X-Git-Url: https://git.chrismorgan.info/anymap/blobdiff_plain/f1710353a039c1d5e95d15bb54effd7cab8e047f..c1c62050536ff169570e82d4c1ba19247968c139:/src/lib.rs diff --git a/src/lib.rs b/src/lib.rs index 0e92822..d856ea6 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -1,359 +1,455 @@ //! This crate provides the `AnyMap` type, a safe and convenient store for one value of each type. -#![feature(default_type_params)] -#![warn(unused_qualifications, non_upper_case_globals, - variant_size_differences, unused_typecasts, - missing_docs, unused_results)] +#![cfg_attr(feature = "unstable", feature(core, std_misc))] +#![cfg_attr(all(feature = "unstable", test), feature(test))] +#![warn(missing_docs, unused_results)] -#[cfg(test)] +#[cfg(all(feature = "unstable", test))] extern crate test; -use std::any::Any; -use std::intrinsics::{forget, TypeId}; -use std::collections::HashMap; -use std::collections::hash_map; -use std::hash::{Hash, Hasher, Writer}; -use std::mem::transmute; -use std::raw::TraitObject; - -struct TypeIdHasher; - -struct TypeIdState { - value: u64, -} - -impl Writer for TypeIdState { - #[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) +use std::any::TypeId; +use std::marker::PhantomData; + +use raw::RawMap; +use any::{UncheckedAnyExt, IntoBox, Any}; + +macro_rules! impl_common_methods { + ( + field: $t:ident.$field:ident; + new() => $new:expr; + with_capacity($with_capacity_arg:ident) => $with_capacity:expr; + ) => { + impl $t { + /// Create an empty collection. + #[inline] + pub fn new() -> $t { + $t { + $field: $new, + } + } + + /// Creates an empty collection with the given initial capacity. + #[inline] + pub fn with_capacity($with_capacity_arg: usize) -> $t { + $t { + $field: $with_capacity, + } + } + + /// Returns the number of elements the collection can hold without reallocating. + #[inline] + pub fn capacity(&self) -> usize { + self.$field.capacity() + } + + /// Reserves capacity for at least `additional` more elements to be inserted + /// in the collection. 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.$field.reserve(additional) + } + + /// Shrinks the capacity of the collection as much as possible. It will drop + /// down as much as possible while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + #[inline] + pub fn shrink_to_fit(&mut self) { + self.$field.shrink_to_fit() + } + + /// Returns the number of items in the collection. + #[inline] + pub fn len(&self) -> usize { + self.$field.len() + } + + /// Returns true if there are no items in the collection. + #[inline] + pub fn is_empty(&self) -> bool { + self.$field.is_empty() + } + + /// Removes all items from the collection. Keeps the allocated memory for reuse. + #[inline] + pub fn clear(&mut self) { + self.$field.clear() + } } } } -impl Hasher for TypeIdHasher { - fn hash>(&self, value: &T) -> u64 { - let mut state = TypeIdState { - value: 0, - }; - value.hash(&mut state); - state.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 downcast_ref_unchecked(self) -> &'a T; -} - -impl<'a> UncheckedAnyRefExt<'a> for &'a Any { - #[inline] - unsafe fn downcast_ref_unchecked(self) -> &'a T { - // Get the raw representation of the trait object - let to: TraitObject = transmute(self); - - // Extract the data pointer - transmute(to.data) - } -} +pub mod any; +pub mod raw; -/// An extension of `AnyMutRefExt` allowing unchecked downcasting of trait objects to `&mut T`. -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 downcast_mut_unchecked(self) -> &'a mut T; -} - -impl<'a> UncheckedAnyMutRefExt<'a> for &'a mut Any { - #[inline] - unsafe fn downcast_mut_unchecked(self) -> &'a mut T { - // Get the raw representation of the trait object - let to: