Add a VariantJson to the prioritized distribution

crates/uv-distribution-filename/src/wheel.rs

@@ -61,8 +61,8 @@ impl Display for WheelFilename {
                 "{}-{}-{}-{}.whl",
                 self.name.as_dist_info_name(),
                 self.version,
-                self.tags
+                self.tags,
-                variant,
+                variant
             )
         } else {
             write!(
@@ -364,8 +364,8 @@ impl WheelFilename {
         Ok(Self {
             name,
             version,
-            variant,
             tags,
+            variant,
         })
     }
 }

crates/uv-distribution-types/src/dist_or_variant_filename.rs

@@ -0,0 +1,9 @@
+use crate::VariantJson;
+use uv_distribution_filename::DistFilename;
+
+/// On an index page, there can be wheels, source distributions and `variant.json` files.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum DistOrVariantFilename {
+    DistFilename(DistFilename),
+    VariantJson(VariantJson),
+}

crates/uv-distribution-types/src/lib.rs

@@ -59,6 +59,7 @@ pub use crate::cached::*;
 pub use crate::dependency_metadata::*;
 pub use crate::diagnostic::*;
 pub use crate::dist_error::*;
+pub use crate::dist_or_variant_filename::*;
 pub use crate::error::*;
 pub use crate::file::*;
 pub use crate::hash::*;
@@ -79,6 +80,7 @@ pub use crate::resolved::*;
 pub use crate::specified_requirement::*;
 pub use crate::status_code_strategy::*;
 pub use crate::traits::*;
+pub use crate::variant_json::*;
 
 mod annotation;
 mod any;
@@ -87,6 +89,7 @@ mod cached;
 mod dependency_metadata;
 mod diagnostic;
 mod dist_error;
+mod dist_or_variant_filename;
 mod error;
 mod file;
 mod hash;
@@ -107,6 +110,7 @@ mod resolved;
 mod specified_requirement;
 mod status_code_strategy;
 mod traits;
+mod variant_json;
 
 #[derive(Debug, Clone)]
 pub enum VersionOrUrlRef<'a, T: Pep508Url = VerbatimUrl> {

crates/uv-distribution-types/src/prioritized_distribution.rs

@@ -13,7 +13,7 @@ use uv_variants::VariantPriority;
 
 use crate::{
     File, InstalledDist, KnownPlatform, RegistryBuiltDist, RegistryBuiltWheel, RegistrySourceDist,
-    ResolvedDistRef,
+    ResolvedDistRef, VariantJson,
 };
 
 /// A collection of distributions that have been filtered by relevance.
@@ -30,6 +30,8 @@ struct PrioritizedDistInner {
     best_wheel_index: Option<usize>,
     /// The set of all wheels associated with this distribution.
     wheels: Vec<(RegistryBuiltWheel, WheelCompatibility)>,
+    /// The `variants.json` file associated with the package version.
+    variants_json: Option<VariantJson>,
     /// The hashes for each distribution.
     hashes: Vec<HashDigest>,
     /// The set of supported platforms for the distribution, described in terms of their markers.
@@ -42,6 +44,7 @@ impl Default for PrioritizedDistInner {
             source: None,
             best_wheel_index: None,
             wheels: Vec::new(),
+            variants_json: None,
             hashes: Vec::new(),
             markers: MarkerTree::FALSE,
         }
@@ -350,6 +353,7 @@ impl PrioritizedDist {
             markers: implied_markers(&dist.filename),
             best_wheel_index: Some(0),
             wheels: vec![(dist, compatibility)],
+            variants_json: None,
             source: None,
             hashes,
         }))
@@ -366,10 +370,23 @@ impl PrioritizedDist {
             best_wheel_index: None,
             wheels: vec![],
             source: Some((dist, compatibility)),
+            variants_json: None,
             hashes,
         }))
     }
 
+    /// Create a new [`PrioritizedDist`] from the `variant.json`.
+    pub fn from_variant_json(variant_json: VariantJson) -> Self {
+        Self(Box::new(PrioritizedDistInner {
+            markers: MarkerTree::TRUE,
+            best_wheel_index: None,
+            wheels: vec![],
+            source: None,
+            variants_json: Some(variant_json),
+            hashes: vec![],
+        }))
+    }
+
     /// Insert the given built distribution into the [`PrioritizedDist`].
     pub fn insert_built(
         &mut self,
@@ -423,6 +440,14 @@ impl PrioritizedDist {
         }
     }
 
