Auto merge of #14630 - Veykril:arc, r=Veykril

internal: `Arc<String>` -> `Arc<str>`

crates/base-db/src/change.rs

@@ -12,7 +12,7 @@
 #[derive(Default)]
 pub struct Change {
     pub roots: Option<Vec<SourceRoot>>,
-    pub files_changed: Vec<(FileId, Option<Arc<String>>)>,
+    pub files_changed: Vec<(FileId, Option<Arc<str>>)>,
     pub crate_graph: Option<CrateGraph>,
     pub proc_macros: Option<ProcMacros>,
 }
@@ -42,7 +42,7 @@ 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>>) {
+    pub fn change_file(&mut self, file_id: FileId, new_text: Option<Arc<str>>) {
         self.files_changed.push((file_id, new_text))
     }
 
@@ -72,7 +72,7 @@ pub fn apply(self, db: &mut dyn SourceDatabaseExt) {
             let source_root = db.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();
+            let text = text.unwrap_or_else(|| Arc::from(""));
             db.set_file_text_with_durability(file_id, text, durability)
         }
         if let Some(crate_graph) = self.crate_graph {

crates/base-db/src/fixture.rs

@@ -190,7 +190,7 @@ pub fn parse_with_proc_macros(
                 default_target_data_layout = meta.target_data_layout;
             }
 
-            change.change_file(file_id, Some(Arc::new(text)));
+            change.change_file(file_id, Some(Arc::from(text)));
             let path = VfsPath::new_virtual_path(meta.path);
             file_set.insert(file_id, path);
             files.push(file_id);
@@ -240,7 +240,7 @@ pub fn parse_with_proc_macros(
             fs.insert(core_file, VfsPath::new_virtual_path("/sysroot/core/lib.rs".to_string()));
             roots.push(SourceRoot::new_library(fs));
 
-            change.change_file(core_file, Some(Arc::new(mini_core.source_code())));
+            change.change_file(core_file, Some(Arc::from(mini_core.source_code())));
 
             let all_crates = crate_graph.crates_in_topological_order();
 
@@ -279,7 +279,7 @@ pub fn parse_with_proc_macros(
             );
             roots.push(SourceRoot::new_library(fs));
 
-            change.change_file(proc_lib_file, Some(Arc::new(source)));
+            change.change_file(proc_lib_file, Some(Arc::from(source)));
 
             let all_crates = crate_graph.crates_in_topological_order();
 

crates/base-db/src/lib.rs

@@ -57,7 +57,7 @@ pub struct FileRange {
 
 pub trait FileLoader {
     /// Text of the file.
-    fn file_text(&self, file_id: FileId) -> Arc<String>;
+    fn file_text(&self, file_id: FileId) -> Arc<str>;
     fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId>;
     fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>>;
 }
@@ -90,7 +90,7 @@ fn parse_query(db: &dyn SourceDatabase, file_id: FileId) -> Parse<ast::SourceFil
 #[salsa::query_group(SourceDatabaseExtStorage)]
 pub trait SourceDatabaseExt: SourceDatabase {
     #[salsa::input]
-    fn file_text(&self, file_id: FileId) -> Arc<String>;
+    fn file_text(&self, file_id: FileId) -> Arc<str>;
     /// Path to a file, relative to the root of its source root.
     /// Source root of the file.
     #[salsa::input]
@@ -118,7 +118,7 @@ fn source_root_crates(db: &dyn SourceDatabaseExt, id: SourceRootId) -> Arc<FxHas
 pub struct FileLoaderDelegate<T>(pub T);
 
 impl<T: SourceDatabaseExt> FileLoader for FileLoaderDelegate<&'_ T> {
-    fn file_text(&self, file_id: FileId) -> Arc<String> {
+    fn file_text(&self, file_id: FileId) -> Arc<str> {
         SourceDatabaseExt::file_text(self.0, file_id)
     }
     fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId> {

crates/hir-def/src/nameres/tests/incremental.rs

@@ -15,7 +15,7 @@ fn check_def_map_is_not_recomputed(ra_fixture_initial: &str, ra_fixture_change:
         });
         assert!(format!("{events:?}").contains("crate_def_map"), "{events:#?}")
     }
-    db.set_file_text(pos.file_id, Arc::new(ra_fixture_change.to_string()));
+    db.set_file_text(pos.file_id, Arc::from(ra_fixture_change));
 
     {
         let events = db.log_executed(|| {
@@ -96,7 +96,7 @@ fn f() {
         });
         assert!(format!("{events:?}").contains("crate_def_map"), "{events:#?}")
     }
-    db.set_file_text(pos.file_id, Arc::new("m!(Y);".to_string()));
+    db.set_file_text(pos.file_id, Arc::from("m!(Y);"));
 
     {
         let events = db.log_executed(|| {
@@ -150,7 +150,7 @@ fn quux() { 92 }
 m!(Y);
 m!(Z);
 "#;
-    db.set_file_text(pos.file_id, Arc::new(new_text.to_string()));
+    db.set_file_text(pos.file_id, Arc::from(new_text));
 
