mirrors/uv
1
0
Fork 0
mirror of https://github.com/astral-sh/uv.git synced 2025-07-07 13:25:00 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 2
uv/crates/uv-resolver/src/resolver/mod.rs
Charlie Marsh e1708689a9
Add a universal resolution mode to pip compile (#4505) 
## Summary

This needs more tests and a few more changes, but checkpointing it for
now.
2024-06-25 21:28:50 +00:00

2438 lines
101 KiB
Rust
Raw Blame History

//! Given a set of requirements, find a set of compatible packages.
use std::borrow::Cow;
use std::collections::{BTreeMap, VecDeque};
use std::fmt::{Display, Formatter};
use std::ops::Bound;
use std::sync::Arc;
use std::{iter, thread};
use dashmap::DashMap;
use either::Either;
use futures::{FutureExt, StreamExt, TryFutureExt};
use itertools::Itertools;
use pubgrub::error::PubGrubError;
use pubgrub::range::Range;
use pubgrub::solver::{Incompatibility, State};
use rustc_hash::{FxHashMap, FxHashSet};
use tokio::sync::mpsc::{self, Receiver, Sender};
use tokio::sync::oneshot;
use tokio_stream::wrappers::ReceiverStream;
use tracing::{debug, enabled, instrument, trace, warn, Level};
use distribution_types::{
BuiltDist, Dist, DistributionMetadata, IncompatibleDist, IncompatibleSource, IncompatibleWheel,
InstalledDist, PythonRequirementKind, RemoteSource, ResolvedDist, ResolvedDistRef, SourceDist,
VersionOrUrlRef,
};
pub(crate) use locals::Locals;
use pep440_rs::{Version, MIN_VERSION};
use pep508_rs::{MarkerEnvironment, MarkerTree};
use platform_tags::Tags;
use pypi_types::{Metadata23, Requirement, VerbatimParsedUrl};
pub(crate) use urls::Urls;
use uv_configuration::{Constraints, Overrides};
use uv_distribution::{ArchiveMetadata, DistributionDatabase};
use uv_git::GitResolver;
use uv_normalize::{ExtraName, GroupName, PackageName};
use uv_types::{BuildContext, HashStrategy, InstalledPackagesProvider};
use crate::candidate_selector::{CandidateDist, CandidateSelector};
use crate::dependency_provider::UvDependencyProvider;
use crate::error::ResolveError;
use crate::manifest::Manifest;
use crate::pins::FilePins;
use crate::preferences::Preferences;
use crate::pubgrub::{
PubGrubDependencies, PubGrubDistribution, PubGrubPackage, PubGrubPackageInner,
PubGrubPriorities, PubGrubPython, PubGrubSpecifier,
};
use crate::python_requirement::PythonRequirement;
use crate::resolution::ResolutionGraph;
pub(crate) use crate::resolver::availability::{
IncompletePackage, ResolverVersion, UnavailablePackage, UnavailableReason, UnavailableVersion,
};
use crate::resolver::batch_prefetch::BatchPrefetcher;
pub(crate) use crate::resolver::index::FxOnceMap;
pub use crate::resolver::index::InMemoryIndex;
pub use crate::resolver::provider::{
DefaultResolverProvider, MetadataResponse, PackageVersionsResult, ResolverProvider,
VersionsResponse, WheelMetadataResult,
};
use crate::resolver::reporter::Facade;
pub use crate::resolver::reporter::{BuildId, Reporter};
use crate::yanks::AllowedYanks;
use crate::{DependencyMode, Exclusions, FlatIndex, Options};
mod availability;
mod batch_prefetch;
mod index;
mod locals;
mod provider;
mod reporter;
mod urls;
pub struct Resolver<Provider: ResolverProvider, InstalledPackages: InstalledPackagesProvider> {
state: ResolverState<InstalledPackages>,
provider: Provider,
}
/// State that is shared between the prefetcher and the PubGrub solver during
/// resolution.
struct ResolverState<InstalledPackages: InstalledPackagesProvider> {
project: Option<PackageName>,
requirements: Vec<Requirement>,
constraints: Constraints,
overrides: Overrides,
dev: Vec<GroupName>,
preferences: Preferences,
git: GitResolver,
exclusions: Exclusions,
urls: Urls,
locals: Locals,
dependency_mode: DependencyMode,
hasher: HashStrategy,
/// When not set, the resolver is in "universal" mode.
markers: Option<MarkerEnvironment>,
python_requirement: PythonRequirement,
/// This is derived from `PythonRequirement` once at initialization
/// time. It's used in universal mode to filter our dependencies with
/// a `python_version` marker expression that has no overlap with the
/// `Requires-Python` specifier.
///
/// This is non-None if and only if the resolver is operating in
/// universal mode. (i.e., when `markers` is `None`.)
requires_python: Option<MarkerTree>,
selector: CandidateSelector,
index: InMemoryIndex,
installed_packages: InstalledPackages,
/// Incompatibilities for packages that are entirely unavailable.
unavailable_packages: DashMap<PackageName, UnavailablePackage>,
/// Incompatibilities for packages that are unavailable at specific versions.
incomplete_packages: DashMap<PackageName, DashMap<Version, IncompletePackage>>,
reporter: Option<Arc<dyn Reporter>>,
}
impl<'a, Context: BuildContext, InstalledPackages: InstalledPackagesProvider>
Resolver<DefaultResolverProvider<'a, Context>, InstalledPackages>
{
/// Initialize a new resolver using the default backend doing real requests.
///
/// Reads the flat index entries.
///
/// # Marker environment
///
/// The marker environment is optional.
///
/// When a marker environment is not provided, the resolver is said to be
/// in "universal" mode. When in universal mode, the resolution produced
/// may contain multiple versions of the same package. And thus, in order
/// to use the resulting resolution, there must be a "universal"-aware
/// reader of the resolution that knows to exclude distributions that can't
/// be used in the current environment.
///
/// When a marker environment is provided, the resolver is in
/// "non-universal" mode, which corresponds to standard `pip` behavior that
/// works only for a specific marker environment.
#[allow(clippy::too_many_arguments)]
pub fn new(
manifest: Manifest,
options: Options,
python_requirement: &'a PythonRequirement,
markers: Option<&'a MarkerEnvironment>,
tags: Option<&'a Tags>,
flat_index: &'a FlatIndex,
index: &'a InMemoryIndex,
hasher: &'a HashStrategy,
build_context: &'a Context,
installed_packages: InstalledPackages,
database: DistributionDatabase<'a, Context>,
) -> Result<Self, ResolveError> {
let provider = DefaultResolverProvider::new(
database,
flat_index,
tags,
python_requirement.clone(),
AllowedYanks::from_manifest(&manifest, markers, options.dependency_mode),
hasher,
options.exclude_newer,
build_context.build_options(),
);
Self::new_custom_io(
manifest,
options,
hasher,
markers,
python_requirement,
index,
build_context.git(),
provider,
installed_packages,
)
}
}
impl<Provider: ResolverProvider, InstalledPackages: InstalledPackagesProvider>
Resolver<Provider, InstalledPackages>
{
/// Initialize a new resolver using a user provided backend.
#[allow(clippy::too_many_arguments)]
pub fn new_custom_io(
manifest: Manifest,
options: Options,
hasher: &HashStrategy,
markers: Option<&MarkerEnvironment>,
python_requirement: &PythonRequirement,
index: &InMemoryIndex,
git: &GitResolver,
provider: Provider,
installed_packages: InstalledPackages,
) -> Result<Self, ResolveError> {
let requires_python = if markers.is_some() {
None
} else {
Some(python_requirement.to_marker_tree())
};
let state = ResolverState {
index: index.clone(),
git: git.clone(),
unavailable_packages: DashMap::default(),
incomplete_packages: DashMap::default(),
selector: CandidateSelector::for_resolution(options, &manifest, markers),
dependency_mode: options.dependency_mode,
urls: Urls::from_manifest(&manifest, markers, git, options.dependency_mode)?,
locals: Locals::from_manifest(&manifest, markers, options.dependency_mode),
project: manifest.project,
requirements: manifest.requirements,
constraints: manifest.constraints,
overrides: manifest.overrides,
dev: manifest.dev,
preferences: manifest.preferences,
exclusions: manifest.exclusions,
hasher: hasher.clone(),
markers: markers.cloned(),
python_requirement: python_requirement.clone(),
requires_python,
reporter: None,
installed_packages,
};
Ok(Self { state, provider })
}
/// Set the [`Reporter`] to use for this installer.
#[must_use]
pub fn with_reporter(self, reporter: impl Reporter + 'static) -> Self {
let reporter = Arc::new(reporter);
Self {
state: ResolverState {
reporter: Some(reporter.clone()),
..self.state
},
provider: self.provider.with_reporter(Facade { reporter }),
}
}
/// Resolve a set of requirements into a set of pinned versions.
pub async fn resolve(self) -> Result<ResolutionGraph, ResolveError> {
let state = Arc::new(self.state);
let provider = Arc::new(self.provider);
// A channel to fetch package metadata (e.g., given `flask`, fetch all versions) and version
// metadata (e.g., given `flask==1.0.0`, fetch the metadata for that version).
