Jeremy Soller
937 lines
28 KiB
Rust
937 lines
28 KiB
Rust
// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! A HashMap wrapper that holds key-value pairs in insertion order.
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//!
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//! # Examples
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//!
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//! ```
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//! use linked_hash_map::LinkedHashMap;
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//!
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//! let mut map = LinkedHashMap::new();
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//! map.insert(2, 20);
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//! map.insert(1, 10);
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//! map.insert(3, 30);
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//! assert_eq!(map[&1], 10);
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//! assert_eq!(map[&2], 20);
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//! assert_eq!(map[&3], 30);
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//!
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//! let items: Vec<(i32, i32)> = map.iter().map(|t| (*t.0, *t.1)).collect();
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//! assert_eq!(items, [(2, 20), (1, 10), (3, 30)]);
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//! ```
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#![forbid(missing_docs)]
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#![cfg_attr(feature = "nightly", feature(hashmap_public_hasher))]
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#![cfg_attr(all(feature = "nightly", test), feature(test))]
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use std::borrow::Borrow;
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use std::cmp::Ordering;
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use std::collections::hash_map::{self, HashMap};
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use std::fmt;
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use std::hash::{BuildHasher, Hash, Hasher};
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use std::iter;
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use std::marker;
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use std::mem;
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use std::ops::{Index, IndexMut};
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use std::ptr;
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struct KeyRef<K> { k: *const K }
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struct LinkedHashMapEntry<K, V> {
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next: *mut LinkedHashMapEntry<K, V>,
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prev: *mut LinkedHashMapEntry<K, V>,
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key: K,
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value: V,
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}
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/// A linked hash map.
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pub struct LinkedHashMap<K, V, S = hash_map::RandomState> {
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map: HashMap<KeyRef<K>, Box<LinkedHashMapEntry<K, V>>, S>,
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head: *mut LinkedHashMapEntry<K, V>,
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free: *mut LinkedHashMapEntry<K, V>,
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}
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impl<K: Hash> Hash for KeyRef<K> {
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fn hash<H: Hasher>(&self, state: &mut H) {
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unsafe { (*self.k).hash(state) }
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}
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}
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impl<K: PartialEq> PartialEq for KeyRef<K> {
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fn eq(&self, other: &Self) -> bool {
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unsafe{ (*self.k).eq(&*other.k) }
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}
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}
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impl<K: Eq> Eq for KeyRef<K> {}
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// This type exists only to support borrowing `KeyRef`s, which cannot be borrowed to `Q` directly
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// due to conflicting implementations of `Borrow`. The layout of `&Qey<Q>` must be identical to
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// `&Q` in order to support transmuting in the `Qey::from_ref` method.
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#[derive(Hash, PartialEq, Eq)]
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struct Qey<Q: ?Sized>(Q);
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impl<Q: ?Sized> Qey<Q> {
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fn from_ref(q: &Q) -> &Self { unsafe { mem::transmute(q) } }
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}
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impl<K, Q: ?Sized> Borrow<Qey<Q>> for KeyRef<K> where K: Borrow<Q> {
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fn borrow(&self) -> &Qey<Q> {
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Qey::from_ref(unsafe { (*self.k).borrow() })
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}
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}
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impl<K, V> LinkedHashMapEntry<K, V> {
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fn new(k: K, v: V) -> Self {
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LinkedHashMapEntry {
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key: k,
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value: v,
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next: ptr::null_mut(),
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prev: ptr::null_mut(),
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}
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}
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}
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unsafe fn drop_empty_entry_box<K, V>(the_box: *mut LinkedHashMapEntry<K, V>) {
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// Prevent compiler from trying to drop the un-initialized key and values in the node.
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let LinkedHashMapEntry { key, value, .. } = *Box::from_raw(the_box);
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mem::forget(key);
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mem::forget(value);
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}
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impl<K: Hash + Eq, V> LinkedHashMap<K, V> {
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/// Creates a linked hash map.
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pub fn new() -> Self { Self::with_map(HashMap::new()) }
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/// Creates an empty linked hash map with the given initial capacity.
