//! This crate provides the `AnyMap` type, a safe and convenient store for one value of each type.
-#![crate_name = "anymap"]
-#![crate_type = "lib"]
-#![feature(default_type_params)]
+#![feature(core, std_misc, hash)]
+#![cfg_attr(test, feature(test))]
#![warn(unused_qualifications, non_upper_case_globals,
variant_size_differences, unused_typecasts,
missing_docs, unused_results)]
#[cfg(test)]
extern crate test;
-use std::any::Any;
-use std::intrinsics::TypeId;
+use std::any::{Any, TypeId};
+use std::mem::forget;
use std::collections::HashMap;
-use std::hash::{Hash, Hasher, Writer};
-use std::mem::{transmute, transmute_copy};
+use std::collections::hash_map;
+use std::hash::Hasher;
+use std::collections::hash_state::HashState;
+use std::mem::transmute;
use std::raw::TraitObject;
+use std::marker::PhantomData;
-struct TypeIdHasher;
-
-struct TypeIdState {
+struct TypeIdHasher {
value: u64,
}
-impl Writer for TypeIdState {
+struct TypeIdState;
+
+impl HashState for TypeIdState {
+ type Hasher = TypeIdHasher;
+
+ fn hasher(&self) -> TypeIdHasher {
+ TypeIdHasher { value: 0 }
+ }
+}
+
+impl Hasher for TypeIdHasher {
#[inline(always)]
fn write(&mut self, bytes: &[u8]) {
// This expects to receive one and exactly one 64-bit value
debug_assert!(bytes.len() == 8);
unsafe {
- std::ptr::copy_nonoverlapping_memory(&mut self.value,
- transmute(&bytes[0]),
- 1)
+ std::ptr::copy_nonoverlapping(&mut self.value, transmute(&bytes[0]), 1)
}
}
-}
-impl Hasher<TypeIdState> for TypeIdHasher {
- fn hash<Sized? T: Hash<TypeIdState>>(&self, value: &T) -> u64 {
- let mut state = TypeIdState {
- value: 0,
- };
- value.hash(&mut state);
- state.value
- }
+ #[inline(always)]
+ fn finish(&self) -> u64 { self.value }
}
/// An extension of `AnyRefExt` allowing unchecked downcasting of trait objects to `&T`.
trait UncheckedAnyRefExt<'a> {
/// Returns a reference to the boxed value, assuming that it is of type `T`. This should only be
/// called if you are ABSOLUTELY CERTAIN of `T` as you will get really wacky output if it’s not.
- unsafe fn as_ref_unchecked<T: 'static>(self) -> &'a T;
+ unsafe fn downcast_ref_unchecked<T: 'static>(self) -> &'a T;
}
-impl<'a> UncheckedAnyRefExt<'a> for &'a Any + 'a {
+impl<'a> UncheckedAnyRefExt<'a> for &'a Any {
#[inline]
- unsafe fn as_ref_unchecked<T: 'static>(self) -> &'a T {
+ unsafe fn downcast_ref_unchecked<T: 'static>(self) -> &'a T {
// Get the raw representation of the trait object
- let to: TraitObject = transmute_copy(&self);
+ let to: TraitObject = transmute(self);
// Extract the data pointer
transmute(to.data)
trait UncheckedAnyMutRefExt<'a> {
/// Returns a reference to the boxed value, assuming that it is of type `T`. This should only be
/// called if you are ABSOLUTELY CERTAIN of `T` as you will get really wacky output if it’s not.
- unsafe fn as_mut_unchecked<T: 'static>(self) -> &'a mut T;
+ unsafe fn downcast_mut_unchecked<T: 'static>(self) -> &'a mut T;
}
-impl<'a> UncheckedAnyMutRefExt<'a> for &'a mut Any + 'a {
+impl<'a> UncheckedAnyMutRefExt<'a> for &'a mut Any {
#[inline]
- unsafe fn as_mut_unchecked<T: 'static>(self) -> &'a mut T {
+ unsafe fn downcast_mut_unchecked<T: 'static>(self) -> &'a mut T {
// Get the raw representation of the trait object
- let to: TraitObject = transmute_copy(&self);
+ let to: TraitObject = transmute(self);
// Extract the data pointer
transmute(to.data)
}
}
-/// A map containing zero or one values for any given type and allowing convenient,
+/// An extension of `BoxAny` allowing unchecked downcasting of trait objects to `Box<T>`.
