6 files changed, 70 insertions, 22 deletions

diff --git a/crates/ra_analysis/src/db.rs b/crates/ra_analysis/src/db.rs
index baf6d915a..d78b6afb9 100644
--- a/crates/ra_analysis/src/db.rs
+++ b/crates/ra_analysis/src/db.rs
@@ -1,7 +1,5 @@
 use std::sync::Arc;
 
-use parking_lot::Mutex;
-
 use ra_editor::LineIndex;
 use ra_syntax::{SourceFileNode, SyntaxNode};
 use salsa::{self, Database};
@@ -11,19 +9,17 @@ use crate::{
     descriptors::{
         DescriptorDatabase, FnScopesQuery, FnSyntaxQuery, ModuleScopeQuery, ModuleTreeQuery,
         SubmodulesQuery,
-        module::{ModuleSource, ModuleId},
     },
-    input::SourceRootId,
     symbol_index::SymbolIndex,
     syntax_ptr::SyntaxPtr,
-    loc2id::Loc2IdMap,
+    loc2id::{IdMaps, IdDatabase},
     Cancelable, Canceled, FileId,
 };
 
 #[derive(Debug)]
 pub(crate) struct RootDatabase {
     runtime: salsa::Runtime<RootDatabase>,
-    loc2id: Arc<Mutex<Loc2IdMap<(SourceRootId, ModuleSource), ModuleId>>>,
+    id_maps: IdMaps,
 }
 
 impl salsa::Database for RootDatabase {
@@ -35,8 +31,8 @@ impl salsa::Database for RootDatabase {
 impl Default for RootDatabase {
     fn default() -> RootDatabase {
         let mut db = RootDatabase {
-            runtime: Default::default(),
-            loc2id: Default::default(),
+            runtime: salsa::Runtime::default(),
+            id_maps: IdMaps::default(),
         };
         db.query_mut(crate::input::SourceRootQuery)
             .set(crate::input::WORKSPACE, Default::default());
@@ -60,11 +56,17 @@ impl salsa::ParallelDatabase for RootDatabase {
     fn snapshot(&self) -> salsa::Snapshot<RootDatabase> {
         salsa::Snapshot::new(RootDatabase {
             runtime: self.runtime.snapshot(self),
-            loc2id: Arc::clone(&self.loc2id),
+            id_maps: self.id_maps.clone(),
         })
     }
 }
 
+impl IdDatabase for RootDatabase {
+    fn id_maps(&self) -> &IdMaps {
+        &self.id_maps
+    }
+}
+
 salsa::database_storage! {
     pub(crate) struct RootDatabaseStorage for RootDatabase {
         impl crate::input::FilesDatabase {
diff --git a/crates/ra_analysis/src/descriptors/function/imp.rs b/crates/ra_analysis/src/descriptors/function/imp.rs
index a989a04cd..a7257acf9 100644
--- a/crates/ra_analysis/src/descriptors/function/imp.rs
+++ b/crates/ra_analysis/src/descriptors/function/imp.rs
@@ -8,9 +8,9 @@ use crate::descriptors::{
 };
 
 /// Resolve `FnId` to the corresponding `SyntaxNode`
-/// TODO: this should return something more type-safe then `SyntaxNode`
 pub(crate) fn fn_syntax(db: &impl DescriptorDatabase, fn_id: FnId) -> FnDefNode {
-    let syntax = db.resolve_syntax_ptr(fn_id.0);
+    let ptr = db.id_maps().fn_ptr(fn_id);
+    let syntax = db.resolve_syntax_ptr(ptr);
     FnDef::cast(syntax.borrowed()).unwrap().owned()
 }
 
diff --git a/crates/ra_analysis/src/descriptors/function/mod.rs b/crates/ra_analysis/src/descriptors/function/mod.rs
index d5db28a64..86eee5e93 100644
--- a/crates/ra_analysis/src/descriptors/function/mod.rs
+++ b/crates/ra_analysis/src/descriptors/function/mod.rs
@@ -8,17 +8,18 @@ use ra_syntax::{
     TextRange, TextUnit,
 };
 
