Don't allocate in PackageId::hash

This hash function is called an enormous number of times in `cargo_rustc`, so
optimizing it is fairly important, and it's also quite trivial to not allocate a
string at all (`semver::Version::hash` already does everything we need).

diff --git a/src/cargo/core/package_id.rs b/src/cargo/core/package_id.rs
index 992e06b9e4073dc2a9075f1afb6893fa92dbb49a..f585a0137c9e4da8f51191eb4abb98ae076e7c25 100644 (file)
--- a/src/cargo/core/package_id.rs
+++ b/src/cargo/core/package_id.rs
@@ -59,7 +59,7 @@ impl Decodable for PackageId {
 impl Hash for PackageId {
     fn hash<S: hash::Hasher>(&self, state: &mut S) {
         self.inner.name.hash(state);
-        self.inner.version.to_string().hash(state);
+        self.inner.version.hash(state);
         self.inner.source_id.hash(state);
     }
 }