Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir_expand/src/ast_id_map.rs')
| -rw-r--r-- | crates/hir_expand/src/ast_id_map.rs | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/crates/hir_expand/src/ast_id_map.rs b/crates/hir_expand/src/ast_id_map.rs index 16cf299076..43c8a3db5c 100644 --- a/crates/hir_expand/src/ast_id_map.rs +++ b/crates/hir_expand/src/ast_id_map.rs @@ -8,12 +8,13 @@ use std::{ any::type_name, fmt, - hash::{Hash, Hasher}, + hash::{BuildHasher, BuildHasherDefault, Hash, Hasher}, marker::PhantomData, }; use la_arena::{Arena, Idx}; use profile::Count; +use rustc_hash::FxHasher; use syntax::{ast, match_ast, AstNode, AstPtr, SyntaxNode, SyntaxNodePtr}; /// `AstId` points to an AST node in a specific file. @@ -60,12 +61,28 @@ impl<N: AstNode> FileAstId<N> { type ErasedFileAstId = Idx<SyntaxNodePtr>; /// Maps items' `SyntaxNode`s to `ErasedFileAstId`s and back. -#[derive(Debug, PartialEq, Eq, Default)] +#[derive(Default)] pub struct AstIdMap { + /// Maps stable id to unstable ptr. arena: Arena<SyntaxNodePtr>, + /// Reverse: map ptr to id. + map: hashbrown::HashMap<Idx<SyntaxNodePtr>, (), ()>, _c: Count<Self>, } +impl fmt::Debug for AstIdMap { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("AstIdMap").field("arena", &self.arena).finish() + } +} + +impl PartialEq for AstIdMap { + fn eq(&self, other: &Self) -> bool { + self.arena == other.arena + } +} +impl Eq for AstIdMap {} + impl AstIdMap { pub(crate) fn from_source(node: &SyntaxNode) -> AstIdMap { assert!(node.parent().is_none()); @@ -89,6 +106,16 @@ impl AstIdMap { } } }); + res.map = hashbrown::HashMap::with_capacity_and_hasher(res.arena.len(), ()); + for (idx, ptr) in res.arena.iter() { + let hash = hash_ptr(ptr); + match res.map.raw_entry_mut().from_hash(hash, |idx2| *idx2 == idx) { + hashbrown::hash_map::RawEntryMut::Occupied(_) => unreachable!(), + hashbrown::hash_map::RawEntryMut::Vacant(entry) => { + entry.insert_with_hasher(hash, idx, (), |&idx| hash_ptr(&res.arena[idx])); + } + } + } res } @@ -98,8 +125,9 @@ impl AstIdMap { } fn erased_ast_id(&self, item: &SyntaxNode) -> ErasedFileAstId { let ptr = SyntaxNodePtr::new(item); - match self.arena.iter().find(|(_id, i)| **i == ptr) { - Some((it, _)) => it, + let hash = hash_ptr(&ptr); + match self.map.raw_entry().from_hash(hash, |&idx| self.arena[idx] == ptr) { + Some((&idx, &())) => idx, None => panic!( "Can't find {:?} in AstIdMap:\n{:?}", item, @@ -117,6 +145,12 @@ impl AstIdMap { } } +fn hash_ptr(ptr: &SyntaxNodePtr) -> u64 { + let mut hasher = BuildHasherDefault::<FxHasher>::default().build_hasher(); + ptr.hash(&mut hasher); + hasher.finish() +} + /// Walks the subtree in bdfs order, calling `f` for each node. What is bdfs /// order? It is a mix of breadth-first and depth first orders. Nodes for which /// `f` returns true are visited breadth-first, all the other nodes are explored |