do as much as possible to preserve already written data in case that happens.
| 1. Low overhead when writing log files. | ||
| 1. Self-contained | ||
| 1. Capture initial simulation state | ||
| 1. Capture topic names, message types, and message definitions |
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Not all topics/message definitions may be available when recording starts, we should accommodate this.
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| ## Requirements | ||
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| 1. Cross-platform and cross-language |
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I think we should note a minimum set of languages to help bound this a little bit.
From what we use in Gazebo, (C++, Ruby, Python, Typescript/Javascript, Go) would cover 99% of our use cases correct?
| 1. Log format version | ||
| 1. Gazebo version | ||
| 1. Date and time of recording | ||
| 1. Optionally include all assets used by simulation. |
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Importantly, I think it would be nice to include these assets in a way that is not "echoing them to a topic" the way that it was typically done in ROS 1 bags.
Signed-off-by: Nate Koenig nate@openrobotics.org
Working on a new log file format for Gazebo. This is a WIP