Use hashed lookup for module-qualified functions and variables.

src/utils.rs

@@ -14,16 +14,26 @@ use crate::stdlib::collections::hash_map::DefaultHasher;
 #[cfg(feature = "no_std")]
 use ahash::AHasher;
 
-/// Calculate a `u64` hash key from a function name and parameter types.
+/// Calculate a `u64` hash key from a module-qualified function name and parameter types.
 ///
-/// Parameter types are passed in via `TypeId` values from an iterator
-/// which can come from any source.
-pub fn calc_fn_spec(fn_name: &str, params: impl Iterator<Item = TypeId>) -> u64 {
+/// Module names are passed in via `&str` references from an iterator.
+/// Parameter types are passed in via `TypeId` values from an iterator.
+///
+/// ### Note
+///
+/// The first module name is skipped.  Hashing starts from the _second_ module in the chain.
+pub fn calc_fn_spec<'a>(
+    modules: impl Iterator<Item = &'a str>,
+    fn_name: &str,
+    params: impl Iterator<Item = TypeId>,
+) -> u64 {
     #[cfg(feature = "no_std")]
     let mut s: AHasher = Default::default();
     #[cfg(not(feature = "no_std"))]
     let mut s = DefaultHasher::new();
 
+    // We always skip the first module
+    modules.skip(1).for_each(|m| m.hash(&mut s));
     s.write(fn_name.as_bytes());
     params.for_each(|t| t.hash(&mut s));
     s.finish()
@@ -45,7 +55,7 @@ pub(crate) fn calc_fn_def(fn_name: &str, num_params: usize) -> u64 {
 ///
 /// This is essentially a knock-off of the [`staticvec`](https://crates.io/crates/staticvec) crate.
 /// This simplified implementation here is to avoid pulling in another crate.
-#[derive(Clone, Default)]
+#[derive(Clone, Hash, Default)]
 pub struct StaticVec<T: Default + Clone> {
     /// Total number of values held.
     len: usize,