+trait UncheckedBoxAny {
+ /// Returns the boxed value, assuming that it is of type `T`. This should only be called if you
+ /// are ABSOLUTELY CERTAIN of `T` as you will get really wacky output if it’s not.
+ unsafe fn downcast_unchecked<T: 'static>(self) -> Box<T>;
+}
+
+impl UncheckedBoxAny for Box<Any + 'static> {
+ #[inline]
+ unsafe fn downcast_unchecked<T: 'static>(self) -> Box<T> {
+ // Get the raw representation of the trait object
+ let to: TraitObject = *transmute::<&Box<Any>, &TraitObject>(&self);
+
+ // Prevent destructor on self being run
+ forget(self);
+
+ // Extract the data pointer
+ transmute(to.data)
+ }
+}
+
+/// A collection containing zero or one values for any given type and allowing convenient,
/// type-safe access to those values.
///
/// ```rust
/// # use anymap::AnyMap;
/// let mut data = AnyMap::new();
-/// assert_eq!(data.find(), None::<&int>);
-/// data.insert(42i);
-/// assert_eq!(data.find(), Some(&42i));
-/// data.remove::<int>();
-/// assert_eq!(data.find::<int>(), None);
+/// assert_eq!(data.get(), None::<&i32>);
+/// data.insert(42i32);
+/// assert_eq!(data.get(), Some(&42i32));
+/// data.remove::<i32>();
+/// assert_eq!(data.get::<i32>(), None);
///
-/// #[deriving(PartialEq, Show)]
+/// #[derive(PartialEq, Debug)]
/// struct Foo {
/// str: String,
/// }
///
-/// assert_eq!(data.find::<Foo>(), None);
-/// data.insert(Foo { str: "foo".to_string() });
-/// assert_eq!(data.find(), Some(&Foo { str: "foo".to_string() }));
-/// data.find_mut::<Foo>().map(|foo| foo.str.push('t'));
-/// assert_eq!(data.find::<Foo>().unwrap().str.as_slice(), "foot");
+/// assert_eq!(data.get::<Foo>(), None);
+/// data.insert(Foo { str: format!("foo") });
+/// assert_eq!(data.get(), Some(&Foo { str: format!("foo") }));
+/// data.get_mut::<Foo>().map(|foo| foo.str.push('t'));
+/// assert_eq!(&*data.get::<Foo>().unwrap().str, "foot");
/// ```
///
/// Values containing non-static references are not permitted.
pub struct AnyMap {
- data: HashMap<TypeId, Box<Any + 'static>, TypeIdHasher>,
+ data: HashMap<TypeId, Box<Any + 'static>, TypeIdState>,
}
impl AnyMap {
/// Construct a new `AnyMap`.
+ #[inline]
pub fn new() -> AnyMap {
AnyMap {
- data: HashMap::with_hasher(TypeIdHasher),
+ data: HashMap::with_hash_state(TypeIdState),
}
}
-}
-impl AnyMap {
- /// Retrieve the value stored in the map for the type `T`, if it exists.
- pub fn find<T: Any + 'static>(&self) -> Option<&T> {
- self.data.find(&TypeId::of::<T>()).map(|any| unsafe { any.as_ref_unchecked::<T>() })
+ /// Creates an empty AnyMap with the given initial capacity.
+ #[inline]
+ pub fn with_capcity(capacity: usize) -> AnyMap {
+ AnyMap {
+ data: HashMap::with_capacity_and_hash_state(capacity, TypeIdState),
+ }
}
- /// Retrieve a mutable reference to the value stored in the map for the type `T`, if it exists.
- pub fn find_mut<T: Any + 'static>(&mut self) -> Option<&mut T> {
- self.data.find_mut(&TypeId::of::<T>()).map(|any| unsafe { any.as_mut_unchecked::<T>() })
+ /// Returns the number of elements the collection can hold without reallocating.
+ #[inline]
+ pub fn capacity(&self) -> usize {
+ self.data.capacity()
}
- /// Set the value contained in the map for the type `T`.
- /// This will override any previous value stored.
- pub fn insert<T: Any + 'static>(&mut self, value: T) {
- self.data.insert(TypeId::of::<T>(), box value as Box<Any>);
+ /// Reserves capacity for at least `additional` more elements to be inserted
+ /// in the `AnyMap`. The collection may reserve more space to avoid
+ /// frequent reallocations.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the new allocation size overflows `usize`.
