Track file index (#452)

Track the index (or at least its url) where we got a file from across
the source code.

Fixes #448

crates/pypi-types/Cargo.toml

@@ -22,6 +22,7 @@ rfc2047-decoder = { workspace = true }
 serde = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
+url = { workspace = true }
 
 [dev-dependencies]
 indoc = { version = "2.0.4" }

crates/pypi-types/src/index_url.rs

@@ -0,0 +1,17 @@
+use url::Url;
+
+/// The url of an index, newtype'd to avoid mixing it with file urls
+#[derive(Debug, Clone, Hash, Eq, PartialEq)]
+pub struct IndexUrl(Url);
+
+impl From<Url> for IndexUrl {
+    fn from(url: Url) -> Self {
+        Self(url)
+    }
+}
+
+impl From<IndexUrl> for Url {
+    fn from(index: IndexUrl) -> Self {
+        index.0
+    }
+}

crates/pypi-types/src/lib.rs

@@ -1,9 +1,11 @@
 pub use direct_url::{ArchiveInfo, DirectUrl, VcsInfo, VcsKind};
+pub use index_url::IndexUrl;
 pub use lenient_requirement::LenientVersionSpecifiers;
 pub use metadata::{Error, Metadata21};
 pub use simple_json::{File, SimpleJson, Yanked};
 
 mod direct_url;
+mod index_url;
 mod lenient_requirement;
 mod metadata;
 mod simple_json;