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pub fn with_capacity(capacity: usize) -> Self {
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Self::with_map(HashMap::with_capacity(capacity))
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}
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}
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impl<K, V, S> LinkedHashMap<K, V, S> {
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fn clear_free_list(&mut self) {
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unsafe {
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let mut free = self.free;
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while ! free.is_null() {
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let next_free = (*free).next;
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drop_empty_entry_box(free);
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free = next_free;
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}
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self.free = ptr::null_mut();
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}
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}
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}
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impl<K: Hash + Eq, V, S: BuildHasher> LinkedHashMap<K, V, S> {
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fn with_map(map: HashMap<KeyRef<K>, Box<LinkedHashMapEntry<K, V>>, S>) -> Self {
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LinkedHashMap {
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map: map,
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head: ptr::null_mut(),
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free: ptr::null_mut(),
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}
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}
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/// Creates an empty linked hash map with the given initial hash state.
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pub fn with_hash_state(hash_state: S) -> Self {
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Self::with_map(HashMap::with_hasher(hash_state))
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}
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/// Creates an empty linked hash map with the given initial capacity and hash state.
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pub fn with_capacity_and_hash_state(capacity: usize, hash_state: S) -> Self {
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Self::with_map(HashMap::with_capacity_and_hasher(capacity, hash_state))
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}
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/// Reserves capacity for at least `additional` more elements to be inserted into the map. The
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/// map may reserve more space to avoid frequent allocations.
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///
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/// # Panics
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///
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/// Panics if the new allocation size overflows `usize.`
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pub fn reserve(&mut self, additional: usize) { self.map.reserve(additional); }
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/// Shrinks the capacity of the map as much as possible. It will drop down as much as possible
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/// while maintaining the internal rules and possibly leaving some space in accordance with the
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/// resize policy.
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pub fn shrink_to_fit(&mut self) {
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self.map.shrink_to_fit();
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self.clear_free_list();
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}
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/// Inserts a key-value pair into the map. If the key already existed, the old value is
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/// returned.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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///
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/// map.insert(1, "a");
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/// map.insert(2, "b");
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/// assert_eq!(map[&1], "a");
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/// assert_eq!(map[&2], "b");
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/// ```
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pub fn insert(&mut self, k: K, v: V) -> Option<V> {
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if self.head.is_null() {
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// allocate the guard node if not present
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unsafe {
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self.head = Box::into_raw(Box::new(mem::uninitialized()));
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(*self.head).next = self.head;
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(*self.head).prev = self.head;
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}
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}
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let (node_ptr, node_opt, old_val) = match self.map.get_mut(&KeyRef{k: &k}) {
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Some(node) => {
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let old_val = mem::replace(&mut node.value, v);
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let node_ptr: *mut LinkedHashMapEntry<K, V> = &mut **node;
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(node_ptr, None, Some(old_val))
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}
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None => {
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let mut node = if self.free.is_null() {
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Box::new(LinkedHashMapEntry::new(k, v))
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} else {
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// use a recycled box
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unsafe {
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let free = self.free;
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self.free = (*free).next;
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ptr::write(free, LinkedHashMapEntry::new(k, v));
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Box::from_raw(free)
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}
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};
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let node_ptr: *mut LinkedHashMapEntry<K, V> = &mut *node;
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(node_ptr, Some(node), None)
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}
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};
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match node_opt {
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None => {
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// Existing node, just update LRU position
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self.detach(node_ptr);
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self.attach(node_ptr);
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}
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Some(node) => {
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let keyref = unsafe { &(*node_ptr).key };
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self.map.insert(KeyRef{k: keyref}, node);
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self.attach(node_ptr);
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}
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}
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old_val
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}
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/// Checks if the map contains the given key.
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pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool where K: Borrow<Q>, Q: Eq + Hash {
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self.map.contains_key(Qey::from_ref(k))
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}
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/// Returns the value corresponding to the key in the map.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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///
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/// map.insert(1, "a");
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/// map.insert(2, "b");
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/// map.insert(2, "c");
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/// map.insert(3, "d");
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///
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/// assert_eq!(map.get(&1), Some(&"a"));
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/// assert_eq!(map.get(&2), Some(&"c"));
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/// ```
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pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V> where K: Borrow<Q>, Q: Eq + Hash {
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self.map.get(Qey::from_ref(k)).map(|e| &e.value)
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}
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/// Returns the mutable reference corresponding to the key in the map.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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///
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/// map.insert(1, "a");
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/// map.insert(2, "b");
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///
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/// *map.get_mut(&1).unwrap() = "c";
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/// assert_eq!(map.get(&1), Some(&"c"));
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/// ```
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pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V> where K: Borrow<Q>, Q: Eq + Hash {
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self.map.get_mut(Qey::from_ref(k)).map(|e| &mut e.value)
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}
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/// Returns the value corresponding to the key in the map.