+ #[inline]
+ pub fn reserve(&mut self, additional: usize) {
+ self.data.reserve(additional)
+ }
+
+ /// Shrinks the capacity of the collection as much as possible. It will drop
+ /// down as much as possible while maintaining the internal rules
+ /// and possibly leaving some space in accordance with the resize policy.
+ #[inline]
+ pub fn shrink_to_fit(&mut self) {
+ self.data.shrink_to_fit()
}
- /// Remove the value for the type `T` if it existed.
- pub fn remove<T: Any + 'static>(&mut self) {
- self.data.remove(&TypeId::of::<T>());
+ /// An iterator visiting all items in the collection in arbitrary order.
+ /// Iterator element type is `&Any`.
+ ///
+ /// This is probably not a great deal of use.
+ #[inline]
+ pub fn iter(&self) -> Iter {
+ Iter {
+ inner: self.data.iter(),
+ }
}
- /// Does a value of type `T` exist?
+ /// An iterator visiting all items in the collection in arbitrary order.
+ /// Iterator element type is `&mut Any`.
+ ///
+ /// This is probably not a great deal of use.
+ #[inline]
+ pub fn iter_mut(&mut self) -> IterMut {
+ IterMut {
+ inner: self.data.iter_mut(),
+ }
+ }
+
+ /// An iterator visiting all items in the collection in arbitrary order.
+ /// Creates a consuming iterator, that is, one that moves each item
+ /// out of the map in arbitrary order. The map cannot be used after
+ /// calling this.
+ ///
+ /// Iterator element type is `Box<Any>`.
+ #[inline]
+ pub fn into_iter(self) -> IntoIter {
+ IntoIter {
+ inner: self.data.into_iter(),
+ }
+ }
+
+ /// Returns a reference to the value stored in the collection for the type `T`, if it exists.
+ pub fn get<T: Any + 'static>(&self) -> Option<&T> {
+ self.data.get(&TypeId::of::<T>())
+ .map(|any| unsafe { any.downcast_ref_unchecked::<T>() })
+ }
+
+ /// Returns a mutable reference to the value stored in the collection for the type `T`,
+ /// if it exists.
+ pub fn get_mut<T: Any + 'static>(&mut self) -> Option<&mut T> {
+ self.data.get_mut(&TypeId::of::<T>())
+ .map(|any| unsafe { any.downcast_mut_unchecked::<T>() })
+ }
+
+ /// Sets the value stored in the collection for the type `T`.
+ /// If the collection already had a value of type `T`, that value is returned.
+ /// Otherwise, `None` is returned.
+ pub fn insert<T: Any + 'static>(&mut self, value: T) -> Option<T> {
+ self.data.insert(TypeId::of::<T>(), Box::new(value) as Box<Any>)
+ .map(|any| *unsafe { any.downcast_unchecked::<T>() })
+ }
+
+ /// Removes the `T` value from the collection,
+ /// returning it if there was one or `None` if there was not.
+ pub fn remove<T: Any + 'static>(&mut self) -> Option<T> {
+ self.data.remove(&TypeId::of::<T>())
+ .map(|any| *unsafe { any.downcast_unchecked::<T>() })
+ }
+
+ /// Returns true if the collection contains a value of type `T`.
pub fn contains<T: Any + 'static>(&self) -> bool {
self.data.contains_key(&TypeId::of::<T>())
}
+ /// Gets the entry for the given type in the collection for in-place manipulation
+ pub fn entry<T: Any + 'static>(&mut self) -> Entry<T> {
+ match self.data.entry(TypeId::of::<T>()) {
+ hash_map::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry {
+ entry: e,
+ type_: PhantomData,
+ }),
+ hash_map::Entry::Vacant(e) => Entry::Vacant(VacantEntry {
+ entry: e,
+ type_: PhantomData,
+ }),
+ }
+ }
+
/// Returns the number of items in the collection.
- pub fn len(&self) -> uint {
+ #[inline]
+ pub fn len(&self) -> usize {
self.data.len()
}
/// Returns true if there are no items in the collection.
+ #[inline]
pub fn is_empty(&self) -> bool {
self.data.is_empty()
}
- /// Removes all items from the collection.
