## Summary
One problem we have in the cache today is that we can't overwrite
entries atomically, because we store unzipped _directories_ in the cache
(which makes installation _much_ faster than storing zipped
directories). So, if you ignore the existing contents of the cache when
writing, you might run into an error, because you might attempt to write
a directory where a directory already exists.
This is especially annoying for cache refresh, because in order to
refresh the cache, we have to purge it (i.e., delete a bunch of stuff),
which is also highly unsafe if Puffin is running across multiple threads
or multiple processes.
The solution I'm proposing here is that whenever we persist a
_directory_ to the cache, we persist it to a special "archive" bucket.
Then, within the other buckets, directory entries are actually symlinks
into that "archive" bucket. With symlinks, we can atomically replace,
which means we can easily overwrite cache entries without having to
delete from the cache.
The main downside is that we'll now accumulate dangling entries in the
"archive" bucket, and so we'll need to implement some form of garbage
collection to ensure that we remove entries with no symlinks. Another
downside is that cache reads and writes will be a bit slower, since we
need to deal with creating and resolving these symlinks.
As an example... after this change, the cache entry for this unzipped
wheel is actually a symlink:

Then, within the archive directory, we actually have two unique entries
(since I intentionally ran the command twice to ensure overwrites were
safe):

## Summary
This PR makes the `pypi_types::File` a response-only type (i.e., a type
that's only used when deserializing over the wire), and adds a separate
internal `File` type. Right now, the representations are similar, but
already, we can avoid the "lenient" deserialization on our internal
`File` type, and avoid the special-casing of the property names that's
required in the JSON. Over time, we can evolve this representation
entirely separately from the representation we receive from PyPI and
other indexes.
This crate started off as generic caching utilities, but we started
adding a lot of Puffin-specific stuff (like the cache buckets
abstraction that knows about Git vs. direct URL vs. indexes and so on).
This PR moves the generic stuff into a new `cache-key` crate.
## Summary
At present, we have two separate phases within the installation pipeline
related to populating wheels into the cache. The first phase downloads
the distribution, and then builds any source distributions into wheels;
the second phase unzips all the built wheels into the cache.
This PR merges those two phases into one, such that we seamlessly
download, build, and unzip wheels in one pass. This is more efficient,
since we can start unzipping while we build. It also ensures that if the
install _fails_ partway through, we don't end up with a bunch of
downloaded wheels that we never had a chance to unzip. The code is also
much simpler.
The main downside is that the user-facing feedback isn't as granular,
since we only have one phase and one progress bar for what was
originally three distinct phases.
Closes https://github.com/astral-sh/puffin/issues/571.
## Test Plan
I ran the benchmark script on two separate requirements files, and saw a
7% and 31% speedup respectively:
```text
+ TARGET=./scripts/benchmarks/requirements.txt
+ hyperfine --runs 100 --warmup 10 --prepare 'virtualenv --clear .venv' './target/release/main pip-sync ./scripts/benchmarks/requirements.txt --no-cache' --prepare 'virtualenv --clear .venv' './target/release/puffin pip-sync ./scripts/benchmarks/requirements.txt --no-cache'
Benchmark 1: ./target/release/main pip-sync ./scripts/benchmarks/requirements.txt --no-cache
Time (mean ± σ): 269.4 ms ± 33.0 ms [User: 42.4 ms, System: 117.5 ms]
Range (min … max): 221.7 ms … 446.7 ms 100 runs
Benchmark 2: ./target/release/puffin pip-sync ./scripts/benchmarks/requirements.txt --no-cache
Time (mean ± σ): 250.6 ms ± 28.3 ms [User: 41.5 ms, System: 127.4 ms]
Range (min … max): 207.6 ms … 336.4 ms 100 runs
Summary
'./target/release/puffin pip-sync ./scripts/benchmarks/requirements.txt --no-cache' ran
1.07 ± 0.18 times faster than './target/release/main pip-sync ./scripts/benchmarks/requirements.txt --no-cache'
```
```text
+ TARGET=./scripts/benchmarks/requirements-large.txt
+ hyperfine --runs 100 --warmup 10 --prepare 'virtualenv --clear .venv' './target/release/main pip-sync ./scripts/benchmarks/requirements-large.txt --no-cache' --prepare 'virtualenv --clear .venv' './target/release/puffin pip-sync ./scripts/benchmarks/requirements-large.txt --no-cache'
Benchmark 1: ./target/release/main pip-sync ./scripts/benchmarks/requirements-large.txt --no-cache
Time (mean ± σ): 5.053 s ± 0.354 s [User: 1.413 s, System: 6.710 s]
Range (min … max): 4.584 s … 6.333 s 100 runs
Benchmark 2: ./target/release/puffin pip-sync ./scripts/benchmarks/requirements-large.txt --no-cache
Time (mean ± σ): 3.845 s ± 0.225 s [User: 1.364 s, System: 6.970 s]
Range (min … max): 3.482 s … 4.715 s 100 runs
Summary
'./target/release/puffin pip-sync ./scripts/benchmarks/requirements-large.txt --no-cache' ran
```
## Summary
This PR enables `puffin clean` to accept package names as command line
arguments, and selectively purge entries from the cache tied to the
given package.
Relate to #572.
## Test Plan
Modified all the caching tests to run an additional step to (1) purge
the cache, and (2) re-install the package.
Path distribution cache reading errors are no longer fatal.