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///
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/// If value is found, it is moved to the end of the list.
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/// This operation can be used in implemenation of LRU cache.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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///
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/// map.insert(1, "a");
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/// map.insert(2, "b");
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/// map.insert(3, "d");
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///
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/// assert_eq!(map.get_refresh(&2), Some(&mut "b"));
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///
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/// assert_eq!((&2, &"b"), map.iter().rev().next().unwrap());
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/// ```
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pub fn get_refresh<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V> where K: Borrow<Q>, Q: Eq + Hash {
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let (value, node_ptr_opt) = match self.map.get_mut(Qey::from_ref(k)) {
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None => (None, None),
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Some(node) => {
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let node_ptr: *mut LinkedHashMapEntry<K, V> = &mut **node;
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(Some(unsafe { &mut(*node_ptr).value }), Some(node_ptr))
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}
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};
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if let Some(node_ptr) = node_ptr_opt {
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self.detach(node_ptr);
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self.attach(node_ptr);
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}
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return value;
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}
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/// Removes and returns the value corresponding to the key from the map.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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///
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/// map.insert(2, "a");
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///
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/// assert_eq!(map.remove(&1), None);
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/// assert_eq!(map.remove(&2), Some("a"));
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/// assert_eq!(map.remove(&2), None);
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/// assert_eq!(map.len(), 0);
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/// ```
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pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V> where K: Borrow<Q>, Q: Eq + Hash {
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let removed = self.map.remove(Qey::from_ref(k));
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removed.map(|mut node| {
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let node_ptr: *mut LinkedHashMapEntry<K,V> = &mut *node;
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self.detach(node_ptr);
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unsafe {
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// add to free list
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(*node_ptr).next = self.free;
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self.free = node_ptr;
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// forget the box but drop the key and return the value
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mem::forget(node);
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drop(ptr::read(&(*node_ptr).key));
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ptr::read(&(*node_ptr).value)
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}
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})
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}
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/// Returns the maximum number of key-value pairs the map can hold without reallocating.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map: LinkedHashMap<i32, &str> = LinkedHashMap::new();
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/// let capacity = map.capacity();
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/// ```
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pub fn capacity(&self) -> usize {
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self.map.capacity()
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}
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/// Removes the first entry.
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///
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/// Can be used in implementation of LRU cache.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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/// map.insert(1, 10);
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/// map.insert(2, 20);
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/// map.pop_front();
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/// assert_eq!(map.get(&1), None);
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/// assert_eq!(map.get(&2), Some(&20));
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/// ```
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#[inline]
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pub fn pop_front(&mut self) -> Option<(K, V)> {
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if self.len() > 0 {
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let lru = unsafe { (*self.head).prev };
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self.detach(lru);
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return self.map
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.remove(&KeyRef{k: unsafe { &(*lru).key }})
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.map(|e| { let e = *e; (e.key, e.value) })
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}
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None
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}
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/// Gets the first entry.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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/// map.insert(1, 10);
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/// map.insert(2, 20);
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/// assert_eq!(map.front(), Some((&1, &10)));
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/// ```
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#[inline]
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pub fn front(&self) -> Option<(&K, &V)> {
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if self.len() > 0 {
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let lru = unsafe { (*self.head).prev };
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return self.map.get(&KeyRef{k: unsafe { &(*lru).key }})
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.map(|e| (&e.key, &e.value))
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}
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None
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}
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/// Removes the last entry.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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/// map.insert(1, 10);
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/// map.insert(2, 20);
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/// map.pop_back();
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/// assert_eq!(map.get(&1), Some(&10));
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/// assert_eq!(map.get(&2), None);
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/// ```
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#[inline]
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pub fn pop_back(&mut self) -> Option<(K, V)> {
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if self.len() > 0 {
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let mru = unsafe { (*self.head).next };
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self.detach(mru);
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return self.map
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.remove(&KeyRef{k: unsafe { &(*mru).key }})
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.map(|e| { let e = *e; (e.key, e.value) })
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}
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None
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}
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/// Gets the last entry.