// Channel size is set large to accommodate batch prefetching.
let (request_sink, request_stream) = mpsc::channel(300);
// Run the fetcher.
let requests_fut = state
.clone()
.fetch(provider.clone(), request_stream)
.map_err(|err| (err, FxHashSet::default()))
.fuse();
// Spawn the PubGrub solver on a dedicated thread.
let solver = state.clone();
let (tx, rx) = oneshot::channel();
thread::Builder::new()
.name("uv-resolver".into())
.spawn(move || {
let result = solver.solve(request_sink);
tx.send(result).unwrap();
})
.unwrap();
let resolve_fut = async move {
rx.await
.map_err(|_| (ResolveError::ChannelClosed, FxHashSet::default()))
.and_then(|result| result)
};
// Wait for both to complete.
match tokio::try_join!(requests_fut, resolve_fut) {
Ok(((), resolution)) => {
state.on_complete();
Ok(resolution)
}
Err((err, visited)) => {
// Add version information to improve unsat error messages.
Err(if let ResolveError::NoSolution(err) = err {
ResolveError::NoSolution(
err.with_available_versions(&visited, state.index.packages())
.with_selector(state.selector.clone())
.with_python_requirement(&state.python_requirement)
.with_index_locations(provider.index_locations())
.with_unavailable_packages(&state.unavailable_packages)
.with_incomplete_packages(&state.incomplete_packages),
)
} else {
err
})
}
}
}
}
impl<InstalledPackages: InstalledPackagesProvider> ResolverState<InstalledPackages> {
#[instrument(skip_all)]
fn solve(
self: Arc<Self>,
request_sink: Sender<Request>,
) -> Result<ResolutionGraph, (ResolveError, FxHashSet<PackageName>)> {
let mut visited = FxHashSet::default();
self.solve_tracked(&mut visited, request_sink)
.map_err(|err| (err, visited))
}
/// Run the PubGrub solver, updating the `visited` set for each package visited during
/// resolution.
#[instrument(skip_all)]
fn solve_tracked(
self: Arc<Self>,
visited: &mut FxHashSet<PackageName>,
request_sink: Sender<Request>,
) -> Result<ResolutionGraph, ResolveError> {
let root = PubGrubPackage::from(PubGrubPackageInner::Root(self.project.clone()));
let mut prefetcher = BatchPrefetcher::default();
let state = SolveState {
pubgrub: State::init(root.clone(), MIN_VERSION.clone()),
next: root,
pins: FilePins::default(),
priorities: PubGrubPriorities::default(),
added_dependencies: FxHashMap::default(),
markers: MarkerTree::And(vec![]),
};
let mut forked_states = vec![state];
let mut resolutions = vec![];
debug!(
"Solving with installed Python version: {}",
self.python_requirement.installed()
);
if let Some(target) = self.python_requirement.target() {
debug!("Solving with target Python version: {}", target);
}
'FORK: while let Some(mut state) = forked_states.pop() {
loop {
// Run unit propagation.
state.pubgrub.unit_propagation(state.next.clone())?;
// Pre-visit all candidate packages, to allow metadata to be fetched in parallel. If
// the dependency mode is direct, we only need to visit the root package.
if self.dependency_mode.is_transitive() {
Self::pre_visit(
state.pubgrub.partial_solution.prioritized_packages(),
&request_sink,
)?;
}
// Choose a package version.
let Some(highest_priority_pkg) = state
.pubgrub
.partial_solution
.pick_highest_priority_pkg(|package, _range| state.priorities.get(package))
else {
if enabled!(Level::DEBUG) {
prefetcher.log_tried_versions();
}
resolutions.push(state.into_resolution());
continue 'FORK;
};
state.next = highest_priority_pkg;
prefetcher.version_tried(state.next.clone());
let term_intersection = state
.pubgrub
.partial_solution
.term_intersection_for_package(&state.next)
.ok_or_else(|| {
PubGrubError::Failure(
"a package was chosen but we don't have a term.".into(),
)
})?;
let decision = self.choose_version(
&state.next,
term_intersection.unwrap_positive(),
&mut state.pins,
visited,
&request_sink,
)?;
// Pick the next compatible version.
let version = match decision {
None => {
debug!("No compatible version found for: {next}", next = state.next);
let term_intersection = state
.pubgrub
.partial_solution
.term_intersection_for_package(&state.next)
.expect("a package was chosen but we don't have a term.");
// Check if the decision was due to the package being unavailable
if let PubGrubPackageInner::Package { ref name, .. } = &*state.next {
if let Some(entry) = self.unavailable_packages.get(name) {
state
.pubgrub
.add_incompatibility(Incompatibility::custom_term(
state.next.clone(),
term_intersection.clone(),
UnavailableReason::Package(entry.clone()),
));
continue;
}
}
state
.pubgrub
.add_incompatibility(Incompatibility::no_versions(
state.next.clone(),
term_intersection.clone(),
));
continue;
}
Some(version) => version,
};
let version = match version {
ResolverVersion::Available(version) => version,
ResolverVersion::Unavailable(version, reason) => {
// Incompatible requires-python versions are special in that we track
// them as incompatible dependencies instead of marking the package version
// as unavailable directly
if let UnavailableVersion::IncompatibleDist(
IncompatibleDist::Source(IncompatibleSource::RequiresPython(
requires_python,
kind,
))
| IncompatibleDist::Wheel(IncompatibleWheel::RequiresPython(
requires_python,
kind,
)),
) = reason
{
let python_version: Range<Version> =
PubGrubSpecifier::try_from(&requires_python)?.into();
let package = &state.next;
state
.pubgrub
.add_incompatibility(Incompatibility::from_dependency(
package.clone(),
Range::singleton(version.clone()),
(
PubGrubPackage::from(PubGrubPackageInner::Python(
match kind {
PythonRequirementKind::Installed => {
PubGrubPython::Installed
}
PythonRequirementKind::Target => {
PubGrubPython::Target
}
},
)),
python_version.clone(),
),
));
state
.pubgrub
.partial_solution
.add_decision(state.next.clone(), version);
continue;
};
state
.pubgrub
.add_incompatibility(Incompatibility::custom_version(
state.next.clone(),
version.clone(),
UnavailableReason::Version(reason),
));
continue;
}
};
prefetcher.prefetch_batches(
&state.next,
&version,
term_intersection.unwrap_positive(),
&request_sink,
&self.index,
&self.selector,
)?;
self.on_progress(&state.next, &version);
if state
.added_dependencies
.entry(state.next.clone())
.or_default()
.insert(version.clone())
{
// Retrieve that package dependencies.
let forked_deps = self.get_dependencies_forking(
&state.next,
&version,
&state.markers,
&mut state.priorities,
&request_sink,
)?;
match forked_deps {
ForkedDependencies::Unavailable(reason) => {
state
.pubgrub
.add_incompatibility(Incompatibility::custom_version(
state.next.clone(),
version.clone(),
UnavailableReason::Version(reason),
));
forked_states.push(state);
}
ForkedDependencies::Unforked(dependencies) => {
state.add_package_version_dependencies(
&version,
dependencies,
&prefetcher,
)?;
forked_states.push(state);
}
ForkedDependencies::Forked {
forks,
diverging_packages,
} => {
debug!(
"Splitting resolution on {} over {}",
state.next,
diverging_packages
.iter()
.map(ToString::to_string)
.join(", ")
);
assert!(forks.len() >= 2);
// This is a somewhat tortured technique to ensure
// that our resolver state is only cloned as much
// as it needs to be. We basically move the state
// into `forked_states`, and then only clone it if
// there is at least one more fork to visit.
let mut cur_state = Some(state);
let forks_len = forks.len();
for (i, fork) in forks.into_iter().enumerate() {
let is_last = i == forks_len - 1;
let mut forked_state = cur_state.take().unwrap();
if !is_last {
cur_state = Some(forked_state.clone());
}
forked_state.markers.and(fork.markers);
forked_state.add_package_version_dependencies(
&version,
fork.dependencies,
&prefetcher,
)?;
forked_states.push(forked_state);
}
}
}
continue 'FORK;
}
// `dep_incompats` are already in `incompatibilities` so we know there are not satisfied
// terms and can add the decision directly.
state
.pubgrub
.partial_solution
.add_decision(state.next.clone(), version);
}
}
let mut combined = Resolution::default();
for resolution in resolutions {
combined.union(resolution);
}
ResolutionGraph::from_state(
&self.requirements,
&self.constraints,
&self.overrides,
&self.preferences,
&self.index,
&self.git,
&self.python_requirement,
combined,
)
}
/// Visit a [`PubGrubPackage`] prior to selection. This should be called on a [`PubGrubPackage`]
/// before it is selected, to allow metadata to be fetched in parallel.
fn visit_package(
&self,
package: &PubGrubPackage,
request_sink: &Sender<Request>,
) -> Result<(), ResolveError> {
match &**package {
PubGrubPackageInner::Root(_) => {}
PubGrubPackageInner::Python(_) => {}
PubGrubPackageInner::Marker {
name, url: None, ..
