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+use std::borrow::Borrow;
+use std::collections::hash_map::{IntoKeys, IntoValues};
+use std::collections::{hash_map, HashMap};
+use std::fmt::{self, Debug};
+use std::hash::{BuildHasher, Hash};
+use std::iter::FromIterator;
+use std::ops::{Deref, DerefMut, Index};
+use std::panic::UnwindSafe;
+
+#[cfg(feature = "serde")]
+use serde::{
+ de::{Deserialize, Deserializer},
+ ser::{Serialize, Serializer},
+};
+
+use crate::RandomState;
+
+/// A [`HashMap`](std::collections::HashMap) using [`RandomState`](crate::RandomState) to hash the items.
+/// (Requires the `std` feature to be enabled.)
+#[derive(Clone)]
+pub struct AHashMap<K, V, S = crate::RandomState>(HashMap<K, V, S>);
+
+impl<K, V> From<HashMap<K, V, crate::RandomState>> for AHashMap<K, V> {
+ fn from(item: HashMap<K, V, crate::RandomState>) -> Self {
+ AHashMap(item)
+ }
+}
+
+impl<K, V, const N: usize> From<[(K, V); N]> for AHashMap<K, V>
+where
+ K: Eq + Hash,
+{
+ /// # Examples
+ ///
+ /// ```
+ /// use ahash::AHashMap;
+ ///
+ /// let map1 = AHashMap::from([(1, 2), (3, 4)]);
+ /// let map2: AHashMap<_, _> = [(1, 2), (3, 4)].into();
+ /// assert_eq!(map1, map2);
+ /// ```
+ fn from(arr: [(K, V); N]) -> Self {
+ Self::from_iter(arr)
+ }
+}
+
+impl<K, V> Into<HashMap<K, V, crate::RandomState>> for AHashMap<K, V> {
+ fn into(self) -> HashMap<K, V, crate::RandomState> {
+ self.0
+ }
+}
+
+impl<K, V> AHashMap<K, V, RandomState> {
+ /// This crates a hashmap using [RandomState::new] which obtains its keys from [RandomSource].
+ /// See the documentation in [RandomSource] for notes about key strength.
+ pub fn new() -> Self {
+ AHashMap(HashMap::with_hasher(RandomState::new()))
+ }
+
+ /// This crates a hashmap with the specified capacity using [RandomState::new].
+ /// See the documentation in [RandomSource] for notes about key strength.
+ pub fn with_capacity(capacity: usize) -> Self {
+ AHashMap(HashMap::with_capacity_and_hasher(capacity, RandomState::new()))
+ }
+}
+
+impl<K, V, S> AHashMap<K, V, S>
+where
+ S: BuildHasher,
+{
+ pub fn with_hasher(hash_builder: S) -> Self {
+ AHashMap(HashMap::with_hasher(hash_builder))
+ }
+
+ pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> Self {
+ AHashMap(HashMap::with_capacity_and_hasher(capacity, hash_builder))
+ }
+}
+
+impl<K, V, S> AHashMap<K, V, S>
+where
+ K: Hash + Eq,
+ S: BuildHasher,
+{
+ /// Returns a reference to the value corresponding to the key.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.get(&1), Some(&"a"));
+ /// assert_eq!(map.get(&2), None);
+ /// ```
+ #[inline]
+ pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ self.0.get(k)
+ }
+
+ /// Returns the key-value pair corresponding to the supplied key.
+ ///
+ /// The supplied key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.get_key_value(&1), Some((&1, &"a")));
+ /// assert_eq!(map.get_key_value(&2), None);
+ /// ```
+ #[inline]
+ pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ self.0.get_key_value(k)
+ }
+
+ /// Returns a mutable reference to the value corresponding to the key.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// if let Some(x) = map.get_mut(&1) {
+ /// *x = "b";
+ /// }
+ /// assert_eq!(map[&1], "b");
+ /// ```
+ #[inline]
+ pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ self.0.get_mut(k)
+ }
+
+ /// Inserts a key-value pair into the map.
+ ///
+ /// If the map did not have this key present, [`None`] is returned.
+ ///
+ /// If the map did have this key present, the value is updated, and the old
+ /// value is returned. The key is not updated, though; this matters for
+ /// types that can be `==` without being identical. See the [module-level
+ /// documentation] for more.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// assert_eq!(map.insert(37, "a"), None);
+ /// assert_eq!(map.is_empty(), false);
+ ///
+ /// map.insert(37, "b");
+ /// assert_eq!(map.insert(37, "c"), Some("b"));
+ /// assert_eq!(map[&37], "c");
+ /// ```
+ #[inline]
+ pub fn insert(&mut self, k: K, v: V) -> Option<V> {
+ self.0.insert(k, v)
+ }
+
+ /// Creates a consuming iterator visiting all the keys in arbitrary order.