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///
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/// # Examples
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///
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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/// let mut map = LinkedHashMap::new();
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/// map.insert(1, 10);
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/// map.insert(2, 20);
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/// assert_eq!(map.back(), Some((&2, &20)));
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/// ```
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#[inline]
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pub fn back(&mut self) -> Option<(&K, &V)> {
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if self.len() > 0 {
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let mru = unsafe { (*self.head).next };
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return self.map.get(&KeyRef{k: unsafe { &(*mru).key }})
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.map(|e| (&e.key, &e.value))
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}
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None
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}
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/// Returns the number of key-value pairs in the map.
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pub fn len(&self) -> usize { self.map.len() }
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/// Returns whether the map is currently empty.
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pub fn is_empty(&self) -> bool { self.len() == 0 }
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/// Clears the map of all key-value pairs.
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pub fn clear(&mut self) {
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self.map.clear();
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// update the guard node if present
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if ! self.head.is_null() {
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unsafe {
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(*self.head).prev = self.head;
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(*self.head).next = self.head;
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}
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}
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}
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/// Returns a double-ended iterator visiting all key-value pairs in order of insertion.
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/// Iterator element type is `(&'a K, &'a V)`
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///
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/// # Examples
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/// ```
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/// use linked_hash_map::LinkedHashMap;
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///
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/// let mut map = LinkedHashMap::new();
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/// map.insert("a", 10);
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/// map.insert("c", 30);
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/// map.insert("b", 20);
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///
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/// let mut iter = map.iter();
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/// assert_eq!((&"a", &10), iter.next().unwrap());
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/// assert_eq!((&"c", &30), iter.next().unwrap());
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/// assert_eq!((&"b", &20), iter.next().unwrap());
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/// assert_eq!(None, iter.next());
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/// ```
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pub fn iter(&self) -> Iter<K, V> {
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let head = if ! self.head.is_null() {
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unsafe { (*self.head).prev }
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} else {
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ptr::null_mut()
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};
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Iter {
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head: head,
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tail: self.head,
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remaining: self.len(),
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marker: marker::PhantomData,
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}
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}
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/// Returns a double-ended iterator visiting all key-value pairs in order of insertion.
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/// Iterator element type is `(&'a K, &'a mut V)`
|
|
/// # Examples
|
|
/// ```
|
|
/// use linked_hash_map::LinkedHashMap;
|
|
///
|
|
/// let mut map = LinkedHashMap::new();
|
|
/// map.insert("a", 10);
|
|
/// map.insert("c", 30);
|
|
/// map.insert("b", 20);
|
|
///
|
|
/// {
|
|
/// let mut iter = map.iter_mut();
|
|
/// let mut entry = iter.next().unwrap();
|
|
/// assert_eq!(&"a", entry.0);
|
|
/// *entry.1 = 17;
|
|
/// }
|
|
///
|
|
/// assert_eq!(&17, map.get(&"a").unwrap());
|
|
/// ```
|
|
pub fn iter_mut(&mut self) -> IterMut<K, V> {
|
|
let head = if ! self.head.is_null() {
|
|
unsafe { (*self.head).prev }
|
|
} else {
|
|
ptr::null_mut()
|
|
};
|
|
IterMut {
|
|
head: head,
|
|
tail: self.head,
|
|
remaining: self.len(),
|
|
marker: marker::PhantomData,
|
|
}
|
|
}
|
|
|
|
/// Returns a double-ended iterator visiting all key in order of insertion.
