//! This module has a map which can be iterated in a deterministic order. See the [`IndexedMap`].
-use crate::prelude::HashMap;
-use alloc::collections::{BTreeMap, btree_map};
+use crate::prelude::{HashMap, hash_map};
+use alloc::vec::Vec;
+use alloc::slice::Iter;
+use core::hash::Hash;
use core::cmp::Ord;
-use core::ops::RangeBounds;
+use core::ops::{Bound, RangeBounds};
/// A map which can be iterated in a deterministic order.
///
/// actually backed by a [`HashMap`], with some additional tracking to ensure we can iterate over
/// keys in the order defined by [`Ord`].
///
+/// This is not exported to bindings users as bindings provide alternate accessors rather than exposing maps directly.
+///
/// [`BTreeMap`]: alloc::collections::BTreeMap
-#[derive(Clone, PartialEq, Eq)]
-pub struct IndexedMap<K: Ord, V> {
- map: BTreeMap<K, V>,
+#[derive(Clone, Debug, Eq)]
+pub struct IndexedMap<K: Hash + Ord, V> {
+ map: HashMap<K, V>,
+ keys: Vec<K>,
}
-impl<K: Ord, V> IndexedMap<K, V> {
+impl<K: Clone + Hash + Ord, V> IndexedMap<K, V> {
/// Constructs a new, empty map
pub fn new() -> Self {
Self {
- map: BTreeMap::new(),
+ map: HashMap::new(),
+ keys: Vec::new(),
+ }
+ }
+
+ /// Constructs a new, empty map with the given capacity pre-allocated
+ pub fn with_capacity(capacity: usize) -> Self {
+ Self {
+ map: HashMap::with_capacity(capacity),
+ keys: Vec::with_capacity(capacity),
}
}
/// Removes the element with the given `key`, returning it, if one exists.
pub fn remove(&mut self, key: &K) -> Option<V> {
- self.map.remove(key)
+ let ret = self.map.remove(key);
+ if let Some(_) = ret {
+ let idx = self.keys.iter().position(|k| k == key).expect("map and keys must be consistent");
+ self.keys.remove(idx);
+ }
+ ret
}
/// Inserts the given `key`/`value` pair into the map, returning the element that was
/// previously stored at the given `key`, if one exists.
pub fn insert(&mut self, key: K, value: V) -> Option<V> {
- self.map.insert(key, value)
+ let ret = self.map.insert(key.clone(), value);
+ if ret.is_none() {
+ self.keys.push(key);
+ }
+ ret
}
/// Returns an [`Entry`] for the given `key` in the map, allowing access to the value.
pub fn entry(&mut self, key: K) -> Entry<'_, K, V> {
- match self.map.entry(key) {
- btree_map::Entry::Vacant(entry) => {
+ match self.map.entry(key.clone()) {
+ hash_map::Entry::Vacant(entry) => {
Entry::Vacant(VacantEntry {
- underlying_entry: entry
+ underlying_entry: entry,
+ key,
+ keys: &mut self.keys,
})
},
- btree_map::Entry::Occupied(entry) => {
+ hash_map::Entry::Occupied(entry) => {
Entry::Occupied(OccupiedEntry {
- underlying_entry: entry
+ underlying_entry: entry,
+ keys: &mut self.keys,
})
}
}
}
/// Returns an iterator which iterates over the `key`/`value` pairs in a given range.
- pub fn range<R: RangeBounds<K>>(&self, range: R) -> btree_map::Range<K, V> {
- self.map.range(range)
+ pub fn range<R: RangeBounds<K>>(&mut self, range: R) -> Range<K, V> {
+ self.keys.sort_unstable();
+ let start = match range.start_bound() {
+ Bound::Unbounded => 0,
+ Bound::Included(key) => self.keys.binary_search(key).unwrap_or_else(|index| index),
+ Bound::Excluded(key) => self.keys.binary_search(key).and_then(|index| Ok(index + 1)).unwrap_or_else(|index| index),
+ };
+ let end = match range.end_bound() {
+ Bound::Unbounded => self.keys.len(),
+ Bound::Included(key) => self.keys.binary_search(key).and_then(|index| Ok(index + 1)).unwrap_or_else(|index| index),
+ Bound::Excluded(key) => self.keys.binary_search(key).unwrap_or_else(|index| index),
+ };
+
+ Range {
+ inner_range: self.keys[start..end].iter(),
+ map: &self.map,
+ }
}
/// Returns the number of `key`/`value` pairs in the map
}
}
+impl<K: Hash + Ord + PartialEq, V: PartialEq> PartialEq for IndexedMap<K, V> {
+ fn eq(&self, other: &Self) -> bool {
+ self.map == other.map
+ }
+}
+
+/// An iterator over a range of values in an [`IndexedMap`]
+///
+/// This is not exported to bindings users as bindings provide alternate accessors rather than exposing maps directly.