}
| PubGrubPackageInner::Extra {
name, url: None, ..
}
| PubGrubPackageInner::Dev {
name, url: None, ..
}
| PubGrubPackageInner::Package {
name, url: None, ..
} => {
// Verify that the package is allowed under the hash-checking policy.
if !self.hasher.allows_package(name) {
return Err(ResolveError::UnhashedPackage(name.clone()));
}
// Emit a request to fetch the metadata for this package.
if self.index.packages().register(name.clone()) {
request_sink.blocking_send(Request::Package(name.clone()))?;
}
}
PubGrubPackageInner::Marker {
name,
url: Some(url),
..
}
| PubGrubPackageInner::Extra {
name,
url: Some(url),
..
}
| PubGrubPackageInner::Dev {
name,
url: Some(url),
..
}
| PubGrubPackageInner::Package {
name,
url: Some(url),
..
} => {
// Verify that the package is allowed under the hash-checking policy.
if !self.hasher.allows_url(&url.verbatim) {
return Err(ResolveError::UnhashedPackage(name.clone()));
}
// Emit a request to fetch the metadata for this distribution.
let dist = Dist::from_url(name.clone(), url.clone())?;
if self.index.distributions().register(dist.version_id()) {
request_sink.blocking_send(Request::Dist(dist))?;
}
}
}
Ok(())
}
/// Visit the set of [`PubGrubPackage`] candidates prior to selection. This allows us to fetch
/// metadata for all packages in parallel.
fn pre_visit<'data>(
packages: impl Iterator<Item = (&'data PubGrubPackage, &'data Range<Version>)>,
request_sink: &Sender<Request>,
) -> Result<(), ResolveError> {
// Iterate over the potential packages, and fetch file metadata for any of them. These
// represent our current best guesses for the versions that we _might_ select.
for (package, range) in packages {
let PubGrubPackageInner::Package {
name,
extra: None,
dev: None,
marker: None,
url: None,
} = &**package
else {
continue;
};
request_sink.blocking_send(Request::Prefetch(name.clone(), range.clone()))?;
}
Ok(())
}
/// Given a set of candidate packages, choose the next package (and version) to add to the
/// partial solution.
///
/// Returns [None] when there are no versions in the given range.
#[instrument(skip_all, fields(%package))]
fn choose_version(
&self,
package: &PubGrubPackage,
range: &Range<Version>,
pins: &mut FilePins,
visited: &mut FxHashSet<PackageName>,
request_sink: &Sender<Request>,
) -> Result<Option<ResolverVersion>, ResolveError> {
match &**package {
PubGrubPackageInner::Root(_) => {
Ok(Some(ResolverVersion::Available(MIN_VERSION.clone())))
}
PubGrubPackageInner::Python(_) => {
// Dependencies on Python are only added when a package is incompatible; as such,
// we don't need to do anything here.
Ok(None)
}
PubGrubPackageInner::Marker {
name,
url: Some(url),
..
}
| PubGrubPackageInner::Extra {
name,
url: Some(url),
..
}
| PubGrubPackageInner::Dev {
name,
url: Some(url),
..
}
| PubGrubPackageInner::Package {
name,
url: Some(url),
..
} => {
debug!(
"Searching for a compatible version of {package} @ {} ({range})",
url.verbatim
);
let dist = PubGrubDistribution::from_url(name, url);
let response = self
.index
.distributions()
.wait_blocking(&dist.version_id())
.ok_or_else(|| ResolveError::UnregisteredTask(dist.version_id().to_string()))?;
// If we failed to fetch the metadata for a URL, we can't proceed.
let metadata = match &*response {
MetadataResponse::Found(archive) => &archive.metadata,
MetadataResponse::Offline => {
self.unavailable_packages
.insert(name.clone(), UnavailablePackage::Offline);
return Ok(None);
}
MetadataResponse::MissingMetadata => {
self.unavailable_packages
.insert(name.clone(), UnavailablePackage::MissingMetadata);
return Ok(None);
}
MetadataResponse::InvalidMetadata(err) => {
self.unavailable_packages.insert(
name.clone(),
UnavailablePackage::InvalidMetadata(err.to_string()),
);
return Ok(None);
}
MetadataResponse::InconsistentMetadata(err) => {
self.unavailable_packages.insert(
name.clone(),
UnavailablePackage::InvalidMetadata(err.to_string()),
);
return Ok(None);
}
MetadataResponse::InvalidStructure(err) => {
self.unavailable_packages.insert(
name.clone(),
UnavailablePackage::InvalidStructure(err.to_string()),
);
return Ok(None);
}
};
let version = &metadata.version;
// The version is incompatible with the requirement.
if !range.contains(version) {
return Ok(None);
}
// The version is incompatible due to its Python requirement.
if let Some(requires_python) = metadata.requires_python.as_ref() {
if let Some(target) = self.python_requirement.target() {
if !target.is_compatible_with(requires_python) {
return Ok(Some(ResolverVersion::Unavailable(
version.clone(),
UnavailableVersion::IncompatibleDist(IncompatibleDist::Source(
IncompatibleSource::RequiresPython(
requires_python.clone(),
PythonRequirementKind::Target,
),
)),
)));
}
}
if !requires_python.contains(self.python_requirement.installed()) {
return Ok(Some(ResolverVersion::Unavailable(
version.clone(),
UnavailableVersion::IncompatibleDist(IncompatibleDist::Source(
IncompatibleSource::RequiresPython(
requires_python.clone(),
PythonRequirementKind::Installed,
),
)),
)));
}
}
Ok(Some(ResolverVersion::Available(version.clone())))
}
PubGrubPackageInner::Marker {
name, url: None, ..
}
| PubGrubPackageInner::Extra {
name, url: None, ..
}
| PubGrubPackageInner::Dev {
name, url: None, ..
}
| PubGrubPackageInner::Package {
name, url: None, ..
} => {
// Wait for the metadata to be available.
let versions_response = self
.index
.packages()
.wait_blocking(name)
.ok_or_else(|| ResolveError::UnregisteredTask(name.to_string()))?;
visited.insert(name.clone());
let version_maps = match *versions_response {
VersionsResponse::Found(ref version_maps) => version_maps.as_slice(),
VersionsResponse::NoIndex => {
self.unavailable_packages
.insert(name.clone(), UnavailablePackage::NoIndex);
&[]
}
VersionsResponse::Offline => {
self.unavailable_packages
.insert(name.clone(), UnavailablePackage::Offline);
&[]
}
VersionsResponse::NotFound => {
self.unavailable_packages
.insert(name.clone(), UnavailablePackage::NotFound);
&[]
}
};
debug!("Searching for a compatible version of {package} ({range})");
// Find a version.
let Some(candidate) = self.selector.select(
name,
range,
version_maps,
&self.preferences,
&self.installed_packages,
&self.exclusions,
) else {
// Short circuit: we couldn't find _any_ versions for a package.
return Ok(None);
};
let dist = match candidate.dist() {
CandidateDist::Compatible(dist) => dist,
CandidateDist::Incompatible(incompatibility) => {
// If the version is incompatible because no distributions are compatible, exit early.
return Ok(Some(ResolverVersion::Unavailable(
candidate.version().clone(),
UnavailableVersion::IncompatibleDist(incompatibility.clone()),
)));
}
};
let filename = match dist.for_installation() {
ResolvedDistRef::InstallableRegistrySourceDist { sdist, .. } => sdist
.filename()
.unwrap_or(Cow::Borrowed("unknown filename")),
ResolvedDistRef::InstallableRegistryBuiltDist { wheel, .. } => wheel
.filename()
.unwrap_or(Cow::Borrowed("unknown filename")),
ResolvedDistRef::Installed(_) => Cow::Borrowed("installed"),
};
debug!(
"Selecting: {}=={} ({})",
package,
candidate.version(),
filename,
);
// We want to return a package pinned to a specific version; but we _also_ want to
// store the exact file that we selected to satisfy that version.
pins.insert(&candidate, dist);
let version = candidate.version().clone();
// Emit a request to fetch the metadata for this version.
if matches!(&**package, PubGrubPackageInner::Package { .. }) {
if self.index.distributions().register(candidate.version_id()) {
let request = Request::from(dist.for_resolution());
request_sink.blocking_send(request)?;
}
}
Ok(Some(ResolverVersion::Available(version)))
}
}
}
/// Given a candidate package and version, return its dependencies.
#[instrument(skip_all, fields(%package, %version))]
fn get_dependencies_forking(
&self,
package: &PubGrubPackage,
version: &Version,
markers: &MarkerTree,
priorities: &mut PubGrubPriorities,
request_sink: &Sender<Request>,
) -> Result<ForkedDependencies, ResolveError> {
let result = self.get_dependencies(package, version, markers, priorities, request_sink);
if self.markers.is_some() {
return result.map(|deps| match deps {
Dependencies::Available(deps) => ForkedDependencies::Unforked(deps),
Dependencies::Unavailable(err) => ForkedDependencies::Unavailable(err),
});
}
Ok(result?.fork())
}
/// Given a candidate package and version, return its dependencies.