     {
         let events = db.log_executed(|| {

crates/hir-def/src/test_db.rs

@@ -71,7 +71,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 impl panic::RefUnwindSafe for TestDB {}
 
 impl FileLoader for TestDB {
-    fn file_text(&self, file_id: FileId) -> Arc<String> {
+    fn file_text(&self, file_id: FileId) -> Arc<str> {
         FileLoaderDelegate(self).file_text(file_id)
     }
     fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId> {

crates/hir-ty/src/test_db.rs

@@ -76,7 +76,7 @@ fn snapshot(&self) -> salsa::Snapshot<TestDB> {
 impl panic::RefUnwindSafe for TestDB {}
 
 impl FileLoader for TestDB {
-    fn file_text(&self, file_id: FileId) -> Arc<String> {
+    fn file_text(&self, file_id: FileId) -> Arc<str> {
         FileLoaderDelegate(self).file_text(file_id)
     }
     fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId> {

crates/hir-ty/src/tests.rs

@@ -572,10 +572,9 @@ fn main() {
             let x = 1;
             x.push(1);
         }
-    "
+    ";
-    .to_string();
 
-    db.set_file_text(pos.file_id, Arc::new(new_text));
+    db.set_file_text(pos.file_id, Arc::from(new_text));
 
     let module = db.module_for_file(pos.file_id);
     let crate_def_map = module.def_map(&db);

crates/hir-ty/src/tests/incremental.rs

@@ -33,10 +33,9 @@ fn foo() -> i32 {
             +
             1
         }
-    "
+    ";
-    .to_string();
 
-    db.set_file_text(pos.file_id, Arc::new(new_text));
+    db.set_file_text(pos.file_id, Arc::from(new_text));
 
     {
         let events = db.log_executed(|| {

crates/ide-db/src/lib.rs

@@ -113,7 +113,7 @@ fn upcast(&self) -> &(dyn HirDatabase + 'static) {
 }
 
 impl FileLoader for RootDatabase {
-    fn file_text(&self, file_id: FileId) -> Arc<String> {
+    fn file_text(&self, file_id: FileId) -> Arc<str> {
         FileLoaderDelegate(self).file_text(file_id)
     }
     fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId> {

crates/ide-db/src/search.rs

@@ -438,11 +438,11 @@ fn match_indices<'a>(
         fn scope_files<'a>(
             sema: &'a Semantics<'_, RootDatabase>,
             scope: &'a SearchScope,
-        ) -> impl Iterator<Item = (Arc<String>, FileId, TextRange)> + 'a {
+        ) -> impl Iterator<Item = (Arc<str>, FileId, TextRange)> + 'a {
             scope.entries.iter().map(|(&file_id, &search_range)| {
                 let text = sema.db.file_text(file_id);
                 let search_range =
-                    search_range.unwrap_or_else(|| TextRange::up_to(TextSize::of(text.as_str())));
+                    search_range.unwrap_or_else(|| TextRange::up_to(TextSize::of(&*text)));
 
                 (text, file_id, search_range)
             })
@@ -553,7 +553,7 @@ fn scope_files<'a>(
 
                 let text = sema.db.file_text(file_id);
                 let search_range =
-                    search_range.unwrap_or_else(|| TextRange::up_to(TextSize::of(text.as_str())));
+                    search_range.unwrap_or_else(|| TextRange::up_to(TextSize::of(&*text)));
 
                 let tree = Lazy::new(|| sema.parse(file_id).syntax().clone());
                 let finder = &Finder::new("self");

crates/ide-ssr/src/lib.rs

@@ -224,7 +224,7 @@ pub fn debug_where_text_equal(&self, file_id: FileId, snippet: &str) -> Vec<Matc
         let file = self.sema.parse(file_id);
         let mut res = Vec::new();
         let file_text = self.sema.db.file_text(file_id);
-        let mut remaining_text = file_text.as_str();
+        let mut remaining_text = &*file_text;
         let mut base = 0;
         let len = snippet.len() as u32;
         while let Some(offset) = remaining_text.find(snippet) {

crates/ide/src/lib.rs

@@ -244,7 +244,7 @@ pub fn from_single_file(text: String) -> (Analysis, FileId) {
             Err("Analysis::from_single_file has no target layout".into()),
             None,
         );
-        change.change_file(file_id, Some(Arc::new(text)));
+        change.change_file(file_id, Some(Arc::from(text)));
         change.set_crate_graph(crate_graph);
         host.apply_change(change);
         (host.analysis(), file_id)
@@ -263,7 +263,7 @@ pub fn parallel_prime_caches<F>(&self, num_worker_threads: u8, cb: F) -> Cancell
     }
 
     /// Gets the text of the source file.
-    pub fn file_text(&self, file_id: FileId) -> Cancellable<Arc<String>> {
+    pub fn file_text(&self, file_id: FileId) -> Cancellable<Arc<str>> {
         self.with_db(|db| db.file_text(file_id))
     }
 

crates/ide/src/status.rs

@@ -164,8 +164,8 @@ fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
     }
 }
 
