8 files changed, 221 insertions, 100 deletions

diff --git a/Cargo.lock b/Cargo.lock
index b9b430262..98f06f53a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -844,14 +844,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "salsa"
-version = "0.1.0"
-dependencies = [
- "im 12.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parking_lot 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "salsa"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
diff --git a/crates/ra_analysis/src/db/mod.rs b/crates/ra_analysis/src/db/mod.rs
index 4eb7d922d..4b3e0fc90 100644
--- a/crates/ra_analysis/src/db/mod.rs
+++ b/crates/ra_analysis/src/db/mod.rs
@@ -1,85 +1,193 @@
-mod imp;
-
 use std::{
+    fmt,
     sync::Arc,
+    hash::{Hash, Hasher},
+    collections::HashSet,
 };
-use im;
 use salsa;
-use crate::{FileId, imp::FileResolverImp};
+use ra_syntax::File;
+use ra_editor::{LineIndex};
+use crate::{
+    symbol_index::SymbolIndex,
+    FileId, FileResolverImp
+};
 
-#[derive(Debug, Default, Clone)]
-pub(crate) struct State {
-    pub(crate) file_map: im::HashMap<FileId, Arc<String>>,
-    pub(crate) file_resolver: FileResolverImp
+#[derive(Default)]
+pub(crate) struct RootDatabase {
+    runtime: salsa::runtime::Runtime<RootDatabase>,
 }
 
-#[derive(Debug)]
-pub(crate) struct Db {
-    imp: imp::Db,
+impl fmt::Debug for RootDatabase {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.write_str("RootDatabase { ... }")
+    }
 }
 
-#[derive(Clone, Copy)]
-pub(crate) struct QueryCtx<'a> {
-    imp: &'a salsa::QueryCtx<State, imp::Data>,
+impl salsa::Database for RootDatabase {
+    fn salsa_runtime(&self) -> &salsa::runtime::Runtime<RootDatabase> {
+        &self.runtime
+    }
 }
 
-pub(crate) struct Query<T, R>(pub(crate) u16, pub(crate) fn(QueryCtx, &T) -> R);
-
-pub(crate) struct QueryRegistry {
-    imp: imp::QueryRegistry,
+salsa::database_storage! {
+    pub(crate) struct RootDatabaseStorage for RootDatabase {
+        impl FilesDatabase {
+            fn file_text() for FileTextQuery;
+            fn file_set() for FileSetQuery;
+        }
+        impl SyntaxDatabase {
+            fn file_syntax() for FileSyntaxQuery;
+            fn file_lines() for FileLinesQuery;
+            fn file_symbols() for FileSymbolsQuery;
+        }
+    }
 }
 
-impl Default for Db {
-    fn default() -> Db {
-        Db::new()
+salsa::query_group! {
+    pub(crate) trait FilesDatabase: salsa::Database {
+        fn file_text(file_id: FileId) -> Arc<String> {
+            type FileTextQuery;
+            storage input;
+        }
+        fn file_set(key: ()) -> Arc<FileSet> {
+            type FileSetQuery;
+            storage input;
+        }
     }
 }
 
-impl Db {
-    pub(crate) fn new() -> Db {
-        let reg = QueryRegistry::new();
-        Db { imp: imp::Db::new(reg.imp) }
-    }
-    pub(crate) fn state(&self) -> &State {
-        self.imp.imp.ground_data()
-    }
-    pub(crate) fn with_changes(&self, new_state: State, changed_files: &[FileId], resolver_changed: bool) -> Db {
-        Db { imp: self.imp.with_changes(new_state, changed_files, resolver_changed) }
-    }
-    pub(crate) fn make_query<F: FnOnce(QueryCtx) -> R, R>(&self, f: F) -> R {
-        let ctx = QueryCtx { imp: &self.imp.imp.query_ctx() };
-        f(ctx)
-    }
-    #[allow(unused)]
-    pub(crate) fn trace_query<F: FnOnce(QueryCtx) -> R, R>(&self, f: F) -> (R, Vec<&'static str>) {
-        let ctx = QueryCtx { imp: &self.imp.imp.query_ctx() };
-        let res = f(ctx);
-        let trace = self.imp.extract_trace(ctx.imp);
-        (res, trace)
-    }
+#[derive(Default, Debug)]
+pub(crate) struct FileSet {
+    pub(crate) files: HashSet<FileId>,
+    pub(crate) resolver: FileResolverImp,
 }
 
