derive: no need to use Arcs to store ConfigKeys

Kijewski · Aug 1, 2024 · 5456f27 · 5456f27
1 parent 64f9781
commit 5456f27
Showing 1 changed file with 12 additions and 13 deletions.
diff --git a/rinja_derive/src/config.rs b/rinja_derive/src/config.rs
@@ -1,6 +1,6 @@
 use std::borrow::{Borrow, Cow};
 use std::collections::btree_map::{BTreeMap, Entry};
-use std::mem::{transmute, ManuallyDrop};
+use std::mem::ManuallyDrop;
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, OnceLock};
@@ -33,8 +33,8 @@ impl Drop for Config {
     }
 }
 
-#[derive(Debug, PartialEq, Eq, Hash, Clone)]
-struct OwnedConfigKey(Arc<ConfigKey<'static>>);
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
+struct OwnedConfigKey(&'static ConfigKey<'static>);
 
 #[derive(Debug, PartialEq, Eq, Hash)]
 struct ConfigKey<'a> {
@@ -47,7 +47,7 @@ impl<'a> ToOwned for ConfigKey<'a> {
     type Owned = OwnedConfigKey;
 
     fn to_owned(&self) -> Self::Owned {
-        OwnedConfigKey(Arc::new(ConfigKey {
+        let owned_key = ConfigKey {
             source: Cow::Owned(self.source.as_ref().to_owned()),
             config_path: self
                 .config_path
@@ -57,13 +57,15 @@ impl<'a> ToOwned for ConfigKey<'a> {
                 .template_whitespace
                 .as_ref()
                 .map(|s| Cow::Owned(s.as_ref().to_owned())),
-        }))
+        };
+        OwnedConfigKey(Box::leak(Box::new(owned_key)))
     }
 }
 
 impl<'a> Borrow<ConfigKey<'a>> for OwnedConfigKey {
+    #[inline]
     fn borrow(&self) -> &ConfigKey<'a> {
-        self.0.as_ref()
+        self.0
     }
 }
 
@@ -85,7 +87,7 @@ impl Config {
             config_span,
             ConfigKey::to_owned,
             |config_span, key| {
-                let config = Config::new_uncached(key.clone(), config_span)?;
+                let config = Config::new_uncached(*key, config_span)?;
                 let config = &*Box::leak(Box::new(config));
                 Ok((config, config))
             },
@@ -99,12 +101,9 @@ impl Config {
         key: OwnedConfigKey,
         config_span: Option<Span>,
     ) -> Result<Config, CompileError> {
-        // SAFETY: the resulting `Config` will keep a reference to the `key`
-        let eternal_key =
-            unsafe { transmute::<&ConfigKey<'_>, &'static ConfigKey<'static>>(key.borrow()) };
-        let s = eternal_key.source.as_ref();
-        let config_path = eternal_key.config_path.as_deref();
-        let template_whitespace = eternal_key.template_whitespace.as_deref();
+        let s = key.0.source.as_ref();
+        let config_path = key.0.config_path.as_deref();
+        let template_whitespace = key.0.template_whitespace.as_deref();
 
         let root = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
         let default_dirs = vec![root.join("templates")];