Reuse code objects for similar dataclass definitions

[brandtbucher]

A little over a year ago, @dabeaz came up with a cool way of speeding up dataclass creation by avoiding unnecessary exec calls. Essentially, his proof-of-concept dataklasses module caches code objects for methods of "similarly-shaped" dataclasses, and patches them with the correct names:

https://github.com/dabeaz/dataklasses

I have a working prototype of a similar idea for the stdlib dataclasses module over in #92650. It basically doubles the speed of dataclass definitions.

CC @ericvsmith

Linked PRs

• GH-100930: Implement dataclass code caching #92650

[ssweber]

I’ve been looking at dataclasses and this interests me. What would need to happen to take this over the finish-line?

[ericvsmith]

For starters, an analysis of memory usage and cache hit ratio for common dataclass usage patterns.

[ssweber]

Thanks! I’m assuming this would take some legwork, as pyperformance lacks a dataclass benchmark (if that issue is still relevant)?

I admit to not being super knowledgeable on the subject, but I like digging into topics. I’ll report back when I have more to contribute.

[brandtbucher]

Closing in favor of #109870, which is the current direction dataclasses seems to be heading in.

[ssweber]

From my understanding, this could be complementary with the combined exec rework.

Combined exec speeds up initial creation, this could further speed up creation of subsequent similar dataclasses.

Maybe once that has landed, we could rework this if there is interest.