+pub struct Range<'a, K: Hash + Ord, V> {
+ inner_range: Iter<'a, K>,
+ map: &'a HashMap<K, V>,
+}
+impl<'a, K: Hash + Ord, V: 'a> Iterator for Range<'a, K, V> {
+ type Item = (&'a K, &'a V);
+ fn next(&mut self) -> Option<(&'a K, &'a V)> {
+ self.inner_range.next().map(|k| {
+ (k, self.map.get(k).expect("map and keys must be consistent"))
+ })
+ }
+}
+
/// An [`Entry`] for a key which currently has no value
-pub struct VacantEntry<'a, K: Ord, V> {
- underlying_entry: btree_map::VacantEntry<'a, K, V>,
+///
+/// This is not exported to bindings users as bindings provide alternate accessors rather than exposing maps directly.
+pub struct VacantEntry<'a, K: Hash + Ord, V> {
+ #[cfg(feature = "hashbrown")]
+ underlying_entry: hash_map::VacantEntry<'a, K, V, hash_map::DefaultHashBuilder>,
+ #[cfg(not(feature = "hashbrown"))]
+ underlying_entry: hash_map::VacantEntry<'a, K, V>,
+ key: K,
+ keys: &'a mut Vec<K>,
}
/// An [`Entry`] for an existing key-value pair
-pub struct OccupiedEntry<'a, K: Ord, V> {
- underlying_entry: btree_map::OccupiedEntry<'a, K, V>,
+///
+/// This is not exported to bindings users as bindings provide alternate accessors rather than exposing maps directly.
+pub struct OccupiedEntry<'a, K: Hash + Ord, V> {
+ #[cfg(feature = "hashbrown")]
+ underlying_entry: hash_map::OccupiedEntry<'a, K, V, hash_map::DefaultHashBuilder>,
+ #[cfg(not(feature = "hashbrown"))]
+ underlying_entry: hash_map::OccupiedEntry<'a, K, V>,
+ keys: &'a mut Vec<K>,
}
/// A mutable reference to a position in the map. This can be used to reference, add, or update the
/// value at a fixed key.
-pub enum Entry<'a, K: Ord, V> {
+///
+/// This is not exported to bindings users as bindings provide alternate accessors rather than exposing maps directly.
+pub enum Entry<'a, K: Hash + Ord, V> {
/// A mutable reference to a position within the map where there is no value.
Vacant(VacantEntry<'a, K, V>),
/// A mutable reference to a position within the map where there is currently a value.
Occupied(OccupiedEntry<'a, K, V>),
}
-impl<'a, K: Ord, V> VacantEntry<'a, K, V> {
+impl<'a, K: Hash + Ord, V> VacantEntry<'a, K, V> {
/// Insert a value into the position described by this entry.
pub fn insert(self, value: V) -> &'a mut V {
+ self.keys.push(self.key);
self.underlying_entry.insert(value)
}
}
-impl<'a, K: Ord, V> OccupiedEntry<'a, K, V> {
+impl<'a, K: Hash + Ord, V> OccupiedEntry<'a, K, V> {
/// Remove the value at the position described by this entry.
pub fn remove_entry(self) -> (K, V) {
- self.underlying_entry.remove_entry()
+ let res = self.underlying_entry.remove_entry();
+ let idx = self.keys.iter().position(|k| k == &res.0).expect("map and keys must be consistent");
+ self.keys.remove(idx);
+ res
}
/// Get a reference to the value at the position described by this entry.