TraitObject = transmute(self); - - // Extract the data pointer - transmute(to.data) - } -} - -/// An extension of `BoxAny` allowing unchecked downcasting of trait objects to `Box`. -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(self) -> Box; -} - -impl UncheckedBoxAny for Box { - #[inline] - unsafe fn downcast_unchecked(self) -> Box { - // Get the raw representation of the trait object - let to: TraitObject = *transmute::<&Box, &TraitObject>(&self); - - // Prevent destructor on self being run - forget(self); - - // Extract the data pointer - transmute(to.data) - } -} - -/// A map containing zero or one values for any given type and allowing convenient, +/// A collection containing zero or one values for any given type and allowing convenient, /// type-safe access to those values. /// +/// The type parameter `A` allows you to use a different value type; normally you will want it to +/// be `anymap::any::Any`, but there are other choices: +/// +/// - If you want the entire map to be cloneable, use `CloneAny` instead of `Any`. +/// - You can add on `+ Send` and/or `+ Sync` (e.g. `Map`) to add those bounds. +/// /// ```rust /// # use anymap::AnyMap; /// let mut data = AnyMap::new(); -/// assert_eq!(data.get(), None::<&int>); -/// data.insert(42i); -/// assert_eq!(data.get(), Some(&42i)); -/// data.remove::(); -/// assert_eq!(data.get::(), None); +/// assert_eq!(data.get(), None::<&i32>); +/// data.insert(42i32); +/// assert_eq!(data.get(), Some(&42i32)); +/// data.remove::(); +/// assert_eq!(data.get::(), None); /// -/// #[deriving(PartialEq, Show)] +/// #[derive(Clone, PartialEq, Debug)] /// struct Foo { /// str: String, /// } /// /// assert_eq!(data.get::(), None); -/// data.insert(Foo { str: "foo".to_string() }); -/// assert_eq!(data.get(), Some(&Foo { str: "foo".to_string() })); +/// data.insert(Foo { str: format!("foo") }); +/// assert_eq!(data.get(), Some(&Foo { str: format!("foo") })); /// data.get_mut::().map(|foo| foo.str.push('t')); -/// assert_eq!(data.get::().unwrap().str.as_slice(), "foot"); +/// assert_eq!(&*data.get::().unwrap().str, "foot"); /// ``` /// /// Values containing non-static references are not permitted. -pub struct AnyMap { - data: HashMap, TypeIdHasher>, +#[derive(Debug)] +pub struct Map { + raw: RawMap, } -impl AnyMap { - /// Construct a new `AnyMap`. - pub fn new() -> AnyMap { - AnyMap { - data: HashMap::with_hasher(TypeIdHasher), +// #[derive(Clone)] would want A to implement Clone, but in reality it’s only Box that can. +impl Clone for Map where Box: Clone { + fn clone(&self) -> Map { + Map { + raw: self.raw.clone(), } } } -impl AnyMap { - /// Deprecated: Renamed to `get`. - #[deprecated = "Renamed to `get`"] - pub fn find(&self) -> Option<&T> { - self.get::() - } - - /// Deprecated: Renamed to `get_mut`. - #[deprecated = "Renamed to `get_mut`"] - pub fn find_mut(&mut self) -> Option<&mut T> { - self.get_mut::() - } +/// The most common type of `Map`: just using `Any`. +/// +/// Why is this a separate type alias rather than a default value for `Map`? `Map::new()` +/// doesn’t seem to be happy to infer that it should go with the default value. +/// It’s a bit sad, really. Ah well, I guess this approach will do. +pub type AnyMap = Map; + +impl_common_methods! { + field: Map.raw; + new() => RawMap::new(); + with_capacity(capacity) => RawMap::with_capacity(capacity); +} - /// Retrieve the value stored in the map for the type `T`, if it exists. - pub fn get(&self) -> Option<&T> { - self.data.get(&TypeId::of::()) +impl Map { + /// Returns a reference to the value stored in the collection for the type `T`, if it exists. + pub fn get>(&self) -> Option<&T> { + self.raw.get(&TypeId::of::()) .map(|any| unsafe { any.downcast_ref_unchecked::() }) } - /// Retrieve a mutable reference to the value stored in the map for the type `T`, if it exists. - pub fn get_mut(&mut self) -> Option<&mut T> { - self.data.get_mut(&TypeId::of::()) + /// Returns a mutable reference to the value stored in the collection for the type `T`, + /// if it exists. + pub fn get_mut>(&mut self) -> Option<&mut T> { + self.raw.get_mut(&TypeId::of::()) .map(|any| unsafe { any.downcast_mut_unchecked::() }) } - /// Set the value contained in the map for the type `T`. - /// If there is a previous value stored, it will be returned. - pub fn insert(&mut self, value: T) -> Option { - self.data.insert(TypeId::of::(), box value as Box) - .map(|any| *unsafe { any.downcast_unchecked::() }) + /// 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>(&mut self, value: T) -> Option { + unsafe { + self.raw.insert(TypeId::of::(), value.into_box()) + .map(|any| *any.downcast_unchecked::()) + } } - /// Remove and return the value for the type `T` if it existed. - pub fn remove(&mut self) -> Option { - self.data.remove(&TypeId::of::()) + /// Removes the `T` value from the collection, + /// returning it if there was one or `None` if there was not. + pub fn remove>(&mut self) -> Option { + self.raw.remove(&TypeId::of::()) .map(|any| *unsafe { any.downcast_unchecked::() }) } - /// Does a value of type `T` exist? - pub fn contains(&self) -> bool { - self.data.contains_key(&TypeId::of::()) + /// Returns true if the collection contains a value of type `T`. + #[inline] + pub fn contains>(&self) -> bool { + self.raw.contains_key(&TypeId::of::()) } - /// Gets the given key's corresponding entry in the map for in-place manipulation - pub fn entry(&mut self) -> Entry { - match self.data.entry(TypeId::of::()) { - hash_map::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry { entry: e }), - hash_map::Entry::Vacant(e) => Entry::Vacant(VacantEntry { entry: e }), + /// Gets the entry for the given type in the collection for in-place manipulation + pub fn entry>(&mut self) -> Entry { + match self.raw.entry(TypeId::of::()) { + raw::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry { + inner: e, + type_: PhantomData, + }), + raw::Entry::Vacant(e) => Entry::Vacant(VacantEntry { + inner: e, + type_: PhantomData, + }), } } +} - /// Returns the number of items in the collection. - pub fn len(&self) -> uint { - self.data.len() +impl AsRef> for Map { + fn as_ref(&self) -> &RawMap { + &self.raw } +} - /// Returns true if there are no items in the collection. - pub fn is_empty(&self) -> bool { - self.data.is_empty() +impl AsMut> for Map { + fn as_mut(&mut self) -> &mut RawMap { + &mut self.raw } +} - /// Removes all items from the collection. - pub fn clear(&mut self) { - self.data.clear(); +impl Into> for Map { + fn into(self) -> RawMap { + self.raw } } -/// A view into a single occupied location in an AnyMap -pub struct OccupiedEntry<'a, V: 'a> { - entry: hash_map::OccupiedEntry<'a, TypeId, Box>, +/// A view into a single occupied location in an `Map`. +pub struct OccupiedEntry<'a, A: ?Sized + UncheckedAnyExt, V: 'a> { + inner: raw::OccupiedEntry<'a, A>, + type_: PhantomData, } -/// A view into a single empty location in an AnyMap -pub struct VacantEntry<'a, V: 'a> { - entry: hash_map::VacantEntry<'a, TypeId, Box>, +/// A view into a single empty location in an `Map`. +pub struct VacantEntry<'a, A: ?Sized + UncheckedAnyExt, V: 'a> { + inner: raw::VacantEntry<'a, A>, + type_: PhantomData, } -/// A view into a single location in a map, which may be vacant or occupied -pub enum Entry<'a, V: 'a> { +/// A view into a single location in an `Map`, which may be vacant or occupied. +pub enum Entry<'a, A: ?Sized + UncheckedAnyExt, V: 'a> { /// An occupied Entry - Occupied(OccupiedEntry<'a, V>), + Occupied(OccupiedEntry<'a, A, V>), /// A vacant Entry - Vacant(VacantEntry<'a, V>), + Vacant(VacantEntry<'a, A, V>), +} + +impl<'a, A: ?Sized + UncheckedAnyExt, V: IntoBox + Clone> Entry<'a, A, V> { + /// Ensures a value is in the entry by inserting the default if empty, and returns + /// a mutable reference to the value in the entry. + pub fn or_insert(self, default: V) -> &'a mut V { + match self { + Entry::Occupied(inner) => inner.into_mut(), + Entry::Vacant(inner) => inner.insert(default), + } + } + + /// Ensures a value is in the entry by inserting the result of the default function if empty, + /// and returns a mutable reference to the value in the entry. + pub fn or_insert_with V>(self, default: F) -> &'a mut V { + match self { + Entry::Occupied(inner) => inner.into_mut(), + Entry::Vacant(inner) => inner.insert(default()), + } + } } -impl<'a, V: 'static> OccupiedEntry<'a, V> { +impl<'a, A: ?Sized + UncheckedAnyExt, V: IntoBox> OccupiedEntry<'a, A, V> { /// Gets a reference to the value in the entry pub fn get(&self) -> &V { - unsafe { self.entry.get().downcast_ref_unchecked() } + unsafe { self.inner.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() } + unsafe { self.inner.get_mut().downcast_mut_unchecked() } } /// Converts the OccupiedEntry into a mutable reference to the value in the entry - /// with a lifetime bound to the map itself + /// with a lifetime bound to the collection itself pub fn into_mut(self) -> &'a mut V { - unsafe { self.entry.into_mut().downcast_mut_unchecked() } + unsafe { self.inner.into_mut().downcast_mut_unchecked() } } /// Sets the value of the entry, and returns the entry's old value - pub fn set(&mut self, value: V) -> V { - unsafe { *self.entry.set(box value as Box).downcast_unchecked() } + pub fn insert(&mut self, value: V) -> V { + unsafe { *self.inner.insert(value.into_box()).downcast_unchecked() } } /// Takes the value out of the entry, and returns it - pub fn take(self) -> V { - unsafe { *self.entry.take().downcast_unchecked() } + pub fn remove(self) -> V { + unsafe { *self.inner.remove().downcast_unchecked() } } } -impl<'a, V: 'static> VacantEntry<'a, V> { +impl<'a, A: ?Sized + UncheckedAnyExt, V: IntoBox> VacantEntry<'a, A, V> { /// Sets the value of the entry with the VacantEntry's key, /// and returns a mutable reference to it - pub fn set(self, value: V) -> &'a mut V { - unsafe { self.entry.set(box value as Box).downcast_mut_unchecked() } + pub fn insert(self, value: V) -> &'a mut V { + unsafe { self.inner.insert(value.into_box()).downcast_mut_unchecked() } } } +#[cfg(feature = "unstable")] #[bench] fn bench_insertion(b: &mut ::test::Bencher) { b.iter(|| { let mut data = AnyMap::new(); - for _ in range(0u, 100) { - let _ = data.insert(42i); + for _ in 0..100 { + let _ = data.insert(42); } }) } +#[cfg(feature = "unstable")] #[bench] fn bench_get_missing(b: &mut ::test::Bencher) { b.iter(|| { let data = AnyMap::new(); - for _ in range(0u, 100) { - assert_eq!(data.get(), None::<&int>); + for _ in 0..100 { + assert_eq!(data.get(), None::<&i32>); } }) } +#[cfg(feature = "unstable")] #[bench] fn bench_get_present(b: &mut ::test::Bencher) { b.iter(|| { let mut data = AnyMap::new(); - let _ = 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.get(), Some(&42i)); + for _ in 0..100 { + assert_eq!(data.get(), Some(&42)); } }) } -#[test] -fn test_entry() { - #[deriving(Show, PartialEq)] struct A(int); - #[deriving(Show, PartialEq)] struct B(int); - #[deriving(Show, PartialEq)] struct C(int); - #[deriving(Show, PartialEq)] struct D(int); - #[deriving(Show, PartialEq)] struct E(int); - #[deriving(Show, PartialEq)] struct F(int); - #[deriving(Show, PartialEq)] struct J(int); - - 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::() { - Entry::Vacant(_) => unreachable!