We now invalidate the path file source dists if its modification
timestamp changed, and invalidate path dir source dists if
`pyproject.toml` or alternatively `setup.py` changed, which seems good
choices since changing pyproject.toml should trigger a rebuild and the
user can `touch` the file as part of their workflow.
`CachedByTimestamp` is now a shared util. It doesn't have methods as i
don't think it's worth it yet for two users.
Closes#478
TODO(konstin): Write a test. This is probably twice as much work as that
fix itself, so i made that PR without one for now.
Ensure we're using atomic writes everywhere in our cache to avoid broken
cache records and error with parallel puffin actions
(https://github.com/astral-sh/puffin/pull/544#issuecomment-1838841581).
All json files that are written to the cache are written atomically and
the build wheels are written to temp dir and then moved atomically. I
didn't touch venv creation though, i don't think that's worth it since
python does not support atomic package installation through its design.
## Summary
Even if this will typically be in the user's application folder (rather
than a local directory), it's still a good practice.
Closes https://github.com/astral-sh/puffin/issues/280.
## Summary and motivation
For a given source dist, we store the metadata of each wheel built
through it in `built-wheel-metadata-v0/pypi/<source dist
filename>/metadata.json`. During resolution, we check the cache status
of the source dist. If it is fresh, we check `metadata.json` for a
matching wheel. If there is one we use that metadata, if there isn't, we
build one. If the source is stale, we build a wheel and override
`metadata.json` with that single wheel. This PR thereby ties the local
built wheel metadata cache to the freshness of the remote source dist.
This functionality is available through `SourceDistCachedBuilder`.
`puffin_installer::Builder`, `puffin_installer::Downloader` and
`Fetcher` are removed, instead there are now `FetchAndBuild` which calls
into the also new `SourceDistCachedBuilder`. `FetchAndBuild` is the new
main high-level abstraction: It spawns parallel fetching/building, for
wheel metadata it calls into the registry client, for wheel files it
fetches them, for source dists it calls `SourceDistCachedBuilder`. It
handles locks around builds, and newly added also inter-process file
locking for git operations.
Fetching and building source distributions now happens in parallel in
`pip-sync`, i.e. we don't have to wait for the largest wheel to be
downloaded to start building source distributions.
In a follow-up PR, I'll also clear built wheels when they've become
stale.
Another effect is that in a fully cached resolution, we need neither zip
reading nor email parsing.
Closes#473
## Source dist cache structure
Entries by supported sources:
* `<build wheel metadata cache>/pypi/foo-1.0.0.zip/metadata.json`
* `<build wheel metadata
cache>/<sha256(index-url)>/foo-1.0.0.zip/metadata.json`
* `<build wheel metadata
cache>/url/<sha256(url)>/foo-1.0.0.zip/metadata.json`
But the url filename does not need to be a valid source dist filename
(<https://github.com/search?q=path%3A**%2Frequirements.txt+master.zip&type=code>),
so it could also be the following and we have to take any string as
filename:
* `<build wheel metadata
cache>/url/<sha256(url)>/master.zip/metadata.json`
Example:
```text
# git source dist
pydantic-extra-types @ git+https://github.com/pydantic/pydantic-extra-types.git
# pypi source dist
django_allauth==0.51.0
# url source dist
werkzeug @ ff1904eb5e2853bf83db817a7dd53d/werkzeug-3.0.1.tar.gz
```
will be stored as
```text
built-wheel-metadata-v0
├── git
│ └── 5c56bc1c58c34c11
│ └── 843b753e9e8cb74e83cac55598719b39a4d5ef1f
│ └── metadata.json
├── pypi
│ └── django-allauth-0.51.0.tar.gz
│ └── metadata.json
└── url
└── 6781bd6440ae72c2
└── werkzeug-3.0.1.tar.gz
└── metadata.json
```
The inside of a `metadata.json`:
```json
{
"data": {
"django_allauth-0.51.0-py3-none-any.whl": {
"metadata-version": "2.1",
"name": "django-allauth",
"version": "0.51.0",
...
}
}
}
```
A consistent cache structure for remote wheel metadata:
* `<wheel metadata cache>/pypi/foo-1.0.0-py3-none-any.json`
* `<wheel metadata
cache>/<digest(index-url)>/foo-1.0.0-py3-none-any.json`
* `<wheel metadata cache>/url/<digest(url)>/foo-1.0.0-py3-none-any.json`
The source dist caching will use a similar structure (#468).
Previously, git requirements would fail when setting `--cache-dir`:
```console
$ cargo run --bin puffin -- pip-compile --cache-dir cache-all-kinds scripts/benchmarks/requirements/all-kinds.in
error: Failed to build distribution from URL: git+https://github.com/pydantic/pydantic-extra-types.git
Caused by: Invalid path URL: cache-all-kinds/git-v0/db/b49ffcfeb6c2e9d8
```
The cause is using a relative and not an absolute path, which `Url` needs, the solution is to turn the cache dir into an absolute path.
This never showed up in the tests since the tests use absolute temp dirs for everything.
Always¹ clear the temporary directories we create.
* Clear source dist downloads: Previously, the temporary directories
would remain in the cache dir, now they are cleared properly
* Clear wheel file downloads: Delete the `.whl` file, we only need to
cache the unpacked wheel
* Consistent handling of cache arguments: Abstract the handling for CLI
cache args away, again making sure we remove the `--no-cache` temp dir.
There are no more `into_path()` calls that persist `TempDir`s that i
could find.
¹Assuming drop is run, and deleting the directory doesn't silently
error.