Store tracked struct ids as Vec on Revisions

Author: MichaReiser

src/function/diff_outputs.rs

@@ -54,7 +54,7 @@ where
             // Remove the outputs that are no longer present in the current revision
             // to prevent that the next revision is seeded with an id mapping that no longer exists.
             tracked_struct_ids
-                .retain(|k, value| !old_outputs.contains(&(k.ingredient_index(), value.index())));
+                .retain(|(k, value)| !old_outputs.contains(&(k.ingredient_index(), value.index())));
         }
 
         for (ingredient_index, key_index) in old_outputs {

src/tracked_struct.rs

@@ -220,12 +220,17 @@ impl Clone for IdentityMap {
             table: self.table.clone(),
         }
     }
-    fn clone_from(&mut self, source: &Self) {
-        self.table.clone_from(&source.table);
-    }
 }
 
 impl IdentityMap {
+    pub(crate) fn from_slice(&mut self, source: &[(Identity, Id)]) {
+        self.table.clear();
+
+        for (key, id) in source {
+            self.insert(*key, *id);
+        }
+    }
+
     pub(crate) fn insert(&mut self, key: Identity, id: Id) -> Option<Id> {
         let entry = self.table.find_mut(key.hash, |&(k, _)| k == key);
         match entry {
@@ -248,16 +253,12 @@ impl IdentityMap {
         self.table.is_empty()
     }
 
-    pub(crate) fn retain(&mut self, mut f: impl FnMut(&Identity, &mut Id) -> bool) {
-        self.table.retain(|(k, v)| f(k, v));
-    }
-
     pub(crate) fn clear(&mut self) {
         self.table.clear()
     }
 
-    pub(crate) fn shrink_to_fit(&mut self) {
-        self.table.shrink_to_fit(|(k, _)| k.hash);
+    pub(crate) fn into_vec(self) -> Vec<(Identity, Id)> {
+        self.table.into_iter().collect()
     }
 }
 

src/zalsa_local.rs

@@ -367,7 +367,7 @@ impl QueryRevisionsExtra {
                 Some(Box::new(QueryRevisionsExtraInner {
                     accumulated,
                     cycle_heads,
-                    tracked_struct_ids,
+                    tracked_struct_ids: tracked_struct_ids.into_vec(),
                 }))
             };
 
@@ -396,7 +396,7 @@ struct QueryRevisionsExtraInner {
     ///   previous revision. To handle this, `diff_outputs` compares
     ///   the structs from the old/new revision and retains
     ///   only entries that appeared in the new revision.
-    tracked_struct_ids: IdentityMap,
+    tracked_struct_ids: Vec<(Identity, Id)>,
 
     /// This result was computed based on provisional values from
     /// these cycle heads. The "cycle head" is the query responsible
@@ -416,7 +416,7 @@ const _: [(); std::mem::size_of::<QueryRevisions>()] = [(); std::mem::size_of::<
 #[cfg(not(feature = "shuttle"))]
 #[cfg(target_pointer_width = "64")]
 const _: [(); std::mem::size_of::<QueryRevisionsExtraInner>()] =
-    [(); std::mem::size_of::<[usize; 9]>()];
+    [(); std::mem::size_of::<[usize; 8]>()];
 
 impl QueryRevisions {
     pub(crate) fn fixpoint_initial(query: DatabaseKeyIndex) -> Self {
@@ -475,16 +475,16 @@ impl QueryRevisions {
     }
 
     /// Returns a reference to the `IdentityMap` for this query, or `None` if the map is empty.
-    pub fn tracked_struct_ids(&self) -> Option<&IdentityMap> {
+    pub fn tracked_struct_ids(&self) -> Option<&[(Identity, Id)]> {
         self.extra
             .0
             .as_ref()
-            .map(|extra| &extra.tracked_struct_ids)
+            .map(|extra| &*extra.tracked_struct_ids)
             .filter(|tracked_struct_ids| !tracked_struct_ids.is_empty())
     }
 
     /// Returns a mutable reference to the `IdentityMap` for this query, or `None` if the map is empty.
-    pub fn tracked_struct_ids_mut(&mut self) -> Option<&mut IdentityMap> {
+    pub fn tracked_struct_ids_mut(&mut self) -> Option<&mut Vec<(Identity, Id)>> {
         self.extra
             .0
             .as_mut()
@@ -836,15 +836,15 @@ pub(crate) struct ActiveQueryGuard<'me> {
 
 impl ActiveQueryGuard<'_> {
     /// Initialize the tracked struct ids with the values from the prior execution.
-    pub(crate) fn seed_tracked_struct_ids(&self, tracked_struct_ids: &IdentityMap) {
+    pub(crate) fn seed_tracked_struct_ids(&self, tracked_struct_ids: &[(Identity, Id)]) {
         self.local_state.with_query_stack_mut(|stack| {
             #[cfg(debug_assertions)]
             assert_eq!(stack.len(), self.push_len);
             let frame = stack.last_mut().unwrap();
             assert!(frame.tracked_struct_ids().is_empty());
             frame
                 .tracked_struct_ids_mut()
-                .clone_from(tracked_struct_ids);
+                .from_slice(tracked_struct_ids);
         })
     }