Allocator api feature for agb hashmap (#694)

This means hashmap can be used in stable.

agb-hashmap/Cargo.toml

@@ -6,6 +6,9 @@ license = "MPL-2.0"
 description = "A simple no_std hashmap implementation intended for use in the `agb` library"
 repository = "https://github.com/agbrs/agb"
 
+[features]
+allocator_api = []
+
 [dependencies]
 rustc-hash = { version = "1", default-features = false }
 

agb-hashmap/src/lib.rs

@@ -1,7 +1,7 @@
 //! A lot of the documentation for this module was copied straight out of the rust
 //! standard library. The implementation however is not.
 #![no_std]
-#![feature(allocator_api)]
+#![cfg_attr(feature = "allocator_api", feature(allocator_api))]
 #![deny(clippy::all)]
 #![deny(clippy::must_use_candidate)]
 #![deny(missing_docs)]
@@ -26,9 +26,25 @@
 
 extern crate alloc;
 
-use alloc::{alloc::Global, vec::Vec};
+pub(crate) use allocate::{Allocator, Global};
+
+#[cfg(not(feature = "allocator_api"))]
+mod allocate {
+    pub trait Allocator {}
+
+    #[derive(Copy, Clone)]
+    pub struct Global;
+
+    impl Allocator for Global {}
+}
+
+#[cfg(feature = "allocator_api")]
+mod allocate {
+    pub(crate) use alloc::alloc::Global;
+    pub(crate) use core::alloc::Allocator;
+}
+
 use core::{
-    alloc::Allocator,
     borrow::Borrow,
     fmt::Debug,
     hash::{BuildHasher, BuildHasherDefault, Hash},
@@ -174,12 +190,6 @@ impl<K, V> HashMap<K, V> {
     pub fn with_capacity(capacity: usize) -> Self {
         Self::with_capacity_in(capacity, Global)
     }
-
-    #[doc(hidden)]
-    #[must_use]
-    pub fn distance_histogram(&self) -> (Vec<usize>, usize) {
-        self.nodes.distance_histogram()
-    }
 }
 
 impl<K, V, ALLOCATOR: ClonableAllocator> HashMap<K, V, ALLOCATOR> {
@@ -583,7 +593,8 @@ impl<K, V, ALLOCATOR: ClonableAllocator> IntoIterator for HashMap<K, V, ALLOCATO
 }
 
 mod entries {
-    use core::{alloc::Allocator, hash::Hash};
+    use crate::allocate::Allocator;
+    use core::hash::Hash;
 
     use super::{ClonableAllocator, HashMap, HashType};
 
@@ -948,6 +959,8 @@ impl core::ops::Add<i32> for HashType {
 mod test {
     use core::{cell::RefCell, hash::Hasher};
 
+    use alloc::vec::Vec;
+
     use super::*;
 
     #[test]

agb-hashmap/src/node_storage.rs

@@ -1,12 +1,14 @@
-use core::{alloc::Allocator, borrow::Borrow, mem};
-
-use alloc::{alloc::Global, vec::Vec};
+use core::{borrow::Borrow, mem};
 
+use crate::allocate::{Allocator, Global};
 use crate::{node::Node, number_before_resize, ClonableAllocator, HashType};
 
+mod vec;
+use vec::MyVec;
+
 #[derive(Clone)]
 pub(crate) struct NodeStorage<K, V, ALLOCATOR: Allocator = Global> {
-    nodes: Vec<Node<K, V>, ALLOCATOR>,
+    nodes: MyVec<Node<K, V>, ALLOCATOR>,
     max_distance_to_initial_bucket: i32,
 
     number_of_items: usize,
@@ -17,7 +19,7 @@ impl<K, V, ALLOCATOR: ClonableAllocator> NodeStorage<K, V, ALLOCATOR> {
     pub(crate) fn with_size_in(capacity: usize, alloc: ALLOCATOR) -> Self {
         assert!(capacity.is_power_of_two(), "Capacity must be a power of 2");
 
-        let mut nodes = Vec::with_capacity_in(capacity, alloc);
+        let mut nodes = MyVec::with_capacity_in(capacity, alloc);
         for _ in 0..capacity {
             nodes.push(Node::new());
         }
@@ -202,22 +204,6 @@ impl<K, V, ALLOCATOR: ClonableAllocator> NodeStorage<K, V, ALLOCATOR> {
         self.nodes.get_unchecked_mut(at)
     }
 
-    pub(crate) fn distance_histogram(&self) -> (Vec<usize>, usize) {
-        let mut ret = Vec::new();
-
-        for node in self.nodes.iter() {
-            let distance = node.distance();
-
-            if distance >= 0 {
-                let distance = distance as usize;
-                ret.resize(ret.len().max(distance + 1), 0);
-                ret[distance] += 1;
-            }
-        }
-
-        (ret, self.max_distance_to_initial_bucket as usize)
-    }
-
     pub(crate) fn clear(&mut self) {
         self.max_distance_to_initial_bucket = 0;
         self.number_of_items = 0;

agb-hashmap/src/node_storage/vec.rs

@@ -0,0 +1,66 @@
+use core::ops::{Deref, DerefMut};
+
+use alloc::vec::Vec;
+
+use crate::{Allocator, Global};
+
+pub(crate) use inner::MyVec;
+
+#[cfg(not(feature = "allocator_api"))]
+mod inner {
+    use super::*;
+
+    #[derive(Clone)]
+    pub(crate) struct MyVec<T, A: Allocator = Global>(Vec<T>, A);
+
+    impl<T, A: Allocator> MyVec<T, A> {
+        pub(crate) fn with_capacity_in(capacity: usize, allocator: A) -> Self {
+            Self(Vec::with_capacity(capacity), allocator)
+        }
+
+        pub(crate) fn allocator(&self) -> &A {
+            &self.1
+        }
+    }
+    impl<T, A: Allocator> Deref for MyVec<T, A> {
+        type Target = Vec<T>;
+
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl<T, A: Allocator> DerefMut for MyVec<T, A> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+}
+
+#[cfg(feature = "allocator_api")]
+mod inner {
+    use super::*;
+
+    #[derive(Clone)]
+    pub(crate) struct MyVec<T, A: Allocator = Global>(Vec<T, A>);
+
+    impl<T, A: Allocator> MyVec<T, A> {
+        pub(crate) fn with_capacity_in(capacity: usize, allocator: A) -> Self {
+            Self(Vec::with_capacity_in(capacity, allocator))
+        }
+    }
+
+    impl<T, A: Allocator> Deref for MyVec<T, A> {
+        type Target = Vec<T, A>;
+
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl<T, A: Allocator> DerefMut for MyVec<T, A> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+}

agb/Cargo.toml

@@ -19,7 +19,7 @@ agb_image_converter = { version = "0.19.1", path = "../agb-image-converter" }
 agb_sound_converter = { version = "0.19.1", path = "../agb-sound-converter" }
 agb_macros = { version = "0.19.1", path = "../agb-macros" }
 agb_fixnum = { version = "0.19.1", path = "../agb-fixnum" }
-agb_hashmap = { version = "0.19.1", path = "../agb-hashmap" }
+agb_hashmap = { version = "0.19.1", path = "../agb-hashmap", features = ["allocator_api"] }
 bilge = "0.2"
 qrcodegen-no-heap = { version = "1.8", optional = true }
 portable-atomic = { version = "1.6.0", default-features = false, features = ["unsafe-assume-single-core"] }