Avoid reparsing wheel URLs (#4947)

## Summary

We currently store wheel URLs in an unparsed state because we don't have
a stable parsed representation to use with rykv. Unfortunately this
means we end up reparsing unnecessarily in a lot of places, especially
when constructing a `Lock`. This PR adds a `UrlString` type that lets us
avoid reparsing without losing the validity of the `Url`.

## Test Plan

Shaves off another ~10 ms from
https://github.com/astral-sh/uv/issues/4860.

```
➜  transformers hyperfine "../../uv/target/profiling/uv lock" "../../uv/target/profiling/baseline lock" --warmup 3
Benchmark 1: ../../uv/target/profiling/uv lock
  Time (mean ± σ):     120.9 ms ±   2.5 ms    [User: 126.0 ms, System: 80.6 ms]
  Range (min … max):   116.8 ms … 125.7 ms    23 runs
 
Benchmark 2: ../../uv/target/profiling/baseline lock
  Time (mean ± σ):     129.9 ms ±   4.2 ms    [User: 127.1 ms, System: 86.1 ms]
  Range (min … max):   123.4 ms … 141.2 ms    23 runs

Summary
  ../../uv/target/profiling/uv lock ran
    1.07 ± 0.04 times faster than ../../uv/target/profiling/baseline lock
```

crates/distribution-types/src/file.rs

@@ -1,11 +1,11 @@
-use std::fmt::{Display, Formatter};
+use std::fmt::{self, Display, Formatter};
 use std::path::PathBuf;
+use std::str::FromStr;
 
 use serde::{Deserialize, Serialize};
 use url::Url;
 
 use pep440_rs::{VersionSpecifiers, VersionSpecifiersParseError};
-use pep508_rs::split_scheme;
 use pypi_types::{CoreMetadata, HashDigest, Yanked};
 
 /// Error converting [`pypi_types::File`] to [`distribution_type::File`].
@@ -56,10 +56,9 @@ impl File {
                 .map_err(|err| FileConversionError::RequiresPython(err.line().clone(), err))?,
             size: file.size,
             upload_time_utc_ms: file.upload_time.map(|dt| dt.timestamp_millis()),
-            url: if split_scheme(&file.url).is_some() {
-                FileLocation::AbsoluteUrl(file.url)
-            } else {
-                FileLocation::RelativeUrl(base.to_string(), file.url)
+            url: match Url::parse(&file.url) {
+                Ok(url) => FileLocation::AbsoluteUrl(url.into()),
+                Err(_) => FileLocation::RelativeUrl(base.to_string(), file.url),
             },
             yanked: file.yanked,
         })
@@ -76,7 +75,7 @@ pub enum FileLocation {
     /// URL relative to the base URL.
     RelativeUrl(String, String),
     /// Absolute URL.
-    AbsoluteUrl(String),
+    AbsoluteUrl(UrlString),
     /// Absolute path to a file.
     Path(#[with(rkyv::with::AsString)] PathBuf),
 }
@@ -107,13 +106,7 @@ impl FileLocation {
                 })?;
                 Ok(joined)
             }
-            FileLocation::AbsoluteUrl(ref absolute) => {
-                let url = Url::parse(absolute).map_err(|err| ToUrlError::InvalidAbsolute {
-                    absolute: absolute.clone(),
-                    err,
-                })?;
-                Ok(url)
-            }
+            FileLocation::AbsoluteUrl(ref absolute) => Ok(absolute.to_url()),
             FileLocation::Path(ref path) => {
                 let path = path
                     .to_str()
@@ -125,18 +118,79 @@ impl FileLocation {
             }
         }
     }
+
+    /// Convert this location to a URL.
+    ///
+    /// This method is identical to [`FileLocation::to_url`] except it avoids parsing absolute URLs
+    /// as they are already guaranteed to be valid.
+    pub fn to_url_string(&self) -> Result<UrlString, ToUrlError> {
+        match *self {
+            FileLocation::AbsoluteUrl(ref absolute) => Ok(absolute.clone()),
+            _ => Ok(self.to_url()?.into()),
+        }
+    }
 }
 
 impl Display for FileLocation {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         match self {
             Self::RelativeUrl(_base, url) => Display::fmt(&url, f),
-            Self::AbsoluteUrl(url) => Display::fmt(&url, f),
+            Self::AbsoluteUrl(url) => Display::fmt(&url.0, f),
             Self::Path(path) => Display::fmt(&path.display(), f),
         }
     }
 }
 
