Use index-level instead of realm-level credential caching for known indexes (#12717)

The current uv behavior is to cache credentials either at the request
URL or realm level. But in general, the expected behavior for indexes is
to apply credentials at the index level (as implemented in #12651). This
means that we also need to cache credentials at this level. Note that
when uv does not detect an index URL for a request URL, it will continue
to apply the old behavior.

Depends on #12651.

Author: jtfmumm

crates/uv-auth/src/cache.rs

@@ -17,8 +17,8 @@ type FxOnceMap<K, V> = OnceMap<K, V, BuildHasherDefault<FxHasher>>;
 pub struct CredentialsCache {
     /// A cache per realm and username
     realms: RwLock<FxHashMap<(Realm, Username), Arc<Credentials>>>,
-    /// A cache tracking the result of fetches from external services
-    pub(crate) fetches: FxOnceMap<(Realm, Username), Option<Arc<Credentials>>>,
+    /// A cache tracking the result of realm or index URL fetches from external services
+    pub(crate) fetches: FxOnceMap<(String, Username), Option<Arc<Credentials>>>,
     /// A cache per URL, uses a trie for efficient prefix queries.
     urls: RwLock<UrlTrie>,
 }

crates/uv-auth/src/index.rs

@@ -53,6 +53,7 @@ impl Display for AuthPolicy {
 // could potentially make sense for a future refactor.
 #[derive(Debug, Clone, Hash, Eq, PartialEq)]
 pub struct Index {
+    pub url: Url,
     /// The root endpoint where authentication is applied.
     /// For PEP 503 endpoints, this excludes `/simple`.
     pub root_url: Url,
@@ -83,8 +84,8 @@ impl Indexes {
         // efficient search.
         self.0
             .iter()
-            .find(|index| url.as_str().starts_with(index.root_url.as_str()))
-            .map(|index| &index.root_url)
+            .find(|index| is_url_prefix(&index.root_url, url))
+            .map(|index| &index.url)
     }
 
     /// Get the [`AuthPolicy`] for a URL.
@@ -93,10 +94,21 @@ impl Indexes {
         // but we could use a trie instead of a HashMap here for more
         // efficient search.
         for index in &self.0 {
-            if url.as_str().starts_with(index.root_url.as_str()) {
+            if is_url_prefix(&index.root_url, url) {
                 return index.auth_policy;
             }
         }
         AuthPolicy::Auto
     }
 }
+
+fn is_url_prefix(base: &Url, url: &Url) -> bool {
+    if base.scheme() != url.scheme()
+        || base.host_str() != url.host_str()
+        || base.port_or_known_default() != url.port_or_known_default()
+    {
+        return false;
+    }
+
+    url.path().starts_with(base.path())
+}