|
|
///
|
|
/// # Examples
|
|
/// ```
|
|
/// use linked_hash_map::LinkedHashMap;
|
|
///
|
|
/// let mut map = LinkedHashMap::new();
|
|
/// map.insert('a', 10);
|
|
/// map.insert('c', 30);
|
|
/// map.insert('b', 20);
|
|
///
|
|
/// let mut keys = map.keys();
|
|
/// assert_eq!(&'a', keys.next().unwrap());
|
|
/// assert_eq!(&'c', keys.next().unwrap());
|
|
/// assert_eq!(&'b', keys.next().unwrap());
|
|
/// assert_eq!(None, keys.next());
|
|
/// ```
|
|
pub fn keys<'a>(&'a self) -> Keys<'a, K, V> {
|
|
fn first<A, B>((a, _): (A, B)) -> A { a }
|
|
let first: fn((&'a K, &'a V)) -> &'a K = first; // coerce to fn ptr
|
|
|
|
Keys { inner: self.iter().map(first) }
|
|
}
|
|
|
|
/// Returns a double-ended iterator visiting all values in order of insertion.
|
|
///
|
|
/// # Examples
|
|
/// ```
|
|
/// use linked_hash_map::LinkedHashMap;
|
|
///
|
|
/// let mut map = LinkedHashMap::new();
|
|
/// map.insert('a', 10);
|
|
/// map.insert('c', 30);
|
|
/// map.insert('b', 20);
|
|
///
|
|
/// let mut values = map.values();
|
|
/// assert_eq!(&10, values.next().unwrap());
|
|
/// assert_eq!(&30, values.next().unwrap());
|
|
/// assert_eq!(&20, values.next().unwrap());
|
|
/// assert_eq!(None, values.next());
|
|
/// ```
|
|
pub fn values<'a>(&'a self) -> Values<'a, K, V> {
|
|
fn second<A, B>((_, b): (A, B)) -> B { b }
|
|
let second: fn((&'a K, &'a V)) -> &'a V = second; // coerce to fn ptr
|
|
|
|
Values { inner: self.iter().map(second) }
|
|
}
|
|
}
|
|
|
|
impl<'a, K, V, S, Q: ?Sized> Index<&'a Q> for LinkedHashMap<K, V, S>
|
|
where K: Hash + Eq + Borrow<Q>, S: BuildHasher, Q: Eq + Hash
|
|
{
|
|
type Output = V;
|
|
|
|
fn index(&self, index: &'a Q) -> &V {
|
|
self.get(index).expect("no entry found for key")
|
|
}
|
|
}
|
|
|
|
impl<'a, K, V, S, Q: ?Sized> IndexMut<&'a Q> for LinkedHashMap<K, V, S>
|
|
where K: Hash + Eq + Borrow<Q>, S: BuildHasher, Q: Eq + Hash
|
|
{
|
|
fn index_mut(&mut self, index: &'a Q) -> &mut V {
|
|
self.get_mut(index).expect("no entry found for key")
|
|
}
|
|
}
|
|
|
|
impl<K: Hash + Eq, V, S: BuildHasher> LinkedHashMap<K, V, S> {
|
|
#[inline]
|
|
fn detach(&mut self, node: *mut LinkedHashMapEntry<K, V>) {
|
|
unsafe {
|
|
(*(*node).prev).next = (*node).next;
|
|
(*(*node).next).prev = (*node).prev;
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn attach(&mut self, node: *mut LinkedHashMapEntry<K, V>) {
|
|
unsafe {
|
|
(*node).next = (*self.head).next;
|
|
(*node).prev = self.head;
|
|
(*self.head).next = node;
|
|
(*(*node).next).prev = node;
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(not(feature = "nightly"))]
|
|
impl<K: Hash + Eq + Clone, V: Clone> Clone for LinkedHashMap<K, V> {
|
|
fn clone(&self) -> Self {
|
|
self.iter().map(|(k, v)| (k.clone(), v.clone())).collect()
|
|
}
|
|
}
|
|
|
|
#[cfg(feature = "nightly")]
|
|
impl<K: Hash + Eq + Clone, V: Clone, S: BuildHasher + Clone> Clone for LinkedHashMap<K, V, S> {
|
|
fn clone(&self) -> Self {
|
|
let mut map = Self::with_hash_state(self.map.hasher().clone());
|
|
map.extend(self.iter().map(|(k, v)| (k.clone(), v.clone())));
|
|
map
|
|
}
|
|
}
|
|
|
|