-impl<'a> QueryCtx<'a> {
-    pub(crate) fn get<Q: imp::EvalQuery>(&self, q: Q, params: Q::Params) -> Arc<Q::Output> {
-        q.get(self, params)
+impl PartialEq for FileSet {
+    fn eq(&self, other: &FileSet) -> bool {
+        self.files == other.files
     }
 }
 
-pub(crate) fn file_text(ctx: QueryCtx, file_id: FileId) -> Arc<String> {
-    imp::file_text(ctx, file_id)
+impl Eq for FileSet {
 }
 
-pub(crate) fn file_set(ctx: QueryCtx) -> Arc<(Vec<FileId>, FileResolverImp)> {
-    imp::file_set(ctx)
-}
-impl QueryRegistry {
-    fn new() -> QueryRegistry {
-        let mut reg = QueryRegistry { imp: imp::QueryRegistry::new() };
-        crate::queries::register_queries(&mut reg);
-        crate::module_map::register_queries(&mut reg);
-        reg
+impl Hash for FileSet {
+    fn hash<H: Hasher>(&self, hasher: &mut H) {
+        let mut files = self.files.iter().cloned().collect::<Vec<_>>();
+        files.sort();
+        files.hash(hasher);
     }
-    pub(crate) fn add<Q: imp::EvalQuery>(&mut self, q: Q, name: &'static str) {
-        self.imp.add(q, name)
+}
+
+salsa::query_group! {
+    pub(crate) trait SyntaxDatabase: FilesDatabase {
+        fn file_syntax(file_id: FileId) -> File {
+            type FileSyntaxQuery;
+        }
+        fn file_lines(file_id: FileId) -> Arc<LineIndex> {
+            type FileLinesQuery;
+        }
+        fn file_symbols(file_id: FileId) -> Arc<SymbolIndex> {
+            type FileSymbolsQuery;
+        }
     }
 }
+
+fn file_syntax(db: &impl SyntaxDatabase, file_id: FileId) -> File {
+    let text = db.file_text(file_id);
+    File::parse(&*text)
+}
+fn file_lines(db: &impl SyntaxDatabase, file_id: FileId) -> Arc<LineIndex> {
+    let text = db.file_text(file_id);
+    Arc::new(LineIndex::new(&*text))
+}
+fn file_symbols(db: &impl SyntaxDatabase, file_id: FileId) -> Arc<SymbolIndex> {
+    let syntax = db.file_syntax(file_id);
+    Arc::new(SymbolIndex::for_file(file_id, syntax))
+}
+
+// mod imp;
+
+// use std::{
+//     sync::Arc,
+// };
+// use im;
+// use salsa;
+// use {FileId, imp::FileResolverImp};
+
+// #[derive(Debug, Default, Clone)]
+// pub(crate) struct State {
+//     pub(crate) file_map: im::HashMap<FileId, Arc<String>>,
+//     pub(crate) file_resolver: FileResolverImp
+// }
+
+// #[derive(Debug)]
+// pub(crate) struct Db {
+//     imp: imp::Db,
+// }
+
+// #[derive(Clone, Copy)]
+// pub(crate) struct QueryCtx<'a> {
+//     imp: &'a salsa::QueryCtx<State, imp::Data>,
+// }
+
+// pub(crate) struct Query<T, R>(pub(crate) u16, pub(crate) fn(QueryCtx, &T) -> R);
+
+// pub(crate) struct QueryRegistry {
+//     imp: imp::QueryRegistry,
+// }
+
+// impl Default for Db {
+//     fn default() -> Db {
+//         Db::new()
+//     }
+// }
+
+// impl Db {
+//     pub(crate) fn new() -> Db {
+//         let reg = QueryRegistry::new();
+//         Db { imp: imp::Db::new(reg.imp) }
+//     }
+//     pub(crate) fn state(&self) -> &State {
+//         self.imp.imp.ground_data()
+//     }
+//     pub(crate) fn with_changes(&self, new_state: State, changed_files: &[FileId], resolver_changed: bool) -> Db {
+//         Db { imp: self.imp.with_changes(new_state, changed_files, resolver_changed) }
+//     }
+//     pub(crate) fn make_query<F: FnOnce(QueryCtx) -> R, R>(&self, f: F) -> R {
+//         let ctx = QueryCtx { imp: &self.imp.imp.query_ctx() };
+//         f(ctx)
+//     }
+//     #[allow(unused)]
+//     pub(crate) fn trace_query<F: FnOnce(QueryCtx) -> R, R>(&self, f: F) -> (R, Vec<&'static str>) {
+//         let ctx = QueryCtx { imp: &self.imp.imp.query_ctx() };
+//         let res = f(ctx);
+//         let trace = self.imp.extract_trace(ctx.imp);
+//         (res, trace)
+//     }
+// }
+
+// impl<'a> QueryCtx<'a> {
+//     pub(crate) fn get<Q: imp::EvalQuery>(&self, q: Q, params: Q::Params) -> Arc<Q::Output> {
+//         q.get(self, params)
+//     }
+// }
+
+// pub(crate) fn file_text(ctx: QueryCtx, file_id: FileId) -> Arc<String> {
+//     imp::file_text(ctx, file_id)
+// }
+
+// pub(crate) fn file_set(ctx: QueryCtx) -> Arc<(Vec<FileId>, FileResolverImp)> {
+//     imp::file_set(ctx)
+// }
+// impl QueryRegistry {
+//     fn new() -> QueryRegistry {
+//         let mut reg = QueryRegistry { imp: imp::QueryRegistry::new() };
+//         ::queries::register_queries(&mut reg);
+//         ::module_map::register_queries(&mut reg);
+//         reg
+//     }
+//     pub(crate) fn add<Q: imp::EvalQuery>(&mut self, q: Q, name: &'static str) {
+//         self.imp.add(q, name)
+//     }
+// }
diff --git a/crates/ra_analysis/src/lib.rs b/crates/ra_analysis/src/lib.rs
index 86c66236c..4c1ccdeaf 100644
--- a/crates/ra_analysis/src/lib.rs
+++ b/crates/ra_analysis/src/lib.rs
@@ -14,12 +14,12 @@ extern crate salsa;
 extern crate rustc_hash;
 