#[instrument(skip_all, fields(%package, %version))]
fn get_dependencies(
&self,
package: &PubGrubPackage,
version: &Version,
markers: &MarkerTree,
priorities: &mut PubGrubPriorities,
request_sink: &Sender<Request>,
) -> Result<Dependencies, ResolveError> {
let (dependencies, name) = match &**package {
PubGrubPackageInner::Root(_) => {
let no_dev_deps = BTreeMap::default();
let requirements = self.flatten_requirements(
&self.requirements,
&no_dev_deps,
None,
None,
None,
markers,
);
let dependencies = PubGrubDependencies::from_requirements(
&requirements,
None,
&self.urls,
&self.locals,
&self.git,
)?;
(dependencies, None)
}
PubGrubPackageInner::Package {
name,
extra,
dev,
marker,
url,
} => {
// If we're excluding transitive dependencies, short-circuit.
if self.dependency_mode.is_direct() {
// If an extra is provided, wait for the metadata to be available, since it's
// still required for generating the lock file.
let dist = match url {
Some(url) => PubGrubDistribution::from_url(name, url),
None => PubGrubDistribution::from_registry(name, version),
};
// Wait for the metadata to be available.
self.index
.distributions()
.wait_blocking(&dist.version_id())
.ok_or_else(|| {
ResolveError::UnregisteredTask(dist.version_id().to_string())
})?;
return Ok(Dependencies::Available(Vec::default()));
}
// Determine the distribution to lookup.
let dist = match url {
Some(url) => PubGrubDistribution::from_url(name, url),
None => PubGrubDistribution::from_registry(name, version),
};
let version_id = dist.version_id();
// If the package does not exist in the registry or locally, we cannot fetch its dependencies
if self.unavailable_packages.get(name).is_some()
&& self.installed_packages.get_packages(name).is_empty()
{
debug_assert!(
false,
"Dependencies were requested for a package that is not available"
);
return Err(ResolveError::Failure(format!(
"The package is unavailable: {name}"
)));
}
// Wait for the metadata to be available.
let response = self
.index
.distributions()
.wait_blocking(&version_id)
.ok_or_else(|| ResolveError::UnregisteredTask(version_id.to_string()))?;
let metadata = match &*response {
MetadataResponse::Found(archive) => &archive.metadata,
MetadataResponse::Offline => {
self.incomplete_packages
.entry(name.clone())
.or_default()
.insert(version.clone(), IncompletePackage::Offline);
return Ok(Dependencies::Unavailable(UnavailableVersion::Offline));
}
MetadataResponse::MissingMetadata => {
self.incomplete_packages
.entry(name.clone())
.or_default()
.insert(version.clone(), IncompletePackage::MissingMetadata);
return Ok(Dependencies::Unavailable(
UnavailableVersion::MissingMetadata,
));
}
MetadataResponse::InvalidMetadata(err) => {
warn!("Unable to extract metadata for {name}: {err}");
self.incomplete_packages
.entry(name.clone())
.or_default()
.insert(
version.clone(),
IncompletePackage::InvalidMetadata(err.to_string()),
);
return Ok(Dependencies::Unavailable(
UnavailableVersion::InvalidMetadata,
));
}
MetadataResponse::InconsistentMetadata(err) => {
warn!("Unable to extract metadata for {name}: {err}");
self.incomplete_packages
.entry(name.clone())
.or_default()
.insert(
version.clone(),
IncompletePackage::InconsistentMetadata(err.to_string()),
);
return Ok(Dependencies::Unavailable(
UnavailableVersion::InconsistentMetadata,
));
}
MetadataResponse::InvalidStructure(err) => {
warn!("Unable to extract metadata for {name}: {err}");
self.incomplete_packages
.entry(name.clone())
.or_default()
.insert(
version.clone(),
IncompletePackage::InvalidStructure(err.to_string()),
);
return Ok(Dependencies::Unavailable(
UnavailableVersion::InvalidStructure,
));
}
};
let requirements = self.flatten_requirements(
&metadata.requires_dist,
&metadata.dev_dependencies,
extra.as_ref(),
dev.as_ref(),
Some(name),
markers,
);
let mut dependencies = PubGrubDependencies::from_requirements(
&requirements,
Some(name),
&self.urls,
&self.locals,
&self.git,
)?;
// If a package has metadata for an enabled dependency group,
// add a dependency from it to the same package with the group
// enabled.
if extra.is_none() && dev.is_none() {
for group in &self.dev {
if !metadata.dev_dependencies.contains_key(group) {
continue;
}
dependencies.push(
PubGrubPackage::from(PubGrubPackageInner::Dev {
name: name.clone(),
dev: group.clone(),
marker: marker.clone(),
url: url.clone(),
}),
Range::singleton(version.clone()),
);
}
}
(dependencies, Some(name))
}
PubGrubPackageInner::Python(_) => return Ok(Dependencies::Available(Vec::default())),
// Add a dependency on both the marker and base package.
PubGrubPackageInner::Marker { name, marker, url } => {
return Ok(Dependencies::Available(
[None, Some(marker)]
.into_iter()
.map(move |marker| {
(
PubGrubPackage::from(PubGrubPackageInner::Package {
name: name.clone(),
extra: None,
dev: None,
marker: marker.cloned(),
url: url.clone(),
}),
Range::singleton(version.clone()),
)
})
.collect(),
))
}
// Add a dependency on both the extra and base package, with and without the marker.
PubGrubPackageInner::Extra {
name,
extra,
marker,
url,
} => {
return Ok(Dependencies::Available(
[None, marker.as_ref()]
.into_iter()
.dedup()
.flat_map(move |marker| {
[None, Some(extra)].into_iter().map(move |extra| {
(
PubGrubPackage::from(PubGrubPackageInner::Package {
name: name.clone(),
extra: extra.cloned(),
dev: None,
marker: marker.cloned(),
url: url.clone(),
}),
Range::singleton(version.clone()),
)
})
})
.collect(),
))
}
// Add a dependency on both the development dependency group and base package, with and
// without the marker.
PubGrubPackageInner::Dev {
name,
dev,
marker,
url,
} => {
return Ok(Dependencies::Available(
[None, marker.as_ref()]
.into_iter()
.dedup()
.flat_map(move |marker| {
[None, Some(dev)].into_iter().map(move |dev| {
(
PubGrubPackage::from(PubGrubPackageInner::Package {
name: name.clone(),
extra: None,
dev: dev.cloned(),
marker: marker.cloned(),
url: url.clone(),
}),
Range::singleton(version.clone()),
)
})
})
.collect(),
))
}
};
for (dep_package, dep_version) in dependencies.iter() {
if let Some(name) = name {
debug!("Adding transitive dependency for {name}=={version}: {dep_package}{dep_version}");
} else {
// A dependency from the root package or requirements.txt.
debug!("Adding direct dependency: {dep_package}{dep_version}");
}
// Update the package priorities.
priorities.insert(dep_package, dep_version);
// Emit a request to fetch the metadata for this package.
self.visit_package(dep_package, request_sink)?;
}
Ok(Dependencies::Available(dependencies.into()))
}
/// The regular and dev dependencies filtered by Python version and the markers of this fork,
/// plus the extras dependencies of the current package (e.g., `black` depending on
/// `black[colorama]`).
fn flatten_requirements<'a>(
&'a self,
dependencies: &'a [Requirement],
dev_dependencies: &'a BTreeMap<GroupName, Vec<Requirement>>,
extra: Option<&'a ExtraName>,
dev: Option<&'a GroupName>,
name: Option<&PackageName>,
markers: &'a MarkerTree,
) -> Vec<&'a Requirement> {
// Start with the requirements for the current extra of the package (for an extra
// requirement) or the non-extra (regular) dependencies (if extra is None), plus
// the constraints for the current package.
let regular_and_dev_dependencies = if let Some(dev) = dev {
Either::Left(dev_dependencies.get(dev).into_iter().flatten())
} else {
Either::Right(dependencies.iter())
};
let mut requirements: Vec<&Requirement> = self
.requirements_for_extra(regular_and_dev_dependencies, extra, markers)
.collect();
// Check if there are recursive self inclusions and we need to go into the expensive branch.
if !requirements
.iter()
.any(|req| name == Some(&req.name) && !req.extras.is_empty())
{
return requirements;
}
// Transitively process all extras that are recursively included, starting with the current
// extra.
let mut seen = FxHashSet::default();
let mut queue: VecDeque<_> = requirements
.iter()
.filter(|req| name == Some(&req.name))
.flat_map(|req| &req.extras)
.collect();
while let Some(extra) = queue.pop_front() {
if !seen.insert(extra) {
continue;
}
// Add each transitively included extra.
queue.extend(
self.requirements_for_extra(dependencies, Some(extra), markers)
.filter(|req| name == Some(&req.name))
.flat_map(|req| &req.extras),
);
// Add the requirements for that extra
requirements.extend(self.requirements_for_extra(dependencies, Some(extra), markers));
}
// Drop all the self-requirements now that we flattened them out.
requirements.retain(|req| name != Some(&req.name));
requirements
}
/// The set of the regular and dev dependencies, filtered by Python version,
/// the markers of this fork and the requested extra.
fn requirements_for_extra<'a>(
&'a self,
dependencies: impl IntoIterator<Item = &'a Requirement>,
extra: Option<&'a ExtraName>,
markers: &'a MarkerTree,
) -> impl Iterator<Item = &'a Requirement> {
self.overrides
.apply(dependencies)
.flat_map(|requirement| {
iter::once(requirement).chain(
// If the requirement was constrained, add those constraints.
self.constraints
.get(&requirement.name)
.into_iter()
.flatten(),
)
})
.filter(move |requirement| {
// If the requirement would not be selected with any Python version
// supported by the root, skip it.
if !satisfies_requires_python(self.requires_python.as_ref(), requirement) {
trace!(
"skipping {requirement} because of Requires-Python {requires_python}",
// OK because this filter only applies when there is a present
// Requires-Python specifier.
requires_python = self.requires_python.as_ref().unwrap()
);
return false;
}
// If we're in universal mode, `fork_markers` might correspond to a
// non-trivial marker expression that provoked the resolver to fork.
