How to update large amounts of text without blocking UI

[yggdr]

While playing around with what textual can do I have built a very simple repository updater, that keeps my source code clones up to date and shows me what's new in a few projects (like e.g. textual).
Works fine so far, it starts up, runs various git pull in background-processes and shows the output in a Static. If I see something that interests me, I can then have a simple git diff run in the background and call Static.update to now render the diff. The problem I have is that Static.update lags immensely once we get to text sizes in the megabytes, which for a git diff of a medium sized project can happen rather quickly. That lag completely blocks the UI for several seconds, as rich.segment.split_and_crop_lines seems to take very long, at least from a cursory investigation via flamegraph.

So what I'm asking is: what is the best approach to such a large-size update in the textual ecosystem if Static.update is not it?

[TomJGooding]

Have you looked at using the Worker API?

[yggdr]

Using a worker (with thread=True or not) doesn't really change much. The UI interruption seems a little less extreme because a few changes are visible earlier. But the UI still does not react to input for essentially the same amount of time.

[yggdr]

I have replaced Static with a Log, which seems to be much faster, although still blocking. This might have to do with the linewise API that I am only just reading up about.

[willmcgugan]

Updating Static with megabytes of data will certainly prompt a lot of work. We're talking hundreds of pages of text being reflowed each update.

Using a Log will updating a line at a time. But you can still freeze the UI if you write many lines in an event handler.

The solution probably involves workers, but I couldn't say for certain without seeing your code. Since you are using a lot of concurrency, you may be blocking without realizing it. And that may not be obvious from profiling.