3 files changed, 10 insertions, 119 deletions

diff --git a/crates/ide_db/src/change.rs b/crates/ide_db/src/apply_change.rs
index 8b4fd7ab8..da16fa21d 100644
--- a/crates/ide_db/src/change.rs
+++ b/crates/ide_db/src/apply_change.rs
@@ -1,58 +1,16 @@
-//! Defines a unit of change that can applied to a state of IDE to get the next
-//! state. Changes are transactional.
+//! Applies changes to the IDE state transactionally.
 
-use std::{fmt, sync::Arc, time};
+use std::{fmt, sync::Arc};
 
 use base_db::{
     salsa::{Database, Durability, SweepStrategy},
-    CrateGraph, FileId, SourceDatabase, SourceDatabaseExt, SourceRoot, SourceRootId,
+    Change, FileId, SourceRootId,
 };
 use profile::{memory_usage, Bytes};
 use rustc_hash::FxHashSet;
 
 use crate::{symbol_index::SymbolsDatabase, RootDatabase};
 
-#[derive(Default)]
-pub struct AnalysisChange {
-    roots: Option<Vec<SourceRoot>>,
-    files_changed: Vec<(FileId, Option<Arc<String>>)>,
-    crate_graph: Option<CrateGraph>,
-}
-
-impl fmt::Debug for AnalysisChange {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        let mut d = fmt.debug_struct("AnalysisChange");
-        if let Some(roots) = &self.roots {
-            d.field("roots", roots);
-        }
-        if !self.files_changed.is_empty() {
-            d.field("files_changed", &self.files_changed.len());
-        }
-        if self.crate_graph.is_some() {
-            d.field("crate_graph", &self.crate_graph);
-        }
-        d.finish()
-    }
-}
-
-impl AnalysisChange {
-    pub fn new() -> AnalysisChange {
-        AnalysisChange::default()
-    }
-
-    pub fn set_roots(&mut self, roots: Vec<SourceRoot>) {
-        self.roots = Some(roots);
-    }
-
-    pub fn change_file(&mut self, file_id: FileId, new_text: Option<Arc<String>>) {
-        self.files_changed.push((file_id, new_text))
-    }
-
-    pub fn set_crate_graph(&mut self, graph: CrateGraph) {
-        self.crate_graph = Some(graph);
-    }
-}
-
 #[derive(Debug)]
 struct AddFile {
     file_id: FileId,
@@ -81,59 +39,31 @@ impl fmt::Debug for RootChange {
     }
 }
 
-const GC_COOLDOWN: time::Duration = time::Duration::from_millis(100);
-
 impl RootDatabase {
     pub fn request_cancellation(&mut self) {
         let _p = profile::span("RootDatabase::request_cancellation");
         self.salsa_runtime_mut().synthetic_write(Durability::LOW);
     }
 
-    pub fn apply_change(&mut self, change: AnalysisChange) {
+    pub fn apply_change(&mut self, change: Change) {
         let _p = profile::span("RootDatabase::apply_change");
         self.request_cancellation();
         log::info!("apply_change {:?}", change);
-        if let Some(roots) = change.roots {
+        if let Some(roots) = &change.roots {
             let mut local_roots = FxHashSet::default();
             let mut library_roots = FxHashSet::default();
-            for (idx, root) in roots.into_iter().enumerate() {
+            for (idx, root) in roots.iter().enumerate() {
                 let root_id = SourceRootId(idx as u32);
-                let durability = durability(&root);
                 if root.is_library {
                     library_roots.insert(root_id);
                 } else {
                     local_roots.insert(root_id);
                 }
-                for file_id in root.iter() {
-                    self.set_file_source_root_with_durability(file_id, root_id, durability);
-                }
-                self.set_source_root_with_durability(root_id, Arc::new(root), durability);
             }
             self.set_local_roots_with_durability(Arc::new(local_roots), Durability::HIGH);
             self.set_library_roots_with_durability(Arc::new(library_roots), Durability::HIGH);
         }
-
-        for (file_id, text) in change.files_changed {
-            let source_root_id = self.file_source_root(file_id);
-            let source_root = self.source_root(source_root_id);
-            let durability = durability(&source_root);
-            // XXX: can't actually remove the file, just reset the text
-            let text = text.unwrap_or_default();
-            self.set_file_text_with_durability(file_id, text, durability)
-        }
-        if let Some(crate_graph) = change.crate_graph {
-            self.set_crate_graph_with_durability(Arc::new(crate_graph), Durability::HIGH)
-        }
-    }
-
-    pub fn maybe_collect_garbage(&mut self) {
-        if cfg!(feature = "wasm") {
-            return;
-        }
-
-        if self.last_gc_check.elapsed() > GC_COOLDOWN {
-            self.last_gc_check = crate::wasm_shims::Instant::now();
-        }
+        change.apply(self);
     }
 
