Implementation for using hmr with uvicorn by uvicorn-hmr

[CNSeniorious000]

• Related to FastAPI with on-demand HOT reload! 🙌 fastapi/fastapi#13192

Currently uvicorn --reload restart the python process every reload, which makes heavy 3rd-party modules being imported everytime.

I implemented a uvicorn-hmr package to solve this problem. The differences between uvicorn main:app --reload and uvicorn-hmr main:app can be concluded as:

1. uvicorn-hmr stop and restart uvicorn servers in the same process, so 3rd-party librarys are cached by default.
2. uvicorn-hmr depends on hmr, which performs fine-grained on-demand dependency tracking on every imported name, it your main module depends on a and b and only a.py is changed, b will not be invalidate at all.

Everybody can have a try by simply replacing uvicorn --reload main:app with uvicorn-hmr main:app.

I've tested this on several of middle-sized ASGI Python servers. Looking forward to any responses!

Caution

hmr are sometimes refer to a feature that updates the page in the browser on the client side when the server code changes. This is not that. This package is a server-side HMR, that reloads the server code when it changes.