Use rustc-hash everywhere when enabled. (#711)

Use it internally for all hashmaps and hashsets, and explicitly enable
it in `rustdoc-types` too.

.github/workflows/ci.yml

@@ -94,6 +94,12 @@ jobs:
       - name: test with rayon
         run: cargo test --features rayon
 
+      - name: compile with rayon and rustc-hash
+        run: cargo test --no-run --features rayon,rustc-hash
+
+      - name: test with rayon and rustc-hash
+        run: cargo test --features rayon,rustc-hash
+
   publish:
     name: Publish to crates.io
     runs-on: ubuntu-latest

Cargo.toml

@@ -37,7 +37,7 @@ default = []
 # definitely increases the memory usage
 rayon = ["dep:rayon"]
 # Use rustc-hash::{FxHashMap, FxHashSet} internally for improved performance
-rustc-hash = ["dep:rustc-hash"]
+rustc-hash = ["dep:rustc-hash", "rustdoc-types/rustc-hash"]
 
 [[bench]]
 name = "indexed_crate"

src/adapter/edges.rs

@@ -1,7 +1,8 @@
+use std::{num::NonZeroUsize, rc::Rc};
+
 use rustdoc_types::{
     GenericBound::TraitBound, GenericParamDefKind, Id, ItemEnum, VariantKind, WherePredicate,
 };
-use std::{num::NonZeroUsize, rc::Rc};
 use trustfall::provider::{
     resolve_neighbors_with, AsVertex, ContextIterator, ContextOutcomeIterator, ResolveEdgeInfo,
     VertexIterator,

src/adapter/enum_variant.rs

@@ -1,11 +1,12 @@
-use rustdoc_types::{Item, ItemEnum, Variant};
 use std::borrow::Cow;
 use std::cell::OnceCell;
 use std::fmt::{self, Debug};
 use std::num::ParseIntError;
 use std::rc::Rc;
 use std::str::FromStr;
 
+use rustdoc_types::{Item, ItemEnum, Variant};
+
 #[non_exhaustive]
 #[derive(Debug, Clone)]
 pub struct EnumVariant<'a> {

src/adapter/optimizations/impl_lookup.rs

@@ -1,5 +1,9 @@
+#[cfg(not(feature = "rustc-hash"))]
 use std::collections::HashMap;
 
+#[cfg(feature = "rustc-hash")]
+use rustc_hash::FxHashMap as HashMap;
+
 use rustdoc_types::{Id, Item};
 use trustfall::{
     provider::{

src/adapter/optimizations/method_lookup.rs

@@ -1,4 +1,10 @@
-use std::collections::{BTreeSet, HashMap};
+use std::collections::BTreeSet;
+
+#[cfg(not(feature = "rustc-hash"))]
+use std::collections::HashMap;
+
+#[cfg(feature = "rustc-hash")]
+use rustc_hash::FxHashMap as HashMap;
 
 use rustdoc_types::{Id, Impl, Item, ItemEnum, Type};
 use trustfall::{

src/indexed_crate.rs

@@ -1,8 +1,10 @@
-use std::{
-    borrow::Borrow,
-    collections::{hash_map::Entry, HashMap, HashSet},
-    sync::Arc,
-};
+use std::{borrow::Borrow, collections::hash_map::Entry, sync::Arc};
+
+#[cfg(not(feature = "rustc-hash"))]
+use std::collections::{HashMap, HashSet};
+
+#[cfg(feature = "rustc-hash")]
+use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
 
 #[cfg(feature = "rayon")]
 use rayon::prelude::*;
@@ -270,7 +272,7 @@ impl<K: std::cmp::Eq + std::hash::Hash, V> Extend<(K, V)> for MapList<K, V> {
 impl<K: std::cmp::Eq + std::hash::Hash, V> MapList<K, V> {
     #[inline]
     pub fn new() -> Self {
-        Self(HashMap::new())
+        Self(HashMap::default())
     }
 
     #[inline]
@@ -786,7 +788,7 @@ fn new_trait(manual_trait_item: &ManualTraitItem, id: Id, crate_id: u32) -> Item
         span: None,
         visibility: rustdoc_types::Visibility::Public,
         docs: None,
-        links: HashMap::new(),
+        links: HashMap::default(),
         attrs: Vec::new(),
         deprecation: None,
         inner: rustdoc_types::ItemEnum::Trait(rustdoc_types::Trait {

src/visibility_tracker.rs

@@ -1,8 +1,9 @@
-#[cfg(feature = "rustc-hash")]
-use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
 #[cfg(not(feature = "rustc-hash"))]
 use std::collections::{HashMap, HashSet};
 
+#[cfg(feature = "rustc-hash")]
+use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
+
 use rustdoc_types::{Crate, GenericArgs, Id, Item, ItemEnum, TypeAlias, Visibility};
 
 #[cfg(feature = "rayon")]