impl<K: Hash + Eq, V, S: BuildHasher + Default> Default for LinkedHashMap<K, V, S> {
|
|
fn default() -> Self { LinkedHashMap::with_hash_state(Default::default()) }
|
|
}
|
|
|
|
impl<K: Hash + Eq, V, S: BuildHasher> Extend<(K, V)> for LinkedHashMap<K, V, S> {
|
|
fn extend<T: IntoIterator<Item=(K, V)>>(&mut self, iter: T) {
|
|
for (k, v) in iter {
|
|
self.insert(k, v);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, K, V, S> Extend<(&'a K, &'a V)> for LinkedHashMap<K, V, S>
|
|
where K: 'a + Hash + Eq + Copy, V: 'a + Copy, S: BuildHasher,
|
|
{
|
|
fn extend<I: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: I) {
|
|
for (&k, &v) in iter {
|
|
self.insert(k, v);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<K: Hash + Eq, V, S: BuildHasher + Default> iter::FromIterator<(K, V)> for LinkedHashMap<K, V, S> {
|
|
fn from_iter<I: IntoIterator<Item=(K, V)>>(iter: I) -> Self {
|
|
let iter = iter.into_iter();
|
|
let mut map = Self::with_capacity_and_hash_state(iter.size_hint().0, Default::default());
|
|
map.extend(iter);
|
|
map
|
|
}
|
|
}
|
|
|
|
impl<A: fmt::Debug + Hash + Eq, B: fmt::Debug, S: BuildHasher> fmt::Debug for LinkedHashMap<A, B, S> {
|
|
/// Returns a string that lists the key-value pairs in insertion order.
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_map().entries(self).finish()
|
|
}
|
|
}
|
|
|
|
impl<K: Hash + Eq, V: PartialEq, S: BuildHasher> PartialEq for LinkedHashMap<K, V, S> {
|
|
fn eq(&self, other: &Self) -> bool {
|
|
self.len() == other.len() && self.iter().eq(other)
|
|
}
|
|
|
|
fn ne(&self, other: &Self) -> bool {
|
|
self.len() != other.len() || self.iter().ne(other)
|
|
}
|
|
}
|
|
|
|
impl<K: Hash + Eq, V: Eq, S: BuildHasher> Eq for LinkedHashMap<K, V, S> {}
|
|
|
|
impl<K: Hash + Eq + PartialOrd, V: PartialOrd, S: BuildHasher> PartialOrd for LinkedHashMap<K, V, S> {
|
|
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
|
|
self.iter().partial_cmp(other)
|
|
}
|
|
|
|
fn lt(&self, other: &Self) -> bool {
|
|
self.iter().lt(other)
|
|
}
|
|
|
|
fn le(&self, other: &Self) -> bool {
|
|
self.iter().le(other)
|
|
}
|
|
|
|
fn ge(&self, other: &Self) -> bool {
|
|
self.iter().ge(other)
|
|
}
|
|
|
|
fn gt(&self, other: &Self) -> bool {
|
|
self.iter().gt(other)
|
|
}
|
|
}
|
|
|
|
impl<K: Hash + Eq + Ord, V: Ord, S: BuildHasher> Ord for LinkedHashMap<K, V, S> {
|
|
fn cmp(&self, other: &Self) -> Ordering {
|
|
self.iter().cmp(other)
|
|
}
|
|
}
|
|
|
|
impl<K: Hash + Eq, V: Hash, S: BuildHasher> Hash for LinkedHashMap<K, V, S> {
|
|
fn hash<H: Hasher>(&self, h: &mut H) { for e in self.iter() { e.hash(h); } }
|
|
}
|
|
|
|
unsafe impl<K: Send, V: Send, S: Send> Send for LinkedHashMap<K, V, S> {}
|
|
|
|
unsafe impl<K: Sync, V: Sync, S: Sync> Sync for LinkedHashMap<K, V, S> {}
|
|
|
|
impl<K, V, S> Drop for LinkedHashMap<K, V, S> {
|
|
fn drop(&mut self) {
|
|
unsafe {
|
|
if ! self.head.is_null() {
|
|
drop_empty_entry_box(self.head);
|
|
}
|
|
self.clear_free_list();
|
|
}
|
|
}
|
|
}
|
|
|
|
/// An insertion-order iterator over a `LinkedHashMap`'s entries, with immutable references to the
|
|
/// values.