-impl StatCollect<FileId, Arc<String>> for FilesStats {
+impl StatCollect<FileId, Arc<str>> for FilesStats {
-    fn collect_entry(&mut self, _: FileId, value: Option<Arc<String>>) {
+    fn collect_entry(&mut self, _: FileId, value: Option<Arc<str>>) {
         self.total += 1;
         self.size += value.unwrap().len();
     }

crates/rust-analyzer/src/cli/load_cargo.rs

@@ -162,9 +162,9 @@ fn load_crate_graph(
     let changes = vfs.take_changes();
     for file in changes {
         if file.exists() {
-            let contents = vfs.file_contents(file.file_id).to_vec();
+            let contents = vfs.file_contents(file.file_id);
-            if let Ok(text) = String::from_utf8(contents) {
+            if let Ok(text) = std::str::from_utf8(contents) {
-                analysis_change.change_file(file.file_id, Some(Arc::new(text)))
+                analysis_change.change_file(file.file_id, Some(Arc::from(text)))
             }
         }
     }

crates/rust-analyzer/src/global_state.rs

@@ -269,7 +269,7 @@ pub(crate) fn process_changes(&mut self) -> bool {
                     String::from_utf8(bytes).ok().and_then(|text| {
                         let (text, line_endings) = LineEndings::normalize(text);
                         line_endings_map.insert(file.file_id, line_endings);
-                        Some(Arc::new(text))
+                        Some(Arc::from(text))
                     })
                 } else {
                     None
@@ -440,6 +440,10 @@ pub(crate) fn cargo_target_for_crate_root(
             ProjectWorkspace::DetachedFiles { .. } => None,
         })
     }
+
+    pub(crate) fn vfs_memory_usage(&self) -> usize {
+        self.vfs.read().0.memory_usage()
+    }
 }
 
 pub(crate) fn file_id_to_url(vfs: &vfs::Vfs, id: FileId) -> Url {

crates/rust-analyzer/src/handlers.rs

@@ -103,6 +103,7 @@ pub(crate) fn handle_analyzer_status(
                 .collect::<Vec<&AbsPath>>()
         );
     }
+    format_to!(buf, "\nVfs memory usage: {}\n", snap.vfs_memory_usage());
     buf.push_str("\nAnalysis:\n");
     buf.push_str(
         &snap

crates/rust-analyzer/src/integrated_benchmarks.rs

@@ -65,7 +65,7 @@ fn integrated_highlighting_benchmark() {
         let mut text = host.analysis().file_text(file_id).unwrap().to_string();
         text.push_str("\npub fn _dummy() {}\n");
         let mut change = Change::new();
-        change.change_file(file_id, Some(Arc::new(text)));
+        change.change_file(file_id, Some(Arc::from(text)));
         host.apply_change(change);
     }
 
@@ -121,7 +121,7 @@ fn integrated_completion_benchmark() {
             patch(&mut text, "db.struct_data(self.id)", "sel;\ndb.struct_data(self.id)")
                 + "sel".len();
         let mut change = Change::new();
-        change.change_file(file_id, Some(Arc::new(text)));
+        change.change_file(file_id, Some(Arc::from(text)));
         host.apply_change(change);
         completion_offset
     };
@@ -160,7 +160,7 @@ fn integrated_completion_benchmark() {
             patch(&mut text, "sel;\ndb.struct_data(self.id)", "self.;\ndb.struct_data(self.id)")
                 + "self.".len();
         let mut change = Change::new();
-        change.change_file(file_id, Some(Arc::new(text)));
+        change.change_file(file_id, Some(Arc::from(text)));
         host.apply_change(change);
         completion_offset
     };

crates/vfs/src/lib.rs

@@ -139,6 +139,11 @@ pub fn file_contents(&self, file_id: FileId) -> &[u8] {
         self.get(file_id).as_deref().unwrap()
     }
 
+    /// Returns the overall memory usage for the stored files.
+    pub fn memory_usage(&self) -> usize {
+        self.data.iter().flatten().map(|d| d.capacity()).sum()
+    }
+
     /// Returns an iterator over the stored ids and their corresponding paths.
     ///
     /// This will skip deleted files.
@@ -158,7 +163,7 @@ pub fn iter(&self) -> impl Iterator<Item = (FileId, &VfsPath)> + '_ {
     ///
     /// If the path does not currently exists in the `Vfs`, allocates a new
     /// [`FileId`] for it.
-    pub fn set_file_contents(&mut self, path: VfsPath, contents: Option<Vec<u8>>) -> bool {
+    pub fn set_file_contents(&mut self, path: VfsPath, mut contents: Option<Vec<u8>>) -> bool {
         let file_id = self.alloc_file_id(path);
         let change_kind = match (self.get(file_id), &contents) {
             (None, None) => return false,
@@ -167,7 +172,9 @@ pub fn set_file_contents(&mut self, path: VfsPath, contents: Option<Vec<u8>>) ->
             (Some(_), None) => ChangeKind::Delete,
             (Some(_), Some(_)) => ChangeKind::Modify,
         };
-
+        if let Some(contents) = &mut contents {
+            contents.shrink_to_fit();
+        }
         *self.get_mut(file_id) = contents;
         self.changes.push(ChangedFile { file_id, change_kind });
         true