// In that case, we should ignore any dependency that cannot possibly
// satisfy the markers that provoked the fork.
if !possible_to_satisfy_markers(markers, requirement) {
trace!("skipping {requirement} because of context resolver markers {markers}");
return false;
}
// If the requirement isn't relevant for the current platform, skip it.
match extra {
Some(source_extra) => {
// Only include requirements that are relevant for the current extra.
if requirement.evaluate_markers(self.markers.as_ref(), &[]) {
return false;
}
if !requirement.evaluate_markers(
self.markers.as_ref(),
std::slice::from_ref(source_extra),
) {
return false;
}
}
None => {
if !requirement.evaluate_markers(self.markers.as_ref(), &[]) {
return false;
}
}
}
true
})
}
/// Fetch the metadata for a stream of packages and versions.
async fn fetch<Provider: ResolverProvider>(
self: Arc<Self>,
provider: Arc<Provider>,
request_stream: Receiver<Request>,
) -> Result<(), ResolveError> {
let mut response_stream = ReceiverStream::new(request_stream)
.map(|request| self.process_request(request, &*provider).boxed_local())
// Allow as many futures as possible to start in the background.
// Backpressure is provided by at a more granular level by `DistributionDatabase`
// and `SourceDispatch`, as well as the bounded request channel.
.buffer_unordered(usize::MAX);
while let Some(response) = response_stream.next().await {
match response? {
Some(Response::Package(package_name, version_map)) => {
trace!("Received package metadata for: {package_name}");
self.index
.packages()
.done(package_name, Arc::new(version_map));
}
Some(Response::Installed { dist, metadata }) => {
trace!("Received installed distribution metadata for: {dist}");
self.index.distributions().done(
dist.version_id(),
Arc::new(MetadataResponse::Found(ArchiveMetadata::from_metadata23(
metadata,
))),
);
}
Some(Response::Dist {
dist: Dist::Built(dist),
metadata,
}) => {
trace!("Received built distribution metadata for: {dist}");
match &metadata {
MetadataResponse::InvalidMetadata(err) => {
warn!("Unable to extract metadata for {dist}: {err}");
}
MetadataResponse::InvalidStructure(err) => {
warn!("Unable to extract metadata for {dist}: {err}");
}
_ => {}
}
self.index
.distributions()
.done(dist.version_id(), Arc::new(metadata));
}
Some(Response::Dist {
dist: Dist::Source(dist),
metadata,
}) => {
trace!("Received source distribution metadata for: {dist}");
match &metadata {
MetadataResponse::InvalidMetadata(err) => {
warn!("Unable to extract metadata for {dist}: {err}");
}
MetadataResponse::InvalidStructure(err) => {
warn!("Unable to extract metadata for {dist}: {err}");
}
_ => {}
}
self.index
.distributions()
.done(dist.version_id(), Arc::new(metadata));
}
None => {}
}
}
Ok::<(), ResolveError>(())
}
#[instrument(skip_all, fields(%request))]
async fn process_request<Provider: ResolverProvider>(
&self,
request: Request,
provider: &Provider,
) -> Result<Option<Response>, ResolveError> {
match request {
// Fetch package metadata from the registry.
Request::Package(package_name) => {
let package_versions = provider
.get_package_versions(&package_name)
.boxed_local()
.await
.map_err(ResolveError::Client)?;
Ok(Some(Response::Package(package_name, package_versions)))
}
// Fetch distribution metadata from the distribution database.
Request::Dist(dist) => {
let metadata = provider
.get_or_build_wheel_metadata(&dist)
.boxed_local()
.await
.map_err(|err| match dist.clone() {
Dist::Built(built_dist @ BuiltDist::Path(_)) => {
ResolveError::Read(Box::new(built_dist), err)
}
Dist::Source(source_dist @ SourceDist::Path(_)) => {
ResolveError::Build(Box::new(source_dist), err)
}
Dist::Source(source_dist @ SourceDist::Directory(_)) => {
ResolveError::Build(Box::new(source_dist), err)
}
Dist::Built(built_dist) => ResolveError::Fetch(Box::new(built_dist), err),
Dist::Source(source_dist) => {
ResolveError::FetchAndBuild(Box::new(source_dist), err)
}
})?;
Ok(Some(Response::Dist { dist, metadata }))
}
Request::Installed(dist) => {
let metadata = dist
.metadata()
.map_err(|err| ResolveError::ReadInstalled(Box::new(dist.clone()), err))?;
Ok(Some(Response::Installed { dist, metadata }))
}
// Pre-fetch the package and distribution metadata.
Request::Prefetch(package_name, range) => {
// Wait for the package metadata to become available.
let versions_response = self
.index
.packages()
.wait(&package_name)
.await
.ok_or_else(|| ResolveError::UnregisteredTask(package_name.to_string()))?;
let version_map = match *versions_response {
VersionsResponse::Found(ref version_map) => version_map,
// Short-circuit if we did not find any versions for the package
VersionsResponse::NoIndex => {
self.unavailable_packages
.insert(package_name.clone(), UnavailablePackage::NoIndex);
return Ok(None);
}
VersionsResponse::Offline => {
self.unavailable_packages
.insert(package_name.clone(), UnavailablePackage::Offline);
return Ok(None);
}
VersionsResponse::NotFound => {
self.unavailable_packages
.insert(package_name.clone(), UnavailablePackage::NotFound);
return Ok(None);
}
};
// Try to find a compatible version. If there aren't any compatible versions,
// short-circuit.
let Some(candidate) = self.selector.select(
&package_name,
&range,
version_map,
&self.preferences,
&self.installed_packages,
&self.exclusions,
) else {
return Ok(None);
};
// If there is not a compatible distribution, short-circuit.
let Some(dist) = candidate.compatible() else {
return Ok(None);
};
// Avoid prefetching source distributions with unbounded lower-bound ranges. This
// often leads to failed attempts to build legacy versions of packages that are
// incompatible with modern build tools.
if !dist.prefetchable() {
if !self.selector.use_highest_version(&package_name) {
if let Some((lower, _)) = range.iter().next() {
if lower == &Bound::Unbounded {
debug!("Skipping prefetch for unbounded minimum-version range: {package_name} ({range})");
return Ok(None);
}
}
}
}
// Emit a request to fetch the metadata for this version.
if self.index.distributions().register(candidate.version_id()) {
let dist = dist.for_resolution().to_owned();
let response = match dist {
ResolvedDist::Installable(dist) => {
let metadata = provider
.get_or_build_wheel_metadata(&dist)
.boxed_local()
.await
.map_err(|err| match dist.clone() {
Dist::Built(built_dist @ BuiltDist::Path(_)) => {
ResolveError::Read(Box::new(built_dist), err)
}
Dist::Source(source_dist @ SourceDist::Path(_)) => {
ResolveError::Build(Box::new(source_dist), err)
}
Dist::Source(source_dist @ SourceDist::Directory(_)) => {
ResolveError::Build(Box::new(source_dist), err)
}
Dist::Built(built_dist) => {
ResolveError::Fetch(Box::new(built_dist), err)
}
Dist::Source(source_dist) => {
ResolveError::FetchAndBuild(Box::new(source_dist), err)
}
})?;
Response::Dist { dist, metadata }
}
ResolvedDist::Installed(dist) => {
let metadata = dist.metadata().map_err(|err| {
ResolveError::ReadInstalled(Box::new(dist.clone()), err)
})?;
Response::Installed { dist, metadata }
}
};
Ok(Some(response))
} else {
Ok(None)
}
}
}
}
fn on_progress(&self, package: &PubGrubPackage, version: &Version) {
if let Some(reporter) = self.reporter.as_ref() {
match &**package {
PubGrubPackageInner::Root(_) => {}
PubGrubPackageInner::Python(_) => {}
PubGrubPackageInner::Marker { .. } => {}
PubGrubPackageInner::Extra { .. } => {}
PubGrubPackageInner::Dev { .. } => {}
PubGrubPackageInner::Package {
name,
url: Some(url),
..
} => {
reporter.on_progress(name, &VersionOrUrlRef::Url(&url.verbatim));
}
PubGrubPackageInner::Package {
name, url: None, ..