|
|
pub struct Iter<'a, K: 'a, V: 'a> {
|
|
head: *const LinkedHashMapEntry<K, V>,
|
|
tail: *const LinkedHashMapEntry<K, V>,
|
|
remaining: usize,
|
|
marker: marker::PhantomData<(&'a K, &'a V)>,
|
|
}
|
|
|
|
/// An insertion-order iterator over a `LinkedHashMap`'s entries, with mutable references to the
|
|
/// values.
|
|
pub struct IterMut<'a, K: 'a, V: 'a> {
|
|
head: *mut LinkedHashMapEntry<K, V>,
|
|
tail: *mut LinkedHashMapEntry<K, V>,
|
|
remaining: usize,
|
|
marker: marker::PhantomData<(&'a K, &'a mut V)>,
|
|
}
|
|
|
|
unsafe impl<'a, K, V> Send for Iter<'a, K, V> where K: Send, V: Send {}
|
|
|
|
unsafe impl<'a, K, V> Send for IterMut<'a, K, V> where K: Send, V: Send {}
|
|
|
|
unsafe impl<'a, K, V> Sync for Iter<'a, K, V> where K: Sync, V: Sync {}
|
|
|
|
unsafe impl<'a, K, V> Sync for IterMut<'a, K, V> where K: Sync, V: Sync {}
|
|
|
|
impl<'a, K, V> Clone for Iter<'a, K, V> {
|
|
fn clone(&self) -> Self { Iter { ..*self } }
|
|
}
|
|
|
|
impl<'a, K, V> Iterator for Iter<'a, K, V> {
|
|
type Item = (&'a K, &'a V);
|
|
|
|
fn next(&mut self) -> Option<(&'a K, &'a V)> {
|
|
if self.head == self.tail {
|
|
None
|
|
} else {
|
|
self.remaining -= 1;
|
|
unsafe {
|
|
let r = Some((&(*self.head).key, &(*self.head).value));
|
|
self.head = (*self.head).prev;
|
|
r
|
|
}
|
|
}
|
|
}
|
|
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
(self.remaining, Some(self.remaining))
|
|
}
|
|
}
|
|
|
|
impl<'a, K, V> Iterator for IterMut<'a, K, V> {
|
|
type Item = (&'a K, &'a mut V);
|
|
|
|
fn next(&mut self) -> Option<(&'a K, &'a mut V)> {
|
|
if self.head == self.tail {
|
|
None
|
|
} else {
|
|
self.remaining -= 1;
|
|
unsafe {
|
|
let r = Some((&(*self.head).key, &mut (*self.head).value));
|
|
self.head = (*self.head).prev;
|
|
r
|
|
}
|
|
}
|
|
}
|
|
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
(self.remaining, Some(self.remaining))
|
|
}
|
|
}
|
|
|
|
impl<'a, K, V> DoubleEndedIterator for Iter<'a, K, V> {
|
|
fn next_back(&mut self) -> Option<(&'a K, &'a V)> {
|
|
if self.head == self.tail {
|
|
None
|
|
} else {
|
|
self.remaining -= 1;
|
|
unsafe {
|
|
self.tail = (*self.tail).next;
|
|
let r = Some((&(*self.tail).key, &(*self.tail).value));
|
|
r
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, K, V> DoubleEndedIterator for IterMut<'a, K, V> {
|
|
fn next_back(&mut self) -> Option<(&'a K, &'a mut V)> {
|
|
if self.head == self.tail {
|
|
None
|
|
} else {
|
|
self.remaining -= 1;
|
|
unsafe {
|
|
self.tail = (*self.tail).next;
|
|
let r = Some((&(*self.tail).key, &mut (*self.tail).value));
|
|
r
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, K, V> ExactSizeIterator for Iter<'a, K, V> {
|
|
fn len(&self) -> usize { self.remaining }
|
|
}
|
|
|
|
impl<'a, K, V> ExactSizeIterator for IterMut<'a, K, V> {
|
|
fn len(&self) -> usize { self.remaining }
|
|
}
|
|
|
|
/// An insertion-order iterator over a `LinkedHashMap`'s keys.
