1 files changed, 189 insertions, 0 deletions

diff --git a/crates/libanalysis/src/module_map_db.rs b/crates/libanalysis/src/module_map_db.rs
new file mode 100644
index 000000000..1ef87ab3f
--- /dev/null
+++ b/crates/libanalysis/src/module_map_db.rs
@@ -0,0 +1,189 @@
+use std::sync::Arc;
+use {
+    FileId,
+    db::{Query, Eval, QueryCtx, FileSyntax, Files},
+    module_map::resolve_submodule,
+};
+
+enum ModuleDescr {}
+impl Query for ModuleDescr {
+    const ID: u32 = 30;
+    type Params = FileId;
+    type Output = Arc<descr::ModuleDescr>;
+}
+
+enum ResolveSubmodule {}
+impl Query for ResolveSubmodule {
+    const ID: u32 = 31;
+    type Params = (FileId, descr::Submodule);
+    type Output = Arc<Vec<FileId>>;
+}
+
+enum ParentModule {}
+impl Query for ParentModule {
+    const ID: u32 = 40;
+    type Params = FileId;
+    type Output = Arc<Vec<FileId>>;
+}
+
+impl Eval for ModuleDescr {
+    fn eval(ctx: &QueryCtx, file_id: &FileId) -> Arc<descr::ModuleDescr> {
+        let file = ctx.get::<FileSyntax>(file_id);
+        Arc::new(descr::ModuleDescr::new(file.ast()))
+    }
+}
+
+impl Eval for ResolveSubmodule {
+    fn eval(ctx: &QueryCtx, &(file_id, ref submodule): &(FileId, descr::Submodule)) -> Arc<Vec<FileId>> {
+        let files = ctx.get::<Files>(&());
+        let res = resolve_submodule(file_id, &submodule.name, &files.file_resolver()).0;
+        Arc::new(res)
+    }
+}
+
+impl Eval for ParentModule {
+    fn eval(ctx: &QueryCtx, file_id: &FileId) -> Arc<Vec<FileId>> {
+        let files = ctx.get::<Files>(&());
+        let res = files.iter()
+            .map(|parent_id| (parent_id, ctx.get::<ModuleDescr>(&parent_id)))
+            .filter(|(parent_id, descr)| {
+                descr.submodules.iter()
+                    .any(|subm| {
+                        ctx.get::<ResolveSubmodule>(&(*parent_id, subm.clone()))
+                            .iter()
+                            .any(|it| it == file_id)
+                    })
+            })
+            .map(|(id, _)| id)
+            .collect();
+        Arc::new(res)
+    }
+}
+
+mod descr {
+    use libsyntax2::{
+        SmolStr,
+        ast::{self, NameOwner},
+    };
+
+    pub struct ModuleDescr {
+        pub submodules: Vec<Submodule>
+    }
+
+    impl ModuleDescr {
+        pub fn new(root: ast::Root) -> ModuleDescr {
+            let submodules = root
+                .modules()
+                .filter_map(|module| {
+                    let name = module.name()?.text();
+                    if !module.has_semi() {
+                        return None;
+                    }
+                    Some(Submodule { name })
+                }).collect();
+
+            ModuleDescr { submodules } }
+    }
+
+    #[derive(Clone, Hash)]
+    pub struct Submodule {
+        pub name: SmolStr,
+    }
+
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use im;
+    use relative_path::{RelativePath, RelativePathBuf};
+    use {
+        db::Db,
+        imp::FileResolverImp,
+        FileId, FileResolver,
+    };
+
+    #[derive(Debug)]
+    struct FileMap(im::HashMap<FileId, RelativePathBuf>);
+
+    impl FileResolver for FileMap {
+        fn file_stem(&self, file_id: FileId) -> String {
+            self.0[&file_id].file_stem().unwrap().to_string()
+        }
+        fn resolve(&self, file_id: FileId, rel: &RelativePath) -> Option<FileId> {
+            let path = self.0[&file_id].join(rel).normalize();
+            self.0.iter()
+                .filter_map(|&(id, ref p)| Some(id).filter(|_| p == &path))
+                .next()
+        }
+    }
+
+    struct Fixture {
+        next_file_id: u32,
+        fm: im::HashMap<FileId, RelativePathBuf>,
+        db: Db,
+    }
+
+    impl Fixture {
+        fn new() -> Fixture {
+            Fixture {
+                next_file_id: 1,
+                fm: im::HashMap::new(),
+                db: Db::new(),
+            }
+        }
+        fn add_file(&mut self, path: &str, text: &str) -> FileId {
+            assert!(path.starts_with("/"));
+            let file_id = FileId(self.next_file_id);
+            self.next_file_id += 1;
+            self.fm.insert(file_id, RelativePathBuf::from(&path[1..]));
+            self.db.change_file(file_id, Some(text.to_string()));
+            self.db.set_file_resolver(FileResolverImp::new(
+                Arc::new(FileMap(self.fm.clone()))
+            ));
+
+            file_id
+        }
+        fn remove_file(&mut self, file_id: FileId) {
+            self.fm.remove(&file_id);
+            self.db.change_file(file_id, None);
+            self.db.set_file_resolver(FileResolverImp::new(
+                Arc::new(FileMap(self.fm.clone()))
+            ))
+        }
+        fn change_file(&mut self, file_id: FileId, new_text: &str) {
+            self.db.change_file(file_id, Some(new_text.to_string()));
+        }
+        fn check_parent_modules(&self, file_id: FileId, expected: &[FileId]) {
+            let ctx = self.db.query_ctx();
+            let actual = ctx.get::<ParentModule>(&file_id);
+            assert_eq!(actual.as_slice(), expected);
+        }
+    }
+
+    #[test]
+    fn test_parent_module() {
+        let mut f = Fixture::new();
+        let foo = f.add_file("/foo.rs", "");
+        f.check_parent_modules(foo, &[]);
+
+        let lib = f.add_file("/lib.rs", "mod foo;");
+        f.check_parent_modules(foo, &[lib]);
+
+        f.change_file(lib, "");
+        f.check_parent_modules(foo, &[]);
+
+        f.change_file(lib, "mod foo;");
+        f.check_parent_modules(foo, &[lib]);
+
+        f.change_file(lib, "mod bar;");
+        f.check_parent_modules(foo, &[]);
+
+        f.change_file(lib, "mod foo;");
+        f.check_parent_modules(foo, &[lib]);
+
+        f.remove_file(lib);
+        f.check_parent_modules(foo, &[]);
+    }
+
+}