Help users diagnose slow prompts

[kovasap]

Do you have any tips/tricks when it comes to determining what parts of prompt.gem are causing a lag in generating the next prompt? I'm hoping to find some kind of general bash profiler that can pin down slow code.

Thanks!

[dimo414]

Thanks for the question; this is something I've wanted to make easier for end-users to investigate, but at the moment it's a bit manual. There are some tools / hooks you can experiment with, however.

• _PGEM_DEBUG=true pgem_reload prints a bunch of diagnostic information, including how long prompt-generation took to execute; you can also directly invoke _prompt_command
• The functions listed in "${COMMAND_FINISHED_CALLBACKS[@]}" and "${ENV_INFO[@]}" are invoked on each prompt, so you can time those functions individually and see if anything stands out
• Expensive ENV_INFO functions are usually cached using bash-cache, which saves redundant computations. You can use bc::benchmark SOME_FUNCTION to see timing data for a function with and without caching to determine whether caching is appropriate
• I haven't used it personally, but there is a Bash debugger you could look into

[dimo414]

Some useful profiling strategies: https://stackoverflow.com/q/5014823/113632

[kovasap]

Thanks for the updates! I've been playing around with a zsh environment right now so I haven't had a chance to try this.

[dimo414]

No worries, this is mostly for my reference - though obviously user feedback is welcome. If there's anything different or more useful about your zsh environment (other than being zsh, obviously) that feedback would also be insightful.