uv/crates/puffin-installer
Charlie Marsh 2a846e76b7
Store unzipped wheels in a cache (#49)
This PR massively speeds up the case in which you need to install wheels
that already exist in the global cache.

The new strategy is as follows:

- Download the wheel into the content-addressed cache.
- Unzip the wheel into the cache, but ignore content-addressing. It
turns out that writing to `cacache` for every file in the zip added a
ton of overhead, and I don't see any actual advantages to doing so.
Instead, we just unzip the contents into a directory at, e.g.,
`~/.cache/puffin/django-4.1.5`.
- (The unzip itself is now parallelized with Rayon.)
- When installing the wheel, we now support unzipping from a directory
instead of a zip archive. This required duplicating and tweaking a few
functions.
- When installing the wheel, we now use reflinks (or copy-on-write
links). These have a few fantastic properties: (1) they're extremely
cheap to create (on macOS, they are allegedly faster than hard links);
(2) they minimize disk space, since we avoid copying files entirely in
the vast majority of cases; and (3) if the user then edits a file
locally, the cache doesn't get polluted. Orogene, Bun, and soon pnpm all
use reflinks.

Puffin is now ~15x faster than `pip` for the common case of installing
cached data into a fresh environment.

Closes https://github.com/astral-sh/puffin/issues/21.

Closes https://github.com/astral-sh/puffin/issues/39.
2023-10-08 04:04:48 +00:00
..
src Store unzipped wheels in a cache (#49) 2023-10-08 04:04:48 +00:00
Cargo.toml Store unzipped wheels in a cache (#49) 2023-10-08 04:04:48 +00:00