refactor: Clean up cache priming cancellation handling

Author: Veykril

crates/hir/src/symbols.rs

@@ -13,13 +13,13 @@ use hir_def::{
 use hir_expand::{HirFileId, name::Name};
 use hir_ty::{
     db::HirDatabase,
-    display::{DisplayTarget, HirDisplay, hir_display_with_store},
+    display::{HirDisplay, hir_display_with_store},
 };
 use intern::Symbol;
 use rustc_hash::FxHashMap;
 use syntax::{AstNode, AstPtr, SmolStr, SyntaxNode, SyntaxNodePtr, ToSmolStr, ast::HasName};
 
-use crate::{Module, ModuleDef, Semantics};
+use crate::{HasCrate, Module, ModuleDef, Semantics};
 
 pub type FxIndexSet<T> = indexmap::IndexSet<T, std::hash::BuildHasherDefault<rustc_hash::FxHasher>>;
 
@@ -66,7 +66,6 @@ pub struct SymbolCollector<'a> {
     symbols: FxIndexSet<FileSymbol>,
     work: Vec<SymbolCollectorWork>,
     current_container_name: Option<SmolStr>,
-    display_target: DisplayTarget,
 }
 
 /// Given a [`ModuleId`] and a [`HirDatabase`], use the DefMap for the module's crate to collect
@@ -78,10 +77,6 @@ impl<'a> SymbolCollector<'a> {
             symbols: Default::default(),
             work: Default::default(),
             current_container_name: None,
-            display_target: DisplayTarget::from_crate(
-                db,
-                *db.all_crates().last().expect("no crate graph present"),
-            ),
         }
     }
 
@@ -93,8 +88,7 @@ impl<'a> SymbolCollector<'a> {
 
     pub fn collect(&mut self, module: Module) {
         let _p = tracing::info_span!("SymbolCollector::collect", ?module).entered();
-        tracing::info!(?module, "SymbolCollector::collect",);
-        self.display_target = module.krate().to_display_target(self.db);
+        tracing::info!(?module, "SymbolCollector::collect");
 
         // The initial work is the root module we're collecting, additional work will
         // be populated as we traverse the module's definitions.
@@ -321,7 +315,10 @@ impl<'a> SymbolCollector<'a> {
         let impl_data = self.db.impl_signature(impl_id);
         let impl_name = Some(
             hir_display_with_store(impl_data.self_ty, &impl_data.store)
-                .display(self.db, self.display_target)
+                .display(
+                    self.db,
+                    crate::Impl::from(impl_id).krate(self.db).to_display_target(self.db),
+                )
                 .to_smolstr(),
         );
         self.with_container_name(impl_name, |s| {

crates/ide-db/src/lib.rs

@@ -78,6 +78,8 @@ pub type FileRange = FileRangeWrapper<FileId>;
 
 #[salsa::db]
 pub struct RootDatabase {
+    // FIXME: Revisit this commit now that we migrated to the new salsa, given we store arcs in this
+    // db directly now
     // We use `ManuallyDrop` here because every codegen unit that contains a
     // `&RootDatabase -> &dyn OtherDatabase` cast will instantiate its drop glue in the vtable,
     // which duplicates `Weak::drop` and `Arc::drop` tens of thousands of times, which makes
@@ -234,14 +236,6 @@ impl RootDatabase {
         // );
         // hir::db::BodyWithSourceMapQuery.in_db_mut(self).set_lru_capacity(2048);
     }
-
-    pub fn snapshot(&self) -> Self {
-        Self {
-            storage: self.storage.clone(),
-            files: self.files.clone(),
-            crates_map: self.crates_map.clone(),
-        }
-    }
 }
 
 #[query_group::query_group]

crates/ide-db/src/prime_caches.rs

@@ -51,6 +51,7 @@ pub fn parallel_prime_caches(
     enum ParallelPrimeCacheWorkerProgress {
         BeginCrate { crate_id: Crate, crate_name: Symbol },
         EndCrate { crate_id: Crate },
+        Cancelled(Cancelled),
     }
 
     // We split off def map computation from other work,
@@ -71,26 +72,32 @@ pub fn parallel_prime_caches(
                 progress_sender
                     .send(ParallelPrimeCacheWorkerProgress::BeginCrate { crate_id, crate_name })?;
 
-                match kind {
+                let cancelled = Cancelled::catch(|| match kind {
                     PrimingPhase::DefMap => _ = db.crate_def_map(crate_id),
                     PrimingPhase::ImportMap => _ = db.import_map(crate_id),
                     PrimingPhase::CrateSymbols => _ = db.crate_symbols(crate_id.into()),
-                }
+                });
 
-                progress_sender.send(ParallelPrimeCacheWorkerProgress::EndCrate { crate_id })?;
+                match cancelled {
+                    Ok(()) => progress_sender
+                        .send(ParallelPrimeCacheWorkerProgress::EndCrate { crate_id })?,
+                    Err(cancelled) => progress_sender
+                        .send(ParallelPrimeCacheWorkerProgress::Cancelled(cancelled))?,
+                }
             }
 