 mod symbol_index;
-mod module_map;
+// mod module_map;
 mod imp;
 mod job;
 mod roots;
 mod db;
-mod queries;
+// mod queries;
 mod descriptors;
 
 use std::{
diff --git a/crates/ra_analysis/src/roots.rs b/crates/ra_analysis/src/roots.rs
index 208acc4c2..7a7d1169e 100644
--- a/crates/ra_analysis/src/roots.rs
+++ b/crates/ra_analysis/src/roots.rs
@@ -1,11 +1,13 @@
 use std::{
+    collections::{HashMap, HashSet},
     sync::Arc,
     panic,
 };
+use parking_lot::RwLock;
 
 use once_cell::sync::OnceCell;
 use rayon::prelude::*;
-use rustc_hash::FxHashMap;
+use salsa::Database;
 use ra_editor::LineIndex;
 use ra_syntax::File;
 
@@ -14,7 +16,7 @@ use crate::{
     imp::FileResolverImp,
     symbol_index::SymbolIndex,
     descriptors::{ModuleDescriptor, ModuleTreeDescriptor},
-    db::Db,
+    db::{self, FilesDatabase, SyntaxDatabase}
 };
 
 pub(crate) trait SourceRoot {
@@ -25,9 +27,9 @@ pub(crate) trait SourceRoot {
     fn symbols(&self, acc: &mut Vec<Arc<SymbolIndex>>);
 }
 
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone)]
 pub(crate) struct WritableSourceRoot {
-    db: Db,
+    db: Arc<RwLock<db::RootDatabase>>,
 }
 
 impl WritableSourceRoot {
@@ -36,51 +38,61 @@ impl WritableSourceRoot {
         changes: &mut dyn Iterator<Item=(FileId, Option<String>)>,
         file_resolver: Option<FileResolverImp>,
     ) -> WritableSourceRoot {
-        let resolver_changed = file_resolver.is_some();
-        let mut changed_files = Vec::new();
-        let mut new_state = self.db.state().clone();
-
+        let db = self.db.write();
+        let mut changed = HashSet::new();
+        let mut removed = HashSet::new();
         for (file_id, text) in changes {
-            changed_files.push(file_id);
             match text {
-                Some(text) => {
-                    new_state.file_map.insert(file_id, Arc::new(text));
-                },
                 None => {
-                    new_state.file_map.remove(&file_id);
+                    removed.insert(file_id);
+                }
+                Some(text) => {
+                    db.query(db::FileTextQuery)
+                        .set(file_id, Arc::new(text));
+                    changed.insert(file_id);
                 }
             }
         }
-        if let Some(file_resolver) = file_resolver {
-            new_state.file_resolver = file_resolver
-        }
-        WritableSourceRoot {
-            db: self.db.with_changes(new_state, &changed_files, resolver_changed)
+        if let Some(resolver) = file_resolver {
+            let mut files: HashSet<FileId> = db.file_set(())
+                .files
+                .clone();
+            for file_id in removed {
+                files.remove(&file_id);
+            }
+            files.extend(changed);
+            db.query(db::FileSetQuery)
+                .set((), Arc::new(db::FileSet { files, resolver }))
         }
+        // TODO: reconcile sasla's API with our needs
+        // https://github.com/salsa-rs/salsa/issues/12
+        self.clone()
     }
 }
 