+/// A [`Url`] represented as a `String`.
+///
+/// This type is guaranteed to be a valid URL but avoids being parsed into the [`Url`] type.
+#[derive(
+    Debug,
+    Clone,
+    Serialize,
+    Deserialize,
+    rkyv::Archive,
+    rkyv::Deserialize,
+    rkyv::Serialize,
+    PartialEq,
+    Eq,
+)]
+#[archive(check_bytes)]
+#[archive_attr(derive(Debug))]
+pub struct UrlString(String);
+
+impl UrlString {
+    /// Converts a [`UrlString`] to a [`Url`].
+    pub fn to_url(&self) -> Url {
+        // This conversion can never fail as the only way to construct a `UrlString` is from a `Url`.
+        Url::from_str(&self.0).unwrap()
+    }
+}
+
+impl AsRef<str> for UrlString {
+    fn as_ref(&self) -> &str {
+        &self.0
+    }
+}
+
+impl From<Url> for UrlString {
+    fn from(value: Url) -> Self {
+        UrlString(value.to_string())
+    }
+}
+
+impl From<UrlString> for String {
+    fn from(value: UrlString) -> Self {
+        value.0
+    }
+}
+
+impl fmt::Display for UrlString {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&self.0, f)
+    }
+}
+
 /// An error that occurs when a `FileLocation` is not a valid URL.
 #[derive(Clone, Debug, Eq, PartialEq, thiserror::Error)]
 pub enum ToUrlError {

crates/uv-client/src/registry_client.rs

@@ -421,7 +421,7 @@ impl RegistryClient {
                         }
                     }
                     FileLocation::AbsoluteUrl(url) => {
-                        let url = Url::parse(url).map_err(ErrorKind::UrlParse)?;
+                        let url = url.to_url();
                         if url.scheme() == "file" {
                             let path = url
                                 .to_file_path()

crates/uv-distribution/src/distribution_database.rs

@@ -160,9 +160,7 @@ impl<'a, Context: BuildContext> DistributionDatabase<'a, Context> {
                     FileLocation::RelativeUrl(base, url) => {
                         pypi_types::base_url_join_relative(base, url)?
                     }
-                    FileLocation::AbsoluteUrl(url) => {
-                        Url::parse(url).map_err(|err| Error::Url(url.clone(), err))?
-                    }
+                    FileLocation::AbsoluteUrl(url) => url.to_url(),
                     FileLocation::Path(path) => {
                         let cache_entry = self.build_context.cache().entry(
                             CacheBucket::Wheels,

crates/uv-distribution/src/source/mod.rs

@@ -102,9 +102,7 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
                     FileLocation::RelativeUrl(base, url) => {
                         pypi_types::base_url_join_relative(base, url)?
                     }
-                    FileLocation::AbsoluteUrl(url) => {
-                        Url::parse(url).map_err(|err| Error::Url(url.clone(), err))?
-                    }
+                    FileLocation::AbsoluteUrl(url) => url.to_url(),
                     FileLocation::Path(path) => {
                         let url = Url::from_file_path(path)
                             .map_err(|()| Error::RelativePath(path.clone()))?;
@@ -280,9 +278,7 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
                     FileLocation::RelativeUrl(base, url) => {
                         pypi_types::base_url_join_relative(base, url)?
                     }
-                    FileLocation::AbsoluteUrl(url) => {
-                        Url::parse(url).map_err(|err| Error::Url(url.clone(), err))?
-                    }
+                    FileLocation::AbsoluteUrl(url) => url.to_url(),
                     FileLocation::Path(path) => {
                         let url = Url::from_file_path(path)
                             .map_err(|()| Error::RelativePath(path.clone()))?;