+ /// Clears the map, returning all items as an iterator.
+ ///
+ /// Iterator element type is `Box<Any>`.
+ ///
+ /// Keeps the allocated memory for reuse.
+ #[inline]
+ pub fn drain(&mut self) -> Drain {
+ Drain {
+ inner: self.data.drain(),
+ }
+ }
+
+ /// Removes all items from the collection. Keeps the allocated memory for reuse.
+ #[inline]
pub fn clear(&mut self) {
self.data.clear();
}
}
+/// A view into a single occupied location in an AnyMap
+pub struct OccupiedEntry<'a, V: 'a> {
+ entry: hash_map::OccupiedEntry<'a, TypeId, Box<Any + 'static>>,
+ type_: PhantomData<V>,
+}
+
+/// A view into a single empty location in an AnyMap
+pub struct VacantEntry<'a, V: 'a> {
+ entry: hash_map::VacantEntry<'a, TypeId, Box<Any + 'static>>,
+ type_: PhantomData<V>,
+}
+
+/// A view into a single location in an AnyMap, which may be vacant or occupied
+pub enum Entry<'a, V: 'a> {
+ /// An occupied Entry
+ Occupied(OccupiedEntry<'a, V>),
+ /// A vacant Entry
+ Vacant(VacantEntry<'a, V>),
+}
+
+impl<'a, V: 'static + Clone> Entry<'a, V> {
+ /// Returns a mutable reference to the entry if occupied, or the VacantEntry if vacant
+ pub fn get(self) -> Result<&'a mut V, VacantEntry<'a, V>> {
+ match self {
+ Entry::Occupied(entry) => Ok(entry.into_mut()),
+ Entry::Vacant(entry) => Err(entry),
+ }
+ }
+}
+
+impl<'a, V: 'static> OccupiedEntry<'a, V> {
+ /// Gets a reference to the value in the entry
+ pub fn get(&self) -> &V {
+ unsafe { self.entry.get().downcast_ref_unchecked() }
+ }
+
+ /// Gets a mutable reference to the value in the entry
+ pub fn get_mut(&mut self) -> &mut V {
+ unsafe { self.entry.get_mut().downcast_mut_unchecked() }
+ }
+
+ /// Converts the OccupiedEntry into a mutable reference to the value in the entry
+ /// with a lifetime bound to the collection itself
+ pub fn into_mut(self) -> &'a mut V {
+ unsafe { self.entry.into_mut().downcast_mut_unchecked() }
+ }
+
+ /// Sets the value of the entry, and returns the entry's old value
+ pub fn insert(&mut self, value: V) -> V {
+ unsafe { *self.entry.insert(Box::new(value) as Box<Any + 'static>).downcast_unchecked() }
+ }
+
+ /// Takes the value out of the entry, and returns it
+ pub fn remove(self) -> V {
+ unsafe { *self.entry.remove().downcast_unchecked() }
+ }
+}
+
+impl<'a, V: 'static> VacantEntry<'a, V> {
+ /// Sets the value of the entry with the VacantEntry's key,
+ /// and returns a mutable reference to it
+ pub fn insert(self, value: V) -> &'a mut V {
+ unsafe { self.entry.insert(Box::new(value) as Box<Any + 'static>).downcast_mut_unchecked() }
+ }
+}
+
+/// `AnyMap` iterator.
+#[derive(Clone)]
+pub struct Iter<'a> {
+ inner: hash_map::Iter<'a, TypeId, Box<Any + 'static>>,
+}
+
+/// `AnyMap` mutable references iterator.
+pub struct IterMut<'a> {
+ inner: hash_map::IterMut<'a, TypeId, Box<Any + 'static>>,
+}
+
+/// `AnyMap` draining iterator.
+pub struct Drain<'a> {
+ inner: hash_map::Drain<'a, TypeId, Box<Any + 'static>>,
+}
+
+/// `AnyMap` move iterator.