-use crate::{syntax_ptr::SyntaxPtr, FileId};
+use crate::{
+    syntax_ptr::SyntaxPtr, FileId,
+    loc2id::IdDatabase,
+};
 
 pub(crate) use self::scope::{resolve_local_name, FnScopes};
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub(crate) struct FnId(SyntaxPtr);
+pub(crate) use crate::loc2id::FnId;
 
 impl FnId {
-    pub(crate) fn new(file_id: FileId, fn_def: ast::FnDef) -> FnId {
+    pub(crate) fn get(db: &impl IdDatabase, file_id: FileId, fn_def: ast::FnDef) -> FnId {
         let ptr = SyntaxPtr::new(file_id, fn_def.syntax());
-        FnId(ptr)
+        db.id_maps().fn_id(ptr)
     }
 }
 
diff --git a/crates/ra_analysis/src/descriptors/mod.rs b/crates/ra_analysis/src/descriptors/mod.rs
index 56bde3849..d602c4e04 100644
--- a/crates/ra_analysis/src/descriptors/mod.rs
+++ b/crates/ra_analysis/src/descriptors/mod.rs
@@ -13,12 +13,13 @@ use crate::{
     descriptors::function::{resolve_local_name, FnId, FnScopes},
     descriptors::module::{ModuleId, ModuleScope, ModuleTree, ModuleSource},
     input::SourceRootId,
+    loc2id::IdDatabase,
     syntax_ptr::LocalSyntaxPtr,
     Cancelable,
 };
 
 salsa::query_group! {
-    pub(crate) trait DescriptorDatabase: SyntaxDatabase {
+    pub(crate) trait DescriptorDatabase: SyntaxDatabase + IdDatabase {
         fn module_tree(source_root_id: SourceRootId) -> Cancelable<Arc<ModuleTree>> {
             type ModuleTreeQuery;
             use fn module::imp::module_tree;
diff --git a/crates/ra_analysis/src/imp.rs b/crates/ra_analysis/src/imp.rs
index 74c248a96..812fed32d 100644
--- a/crates/ra_analysis/src/imp.rs
+++ b/crates/ra_analysis/src/imp.rs
@@ -621,7 +621,7 @@ fn resolve_local_name(
     name_ref: ast::NameRef,
 ) -> Option<(SmolStr, TextRange)> {
     let fn_def = name_ref.syntax().ancestors().find_map(ast::FnDef::cast)?;
-    let fn_id = FnId::new(file_id, fn_def);
+    let fn_id = FnId::get(db, file_id, fn_def);
     let scopes = db.fn_scopes(fn_id);
     let scope_entry = crate::descriptors::function::resolve_local_name(name_ref, &scopes)?;
     let syntax = db.resolve_syntax_ptr(scope_entry.ptr().into_global(file_id));
diff --git a/crates/ra_analysis/src/loc2id.rs b/crates/ra_analysis/src/loc2id.rs
index a53ce8348..8eaa24997 100644
--- a/crates/ra_analysis/src/loc2id.rs
+++ b/crates/ra_analysis/src/loc2id.rs
@@ -1,7 +1,16 @@
-use std::hash::Hash;
+use parking_lot::Mutex;
+
+use std::{
+    hash::Hash,
+    sync::Arc,
+};
 
 use rustc_hash::FxHashMap;
 
+use crate::{
+    syntax_ptr::SyntaxPtr,
+};
+
 /// There are two principle ways to refer to things:
 ///   - by their locatinon (module in foo/bar/baz.rs at line 42)
 ///   - by their numeric id (module `ModuleId(42)`)
@@ -53,8 +62,8 @@ where
         id
     }
 
-    pub fn id2loc(&self, id: &ID) -> L {
-        self.id2loc[id].clone()
+    pub fn id2loc(&self, id: ID) -> L {
+        self.id2loc[&id].clone()
     }
 }
 
@@ -62,3 +71,38 @@ pub(crate) trait NumericId: Clone + Eq + Hash {
     fn from_u32(id: u32) -> Self;
     fn to_u32(self) -> u32;
 }
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub(crate) struct FnId(u32);
+
+impl NumericId for FnId {
+    fn from_u32(id: u32) -> FnId {
+        FnId(id)
+    }
+    fn to_u32(self) -> u32 {
+        self.0
+    }
+}
+
+pub(crate) trait IdDatabase: salsa::Database {
+    fn id_maps(&self) -> &IdMaps;
+}
+
+#[derive(Debug, Default, Clone)]
+pub(crate) struct IdMaps {
+    inner: Arc<IdMapsInner>,
+}
+
+impl IdMaps {
+    pub(crate) fn fn_id(&self, ptr: SyntaxPtr) -> FnId {
+        self.inner.fns.lock().loc2id(&ptr)
+    }
+    pub(crate) fn fn_ptr(&self, fn_id: FnId) -> SyntaxPtr {
+        self.inner.fns.lock().id2loc(fn_id)
+    }
+}
+
+#[derive(Debug, Default)]
+struct IdMapsInner {
+    fns: Mutex<Loc2IdMap<SyntaxPtr, FnId>>,
+}