     pub fn collect_garbage(&mut self) {
@@ -142,7 +72,6 @@ impl RootDatabase {
         }
 
         let _p = profile::span("RootDatabase::collect_garbage");
-        self.last_gc = crate::wasm_shims::Instant::now();
 
         let sweep = SweepStrategy::default().discard_values().sweep_all_revisions();
 
@@ -308,11 +237,3 @@ impl RootDatabase {
         acc
     }
 }
-
-fn durability(source_root: &SourceRoot) -> Durability {
-    if source_root.is_library {
-        Durability::HIGH
-    } else {
-        Durability::LOW
-    }
-}
diff --git a/crates/ide_db/src/lib.rs b/crates/ide_db/src/lib.rs
index 70ada02f3..7eff247c7 100644
--- a/crates/ide_db/src/lib.rs
+++ b/crates/ide_db/src/lib.rs
@@ -2,15 +2,14 @@
 //!
 //! It is mainly a `HirDatabase` for semantic analysis, plus a `SymbolsDatabase`, for fuzzy search.
 
+mod apply_change;
 pub mod label;
 pub mod line_index;
 pub mod symbol_index;
-pub mod change;
 pub mod defs;
 pub mod search;
 pub mod imports_locator;
 pub mod source_change;
-mod wasm_shims;
 
 use std::{fmt, sync::Arc};
 
@@ -36,8 +35,6 @@ use crate::{line_index::LineIndex, symbol_index::SymbolsDatabase};
 )]
 pub struct RootDatabase {
     storage: salsa::Storage<RootDatabase>,
-    pub last_gc: crate::wasm_shims::Instant,
-    pub last_gc_check: crate::wasm_shims::Instant,
 }
 
 impl fmt::Debug for RootDatabase {
@@ -99,11 +96,7 @@ impl Default for RootDatabase {
 
 impl RootDatabase {
     pub fn new(lru_capacity: Option<usize>) -> RootDatabase {
-        let mut db = RootDatabase {
-            storage: salsa::Storage::default(),
-            last_gc: crate::wasm_shims::Instant::now(),
-            last_gc_check: crate::wasm_shims::Instant::now(),
-        };
+        let mut db = RootDatabase { storage: salsa::Storage::default() };
         db.set_crate_graph_with_durability(Default::default(), Durability::HIGH);
         db.set_local_roots_with_durability(Default::default(), Durability::HIGH);
         db.set_library_roots_with_durability(Default::default(), Durability::HIGH);
@@ -121,11 +114,7 @@ impl RootDatabase {
 
 impl salsa::ParallelDatabase for RootDatabase {
     fn snapshot(&self) -> salsa::Snapshot<RootDatabase> {
-        salsa::Snapshot::new(RootDatabase {
-            storage: self.storage.snapshot(),
-            last_gc: self.last_gc,
-            last_gc_check: self.last_gc_check,
-        })
+        salsa::Snapshot::new(RootDatabase { storage: self.storage.snapshot() })
     }
 }
 
diff --git a/crates/ide_db/src/wasm_shims.rs b/crates/ide_db/src/wasm_shims.rs
deleted file mode 100644
index 7af9f9d9b..000000000
--- a/crates/ide_db/src/wasm_shims.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-//! A version of `std::time::Instant` that doesn't panic in WASM.
-
-#[cfg(not(feature = "wasm"))]
-pub use std::time::Instant;
-
-#[cfg(feature = "wasm")]
-#[derive(Clone, Copy, Debug)]
-pub struct Instant;
-
-#[cfg(feature = "wasm")]
-impl Instant {
-    pub fn now() -> Self {
-        Self
-    }
-
-    pub fn elapsed(&self) -> std::time::Duration {
-        std::time::Duration::new(0, 0)
-    }
-}