From e7aa17b5605bdf393c76549ff1507110a94b4cca Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 19 Dec 2018 00:35:13 +0300
Subject: [PATCH 1/2] Gc syntax trees after every modification

---
 crates/ra_analysis/src/imp.rs | 21 +++++++++++++++++----
 crates/ra_hir/src/db.rs       |  4 ----
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/crates/ra_analysis/src/imp.rs b/crates/ra_analysis/src/imp.rs
index 03d17de0ddd..843f28d05cd 100644
--- a/crates/ra_analysis/src/imp.rs
+++ b/crates/ra_analysis/src/imp.rs
@@ -10,7 +10,7 @@ use ra_syntax::{
     SyntaxKind::*,
     SyntaxNodeRef, TextRange, TextUnit,
 };
-use ra_db::{FilesDatabase, SourceRoot, SourceRootId, WORKSPACE, SyntaxDatabase, SourceFileQuery};
+use ra_db::{FilesDatabase, SourceRoot, SourceRootId, WORKSPACE, SyntaxDatabase};
 use rayon::prelude::*;
 use rustc_hash::FxHashSet;
 use salsa::{Database, ParallelDatabase};
@@ -43,6 +43,7 @@ impl AnalysisHostImpl {
     }
     pub fn apply_change(&mut self, change: AnalysisChange) {
         log::info!("apply_change {:?}", change);
+        self.gc_syntax_trees();
 
         for (file_id, text) in change.files_changed {
             self.db
@@ -115,6 +116,21 @@ impl AnalysisHostImpl {
                 .set((), Arc::new(crate_graph))
         }
     }
+
+    fn gc_syntax_trees(&mut self) {
+        self.db
+            .query(ra_db::SourceFileQuery)
+            .sweep(salsa::SweepStrategy::default().discard_values());
+        self.db
+            .query(hir::db::FnSyntaxQuery)
+            .sweep(salsa::SweepStrategy::default().discard_values());
+        self.db
+            .query(hir::db::SourceFileItemsQuery)
+            .sweep(salsa::SweepStrategy::default().discard_values());
+        self.db
+            .query(hir::db::FileItemQuery)
+            .sweep(salsa::SweepStrategy::default().discard_values());
+    }
 }
 
 pub(crate) struct AnalysisImpl {
@@ -160,9 +176,6 @@ impl AnalysisImpl {
                 .filter_map(|it| it.ok())
                 .collect()
         };
-        self.db
-            .query(SourceFileQuery)
-            .sweep(salsa::SweepStrategy::default().discard_values());
         Ok(query.search(&buf))
     }
     /// This returns `Vec` because a module may be included from several places. We
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index ff41fd326a0..62cf9ab17c2 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -27,20 +27,16 @@ pub trait HirDatabase: SyntaxDatabase
     }
     fn fn_syntax(fn_id: FnId) -> FnDefNode {
         type FnSyntaxQuery;
-        // Don't retain syntax trees in memory
-        storage dependencies;
         use fn query_definitions::fn_syntax;
     }
 
     fn file_items(file_id: FileId) -> Arc<SourceFileItems> {
         type SourceFileItemsQuery;
-        storage dependencies;
         use fn query_definitions::file_items;
     }
 
     fn file_item(source_item_id: SourceItemId) -> SyntaxNode {
         type FileItemQuery;
-        storage dependencies;
         use fn query_definitions::file_item;
     }
 

From d20d788571b9d1b5f4b9a386b8ca82ee0b278c17 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 19 Dec 2018 01:10:03 +0300
Subject: [PATCH 2/2] disable gc for now

---
 crates/ra_analysis/src/imp.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/crates/ra_analysis/src/imp.rs b/crates/ra_analysis/src/imp.rs
index 843f28d05cd..0de0e2645be 100644
--- a/crates/ra_analysis/src/imp.rs
+++ b/crates/ra_analysis/src/imp.rs
@@ -43,7 +43,7 @@ impl AnalysisHostImpl {
     }
     pub fn apply_change(&mut self, change: AnalysisChange) {
         log::info!("apply_change {:?}", change);
-        self.gc_syntax_trees();
+        // self.gc_syntax_trees();
 
         for (file_id, text) in change.files_changed {
             self.db
@@ -117,6 +117,10 @@ impl AnalysisHostImpl {
         }
     }
 
+    #[allow(unused)]
+    /// Ideally, we should call this function from time to time to collect heavy
+    /// syntax trees. However, if we actually do that, everything is recomputed
+    /// for some reason. Needs investigation.
     fn gc_syntax_trees(&mut self) {
         self.db
             .query(ra_db::SourceFileQuery)