+ /// The map cannot be used after calling this.
+ /// The iterator element type is `K`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let map = HashMap::from([
+ /// ("a", 1),
+ /// ("b", 2),
+ /// ("c", 3),
+ /// ]);
+ ///
+ /// let mut vec: Vec<&str> = map.into_keys().collect();
+ /// // The `IntoKeys` iterator produces keys in arbitrary order, so the
+ /// // keys must be sorted to test them against a sorted array.
+ /// vec.sort_unstable();
+ /// assert_eq!(vec, ["a", "b", "c"]);
+ /// ```
+ ///
+ /// # Performance
+ ///
+ /// In the current implementation, iterating over keys takes O(capacity) time
+ /// instead of O(len) because it internally visits empty buckets too.
+ #[inline]
+ pub fn into_keys(self) -> IntoKeys<K, V> {
+ self.0.into_keys()
+ }
+
+ /// Creates a consuming iterator visiting all the values in arbitrary order.
+ /// The map cannot be used after calling this.
+ /// The iterator element type is `V`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let map = HashMap::from([
+ /// ("a", 1),
+ /// ("b", 2),
+ /// ("c", 3),
+ /// ]);
+ ///
+ /// let mut vec: Vec<i32> = map.into_values().collect();
+ /// // The `IntoValues` iterator produces values in arbitrary order, so
+ /// // the values must be sorted to test them against a sorted array.
+ /// vec.sort_unstable();
+ /// assert_eq!(vec, [1, 2, 3]);
+ /// ```
+ ///
+ /// # Performance
+ ///
+ /// In the current implementation, iterating over values takes O(capacity) time
+ /// instead of O(len) because it internally visits empty buckets too.
+ #[inline]
+ pub fn into_values(self) -> IntoValues<K, V> {
+ self.0.into_values()
+ }
+
+ /// Removes a key from the map, returning the value at the key if the key
+ /// was previously in the map.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.remove(&1), Some("a"));
+ /// assert_eq!(map.remove(&1), None);
+ /// ```
+ #[inline]
+ pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ self.0.remove(k)
+ }
+}
+
+impl<K, V, S> Deref for AHashMap<K, V, S> {
+ type Target = HashMap<K, V, S>;
+ fn deref(&self) -> &Self::Target {
+ &self.0
+ }
+}
+
+impl<K, V, S> DerefMut for AHashMap<K, V, S> {
+ fn deref_mut(&mut self) -> &mut Self::Target {
+ &mut self.0
+ }
+}
+
+impl<K, V, S> UnwindSafe for AHashMap<K, V, S>
+where
+ K: UnwindSafe,
+ V: UnwindSafe,
+{
+}
+
+impl<K, V, S> PartialEq for AHashMap<K, V, S>
+where
+ K: Eq + Hash,
+ V: PartialEq,
+ S: BuildHasher,
+{
+ fn eq(&self, other: &AHashMap<K, V, S>) -> bool {
+ self.0.eq(&other.0)
+ }
+}
+
+impl<K, V, S> Eq for AHashMap<K, V, S>
+where
+ K: Eq + Hash,
+ V: Eq,
+ S: BuildHasher,
+{
+}
+
+impl<K, Q: ?Sized, V, S> Index<&Q> for AHashMap<K, V, S>
+where
+ K: Eq + Hash + Borrow<Q>,
+ Q: Eq + Hash,
+ S: BuildHasher,
+{
+ type Output = V;
+
+ /// Returns a reference to the value corresponding to the supplied key.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the key is not present in the `HashMap`.
+ #[inline]
+ fn index(&self, key: &Q) -> &V {
+ self.0.index(key)
+ }
+}
+
+impl<K, V, S> Debug for AHashMap<K, V, S>
+where
+ K: Debug,
+ V: Debug,
+ S: BuildHasher,
+{
+ fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+ self.0.fmt(fmt)
+ }
+}
+
+impl<K, V> FromIterator<(K, V)> for AHashMap<K, V, RandomState>
+where
+ K: Eq + Hash,
+{
+ /// This crates a hashmap from the provided iterator using [RandomState::new].
+ /// See the documentation in [RandomSource] for notes about key strength.
+ fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self {
+ let mut inner = HashMap::with_hasher(RandomState::new());
+ inner.extend(iter);
+ AHashMap(inner)
+ }
+}
+
+impl<'a, K, V, S> IntoIterator for &'a AHashMap<K, V, S> {
+ type Item = (&'a K, &'a V);
+ type IntoIter = hash_map::Iter<'a, K, V>;
+ fn into_iter(self) -> Self::IntoIter {
+ (&self.0).iter()
+ }
+}
+
+impl<'a, K, V, S> IntoIterator for &'a mut AHashMap<K, V, S> {
+ type Item = (&'a K, &'a mut V);
+ type IntoIter = hash_map::IterMut<'a, K, V>;
+ fn into_iter(self) -> Self::IntoIter {
+ (&mut self.0).iter_mut()
+ }
+}
+
+impl<K, V, S> IntoIterator for AHashMap<K, V, S> {
+ type Item = (K, V);
+ type IntoIter = hash_map::IntoIter<K, V>;
+ fn into_iter(self) -> Self::IntoIter {
+ self.0.into_iter()
+ }
+}
+
+impl<K, V, S> Extend<(K, V)> for AHashMap<K, V, S>
+where
+ K: Eq + Hash,
+ S: BuildHasher,
+{
+ #[inline]
+ fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T) {
+ self.0.extend(iter)
+ }
+}
+
+impl<'a, K, V, S> Extend<(&'a K, &'a V)> for AHashMap<K, V, S>
+where
+ K: Eq + Hash + Copy + 'a,
+ V: Copy + 'a,
+ S: BuildHasher,
+{
+ #[inline]
+ fn extend<T: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: T) {
+ self.0.extend(iter)
+ }
+}
+
+/// NOTE: For safety this trait impl is only available available if either of the flags `runtime-rng` (on by default) or
+/// `compile-time-rng` are enabled. This is to prevent weakly keyed maps from being accidentally created. Instead one of
+/// constructors for [RandomState] must be used.
+#[cfg(any(feature = "compile-time-rng", feature = "runtime-rng", feature = "no-rng"))]
+impl<K, V> Default for AHashMap<K, V, RandomState> {
+ #[inline]
+ fn default() -> AHashMap<K, V, RandomState> {
+ AHashMap(HashMap::default())
+ }
+}
+
+#[cfg(feature = "serde")]
+impl<K, V> Serialize for AHashMap<K, V>
+where
+ K: Serialize + Eq + Hash,
+ V: Serialize,
+{
+ fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+ self.deref().serialize(serializer)
+ }
+}
+
+#[cfg(feature = "serde")]
+impl<'de, K, V> Deserialize<'de> for AHashMap<K, V>
+where
+ K: Deserialize<'de> + Eq + Hash,
+ V: Deserialize<'de>,
+{
+ fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+ let hash_map = HashMap::deserialize(deserializer);
+ hash_map.map(|hash_map| Self(hash_map))
+ }
+
+ fn deserialize_in_place<D: Deserializer<'de>>(deserializer: D, place: &mut Self) -> Result<(), D::Error> {
+ use serde::de::{MapAccess, Visitor};
+
+ struct MapInPlaceVisitor<'a, K: 'a, V: 'a>(&'a mut AHashMap<K, V>);
+
+ impl<'a, 'de, K, V> Visitor<'de> for MapInPlaceVisitor<'a, K, V>
+ where
+ K: Deserialize<'de> + Eq + Hash,
+ V: Deserialize<'de>,
+ {
+ type Value = ();
+
+ fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ formatter.write_str("a map")
+ }
+
+ fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+ where
+ A: MapAccess<'de>,
+ {
+ self.0.clear();
+ self.0.reserve(map.size_hint().unwrap_or(0).min(4096));
+
+ while let Some((key, value)) = map.next_entry()? {
+ self.0.insert(key, value);
+ }
+
+ Ok(())
+ }
+ }
+
+ deserializer.deserialize_map(MapInPlaceVisitor(place))
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use super::*;
+ #[test]
+ fn test_borrow() {
+ let mut map: AHashMap<String, String> = AHashMap::new();
+ map.insert("foo".to_string(), "Bar".to_string());
+ map.insert("Bar".to_string(), map.get("foo").unwrap().to_owned());
+ }
+
+ #[cfg(feature = "serde")]
+ #[test]
+ fn test_serde() {
+ let mut map = AHashMap::new();
+ map.insert("for".to_string(), 0);
+ map.insert("bar".to_string(), 1);
+ let mut serialization = serde_json::to_string(&map).unwrap();
+ let mut deserialization: AHashMap<String, u64> = serde_json::from_str(&serialization).unwrap();
+ assert_eq!(deserialization, map);
+
+ map.insert("baz".to_string(), 2);
+ serialization = serde_json::to_string(&map).unwrap();
+ let mut deserializer = serde_json::Deserializer::from_str(&serialization);
+ AHashMap::deserialize_in_place(&mut deserializer, &mut deserialization).unwrap();
+ assert_eq!(deserialization, map);
+ }
+}
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