} => {
reporter.on_progress(name, &VersionOrUrlRef::Version(version));
}
}
}
}
fn on_complete(&self) {
if let Some(reporter) = self.reporter.as_ref() {
reporter.on_complete();
}
}
}
/// State that is used during unit propagation in the resolver.
#[derive(Clone)]
struct SolveState {
/// The internal state used by the resolver.
///
/// Note that not all parts of this state are strictly internal. For
/// example, the edges in the dependency graph generated as part of the
/// output of resolution are derived from the "incompatibilities" tracked
/// in this state. We also ultimately retrieve the final set of version
/// assignments (to packages) from this state's "partial solution."
pubgrub: State<UvDependencyProvider>,
/// The next package on which to run unit propagation.
next: PubGrubPackage,
/// The set of pinned versions we accrue throughout resolution.
///
/// The key of this map is a package name, and each package name maps to
/// a set of versions for that package. Each version in turn is mapped
/// to a single `ResolvedDist`. That `ResolvedDist` represents, at time
/// of writing (2024/05/09), at most one wheel. The idea here is that
/// `FilePins` tracks precisely which wheel was selected during resolution.
/// After resolution is finished, this maps is consulted in order to select
/// the wheel chosen during resolution.
pins: FilePins,
/// When dependencies for a package are retrieved, this map of priorities
/// is updated based on how each dependency was specified. Certain types
/// of dependencies have more "priority" than others (like direct URL
/// dependencies). These priorities help determine which package to
/// consider next during resolution.
priorities: PubGrubPriorities,
/// This keeps track of the set of versions for each package that we've
/// already visited during resolution. This avoids doing redundant work.
added_dependencies: FxHashMap<PubGrubPackage, FxHashSet<Version>>,
/// The marker expression that created this state.
///
/// The root state always corresponds to a marker expression that is always
/// `true` for every `MarkerEnvironment`.
///
/// In non-universal mode, forking never occurs and so this marker
/// expression is always `true`.
///
/// Whenever dependencies are fetched, all requirement specifications
/// are checked for disjointness with the marker expression of the fork
/// in which those dependencies were fetched. If a requirement has a
/// completely disjoint marker expression (i.e., it can never be true given
/// that the marker expression that provoked the fork is true), then that
/// dependency is completely ignored.
markers: MarkerTree,
}
impl SolveState {
/// Add the dependencies for the selected version of the current package.
fn add_package_version_dependencies(
&mut self,
version: &Version,
dependencies: Vec<(PubGrubPackage, Range<Version>)>,
prefetcher: &BatchPrefetcher,
) -> Result<(), ResolveError> {
if dependencies
.iter()
.any(|(dependency, _)| dependency == &self.next)
{
if enabled!(Level::DEBUG) {
prefetcher.log_tried_versions();
}
return Err(PubGrubError::SelfDependency {
package: self.next.clone(),
version: version.clone(),
}
.into());
}
self.pubgrub.add_package_version_dependencies(
self.next.clone(),
version.clone(),
dependencies,
);
Ok(())
}
fn into_resolution(self) -> Resolution {
let solution = self.pubgrub.partial_solution.extract_solution();
let mut dependencies: FxHashMap<
ResolutionDependencyNames,
FxHashSet<ResolutionDependencyVersions>,
> = FxHashMap::default();
for (package, self_version) in &solution {
for id in &self.pubgrub.incompatibilities[package] {
let pubgrub::solver::Kind::FromDependencyOf(
ref self_package,
ref self_range,
ref dependency_package,
ref dependency_range,
) = self.pubgrub.incompatibility_store[*id].kind
else {
continue;
};
if package != self_package {
continue;
}
if !self_range.contains(self_version) {
continue;
}
let Some(dependency_version) = solution.get(dependency_package) else {
continue;
};
if !dependency_range.contains(dependency_version) {
continue;
}
let (self_name, self_extra, self_dev) = match &**self_package {
PubGrubPackageInner::Package {
name: self_name,
extra: self_extra,
dev: self_dev,
..
} => (Some(self_name), self_extra.as_ref(), self_dev.as_ref()),
PubGrubPackageInner::Root(_) => (None, None, None),
_ => continue,
};
match **dependency_package {
PubGrubPackageInner::Package {
name: ref dependency_name,
extra: ref dependency_extra,
dev: ref dependency_dev,
..
} => {
if self_name.is_some_and(|self_name| self_name == dependency_name) {
continue;
}
let names = ResolutionDependencyNames {
from: self_name.cloned(),
to: dependency_name.clone(),
};
let versions = ResolutionDependencyVersions {
from_version: self_version.clone(),
from_extra: self_extra.cloned(),
from_dev: self_dev.cloned(),
to_version: dependency_version.clone(),
to_extra: dependency_extra.clone(),
to_dev: dependency_dev.clone(),
marker: None,
};
dependencies.entry(names).or_default().insert(versions);
}
PubGrubPackageInner::Marker {
name: ref dependency_name,
marker: ref dependency_marker,
..
} => {
if self_name.is_some_and(|self_name| self_name == dependency_name) {
continue;
}
let names = ResolutionDependencyNames {
from: self_name.cloned(),
to: dependency_name.clone(),
};
let versions = ResolutionDependencyVersions {
from_version: self_version.clone(),
from_extra: self_extra.cloned(),
from_dev: self_dev.cloned(),
to_version: dependency_version.clone(),
to_extra: None,
to_dev: None,
marker: Some(dependency_marker.clone()),
};
dependencies.entry(names).or_default().insert(versions);
}
PubGrubPackageInner::Extra {
name: ref dependency_name,
extra: ref dependency_extra,
marker: ref dependency_marker,
..
} => {
if self_name.is_some_and(|self_name| self_name == dependency_name) {
continue;
}
let names = ResolutionDependencyNames {
from: self_name.cloned(),
to: dependency_name.clone(),
};
let versions = ResolutionDependencyVersions {
from_version: self_version.clone(),
from_extra: self_extra.cloned(),
from_dev: self_dev.cloned(),
to_version: dependency_version.clone(),
to_extra: Some(dependency_extra.clone()),
to_dev: None,
marker: dependency_marker.clone(),
};
dependencies.entry(names).or_default().insert(versions);
}
PubGrubPackageInner::Dev {
name: ref dependency_name,
dev: ref dependency_dev,
marker: ref dependency_marker,
..
} => {
if self_name.is_some_and(|self_name| self_name == dependency_name) {
continue;
}
let names = ResolutionDependencyNames {
from: self_name.cloned(),
to: dependency_name.clone(),
};
let versions = ResolutionDependencyVersions {
from_version: self_version.clone(),
from_extra: self_extra.cloned(),
from_dev: self_dev.cloned(),
to_version: dependency_version.clone(),
to_extra: None,
to_dev: Some(dependency_dev.clone()),
marker: dependency_marker.clone(),
};
dependencies.entry(names).or_default().insert(versions);
}
_ => {}
}
}
}
let packages = solution
.into_iter()
.filter_map(|(package, version)| {
if let PubGrubPackageInner::Package {
name,
extra,
dev,
url,
marker: None,
} = &*package
{
Some((
ResolutionPackage {
name: name.clone(),
extra: extra.clone(),
dev: dev.clone(),
url: url.clone(),
},
FxHashSet::from_iter([version]),
))
} else {
None
}
})
.collect();
Resolution {
packages,
dependencies,
pins: self.pins,
}
}
}
#[derive(Debug, Default)]
pub(crate) struct Resolution {
pub(crate) packages: FxHashMap<ResolutionPackage, FxHashSet<Version>>,
pub(crate) dependencies:
FxHashMap<ResolutionDependencyNames, FxHashSet<ResolutionDependencyVersions>>,
pub(crate) pins: FilePins,
}
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub(crate) struct ResolutionPackage {
pub(crate) name: PackageName,
pub(crate) extra: Option<ExtraName>,
pub(crate) dev: Option<GroupName>,
pub(crate) url: Option<VerbatimParsedUrl>,
}
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub(crate) struct ResolutionDependencyNames {
pub(crate) from: Option<PackageName>,
pub(crate) to: PackageName,
}
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub(crate) struct ResolutionDependencyVersions {
pub(crate) from_version: Version,
pub(crate) from_extra: Option<ExtraName>,
pub(crate) from_dev: Option<GroupName>,
pub(crate) to_version: Version,
pub(crate) to_extra: Option<ExtraName>,
pub(crate) to_dev: Option<GroupName>,
pub(crate) marker: Option<MarkerTree>,
}
impl Resolution {
fn union(&mut self, other: Resolution) {
for (other_package, other_versions) in other.packages {
self.packages
.entry(other_package)
.or_default()
.extend(other_versions);
}
for (names, versions) in other.dependencies {
self.dependencies.entry(names).or_default().extend(versions);
}
self.pins.union(other.pins);
}
}
/// Fetch the metadata for an item
#[derive(Debug)]
#[allow(clippy::large_enum_variant)]
pub(crate) enum Request {
/// A request to fetch the metadata for a package.
