rust/src/librustc_data_structures/stable_map.rs
Shivani Bhardwaj 800bd3a11c data_structures: Add deterministic FxHashMap and FxHashSet wrappers
StableMap
A wrapper for FxHashMap that allows to insert, remove, get and get_mut
but no iteration support.

StableSet
A wrapper for FxHashSet that allows to insert, remove, get and create a
sorted vector from a hashset but no iteration support.
2019-09-28 14:35:20 +05:30

100 lines
2.0 KiB
Rust

pub use rustc_hash::FxHashMap;
use std::borrow::Borrow;
use std::collections::hash_map::Entry;
use std::fmt;
use std::hash::Hash;
/// A deterministic wrapper around FxHashMap that does not provide iteration support.
///
/// It supports insert, remove, get and get_mut functions from FxHashMap.
/// It also allows to convert hashmap to a sorted vector with the method `into_sorted_vector()`.
#[derive(Clone)]
pub struct StableMap<K, V> {
base: FxHashMap<K, V>,
}
impl<K, V> Default for StableMap<K, V>
where
K: Eq + Hash,
{
fn default() -> StableMap<K, V> {
StableMap::new()
}
}
impl<K, V> fmt::Debug for StableMap<K, V>
where
K: Eq + Hash + fmt::Debug,
V: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?}", self.base)
}
}
impl<K, V> PartialEq for StableMap<K, V>
where
K: Eq + Hash,
V: PartialEq,
{
fn eq(&self, other: &StableMap<K, V>) -> bool {
self.base == other.base
}
}
impl<K, V> Eq for StableMap<K, V>
where
K: Eq + Hash,
V: Eq,
{}
impl<K, V> StableMap<K, V>
where
K: Eq + Hash,
{
pub fn new() -> StableMap<K, V> {
StableMap { base: FxHashMap::default() }
}
pub fn into_sorted_vector(self) -> Vec<(K, V)>
where
K: Ord + Copy,
{
let mut vector = self.base.into_iter().collect::<Vec<_>>();
vector.sort_unstable_by_key(|pair| pair.0);
vector
}
pub fn entry(&mut self, k: K) -> Entry<'_, K, V> {
self.base.entry(k)
}
pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.get(k)
}
pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.get_mut(k)
}
pub fn insert(&mut self, k: K, v: V) -> Option<V> {
self.base.insert(k, v)
}
pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.remove(k)
}
}