Performance improvements in Rosbag2 recorder discovery

[Rayman]

• This PR improves the performance of the Rosbag2 recorder discovery by moving graph checks such as topic_is_unpublished(topic_name, *node_graph_)) and is_leaf_topic(topic_name, *node_graph_)), which are expensive to the end of the checklist.

• This PR is similar to the fix from 51a83f4 which was discussed in CPU overhead when discovery is used #1485. This gives a massive CPU improvement.

• In the screenshot below you can see the performance difference:

[MichaelOrlov]

@Rayman I would say that PR description "Reintroduce Don't warn for unknown types if topics are not selected" and reference to the

Reintroduce the fix from 51a83f4

Is incorrect in this case. While both PRs improve performance in the discovery, they are completely different.

[fujitatomoya]

@MichaelOrlov @Rayman so this discovery improvement provided originally #1466, kinda rolled back because of #1480, right? just checking if i understand correctly.

CC: @Barry-Xu-2018

[fujitatomoya]

I think that checking recording options parameter and return immediately before time expensive API call for NodeGraph would be better for user experience.

[Rayman]

Yes, I'm referencing the commit Move checks for single type and hidden topics to the bottom from that squashed PR 51a83f4. That commit got rolled back because of #1485. The node graph checks are quite expensive so I'd move them to the bottom.

[MichaelOrlov]

@Rayman To be clear in this PR you are not doing "Move checks for single type and hidden topics to the bottom" - therefore we can't say that this PR reintroducing changes from the 51a83f4

I've changed PR title and description accordingly.

[MichaelOrlov]

Now, with the corrected PR title and description, it looks good to me.

[MichaelOrlov]

Pulls: #1825
Gist: https://gist.githubusercontent.com/MichaelOrlov/bc40716811cdff501cae1551da0b955c/raw/5d6c90a2f967cc06fbc14d9efb7d1296caf4ed8c/ros2.repos
BUILD args: --packages-above-and-dependencies rosbag2_transport
TEST args: --packages-above rosbag2_transport
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/14653

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[MichaelOrlov]

https://github.com/Mergifyio backport jazzy

[mergify]

backport jazzy

✅ Backports have been created

• #1827 Performance improvements in Rosbag2 recorder discovery (backport #1825) has been created for branch jazzy