Add IngredientIndex to KeyStruct

src/active_query.rs

@@ -7,7 +7,7 @@ use crate::{
     key::{DatabaseKeyIndex, DependencyIndex},
     tracked_struct::{Disambiguator, KeyStruct},
     zalsa_local::EMPTY_DEPENDENCIES,
-    Cycle, Revision,
+    Cycle, IngredientIndex, Revision,
 };
 
 use super::zalsa_local::{EdgeKind, QueryEdges, QueryOrigin, QueryRevisions};
@@ -45,7 +45,7 @@ pub(crate) struct ActiveQuery {
     /// This table starts empty as the query begins and is gradually populated.
     /// Note that if a query executes in 2 different revisions but creates the same
     /// set of tracked structs, they will get the same disambiguator values.
-    disambiguator_map: FxHashMap<u64, Disambiguator>,
+    disambiguator_map: FxHashMap<(IngredientIndex, u64), Disambiguator>,
 
     /// Map from tracked struct keys (which include the hash + disambiguator) to their
     /// final id.
@@ -155,10 +155,14 @@ impl ActiveQuery {
         self.input_outputs.clone_from(&cycle_query.input_outputs);
     }
 
-    pub(super) fn disambiguate(&mut self, hash: u64) -> Disambiguator {
+    pub(super) fn disambiguate(
+        &mut self,
+        ingredient_index: IngredientIndex,
+        hash: u64,
+    ) -> Disambiguator {
         let disambiguator = self
             .disambiguator_map
-            .entry(hash)
+            .entry((ingredient_index, hash))
             .or_insert(Disambiguator(0));
         let result = *disambiguator;
         disambiguator.0 += 1;

src/tracked_struct.rs

@@ -148,6 +148,9 @@ where
 /// struct and later moved to the [`Memo`](`crate::function::memo::Memo`).
 #[derive(Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Copy, Clone)]
 pub(crate) struct KeyStruct {
+    /// IngredientIndex of the tracked struct
+    ingredient_index: IngredientIndex,
+
     /// The hash of the `#[id]` fields of this struct.
     /// Note that multiple structs may share the same hash.
     data_hash: u64,
@@ -255,11 +258,13 @@ where
     ) -> C::Struct<'db> {
         let (zalsa, zalsa_local) = db.zalsas();
 
-        let data_hash = crate::hash::hash(&C::id_fields(&fields));
+        let data_hash = crate::hash::hash(&(C::id_fields(&fields)));
 
-        let (current_deps, disambiguator) = zalsa_local.disambiguate(data_hash);
+        let (current_deps, disambiguator) =
+            zalsa_local.disambiguate(self.ingredient_index, data_hash);
 
         let key_struct = KeyStruct {
+            ingredient_index: self.ingredient_index,
             disambiguator,
             data_hash,
         };

src/zalsa_local.rs

@@ -262,7 +262,11 @@ impl ZalsaLocal {
     ///   * the current dependencies (durability, changed_at) of current query
     ///   * the disambiguator index
     #[track_caller]
-    pub(crate) fn disambiguate(&self, data_hash: u64) -> (StampedValue<()>, Disambiguator) {
+    pub(crate) fn disambiguate(
+        &self,
+        ingredient_index: IngredientIndex,
+        data_hash: u64,
+    ) -> (StampedValue<()>, Disambiguator) {
         assert!(
             self.query_in_progress(),
             "cannot create a tracked struct disambiguator outside of a tracked function"
@@ -270,7 +274,7 @@ impl ZalsaLocal {
 
         self.with_query_stack(|stack| {
             let top_query = stack.last_mut().unwrap();
-            let disambiguator = top_query.disambiguate(data_hash);
+            let disambiguator = top_query.disambiguate(ingredient_index, data_hash);
             (
                 StampedValue {
                     value: (),

tests/hash_collision.rs

@@ -0,0 +1,32 @@
+use std::hash::Hash;
+
+#[test]
+fn hello() {
+    use salsa::{Database, DatabaseImpl, Setter};
+
+    #[salsa::input]
+    struct Bool {
+        value: bool,
+    }
+
+    #[salsa::tracked]
+    struct True<'db> {}
+
+    #[salsa::tracked]
+    struct False<'db> {}
+
+    #[salsa::tracked]
+    fn hello(db: &dyn Database, bool: Bool) {
+        if bool.value(db) {
+            True::new(db);
+        } else {
+            False::new(db);
+        }
+    }
+
+    let mut db = DatabaseImpl::new();
+    let input = Bool::new(&db, false);
+    hello(&db, input);
+    input.set_value(&mut db).to(true);
+    hello(&db, input);
+}