Package(PackageName),
/// A request to fetch the metadata for a built or source distribution.
Dist(Dist),
/// A request to fetch the metadata from an already-installed distribution.
Installed(InstalledDist),
/// A request to pre-fetch the metadata for a package and the best-guess distribution.
Prefetch(PackageName, Range<Version>),
}
impl<'a> From<ResolvedDistRef<'a>> for Request {
fn from(dist: ResolvedDistRef<'a>) -> Request {
// N.B. This is almost identical to `ResolvedDistRef::to_owned`, but
// creates a `Request` instead of a `ResolvedDist`. There's probably
// some room for DRYing this up a bit. The obvious way would be to
// add a method to create a `Dist`, but a `Dist` cannot be represented
// as an installed dist.
match dist {
ResolvedDistRef::InstallableRegistrySourceDist { sdist, prioritized } => {
// This is okay because we're only here if the prioritized dist
// has an sdist, so this always succeeds.
let source = prioritized.source_dist().expect("a source distribution");
assert_eq!(
(&sdist.name, &sdist.version),
(&source.name, &source.version),
"expected chosen sdist to match prioritized sdist"
);
Request::Dist(Dist::Source(SourceDist::Registry(source)))
}
ResolvedDistRef::InstallableRegistryBuiltDist {
wheel, prioritized, ..
} => {
assert_eq!(
Some(&wheel.filename),
prioritized.best_wheel().map(|(wheel, _)| &wheel.filename),
"expected chosen wheel to match best wheel"
);
// This is okay because we're only here if the prioritized dist
// has at least one wheel, so this always succeeds.
let built = prioritized.built_dist().expect("at least one wheel");
Request::Dist(Dist::Built(BuiltDist::Registry(built)))
}
ResolvedDistRef::Installed(dist) => Request::Installed(dist.clone()),
}
}
}
impl Display for Request {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
match self {
Self::Package(package_name) => {
write!(f, "Versions {package_name}")
}
Self::Dist(dist) => {
write!(f, "Metadata {dist}")
}
Self::Installed(dist) => {
write!(f, "Installed metadata {dist}")
}
Self::Prefetch(package_name, range) => {
write!(f, "Prefetch {package_name} {range}")
}
}
}
}
#[derive(Debug)]
#[allow(clippy::large_enum_variant)]
enum Response {
/// The returned metadata for a package hosted on a registry.
Package(PackageName, VersionsResponse),
/// The returned metadata for a distribution.
Dist {
dist: Dist,
metadata: MetadataResponse,
},
/// The returned metadata for an already-installed distribution.
Installed {
dist: InstalledDist,
metadata: Metadata23,
},
}
/// Information about the dependencies for a particular package.
///
/// This effectively distills the dependency metadata of a package down into
/// its pubgrub specific constituent parts: each dependency package has a range
/// of possible versions.
#[derive(Clone)]
enum Dependencies {
/// Package dependencies are not available.
Unavailable(UnavailableVersion),
/// Container for all available package versions.
///
/// Note that in universal mode, it is possible and allowed for multiple
/// `PubGrubPackage` values in this list to have the same package name.
/// These conflicts are resolved via `Dependencies::fork`.
Available(Vec<(PubGrubPackage, Range<Version>)>),
}
impl Dependencies {
/// Turn this flat list of dependencies into a potential set of forked
/// groups of dependencies.
///
/// A fork *only* occurs when there are multiple dependencies with the same
/// name *and* those dependency specifications have corresponding marker
/// expressions that are completely disjoint with one another.
fn fork(self) -> ForkedDependencies {
use std::collections::hash_map::Entry;
let deps = match self {
Dependencies::Available(deps) => deps,
Dependencies::Unavailable(err) => return ForkedDependencies::Unavailable(err),
};
let mut by_name: FxHashMap<&PackageName, PossibleForks> = FxHashMap::default();
for (index, (ref pkg, _)) in deps.iter().enumerate() {
// A root can never be a dependency of another package,
// and a `Python` pubgrub package is never returned by
// `get_dependencies`. So a pubgrub package always has a
// name in this context.
let name = pkg.name().expect("dependency always has a name");
let marker = pkg.marker();
let Some(marker) = marker else {
// When no marker is found, it implies there is a dependency on
// this package that is unconditional with respect to marker
// expressions. Therefore, it should never be the cause of a
// fork since it is necessarily overlapping with every other
// possible marker expression that isn't pathological.
match by_name.entry(name) {
Entry::Vacant(e) => {
e.insert(PossibleForks::NoForkPossible(vec![index]));
}
Entry::Occupied(mut e) => {
e.get_mut().push_unconditional_package(index);
}
}
continue;
};
let possible_forks = match by_name.entry(name) {
// If one doesn't exist, then this is the first dependency
// with this package name. And since it has a marker, we can
// add it as the initial instance of a possibly forking set of
// dependencies. (A fork will only actually happen if another
// dependency is found with the same package name *and* where
// its marker expression is disjoint with this one.)
Entry::Vacant(e) => {
let possible_fork = PossibleFork {
packages: vec![(index, marker)],
};
let fork_groups = PossibleForkGroups {
forks: vec![possible_fork],
};
e.insert(PossibleForks::PossiblyForking(fork_groups));
continue;
}
// Now that we have a marker, look for an existing entry. If
// one already exists and is "no fork possible," then we know
// we can't fork.
Entry::Occupied(e) => match *e.into_mut() {
PossibleForks::NoForkPossible(ref mut indices) => {
indices.push(index);
continue;
}
PossibleForks::PossiblyForking(ref mut possible_forks) => possible_forks,
},
};
// At this point, we know we 1) have a duplicate dependency on
// a package and 2) the original and this one both have marker
// expressions. This still doesn't guarantee that a fork occurs
// though. A fork can only occur when the marker expressions from
// (2) are provably disjoint. Otherwise, we could end up with
// a resolution that would result in installing two different
// versions of the same package. Specifically, this could occur in
// precisely the cases where the marker expressions intersect.
//
// By construction, the marker expressions *in* each fork group
// have some non-empty intersection, and the marker expressions
// *between* each fork group are completely disjoint. So what we do
// is look for a group in which there is some overlap. If so, this
// package gets added to that fork group. Otherwise, we create a
// new fork group.
let Some(possible_fork) = possible_forks.find_overlapping_fork_group(marker) else {
// Create a new fork since there was no overlap.
possible_forks.forks.push(PossibleFork {
packages: vec![(index, marker)],
});
continue;
};
// Add to an existing fork since there was overlap.
possible_fork.packages.push((index, marker));
}
// If all possible forks have exactly 1 group, then there is no forking.
if !by_name.values().any(PossibleForks::has_fork) {
return ForkedDependencies::Unforked(deps);
}
let mut forks = vec![Fork {
dependencies: vec![],
markers: MarkerTree::And(vec![]),
}];
let mut diverging_packages = Vec::new();
for (name, possible_forks) in by_name {
let fork_groups = match possible_forks.finish() {
// 'finish()' guarantees that 'PossiblyForking' implies
// 'DefinitelyForking'.
PossibleForks::PossiblyForking(fork_groups) => fork_groups,
PossibleForks::NoForkPossible(indices) => {
// No fork is provoked by this package, so just add
// everything in this group to each of the forks.
for index in indices {
for fork in &mut forks {
fork.add_nonfork_package(deps[index].clone());
}
}
continue;
}
};
assert!(fork_groups.forks.len() >= 2, "expected definitive fork");
let mut new_forks: Vec<Fork> = vec![];
for group in fork_groups.forks {
let mut new_forks_for_group = forks.clone();
for (index, _) in group.packages {
for fork in &mut new_forks_for_group {
fork.add_forked_package(deps[index].clone());
}
}
new_forks.extend(new_forks_for_group);
}
forks = new_forks;
diverging_packages.push(name.clone());
}
ForkedDependencies::Forked {
forks,
diverging_packages,
}
}
}
/// Information about the (possibly forked) dependencies for a particular
/// package.
///
/// This is like `Dependencies` but with an extra variant that only occurs when
/// a `Dependencies` list has multiple dependency specifications with the same
/// name and non-overlapping marker expressions (i.e., a fork occurs).
#[derive(Debug)]
enum ForkedDependencies {
/// Package dependencies are not available.
Unavailable(UnavailableVersion),
/// No forking occurred.
///
/// This is the same as `Dependencies::Available`.
Unforked(Vec<(PubGrubPackage, Range<Version>)>),
/// Forked containers for all available package versions.
///
/// Note that there is always at least two forks. If there would
/// be fewer than 2 forks, then there is no fork at all and the
/// `Unforked` variant is used instead.
Forked {
forks: Vec<Fork>,
/// The package(s) with different requirements for disjoint markers.
diverging_packages: Vec<PackageName>,
},
}
/// A single fork in a list of dependencies.
///
/// A fork corresponds to the full list of dependencies for a package,
/// but with any conflicting dependency specifications omitted. For
/// example, if we have `a<2 ; sys_platform == 'foo'` and `a>=2 ;
/// sys_platform == 'bar'`, then because the dependency specifications
/// have the same name and because the marker expressions are disjoint,
/// a fork occurs. One fork will contain `a<2` but not `a>=2`, while
/// the other fork will contain `a>=2` but not `a<2`.
