use parking_lot::Mutex; use std::{ hash::Hash, sync::Arc, }; use rustc_hash::FxHashMap; use crate::{ syntax_ptr::SyntaxPtr, }; /// There are two principle ways to refer to things: /// - by their locatinon (module in foo/bar/baz.rs at line 42) /// - by their numeric id (module `ModuleId(42)`) /// /// The first one is more powerful (you can actually find the thing in question /// by id), but the second one is so much more compact. /// /// `Loc2IdMap` allows us to have a cake an eat it as well: by maintaining a /// bidirectional mapping between positional and numeric ids, we can use compact /// representation wich still allows us to get the actual item #[derive(Debug)] pub(crate) struct Loc2IdMap where ID: NumericId, L: Clone + Eq + Hash, { loc2id: FxHashMap, id2loc: FxHashMap, } impl Default for Loc2IdMap where ID: NumericId, L: Clone + Eq + Hash, { fn default() -> Self { Loc2IdMap { loc2id: FxHashMap::default(), id2loc: FxHashMap::default(), } } } impl Loc2IdMap where ID: NumericId, L: Clone + Eq + Hash, { pub fn loc2id(&mut self, loc: &L) -> ID { match self.loc2id.get(loc) { Some(id) => return id.clone(), None => (), } let id = self.loc2id.len(); assert!(id < u32::max_value() as usize); let id = ID::from_u32(id as u32); self.loc2id.insert(loc.clone(), id.clone()); self.id2loc.insert(id.clone(), loc.clone()); id } pub fn id2loc(&self, id: ID) -> L { self.id2loc[&id].clone() } } pub(crate) trait NumericId: Clone + Eq + Hash { fn from_u32(id: u32) -> Self; fn to_u32(self) -> u32; } #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] pub(crate) struct FnId(u32); impl NumericId for FnId { fn from_u32(id: u32) -> FnId { FnId(id) } fn to_u32(self) -> u32 { self.0 } } pub(crate) trait IdDatabase: salsa::Database { fn id_maps(&self) -> &IdMaps; } #[derive(Debug, Default, Clone)] pub(crate) struct IdMaps { inner: Arc, } impl IdMaps { pub(crate) fn fn_id(&self, ptr: SyntaxPtr) -> FnId { self.inner.fns.lock().loc2id(&ptr) } pub(crate) fn fn_ptr(&self, fn_id: FnId) -> SyntaxPtr { self.inner.fns.lock().id2loc(fn_id) } } #[derive(Debug, Default)] struct IdMapsInner { fns: Mutex>, }