crates/uv-resolver/src/lock.rs

@@ -17,7 +17,7 @@ use distribution_filename::WheelFilename;
 use distribution_types::{
     BuiltDist, DirectUrlBuiltDist, DirectUrlSourceDist, DirectorySourceDist, Dist, FileLocation,
     GitSourceDist, IndexUrl, PathBuiltDist, PathSourceDist, RegistryBuiltDist, RegistryBuiltWheel,
-    RegistrySourceDist, RemoteSource, Resolution, ResolvedDist, ToUrlError,
+    RegistrySourceDist, RemoteSource, Resolution, ResolvedDist, ToUrlError, UrlString,
 };
 use pep440_rs::{Version, VersionSpecifiers};
 use pep508_rs::{
@@ -716,7 +716,7 @@ impl Distribution {
                         requires_python: None,
                         size: sdist.size(),
                         upload_time_utc_ms: None,
-                        url: FileLocation::AbsoluteUrl(file_url.to_string()),
+                        url: FileLocation::AbsoluteUrl(file_url.clone().into()),
                         yanked: None,
                     });
                     let index = IndexUrl::Url(VerbatimUrl::from_url(url.clone()));
@@ -1705,7 +1705,7 @@ struct Wheel {
     /// against was found. The location does not need to exist in the future,
     /// so this should be treated as only a hint to where to look and/or
     /// recording where the wheel file originally came from.
-    url: Url,
+    url: UrlString,
     /// A hash of the built distribution.
     ///
     /// This is only present for wheels that come from registries and direct
@@ -1773,7 +1773,7 @@ impl Wheel {
         let url = wheel
             .file
             .url
-            .to_url()
+            .to_url_string()
             .map_err(LockErrorKind::InvalidFileUrl)
             .map_err(LockError::from)?;
         let hash = wheel.file.hashes.first().cloned().map(Hash::from);
@@ -1788,7 +1788,7 @@ impl Wheel {
 
     fn from_direct_dist(direct_dist: &DirectUrlBuiltDist, hashes: &[HashDigest]) -> Wheel {
         Wheel {
-            url: direct_dist.url.to_url(),
+            url: direct_dist.url.to_url().into(),
             hash: hashes.first().cloned().map(Hash::from),
             size: None,
             filename: direct_dist.filename.clone(),
@@ -1797,7 +1797,7 @@ impl Wheel {
 
     fn from_path_dist(path_dist: &PathBuiltDist, hashes: &[HashDigest]) -> Wheel {
         Wheel {
-            url: path_dist.url.to_url(),
+            url: path_dist.url.to_url().into(),
             hash: hashes.first().cloned().map(Hash::from),
             size: None,
             filename: path_dist.filename.clone(),
@@ -1813,7 +1813,7 @@ impl Wheel {
             requires_python: None,
             size: self.size,
             upload_time_utc_ms: None,
-            url: FileLocation::AbsoluteUrl(self.url.to_string()),
+            url: FileLocation::AbsoluteUrl(self.url.clone()),
             yanked: None,
         });
         let index = IndexUrl::Url(VerbatimUrl::from_url(url.clone()));
@@ -1872,7 +1872,7 @@ impl TryFrom<WheelWire> for Wheel {
             .map_err(|err| format!("failed to parse `{filename}` as wheel filename: {err}"))?;
 
         Ok(Wheel {
-            url: wire.url,
+            url: wire.url.into(),
             hash: wire.hash,
             size: wire.size,
             filename,

crates/uv-resolver/src/snapshots/uv_resolver__lock__tests__hash_optional_missing.snap

@@ -19,17 +19,9 @@ Ok(
                 sdist: None,
                 wheels: [
                     Wheel {
-                        url: Url {
-                            scheme: "file",
-                            cannot_be_a_base: false,
-                            username: "",
-                            password: None,
-                            host: None,
-                            port: None,
-                            path: "/foo/bar/anyio-4.3.0-py3-none-any.whl",
-                            query: None,
-                            fragment: None,
-                        },
+                        url: UrlString(
+                            "file:///foo/bar/anyio-4.3.0-py3-none-any.whl",
+                        ),
                         hash: Some(
                             Hash(
                                 HashDigest {