 impl SourceRoot for WritableSourceRoot {
     fn module_tree(&self) -> Arc<ModuleTreeDescriptor> {
-        self.db.make_query(crate::module_map::module_tree)
+        unimplemented!()
+        //self.db.make_query(::module_map::module_tree)
     }
 
     fn contains(&self, file_id: FileId) -> bool {
-        self.db.state().file_map.contains_key(&file_id)
+        self.db.read().file_set(()).files.contains(&file_id)
     }
     fn lines(&self, file_id: FileId) -> Arc<LineIndex> {
-        self.db.make_query(|ctx| crate::queries::file_lines(ctx, file_id))
+        self.db.read().file_lines(file_id)
     }
     fn syntax(&self, file_id: FileId) -> File {
-        self.db.make_query(|ctx| crate::queries::file_syntax(ctx, file_id))
+        self.db.read().file_syntax(file_id)
     }
     fn symbols<'a>(&'a self, acc: &mut Vec<Arc<SymbolIndex>>) {
-        self.db.make_query(|ctx| {
-            let file_set = crate::queries::file_set(ctx);
-            let syms = file_set.0.iter()
-                .map(|file_id| crate::queries::file_symbols(ctx, *file_id));
-            acc.extend(syms);
-        });
+        let db = self.db.read();
+        let symbols =  db.file_set(());
+        let symbols = symbols
+            .files
+            .iter()
+            .map(|&file_id| db.file_symbols(file_id));
+        acc.extend(symbols);
     }
 }
 
diff --git a/crates/ra_analysis/src/symbol_index.rs b/crates/ra_analysis/src/symbol_index.rs
index e5d83d365..54672fde4 100644
--- a/crates/ra_analysis/src/symbol_index.rs
+++ b/crates/ra_analysis/src/symbol_index.rs
@@ -17,6 +17,15 @@ pub(crate) struct SymbolIndex {
     map: fst::Map,
 }
 
+impl PartialEq for SymbolIndex {
+    fn eq(&self, other: &SymbolIndex) -> bool {
+        self.symbols == other.symbols
+    }
+}
+
+impl Eq for SymbolIndex {
+}
+
 impl Hash for SymbolIndex {
     fn hash<H: Hasher>(&self, hasher: &mut H) {
         self.symbols.hash(hasher)
diff --git a/crates/ra_editor/src/line_index.rs b/crates/ra_editor/src/line_index.rs
index 6ccfdbd83..95d64b8a8 100644
--- a/crates/ra_editor/src/line_index.rs
+++ b/crates/ra_editor/src/line_index.rs
@@ -1,7 +1,7 @@
 use superslice::Ext;
 use crate::TextUnit;
 
-#[derive(Clone, Debug, Hash)]
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct LineIndex {
     newlines: Vec<TextUnit>,
 }
diff --git a/crates/ra_editor/src/symbols.rs b/crates/ra_editor/src/symbols.rs
index 6211ed547..d9e4b2df7 100644
--- a/crates/ra_editor/src/symbols.rs
+++ b/crates/ra_editor/src/symbols.rs
@@ -17,7 +17,7 @@ pub struct StructureNode {
     pub kind: SyntaxKind,
 }
 
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct FileSymbol {
     pub name: SmolStr,
     pub node_range: TextRange,
diff --git a/crates/ra_syntax/src/lib.rs b/crates/ra_syntax/src/lib.rs
index 5bb54aba1..7eba5ee61 100644
--- a/crates/ra_syntax/src/lib.rs
+++ b/crates/ra_syntax/src/lib.rs
@@ -59,7 +59,7 @@ use crate::{
     yellow::{GreenNode},
 };
 
-#[derive(Clone, Debug, Hash)]
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct File {
     root: SyntaxNode
 }