From a7fe84aa03d054ca07a47126d5e74f5fcfb7212c Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Tue, 14 Jan 2025 22:29:08 -0500
Subject: [PATCH] Avoid allocating when stripping source distribution extension
 (#10625)

---
 .../uv-distribution-filename/src/extension.rs | 23 +++++++++++--------
 .../src/source_dist.rs                        |  8 +++----
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/crates/uv-distribution-filename/src/extension.rs b/crates/uv-distribution-filename/src/extension.rs
index 645b3cec3..317970426 100644
--- a/crates/uv-distribution-filename/src/extension.rs
+++ b/crates/uv-distribution-filename/src/extension.rs
@@ -83,19 +83,24 @@ impl SourceDistExtension {
             _ => Err(ExtensionError::SourceDist),
         }
     }
+
+    /// Return the name for the extension.
+    pub fn name(&self) -> &'static str {
+        match self {
+            Self::Zip => "zip",
+            Self::TarGz => "tar.gz",
+            Self::TarBz2 => "tar.bz2",
+            Self::TarXz => "tar.xz",
+            Self::TarZst => "tar.zst",
+            Self::TarLzma => "tar.lzma",
+            Self::Tar => "tar",
+        }
+    }
 }
 
 impl Display for SourceDistExtension {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Self::Zip => f.write_str("zip"),
-            Self::TarGz => f.write_str("tar.gz"),
-            Self::TarBz2 => f.write_str("tar.bz2"),
-            Self::TarXz => f.write_str("tar.xz"),
-            Self::TarZst => f.write_str("tar.zst"),
-            Self::TarLzma => f.write_str("tar.lzma"),
-            Self::Tar => f.write_str("tar"),
-        }
+        f.write_str(self.name())
     }
 }
 
diff --git a/crates/uv-distribution-filename/src/source_dist.rs b/crates/uv-distribution-filename/src/source_dist.rs
index 2dfacc090..4596c0f33 100644
--- a/crates/uv-distribution-filename/src/source_dist.rs
+++ b/crates/uv-distribution-filename/src/source_dist.rs
@@ -38,14 +38,14 @@ impl SourceDistFilename {
         package_name: &PackageName,
     ) -> Result<Self, SourceDistFilenameError> {
         // Drop the extension (e.g., given `tar.gz`, drop `.tar.gz`).
-        if filename.len() <= extension.to_string().len() + 1 {
+        if filename.len() <= extension.name().len() + 1 {
             return Err(SourceDistFilenameError {
                 filename: filename.to_string(),
                 kind: SourceDistFilenameErrorKind::Extension,
             });
         }
 
-        let stem = &filename[..(filename.len() - (extension.to_string().len() + 1))];
+        let stem = &filename[..(filename.len() - (extension.name().len() + 1))];
 
         if stem.len() <= package_name.as_ref().len() + "-".len() {
             return Err(SourceDistFilenameError {
@@ -94,14 +94,14 @@ impl SourceDistFilename {
         };
 
         // Drop the extension (e.g., given `tar.gz`, drop `.tar.gz`).
-        if filename.len() <= extension.to_string().len() + 1 {
+        if filename.len() <= extension.name().len() + 1 {
             return Err(SourceDistFilenameError {
                 filename: filename.to_string(),
                 kind: SourceDistFilenameErrorKind::Extension,
             });
         }
 
-        let stem = &filename[..(filename.len() - (extension.to_string().len() + 1))];
+        let stem = &filename[..(filename.len() - (extension.name().len() + 1))];
 
         let Some((package_name, version)) = stem.rsplit_once('-') else {
             return Err(SourceDistFilenameError {