85 lines
2.0 KiB
Rust
85 lines
2.0 KiB
Rust
// Copyright 2019-2025 Parity Technologies (UK) Ltd.
|
|
// This file is dual-licensed as Apache-2.0 or GPL-3.0.
|
|
// see LICENSE for license details.
|
|
|
|
use alloc::vec::Vec;
|
|
use hashbrown::HashMap;
|
|
|
|
/// A minimal ordered map to let one search for
|
|
/// things by key or get the values in insert order.
|
|
#[derive(Debug, Clone)]
|
|
pub struct OrderedMap<K, V> {
|
|
values: Vec<V>,
|
|
map: HashMap<K, usize>,
|
|
}
|
|
|
|
impl<K, V> Default for OrderedMap<K, V> {
|
|
fn default() -> Self {
|
|
Self {
|
|
values: Default::default(),
|
|
map: Default::default(),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<K, V> OrderedMap<K, V>
|
|
where
|
|
K: PartialEq + Eq + core::hash::Hash,
|
|
{
|
|
/// Create a new, empty [`OrderedMap`].
|
|
pub fn new() -> Self {
|
|
Self::default()
|
|
}
|
|
|
|
/// Number of entries in the map.
|
|
#[allow(dead_code)]
|
|
pub fn len(&self) -> usize {
|
|
self.values.len()
|
|
}
|
|
|
|
/// Is the map empty.
|
|
#[allow(dead_code)]
|
|
pub fn is_empty(&self) -> bool {
|
|
self.values.is_empty()
|
|
}
|
|
|
|
/// Push/insert an item to the end of the map.
|
|
pub fn push_insert(&mut self, key: K, value: V) {
|
|
let idx = self.values.len();
|
|
self.values.push(value);
|
|
self.map.insert(key, idx);
|
|
}
|
|
|
|
/// Get an item by its key.
|
|
pub fn get_by_key<Q>(&self, key: &Q) -> Option<&V>
|
|
where
|
|
K: alloc::borrow::Borrow<Q>,
|
|
Q: core::hash::Hash + Eq + ?Sized,
|
|
{
|
|
self.map.get(key).and_then(|&v| self.values.get(v))
|
|
}
|
|
|
|
/// Get an item by its index.
|
|
pub fn get_by_index(&self, i: usize) -> Option<&V> {
|
|
self.values.get(i)
|
|
}
|
|
|
|
/// Access the underlying values.
|
|
pub fn values(&self) -> &[V] {
|
|
&self.values
|
|
}
|
|
}
|
|
|
|
impl<K, V> FromIterator<(K, V)> for OrderedMap<K, V>
|
|
where
|
|
K: PartialEq + Eq + core::hash::Hash,
|
|
{
|
|
fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self {
|
|
let mut map = OrderedMap::new();
|
|
for (k, v) in iter {
|
|
map.push_insert(k, v)
|
|
}
|
|
map
|
|
}
|
|
}
|