+    pub fn insert_variant_json(&mut self, variant_json: VariantJson) {
+        debug_assert!(
+            self.0.variants_json.is_none(),
+            "The variant.json filename is unique"
+        );
+        self.0.variants_json = Some(variant_json);
+    }
+
     /// Return the highest-priority distribution for the package version, if any.
     pub fn get(&self) -> Option<CompatibleDist> {
         let best_wheel = self.0.best_wheel_index.map(|i| &self.0.wheels[i]);

crates/uv-distribution-types/src/variant_json.rs

@@ -0,0 +1,11 @@
+use crate::FileLocation;
+use uv_normalize::PackageName;
+use uv_pep440::Version;
+
+/// A `<name>-<version>-variant.json` file.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct VariantJson {
+    pub name: PackageName,
+    pub version: Version,
+    pub file_location: FileLocation,
+}

crates/uv-resolver/src/flat_index.rs

@@ -8,8 +8,8 @@ use uv_client::{FlatIndexEntries, FlatIndexEntry};
 use uv_configuration::BuildOptions;
 use uv_distribution_filename::{DistFilename, SourceDistFilename, WheelFilename};
 use uv_distribution_types::{
-    File, HashComparison, HashPolicy, IncompatibleSource, IncompatibleWheel, IndexUrl,
+    DistOrVariantFilename, File, HashComparison, HashPolicy, IncompatibleSource, IncompatibleWheel,
-    PrioritizedDist, RegistryBuiltWheel, RegistrySourceDist, SourceDistCompatibility,
+    IndexUrl, PrioritizedDist, RegistryBuiltWheel, RegistrySourceDist, SourceDistCompatibility,
     WheelCompatibility,
 };
 use uv_normalize::PackageName;
@@ -46,7 +46,7 @@ impl FlatIndex {
             let distributions = index.entry(entry.filename.name().clone()).or_default();
             distributions.add_file(
                 entry.file,
-                entry.filename,
+                DistOrVariantFilename::DistFilename(entry.filename),
                 tags,
                 variants,
                 hasher,
@@ -92,7 +92,7 @@ impl FlatDistributions {
         for entry in entries {
             distributions.add_file(
                 entry.file,
-                entry.filename,
+                DistOrVariantFilename::DistFilename(entry.filename),
                 tags,
                 variants,
                 hasher,
@@ -117,7 +117,7 @@ impl FlatDistributions {
     fn add_file(
         &mut self,
         file: File,
-        filename: DistFilename,
+        filename: DistOrVariantFilename,
         tags: Option<&Tags>,
         variants: Option<&VariantSet>,
         hasher: &HashStrategy,
@@ -127,7 +127,7 @@ impl FlatDistributions {
         // No `requires-python` here: for source distributions, we don't have that information;
         // for wheels, we read it lazily only when selected.
         match filename {
-            DistFilename::WheelFilename(filename) => {
+            DistOrVariantFilename::DistFilename(DistFilename::WheelFilename(filename)) => {
                 let version = filename.version.clone();
 
                 let compatibility = Self::wheel_compatibility(
@@ -152,7 +152,7 @@ impl FlatDistributions {
                     }
                 }
             }
-            DistFilename::SourceDistFilename(filename) => {
+            DistOrVariantFilename::DistFilename(DistFilename::SourceDistFilename(filename)) => {
                 let compatibility = Self::source_dist_compatibility(
                     &filename,
                     file.hashes.as_slice(),
@@ -176,6 +176,16 @@ impl FlatDistributions {
                     }
                 }
             }
+            DistOrVariantFilename::VariantJson(variant_json) => {
+                match self.0.entry(variant_json.version.clone()) {
+                    Entry::Occupied(mut entry) => {
+                        entry.get_mut().insert_variant_json(variant_json);
+                    }
+                    Entry::Vacant(entry) => {
+                        entry.insert(PrioritizedDist::from_variant_json(variant_json));
+                    }
+                }
+            }
         }
     }