version_id_cacher: Use (String, String) key instead of format!(...)

Author: Turbo87

src/app.rs

@@ -36,7 +36,7 @@ pub struct App {
     ///
     /// This is used by the download endpoint to reduce the number of database queries. The
     /// `version_id` is only cached under the canonical spelling of the crate name.
-    pub(crate) version_id_cacher: DashMap<String, i32>,
+    pub(crate) version_id_cacher: DashMap<(String, String), i32>,
 
     /// Count downloads and periodically persist them in the database
     pub downloads_counter: DownloadsCounter,

src/controllers/version/downloads.rs

@@ -21,10 +21,8 @@ pub fn download(req: &mut dyn RequestExt) -> EndpointResult {
 
     let mut log_metadata = None;
 
-    match app
-        .version_id_cacher
-        .entry(format!("{}:{}", crate_name, version))
-    {
+    let key = (crate_name.to_string(), version.to_string());
+    match app.version_id_cacher.entry(key) {
         // The version_id is cached. This also means that the provided crate_name is canonical
         // and that no fixup is necessary before redirecting.
         Entry::Occupied(entry) => {