Upgrade salsa (#15039)

The only code change is that Salsa now requires the `Db` to implement
`Clone` to create "lightweight" snapshots.

Cargo.lock

@@ -3193,7 +3193,7 @@ checksum = "e86697c916019a8588c99b5fac3cead74ec0b4b819707a682fd4d23fa0ce1ba1"
 [[package]]
 name = "salsa"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=254c749b02cde2fd29852a7463a33e800b771758#254c749b02cde2fd29852a7463a33e800b771758"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
 dependencies = [
  "append-only-vec",
  "arc-swap",
@@ -3203,6 +3203,7 @@ dependencies = [
  "indexmap",
  "lazy_static",
  "parking_lot",
+ "rayon",
  "rustc-hash 2.1.0",
  "salsa-macro-rules",
  "salsa-macros",
@@ -3213,12 +3214,12 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.1.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=254c749b02cde2fd29852a7463a33e800b771758#254c749b02cde2fd29852a7463a33e800b771758"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
 
 [[package]]
 name = "salsa-macros"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=254c749b02cde2fd29852a7463a33e800b771758#254c749b02cde2fd29852a7463a33e800b771758"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
 dependencies = [
  "heck",
  "proc-macro2",

Cargo.toml

@@ -118,7 +118,7 @@ rand = { version = "0.8.5" }
 rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "254c749b02cde2fd29852a7463a33e800b771758" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "3c7f1694c9efba751dbeeacfbc93b227586e316a" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }

crates/red_knot/src/main.rs

@@ -279,7 +279,7 @@ impl MainLoop {
         while let Ok(message) = self.receiver.recv() {
             match message {
                 MainLoopMessage::CheckWorkspace => {
-                    let db = db.snapshot();
+                    let db = db.clone();
                     let sender = self.sender.clone();
 
                     // Spawn a new task that checks the workspace. This needs to be done in a separate thread

crates/red_knot_python_semantic/src/db.rs

@@ -27,6 +27,7 @@ pub(crate) mod tests {
     use ruff_db::{Db as SourceDb, Upcast};
 
     #[salsa::db]
+    #[derive(Clone)]
     pub(crate) struct TestDb {
         storage: salsa::Storage<Self>,
         files: Files,

crates/red_knot_server/src/server/api.rs

@@ -91,11 +91,11 @@ fn background_request_task<'a, R: traits::BackgroundDocumentRequestHandler>(
         let db = match path {
             AnySystemPath::System(path) => {
                 match session.workspace_db_for_path(path.as_std_path()) {
-                    Some(db) => db.snapshot(),
+                    Some(db) => db.clone(),
-                    None => session.default_workspace_db().snapshot(),
+                    None => session.default_workspace_db().clone(),
                 }
             }
-            AnySystemPath::SystemVirtual(_) => session.default_workspace_db().snapshot(),
+            AnySystemPath::SystemVirtual(_) => session.default_workspace_db().clone(),
         };
 
         let Some(snapshot) = session.take_snapshot(url) else {

crates/red_knot_test/src/db.rs

@@ -9,6 +9,7 @@ use ruff_db::vendored::VendoredFileSystem;
 use ruff_db::{Db as SourceDb, Upcast};
 
 #[salsa::db]
+#[derive(Clone)]
 pub(crate) struct Db {
     workspace_root: SystemPathBuf,
     storage: salsa::Storage<Self>,

crates/red_knot_workspace/src/db.rs

@@ -21,6 +21,7 @@ pub trait Db: SemanticDb + Upcast<dyn SemanticDb> {
 }
 
 #[salsa::db]
+#[derive(Clone)]
 pub struct RootDatabase {
     workspace: Option<Workspace>,
     storage: salsa::Storage<RootDatabase>,
@@ -80,17 +81,6 @@ impl RootDatabase {
     {
         Cancelled::catch(|| f(self))
     }
-
-    #[must_use]
-    pub fn snapshot(&self) -> Self {
-        Self {
-            workspace: self.workspace,
-            storage: self.storage.clone(),
-            files: self.files.snapshot(),
-            system: Arc::clone(&self.system),
-            rule_selection: Arc::clone(&self.rule_selection),
-        }
-    }
 }
 
 impl Upcast<dyn SemanticDb> for RootDatabase {
@@ -184,6 +174,7 @@ pub(crate) mod tests {
     use crate::DEFAULT_LINT_REGISTRY;
 
