blackfast

Make black faster, with rust.

Build Status

OS	Status
Linux
MacOS
Windows

Benchmarks

These are generated with tools/benchmark.py.

name                        mean    median    stdev
-----------------------  -------  --------  -------
black_cached             0.17876   0.18076  0.00433
black_uncached           0.17931   0.17946  0.00514
blackfast_cached_cold    0.89011   0.86907  0.03016
blackfast_uncached_cold  0.92398   0.93126  0.04577
blackfast_cached_hot     0.04327   0.04298  0.00097
blackfast_uncached_hot   0.04538   0.04424  0.00365

How it works

Python startup is slow. So we don't start Python to use black, instead run a server which runs black and have a tiny rust cli program that communicates with that server.

How to run this experiment

You'll need Python 3.7, poetry and rust nightly.

1. Run poetry install or poetry develop.
2. Run cargo build --release
3. Run target/release/blackfast <normal-args-you-would-pass-to-black>

Alternatively for 3 and 4 you can use cargo run <...args>.

How to build a wheel

1. Run python build.py

What needs to be done for this to be useful?

• [?] Make it work on Windows/any platform (Maybe done?)
• Manage starting/running the server automatically. Running blackfast should start the server if not running or use an already running one.
• Move the socket to a "well known" location (appdirs?cachedir?) so it doesn't need to be provided. This needs to work with more than one black version on a single system.
• support multiple versions to be installed/used
• Make it installable (how to handle the rust part?!)
• Handle errors
• Add support for styled output
• Eventually: Don't read/write the cache on each request.