             Ok::<_, crossbeam_channel::SendError<_>>(())
         };
 
         for id in 0..num_worker_threads {
-            let worker = prime_caches_worker.clone();
-            let db = db.snapshot();
-
             stdx::thread::Builder::new(stdx::thread::ThreadIntent::Worker)
                 .allow_leak(true)
                 .name(format!("PrimeCaches#{id}"))
-                .spawn(move || Cancelled::catch(|| worker(db.snapshot())))
+                .spawn({
+                    let worker = prime_caches_worker.clone();
+                    let db = db.clone();
+                    move || worker(db)
+                })
                 .expect("failed to spawn thread");
         }
 
@@ -142,9 +149,14 @@ pub fn parallel_prime_caches(
                 continue;
             }
             Err(crossbeam_channel::RecvTimeoutError::Disconnected) => {
-                // our workers may have died from a cancelled task, so we'll check and re-raise here.
-                db.unwind_if_revision_cancelled();
-                break;
+                // all our workers have exited, mark us as finished and exit
+                cb(ParallelPrimeCachesProgress {
+                    crates_currently_indexing: vec![],
+                    crates_done,
+                    crates_total: crates_done,
+                    work_type: "Indexing",
+                });
+                return;
             }
         };
         match worker_progress {
@@ -156,6 +168,10 @@ pub fn parallel_prime_caches(
                 crates_to_prime.mark_done(crate_id);
                 crates_done += 1;
             }
+            ParallelPrimeCacheWorkerProgress::Cancelled(cancelled) => {
+                // Cancelled::throw should probably be public
+                std::panic::resume_unwind(Box::new(cancelled));
+            }
         };
 
         let progress = ParallelPrimeCachesProgress {
@@ -186,9 +202,14 @@ pub fn parallel_prime_caches(
                 continue;
             }
             Err(crossbeam_channel::RecvTimeoutError::Disconnected) => {
-                // our workers may have died from a cancelled task, so we'll check and re-raise here.
-                db.unwind_if_revision_cancelled();
-                break;
+                // all our workers have exited, mark us as finished and exit
+                cb(ParallelPrimeCachesProgress {
+                    crates_currently_indexing: vec![],
+                    crates_done,
+                    crates_total: crates_done,
+                    work_type: "Populating symbols",
+                });
+                return;
             }
         };
         match worker_progress {
@@ -199,6 +220,10 @@ pub fn parallel_prime_caches(
                 crates_currently_indexing.swap_remove(&crate_id);
                 crates_done += 1;
             }
+            ParallelPrimeCacheWorkerProgress::Cancelled(cancelled) => {
+                // Cancelled::throw should probably be public
+                std::panic::resume_unwind(Box::new(cancelled));
+            }
         };
 
         let progress = ParallelPrimeCachesProgress {

crates/ide/src/lib.rs

@@ -182,7 +182,7 @@ impl AnalysisHost {
     /// Returns a snapshot of the current state, which you can query for
     /// semantic information.
     pub fn analysis(&self) -> Analysis {
-        Analysis { db: self.db.snapshot() }
+        Analysis { db: self.db.clone() }
     }
 
     /// Applies changes to the current state of the world. If there are
@@ -864,7 +864,7 @@ impl Analysis {
     where
         F: FnOnce(&RootDatabase) -> T + std::panic::UnwindSafe,
     {
-        let snap = self.db.snapshot();
+        let snap = self.db.clone();
         Cancelled::catch(|| f(&snap))
     }
 }

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

@@ -701,10 +701,9 @@ impl flags::AnalysisStats {
 
         if self.parallel {
             let mut inference_sw = self.stop_watch();
-            let snap = db.snapshot();
             bodies
                 .par_iter()
-                .map_with(snap, |snap, &body| {
+                .map_with(db.clone(), |snap, &body| {
                     snap.body(body.into());
                     snap.infer(body.into());
                 })

crates/rust-analyzer/src/discover.rs

@@ -126,10 +126,8 @@ impl CargoParser<DiscoverProjectMessage> for DiscoverProjectParser {
                 Some(msg)
             }
             Err(err) => {
-                let err = DiscoverProjectData::Error {
-                    error: format!("{:#?}\n{}", err, line),
-                    source: None,
-                };
+                let err =
+                    DiscoverProjectData::Error { error: format!("{err:#?}\n{line}"), source: None };
                 Some(DiscoverProjectMessage::new(err))
             }
         }

crates/stdx/src/thread.rs

@@ -56,6 +56,8 @@ impl Builder {
         Self { inner: self.inner.stack_size(size), ..self }
     }
 
+    /// Whether dropping should detach the thread
+    /// instead of joining it.
     #[must_use]
     pub fn allow_leak(self, allow_leak: bool) -> Self {
         Self { allow_leak, ..self }