+pub struct IntoIter {
+ inner: hash_map::IntoIter<TypeId, Box<Any + 'static>>,
+}
+
+impl<'a> Iterator for Iter<'a> {
+ type Item = &'a Any;
+
+ #[inline]
+ fn next(&mut self) -> Option<&'a Any> {
+ self.inner.next().map(|item| &**item.1)
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
+}
+
+impl<'a> Iterator for IterMut<'a> {
+ type Item = &'a mut Any;
+
+ #[inline]
+ fn next(&mut self) -> Option<&'a mut Any> {
+ self.inner.next().map(|item| &mut **item.1)
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
+}
+
+impl<'a> Iterator for Drain<'a> {
+ type Item = Box<Any + 'static>;
+
+ #[inline]
+ fn next(&mut self) -> Option<Box<Any + 'static>> {
+ self.inner.next().map(|item| item.1)
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
+}
+
+impl Iterator for IntoIter {
+ type Item = Box<Any + 'static>;
+
+ #[inline]
+ fn next(&mut self) -> Option<Box<Any + 'static>> {
+ self.inner.next().map(|item| item.1)
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
+}
+
#[bench]
fn bench_insertion(b: &mut ::test::Bencher) {
b.iter(|| {
let mut data = AnyMap::new();
- for _ in range(0u, 100) {
- data.insert(42i);
+ for _ in 0..100 {
+ let _ = data.insert(42);
}
})
}
#[bench]
-fn bench_find_missing(b: &mut ::test::Bencher) {
+fn bench_get_missing(b: &mut ::test::Bencher) {
b.iter(|| {
let data = AnyMap::new();
- for _ in range(0u, 100) {
- assert_eq!(data.find(), None::<&int>);
+ for _ in 0..100 {
+ assert_eq!(data.get(), None::<&i32>);
}
})
}
#[bench]
-fn bench_find_present(b: &mut ::test::Bencher) {
+fn bench_get_present(b: &mut ::test::Bencher) {
b.iter(|| {
let mut data = AnyMap::new();
- data.insert(42i);
+ let _ = data.insert(42);
// These inner loops are a feeble attempt to drown the other factors.
- for _ in range(0u, 100) {
- assert_eq!(data.find(), Some(&42i));
+ for _ in 0..100 {
+ assert_eq!(data.get(), Some(&42));
}
})
}
+
+#[test]
+fn test_entry() {
+ #[derive(Debug, PartialEq)] struct A(i32);
+ #[derive(Debug, PartialEq)] struct B(i32);
+ #[derive(Debug, PartialEq)] struct C(i32);
+ #[derive(Debug, PartialEq)] struct D(i32);
+ #[derive(Debug, PartialEq)] struct E(i32);
+ #[derive(Debug, PartialEq)] struct F(i32);
+ #[derive(Debug, PartialEq)] struct J(i32);
+
+ let mut map: AnyMap = AnyMap::new();
+ assert_eq!(map.insert(A(10)), None);
+ assert_eq!(map.insert(B(20)), None);
+ assert_eq!(map.insert(C(30)), None);
+ assert_eq!(map.insert(D(40)), None);
+ assert_eq!(map.insert(E(50)), None);
+ assert_eq!(map.insert(F(60)), None);
+
+ // Existing key (insert)
+ match map.entry::<A>() {
+ Entry::Vacant(_) => unreachable!(),
+ Entry::Occupied(mut view) => {
+ assert_eq!(view.get(), &A(10));
+ assert_eq!(view.insert(A(100)), A(10));
+ }
+ }
+ assert_eq!(map.get::<A>().unwrap(), &A(100));
+ assert_eq!(map.len(), 6);
+
+
+ // Existing key (update)
+ match map.entry::<B>() {
+ Entry::Vacant(_) => unreachable!(),
+ Entry::Occupied(mut view) => {
+ let v = view.get_mut();
+ let new_v = B(v.0 * 10);
+ *v = new_v;
+ }
+ }
+ assert_eq!(map.get().unwrap(), &B(200));
+ assert_eq!(map.len(), 6);
+
+
+ // Existing key (remove)
+ match map.entry::<C>() {
+ Entry::Vacant(_) => unreachable!(),
+ Entry::Occupied(view) => {
+ assert_eq!(view.remove(), C(30));
+ }
+ }
+ assert_eq!(map.get::<C>(), None);
+ assert_eq!(map.len(), 5);
+
+
+ // Inexistent key (insert)
+ match map.entry::<J>() {
+ Entry::Occupied(_) => unreachable!(),
+ Entry::Vacant(view) => {
+ assert_eq!(*view.insert(J(1000)), J(1000));
+ }
+ }
+ assert_eq!(map.get::<J>().unwrap(), &J(1000));
+ assert_eq!(map.len(), 6);
+}