#[derive(Clone, Debug)]
struct Fork {
/// The list of dependencies for this fork, guaranteed to be conflict
/// free. (i.e., There are no two packages with the same name with
/// non-overlapping marker expressions.)
///
/// Note that callers shouldn't mutate this sequence directly. Instead,
/// they should use `add_forked_package` or `add_nonfork_package`. Namely,
/// it should be impossible for a package with a marker expression that is
/// disjoint from the marker expression on this fork to be added.
dependencies: Vec<(PubGrubPackage, Range<Version>)>,
/// The markers that provoked this fork.
///
/// So in the example above, the `a<2` fork would have
/// `sys_platform == 'foo'`, while the `a>=2` fork would have
/// `sys_platform == 'bar'`.
///
/// (This doesn't include any marker expressions from a parent fork.)
markers: MarkerTree,
}
impl Fork {
/// Add the given dependency to this fork with the assumption that it
/// provoked this fork into existence.
///
/// In particular, the markers given should correspond to the markers
/// associated with that dependency, and they are combined (via
/// conjunction) with the markers on this fork.
///
/// Finally, and critically, any dependencies that are already in this
/// fork that are disjoint with the markers given are removed. This is
/// because a fork provoked by the given marker should not have packages
/// whose markers are disjoint with it. While it might seem harmless, this
/// can cause the resolver to explore otherwise impossible resolutions,
/// and also run into conflicts (and thus a failed resolution) that don't
/// actually exist.
fn add_forked_package(&mut self, (pkg, range): (PubGrubPackage, Range<Version>)) {
// OK because a package without a marker is unconditional and
// thus can never provoke a fork.
let marker = pkg
.marker()
.cloned()
.expect("forked package always has a marker");
self.remove_disjoint_packages(&marker);
self.dependencies.push((pkg, range));
// Each marker expression in a single fork is,
// by construction, overlapping with at least
// one other marker expression in this fork.
// However, the symmetric differences may be
// non-empty. Therefore, the markers need to be
// combined on the corresponding fork.
self.markers.and(marker);
}
/// Add the given dependency to this fork.
///
/// This works by assuming the given package did *not* provoke a fork.
///
/// It is only added if the markers on the given package are not disjoint
/// with this fork's markers.
fn add_nonfork_package(&mut self, (pkg, range): (PubGrubPackage, Range<Version>)) {
use crate::marker::is_disjoint;
if pkg
.marker()
.map_or(true, |marker| !is_disjoint(marker, &self.markers))
{
self.dependencies.push((pkg, range));
}
}
/// Removes any dependencies in this fork whose markers are disjoint with
/// the given markers.
fn remove_disjoint_packages(&mut self, fork_marker: &MarkerTree) {
use crate::marker::is_disjoint;
self.dependencies.retain(|(pkg, _)| {
pkg.marker()
.map_or(true, |pkg_marker| !is_disjoint(pkg_marker, fork_marker))
});
}
}
/// Intermediate state that represents a *possible* grouping of forks
/// for one package name.
///
/// This accumulates state while examining a `Dependencies` list. In
/// particular, it accumulates conflicting dependency specifications and marker
/// expressions. As soon as a fork can be ruled out, this state is switched to
/// `NoForkPossible`. If, at the end of visiting all `Dependencies`, we still
/// have `PossibleForks::PossiblyForking`, then a fork exists if and only if
/// one of its groups has length bigger than `1`.
///
/// One common way for a fork to be known to be impossible is if there exists
/// conflicting dependency specifications where at least one is unconditional.
/// For example, `a<2` and `a>=2 ; sys_platform == 'foo'`. In this case, `a<2`
/// has a marker expression that is always true and thus never disjoint with
/// any other marker expression. Therefore, there can be no fork for `a`.
///
/// Note that we use indices into a `Dependencies` list to represent packages.
/// This avoids excessive cloning.
#[derive(Debug)]
enum PossibleForks<'a> {
/// A group of dependencies (all with the same package name) where it is
/// known that no forks exist.
NoForkPossible(Vec<usize>),
/// A group of groups dependencies (all with the same package name) where
/// it is possible for each group to correspond to a fork.
PossiblyForking(PossibleForkGroups<'a>),
}
impl<'a> PossibleForks<'a> {
/// Returns true if and only if this contains a fork assuming there are
/// no other dependencies to be considered.
fn has_fork(&self) -> bool {
let PossibleForks::PossiblyForking(ref fork_groups) = *self else {
return false;
};
fork_groups.forks.len() > 1
}
/// Consumes this possible set of forks and converts a "possibly forking"
/// variant to a "no fork possible" variant if there are no actual forks.
///
/// This should be called when all dependencies for one package have been
/// considered. It will normalize this value such that `PossiblyForking`
/// means `DefinitelyForking`.
fn finish(mut self) -> PossibleForks<'a> {
let PossibleForks::PossiblyForking(ref fork_groups) = self else {
return self;
};
if fork_groups.forks.len() == 1 {
self.make_no_forks_possible();
return self;
}
self
}
/// Pushes an unconditional index to a package.
///
/// If this previously contained possible forks, those are combined into
/// one single set of dependencies that can never be forked.
///
/// That is, adding an unconditional package means it is not disjoint with
/// all other possible dependencies using the same package name.
fn push_unconditional_package(&mut self, index: usize) {
self.make_no_forks_possible();
let PossibleForks::NoForkPossible(ref mut indices) = *self else {
unreachable!("all forks should be eliminated")
};
indices.push(index);
}
/// Convert this set of possible forks into something that can never fork.
///
/// This is useful in cases where a dependency on a package is found
/// without any marker expressions at all. In this case, it is never
/// possible for this package to provoke a fork. Since it is unconditional,
/// it implies it is never disjoint with any other dependency specification
/// on the same package. (Except for pathological cases of marker
/// expressions that always evaluate to false. But we generally ignore
/// those.)
fn make_no_forks_possible(&mut self) {
let PossibleForks::PossiblyForking(ref fork_groups) = *self else {
return;
};
let mut indices = vec![];
for possible_fork in &fork_groups.forks {
for &(index, _) in &possible_fork.packages {
indices.push(index);
}
}
*self = PossibleForks::NoForkPossible(indices);
}
}
/// A list of groups of dependencies (all with the same package name), where
/// each group may correspond to a fork.
#[derive(Debug)]
struct PossibleForkGroups<'a> {
/// The list of forks.
forks: Vec<PossibleFork<'a>>,
}
impl<'a> PossibleForkGroups<'a> {
/// Given a marker expression, if there is a fork in this set of fork
/// groups with non-empty overlap with it, then that fork group is
/// returned. Otherwise, `None` is returned.
fn find_overlapping_fork_group<'g>(
&'g mut self,
marker: &MarkerTree,
) -> Option<&'g mut PossibleFork<'a>> {
self.forks
.iter_mut()
.find(|fork| fork.is_overlapping(marker))
}
}
/// Intermediate state representing a single possible fork.
///
/// The key invariant here is that, beyond a singleton fork, for all packages
/// in this fork, its marker expression must be overlapping with at least one
/// other package's marker expression. That is, when considering whether a
/// dependency specification with a conflicting package name provokes a fork
/// or not, one must look at the existing possible groups of forks. If any of
/// those groups have a package with an overlapping marker expression, then
/// the conflicting package name cannot possibly introduce a new fork. But if
/// there is no existing fork with an overlapping marker expression, then the
/// conflict provokes a new fork.
///
/// As with other intermediate data types, we use indices into a list of
/// `Dependencies` to represent packages to avoid excessive cloning.
#[derive(Debug)]
struct PossibleFork<'a> {
packages: Vec<(usize, &'a MarkerTree)>,
}
impl<'a> PossibleFork<'a> {
/// Returns true if and only if the given marker expression has a non-empty
/// intersection with *any* of the package markers within this possible
/// fork.
fn is_overlapping(&self, candidate_package_markers: &MarkerTree) -> bool {
use crate::marker::is_disjoint;
for (_, package_markers) in &self.packages {
if !is_disjoint(candidate_package_markers, package_markers) {
return true;
}
}
false
}
}
/// Returns true if and only if the given requirement's marker expression has a
/// possible true value given the `requires_python` specifier given.
///
/// While this is always called, a `requires_python` is only non-None when in
/// universal resolution mode. In non-universal mode, `requires_python` is
/// `None` and this always returns `true`.
fn satisfies_requires_python(
requires_python: Option<&MarkerTree>,
requirement: &Requirement,
) -> bool {
let Some(requires_python) = requires_python else {
return true;
};
possible_to_satisfy_markers(requires_python, requirement)
}
/// Returns true if and only if the given requirement's marker expression has a
/// possible true value given the `markers` expression given.
fn possible_to_satisfy_markers(markers: &MarkerTree, requirement: &Requirement) -> bool {
let Some(marker) = requirement.marker.as_ref() else {
return true;
};
!crate::marker::is_disjoint(markers, marker)
}
Reference in a new issue View git blame Copy permalink