     #[salsa::db]
+    #[derive(Clone)]
     pub(crate) struct TestDb {
         storage: salsa::Storage<Self>,
         events: Arc<std::sync::Mutex<Vec<Event>>>,

crates/red_knot_workspace/src/workspace.rs

@@ -195,13 +195,13 @@ impl Workspace {
         let result = Arc::new(std::sync::Mutex::new(Vec::new()));
         let inner_result = Arc::clone(&result);
 
-        let db = db.snapshot();
+        let db = db.clone();
         let workspace_span = workspace_span.clone();
 
         rayon::scope(move |scope| {
             for file in &files {
                 let result = inner_result.clone();
-                let db = db.snapshot();
+                let db = db.clone();
                 let workspace_span = workspace_span.clone();
 
                 scope.spawn(move |_| {

crates/ruff/src/commands/analyze_graph.rs

@@ -81,7 +81,7 @@ pub(crate) fn analyze_graph(
         // Collect and resolve the imports for each file.
         let result = Arc::new(Mutex::new(Vec::new()));
         let inner_result = Arc::clone(&result);
-        let db = db.snapshot();
+        let db = db.clone();
 
         rayon::scope(move |scope| {
             for resolved_file in paths {
@@ -137,7 +137,7 @@ pub(crate) fn analyze_graph(
                     continue;
                 };
 
-                let db = db.snapshot();
+                let db = db.clone();
                 let glob_resolver = glob_resolver.clone();
                 let root = root.clone();
                 let result = inner_result.clone();

crates/ruff_db/src/files.rs

@@ -48,7 +48,7 @@ pub fn vendored_path_to_file(
 }
 
 /// Lookup table that maps [file paths](`FilePath`) to salsa interned [`File`] instances.
-#[derive(Default)]
+#[derive(Default, Clone)]
 pub struct Files {
     inner: Arc<FilesInner>,
 }
@@ -253,13 +253,6 @@ impl Files {
             root.set_revision(db).to(FileRevision::now());
         }
     }
-
-    #[must_use]
-    pub fn snapshot(&self) -> Self {
-        Self {
-            inner: Arc::clone(&self.inner),
-        }
-    }
 }
 
 impl std::fmt::Debug for Files {

crates/ruff_db/src/lib.rs

@@ -48,13 +48,13 @@ mod tests {
     ///
     /// Uses an in memory filesystem and it stubs out the vendored files by default.
     #[salsa::db]
-    #[derive(Default)]
+    #[derive(Default, Clone)]
     pub(crate) struct TestDb {
         storage: salsa::Storage<Self>,
         files: Files,
         system: TestSystem,
         vendored: VendoredFileSystem,
-        events: std::sync::Arc<std::sync::Mutex<Vec<salsa::Event>>>,
+        events: Arc<std::sync::Mutex<Vec<salsa::Event>>>,
     }
 
     impl TestDb {

crates/ruff_graph/src/db.rs

@@ -16,7 +16,7 @@ static EMPTY_VENDORED: std::sync::LazyLock<VendoredFileSystem> = std::sync::Lazy
 });
 
 #[salsa::db]
-#[derive(Default)]
+#[derive(Default, Clone)]
 pub struct ModuleDb {
     storage: salsa::Storage<Self>,
     files: Files,
@@ -55,17 +55,6 @@ impl ModuleDb {
 
         Ok(db)
     }
-
-    /// Create a snapshot of the current database.
-    #[must_use]
-    pub fn snapshot(&self) -> Self {
-        Self {
-            storage: self.storage.clone(),
-            system: self.system.clone(),
-            files: self.files.snapshot(),
-            rule_selection: Arc::clone(&self.rule_selection),
-        }
-    }
 }
 
 impl Upcast<dyn SourceDb> for ModuleDb {

fuzz/fuzz_targets/red_knot_check_invalid_syntax.rs

@@ -22,12 +22,13 @@ use ruff_python_parser::{parse_unchecked, Mode};
 ///
 /// Uses an in memory filesystem and it stubs out the vendored files by default.
 #[salsa::db]
+#[derive(Clone)]
 struct TestDb {
     storage: salsa::Storage<Self>,
     files: Files,
     system: TestSystem,
     vendored: VendoredFileSystem,
-    events: std::sync::Arc<std::sync::Mutex<Vec<salsa::Event>>>,
+    events: std::sync::Arc<Mutex<Vec<salsa::Event>>>,
     rule_selection: std::sync::Arc<RuleSelection>,
 }