(), - Entry::Occupied(mut view) => { - assert_eq!(view.get(), &A(10)); - assert_eq!(view.set(A(100)), A(10)); +#[cfg(test)] +mod tests { + use {Map, AnyMap, Entry}; + use any::{Any, CloneAny}; + + #[derive(Clone, Debug, PartialEq)] struct A(i32); + #[derive(Clone, Debug, PartialEq)] struct B(i32); + #[derive(Clone, Debug, PartialEq)] struct C(i32); + #[derive(Clone, Debug, PartialEq)] struct D(i32); + #[derive(Clone, Debug, PartialEq)] struct E(i32); + #[derive(Clone, Debug, PartialEq)] struct F(i32); + #[derive(Clone, Debug, PartialEq)] struct J(i32); + + #[test] + fn test_entry() { + 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::() { + 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::().unwrap(), &A(100)); - assert_eq!(map.len(), 6); + assert_eq!(map.get::().unwrap(), &A(100)); + assert_eq!(map.len(), 6); + + + // Existing key (update) + match map.entry::() { + 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 (update) - match map.entry::() { - Entry::Vacant(_) => unreachable!(), - Entry::Occupied(mut view) => { - let v = view.get_mut(); - let new_v = B(v.0 * 10); - *v = new_v; + // Existing key (remove) + match map.entry::() { + Entry::Vacant(_) => unreachable!(), + Entry::Occupied(view) => { + assert_eq!(view.remove(), C(30)); + } } - } - assert_eq!(map.get().unwrap(), &B(200)); - assert_eq!(map.len(), 6); + assert_eq!(map.get::(), None); + assert_eq!(map.len(), 5); - // Existing key (take) - match map.entry::() { - Entry::Vacant(_) => unreachable!(), - Entry::Occupied(view) => { - assert_eq!(view.take(), C(30)); + // Inexistent key (insert) + match map.entry::() { + Entry::Occupied(_) => unreachable!(), + Entry::Vacant(view) => { + assert_eq!(*view.insert(J(1000)), J(1000)); + } } + assert_eq!(map.get::().unwrap(), &J(1000)); + assert_eq!(map.len(), 6); + + // Entry.or_insert on existing key + map.entry::().or_insert(B(71)).0 += 1; + assert_eq!(map.get::().unwrap(), &B(201)); + assert_eq!(map.len(), 6); + + // Entry.or_insert on nonexisting key + map.entry::().or_insert(C(300)).0 += 1; + assert_eq!(map.get::().unwrap(), &C(301)); + assert_eq!(map.len(), 7); } - assert_eq!(map.get::(), None); - assert_eq!(map.len(), 5); + #[test] + fn test_clone() { + let mut map: Map = Map::new(); + let _ = map.insert(A(1)); + let _ = map.insert(B(2)); + let _ = map.insert(D(3)); + let _ = map.insert(E(4)); + let _ = map.insert(F(5)); + let _ = map.insert(J(6)); + let map2 = map.clone(); + assert_eq!(map2.len(), 6); + assert_eq!(map2.get::(), Some(&A(1))); + assert_eq!(map2.get::(), Some(&B(2))); + assert_eq!(map2.get::(), None); + assert_eq!(map2.get::(), Some(&D(3))); + assert_eq!(map2.get::(), Some(&E(4))); + assert_eq!(map2.get::(), Some(&F(5))); + assert_eq!(map2.get::(), Some(&J(6))); + } - // Inexistent key (insert) - match map.entry::() { - Entry::Occupied(_) => unreachable!(), - Entry::Vacant(view) => { - assert_eq!(*view.set(J(1000)), J(1000)); - } + #[test] + fn test_varieties() { + fn assert_send() { } + fn assert_sync() { } + fn assert_clone() { } + fn assert_debug() { } + assert_send::>(); + assert_send::>(); + assert_sync::>(); + assert_sync::>(); + assert_debug::>(); + assert_debug::>(); + assert_debug::>(); + assert_debug::>(); + assert_send::>(); + assert_send::>(); + assert_sync::>(); + assert_sync::>(); + assert_clone::>(); + assert_clone::>(); + assert_clone::>(); + assert_clone::>(); + assert_debug::>(); + assert_debug::>(); + assert_debug::>(); + assert_debug::>(); } - assert_eq!(map.get::().unwrap(), &J(1000)); - assert_eq!(map.len(), 6); }