|
|
pub struct Keys<'a, K: 'a, V: 'a> {
|
|
inner: iter::Map<Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a K>
|
|
}
|
|
|
|
impl<'a, K, V> Clone for Keys<'a, K, V> {
|
|
fn clone(&self) -> Self { Keys { inner: self.inner.clone() } }
|
|
}
|
|
|
|
impl<'a, K, V> Iterator for Keys<'a, K, V> {
|
|
type Item = &'a K;
|
|
|
|
#[inline] fn next(&mut self) -> Option<(&'a K)> { self.inner.next() }
|
|
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
|
|
}
|
|
|
|
impl<'a, K, V> DoubleEndedIterator for Keys<'a, K, V> {
|
|
#[inline] fn next_back(&mut self) -> Option<(&'a K)> { self.inner.next_back() }
|
|
}
|
|
|
|
impl<'a, K, V> ExactSizeIterator for Keys<'a, K, V> {
|
|
fn len(&self) -> usize { self.inner.len() }
|
|
}
|
|
|
|
/// An insertion-order iterator over a `LinkedHashMap`'s values.
|
|
pub struct Values<'a, K: 'a, V: 'a> {
|
|
inner: iter::Map<Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a V>
|
|
}
|
|
|
|
impl<'a, K, V> Clone for Values<'a, K, V> {
|
|
fn clone(&self) -> Self { Values { inner: self.inner.clone() } }
|
|
}
|
|
|
|
impl<'a, K, V> Iterator for Values<'a, K, V> {
|
|
type Item = &'a V;
|
|
|
|
#[inline] fn next(&mut self) -> Option<(&'a V)> { self.inner.next() }
|
|
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
|
|
}
|
|
|
|
impl<'a, K, V> DoubleEndedIterator for Values<'a, K, V> {
|
|
#[inline] fn next_back(&mut self) -> Option<(&'a V)> { self.inner.next_back() }
|
|
}
|
|
|
|
impl<'a, K, V> ExactSizeIterator for Values<'a, K, V> {
|
|
fn len(&self) -> usize { self.inner.len() }
|
|
}
|
|
|
|
impl<'a, K: Hash + Eq, V, S: BuildHasher> IntoIterator for &'a LinkedHashMap<K, V, S> {
|
|
type Item = (&'a K, &'a V);
|
|
type IntoIter = Iter<'a, K, V>;
|
|
fn into_iter(self) -> Iter<'a, K, V> { self.iter() }
|
|
}
|
|
|
|
impl<'a, K: Hash + Eq, V, S: BuildHasher> IntoIterator for &'a mut LinkedHashMap<K, V, S> {
|
|
type Item = (&'a K, &'a mut V);
|
|
type IntoIter = IterMut<'a, K, V>;
|
|
fn into_iter(self) -> IterMut<'a, K, V> { self.iter_mut() }
|
|
}
|
|
|
|
#[cfg(all(feature = "nightly", test))]
|
|
mod bench {
|
|
extern crate test;
|
|
|
|
use super::LinkedHashMap;
|
|
|
|
#[bench]
|
|
fn not_recycled_cycling(b: &mut test::Bencher) {
|
|
let mut hash_map = LinkedHashMap::with_capacity(1000);
|
|
for i in 0usize..1000 {
|
|
hash_map.insert(i, i);
|
|
}
|
|
b.iter(|| {
|
|
for i in 0usize..1000 {
|
|
hash_map.remove(&i);
|
|
}
|
|
hash_map.clear_free_list();
|
|
for i in 0usize..1000 {
|
|
hash_map.insert(i, i);
|
|
}
|
|
})
|
|
}
|
|
|
|
#[bench]
|
|
fn recycled_cycling(b: &mut test::Bencher) {
|
|
let mut hash_map = LinkedHashMap::with_capacity(1000);
|
|
for i in 0usize..1000 {
|
|
hash_map.insert(i, i);
|
|
}
|
|
b.iter(|| {
|
|
for i in 0usize..1000 {
|
|
hash_map.remove(&i);
|
|
}
|
|
for i in 0usize..1000 {
|
|
hash_map.insert(i, i);
|
|
}
|
|
})
|
|
}
|
|
}
|