Merge #9206

9206: minor: Speed up fst items lookup during completions r=SomeoneToIgnore a=SomeoneToIgnore

Part of https://github.com/rust-analyzer/rust-analyzer/issues/7542

A number of profile calls added for `import_on_the_fly` contents.
Before:
<img width="606" alt="Screenshot 2021-06-11 at 00 19 13" src="https://user-images.githubusercontent.com/2690773/121598998-22321e80-ca4b-11eb-9a3d-dc9cb2936705.png">

After:
<img width="859" alt="Screenshot 2021-06-11 at 00 19 27" src="https://user-images.githubusercontent.com/2690773/121599022-2a8a5980-ca4b-11eb-82b6-13ab0ed56d58.png">

As a result, low hanging fruit was spotted: crazy amount of `fst_path` calls. Reducing that won ~200ms in the `import_on_the_fly @ sel` case in the `integrated_completion_benchmark`:

<img width="861" alt="Screenshot 2021-06-11 at 00 19 38" src="https://user-images.githubusercontent.com/2690773/121599277-7d641100-ca4b-11eb-8667-53206994de27.png">

I'm not sure how to proceed with the remaining `???` marks in such methods as `collect_import_map` though: there's nothing but library calls in cycles, but maybe I'll come up with something later.

Co-authored-by: Kirill Bulatov <[email protected]>

1 files changed, 4 insertions, 0 deletions

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index debc3ee62..b9c1dc44d 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -191,6 +191,7 @@ impl Crate {
         db: &dyn DefDatabase,
         query: import_map::Query,
     ) -> impl Iterator<Item = Either<ModuleDef, MacroDef>> {
+        let _p = profile::span("query_external_importables");
         import_map::search_dependencies(db, self.into(), query).into_iter().map(|item| match item {
             ItemInNs::Types(mod_id) | ItemInNs::Values(mod_id) => Either::Left(mod_id.into()),
             ItemInNs::Macros(mac_id) => Either::Right(mac_id.into()),
@@ -2185,6 +2186,7 @@ impl Type {
         name: Option<&Name>,
         mut callback: impl FnMut(&Ty, Function) -> Option<T>,
     ) -> Option<T> {
+        let _p = profile::span("iterate_method_candidates");
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
@@ -2218,6 +2220,7 @@ impl Type {
         name: Option<&Name>,
         mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
     ) -> Option<T> {
+        let _p = profile::span("iterate_path_candidates");
         let canonical = hir_ty::replace_errors_with_variables(&self.ty);
 
         let env = self.env.clone();
@@ -2255,6 +2258,7 @@ impl Type {
         &'a self,
         db: &'a dyn HirDatabase,
     ) -> impl Iterator<Item = Trait> + 'a {
+        let _p = profile::span("applicable_inherent_traits");
         self.autoderef(db)
             .filter_map(|derefed_type| derefed_type.ty.dyn_trait())
             .flat_map(move |dyn_trait_id| hir_ty::all_super_traits(db.upcast(), dyn_trait_id))