remove DatabaseKey associated type

components/salsa-macros/src/database_storage.rs

@@ -34,29 +34,18 @@ pub(crate) fn database(args: TokenStream, input: TokenStream) -> TokenStream {
         })
         .collect();
 
-    let query_group_key_names: Vec<_> = query_groups
-        .iter()
-        .map(|QueryGroup { group_path }| {
-            quote! {
-                <#group_path as salsa::plumbing::QueryGroup<#database_name>>::GroupKey
-            }
-        })
-        .collect();
-
     // For each query group `foo::MyGroup` create a link to its
     // `foo::MyGroupGroupStorage`
     let mut storage_fields = proc_macro2::TokenStream::new();
     let mut storage_initializers = proc_macro2::TokenStream::new();
     let mut has_group_impls = proc_macro2::TokenStream::new();
-    for ((((query_group, group_name_snake), group_storage), group_key), group_index) in query_groups
+    for (((query_group, group_name_snake), group_storage), group_index) in query_groups
         .iter()
         .zip(&query_group_names_snake)
         .zip(&query_group_storage_names)
-        .zip(&query_group_key_names)
         .zip(0_u16..)
     {
         let group_path = &query_group.group_path;
-        let group_name = query_group.name();
 
         // rewrite the last identifier (`MyGroup`, above) to
         // (e.g.) `MyGroupGroupStorage`.
@@ -77,12 +66,6 @@ pub(crate) fn database(args: TokenStream, input: TokenStream) -> TokenStream {
                     let runtime = salsa::Database::salsa_runtime(db);
                     &runtime.storage().#group_name_snake
                 }
-
-                fn database_key(group_key: #group_key) -> __SalsaDatabaseKey {
-                    __SalsaDatabaseKey {
-                        kind: __SalsaDatabaseKeyKind::#group_name(group_key),
-                    }
-                }
             }
         });
         // ANCHOR_END:HasQueryGroup
@@ -104,34 +87,6 @@ pub(crate) fn database(args: TokenStream, input: TokenStream) -> TokenStream {
         }
     });
 
-    // create query database_key wrapper struct
-    output.extend(quote! {
-        #[derive(Clone, Debug, PartialEq, Eq, Hash)]
-        #[doc(hidden)]
-        #visibility struct __SalsaDatabaseKey {
-            kind: __SalsaDatabaseKeyKind
-        }
-    });
-
-    // For each query `fn foo() for FooType` create
-    //
-    // ```
-    // foo(<FooType as salsa::Query<#database_name>>::Key),
-    // ```
-    let mut variants = proc_macro2::TokenStream::new();
-    for (query_group, group_key) in query_groups.iter().zip(&query_group_key_names) {
-        let group_name = query_group.name();
-        variants.extend(quote!(
-            #group_name(#group_key),
-        ));
-    }
-    output.extend(quote! {
-        #[derive(Clone, Debug, PartialEq, Eq, Hash)]
-        enum __SalsaDatabaseKeyKind {
-            #variants
-        }
-    });
-
     // Create a tuple (D1, D2, ...) where Di is the data for a given query group.
     let mut database_data = vec![];
     for QueryGroup { group_path } in query_groups {
@@ -143,7 +98,6 @@ pub(crate) fn database(args: TokenStream, input: TokenStream) -> TokenStream {
     // ANCHOR:DatabaseStorageTypes
     output.extend(quote! {
         impl salsa::plumbing::DatabaseStorageTypes for #database_name {
-            type DatabaseKey = __SalsaDatabaseKey;
             type DatabaseStorage = __SalsaDatabaseStorage;
         }
     });
@@ -212,13 +166,6 @@ pub(crate) fn database(args: TokenStream, input: TokenStream) -> TokenStream {
     });
     // ANCHOR_END:DatabaseOps
 
-    // ANCHOR:DatabaseKey
-    output.extend(quote! {
-        impl salsa::plumbing::DatabaseKey<#database_name> for __SalsaDatabaseKey {
-        }
-    });
-    // ANCHOR_END:DatabaseKey
-
     output.extend(has_group_impls);
 
     if std::env::var("SALSA_DUMP").is_ok() {

src/derived/slot.rs

@@ -1026,7 +1026,6 @@ where
     Q: QueryFunction<DB>,
     DB: Database + HasQueryGroup<Q::Group>,
     MP: MemoizationPolicy<DB, Q>,
-    DB::DatabaseKey: Send + Sync,
     Q::Key: Send + Sync,
     Q::Value: Send + Sync,
 {

src/plumbing.rs

@@ -30,14 +30,6 @@ pub struct CycleDetected {
 /// the `database_storage` macro, so you shouldn't need to mess
 /// with this trait directly.
 pub trait DatabaseStorageTypes: Sized {
-    /// A "query descriptor" packages up all the possible queries and a key.
-    /// It is used to store information about (e.g.) the stack.
-    ///
-    /// At runtime, it can be implemented in various ways: a monster enum
-    /// works for a fixed set of queries, but a boxed trait object is good
-    /// for a more open-ended option.
-    type DatabaseKey: DatabaseKey<Self>;
-
     /// Defines the "storage type", where all the query data is kept.
     /// This type is defined by the `database_storage` macro.
     type DatabaseStorage: Default;
@@ -95,9 +87,6 @@ pub trait GetQueryTable<Q: Query<Self>>: Database {
     /// Create a mutable query table, which has access to the storage
     /// for the query and offers methods like `set`.
     fn get_query_table_mut(db: &mut Self) -> QueryTableMut<'_, Self, Q>;
-
-    /// Create a query descriptor given a key for this query.
-    fn database_key(db: &Self, key: Q::Key) -> Self::DatabaseKey;
 }
 
 impl<DB, Q> GetQueryTable<Q> for DB
@@ -117,14 +106,6 @@ where
         let query_storage = Q::query_storage(group_storage).clone();
         QueryTableMut::new(db, query_storage)
     }
-
-    fn database_key(
-        _db: &DB,
-        key: <Q as Query<DB>>::Key,
-    ) -> <DB as DatabaseStorageTypes>::DatabaseKey {
-        let group_key = Q::group_key(key);
-        <DB as HasQueryGroup<_>>::database_key(group_key)
-    }
 }
 
 pub trait QueryGroup<DB: Database> {
@@ -140,9 +121,6 @@ where
 {
     /// Access the group storage struct from the database.
     fn group_storage(db: &Self) -> &G::GroupStorage;
-
-    /// "Upcast" a group key into a database key.
-    fn database_key(group_key: G::GroupKey) -> Self::DatabaseKey;
 }
 
 pub trait QueryStorageOps<DB, Q>