X-Git-Url: https://git.chrismorgan.info/anymap/blobdiff_plain/036d7b0231a968f1d5ae14df49c5aa670423999e..97ec79029fa6a67dbc62124444e78c72c11951dc:/src/lib.rs diff --git a/src/lib.rs b/src/lib.rs index 4c0e9da..8076981 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -1,162 +1,290 @@ //! This crate provides the `AnyMap` type, a safe and convenient store for one value of each type. -#![crate_id = "anymap#0.9.0"] -#![crate_type = "rlib"] -#![crate_type = "dylib"] -#![feature(default_type_params)] -#![warn(unnecessary_qualification, non_uppercase_statics, - variant_size_difference, managed_heap_memory, unnecessary_typecast, - missing_doc, unused_result)] +#![feature(core, std_misc)] +#![cfg_attr(test, feature(test))] +#![warn(missing_docs, unused_results)] #[cfg(test)] extern crate test; -use std::any::Any; -use std::intrinsics::TypeId; -use std::collections::{Collection, HashMap, Mutable}; -use std::hash::{Hash, Hasher, Writer}; -use std::mem::{transmute, transmute_copy}; -use std::raw::TraitObject; +use std::any::{Any, TypeId}; +use std::marker::PhantomData; -struct TypeIdHasher; +use raw::RawAnyMap; +use unchecked_any::UncheckedAnyExt; -struct TypeIdState { - value: u64, -} +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: $new, + } + } -impl Writer for TypeIdState { - #[inline(always)] - fn write(&mut self, bytes: &[u8]) { - // This expects to receive one and exactly one 64-bit value - debug_assert!(bytes.len() == 8); - unsafe { - std::ptr::copy_nonoverlapping_memory(&mut self.value, - transmute(&bytes[0]), - 1) - } - } -} + /// Creates an empty collection with the given initial capacity. + #[inline] + pub fn with_capacity($with_capacity_arg: usize) -> $t { + $t { + $field: $with_capacity, + } + } -impl Hasher for TypeIdHasher { - fn hash>(&self, value: &T) -> u64 { - let mut state = TypeIdState { - value: 0, - }; - value.hash(&mut state); - state.value - } -} + /// Returns the number of elements the collection can hold without reallocating. + #[inline] + pub fn capacity(&self) -> usize { + self.$field.capacity() + } -/// 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(self) -> &'a T; -} + /// 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.$field.reserve(additional) + } -impl<'a> UncheckedAnyRefExt<'a> for &'a Any { - #[inline] - unsafe fn as_ref_unchecked(self) -> &'a T { - // Get the raw representation of the trait object - let to: TraitObject = transmute_copy(&self); + /// Shrinks the capacity of the collection as much as possible. It will drop + /// down as much as possible while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + #[inline] + pub fn shrink_to_fit(&mut self) { + self.$field.shrink_to_fit() + } - // Extract the data pointer - transmute(to.data) - } -} + /// Returns the number of items in the collection. + #[inline] + pub fn len(&self) -> usize { + self.$field.len() + } -/// An extension of `AnyMutRefExt` allowing unchecked downcasting of trait objects to `&mut T`. -trait UncheckedAnyMutRefExt<'a> { - /// Returns a reference to the boxed value, assuming that it is of type `T`. This should only be - /// called if you are ABSOLUTELY CERTAIN of `T` as you will get really wacky output if it’s not. - unsafe fn as_mut_unchecked(self) -> &'a mut T; -} + /// Returns true if there are no items in the collection. + #[inline] + pub fn is_empty(&self) -> bool { + self.$field.is_empty() + } -impl<'a> UncheckedAnyMutRefExt<'a> for &'a mut Any { - #[inline] - unsafe fn as_mut_unchecked(self) -> &'a mut T { - // Get the raw representation of the trait object - let to: TraitObject = transmute_copy(&self); - - // Extract the data pointer - transmute(to.data) + /// Removes all items from the collection. Keeps the allocated memory for reuse. + #[inline] + pub fn clear(&mut self) { + self.$field.clear() + } + } } } -/// A map containing zero or one values for any given type and allowing convenient, +mod unchecked_any; +pub mod raw; + +/// 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::(); -/// assert_eq!(data.find::(), 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(PartialEq, Debug)] /// struct Foo { /// str: String, /// } /// -/// assert_eq!(data.find::(), None); -/// data.insert(Foo { str: "foo".to_string() }); -/// assert_eq!(data.find(), Some(&Foo { str: "foo".to_string() })); -/// data.find_mut::().map(|foo| foo.str.push_char('t')); -/// assert_eq!(data.find::().unwrap().str.as_slice(), "foot"); +/// assert_eq!(data.get::(), None); +/// 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, "foot"); /// ``` /// /// Values containing non-static references are not permitted. +#[derive(Debug)] pub struct AnyMap { - data: HashMap, TypeIdHasher>, + raw: RawAnyMap, +} + +impl_common_methods! { + field: AnyMap.raw; + new() => RawAnyMap::new(); + with_capacity(capacity) => RawAnyMap::with_capacity(capacity); } impl AnyMap { - /// Construct a new `AnyMap`. - pub fn new() -> AnyMap { + /// 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::() }) + } + + /// 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::() }) + } + + /// 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::(), Box::new(value)) + .map(|any| *any.downcast_unchecked::()) + } + } + + /// 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::() }) + } + + /// 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 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, + }), + } + } + + /// Get a reference to the raw untyped map underlying the `AnyMap`. + /// + /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may + /// just find a use for it occasionally. + #[inline] + pub fn as_raw(&self) -> &RawAnyMap { + &self.raw + } + + /// Get a mutable reference to the raw untyped map underlying the `AnyMap`. + /// + /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may + /// just find a use for it occasionally. + #[inline] + pub fn as_raw_mut(&mut self) -> &mut RawAnyMap { + &mut self.raw + } + + /// Convert the `AnyMap` into the raw untyped map that underlyies it. + /// + /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may + /// just find a use for it occasionally. + #[inline] + pub fn into_raw(self) -> RawAnyMap { + self.raw + } + + /// Convert a raw untyped map into an `AnyMap`. + /// + /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may + /// just find a use for it occasionally. + #[inline] + pub fn from_raw(raw: RawAnyMap) -> AnyMap { AnyMap { - data: HashMap::with_hasher(TypeIdHasher), + raw: raw, } } } -impl AnyMap { - /// Retrieve the value stored in the map for the type `T`, if it exists. - pub fn find<'a, T: 'static>(&'a self) -> Option<&'a T> { - self.data.find(&TypeId::of::()).map(|any| unsafe { any.as_ref_unchecked::() }) +/// A view into a single occupied location in an `AnyMap`. +pub struct OccupiedEntry<'a, V: 'a> { + inner: raw::OccupiedEntry<'a>, + type_: PhantomData, +} + +/// A view into a single empty location in an `AnyMap`. +pub struct VacantEntry<'a, V: 'a> { + inner: raw::VacantEntry<'a>, + type_: PhantomData, +} + +/// 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: Any + Clone> Entry<'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), + } } - /// Retrieve a mutable reference to the value stored in the map for the type `T`, if it exists. - pub fn find_mut<'a, T: 'static>(&'a mut self) -> Option<&'a mut T> { - self.data.find_mut(&TypeId::of::()).map(|any| unsafe { any.as_mut_unchecked::() }) + /// 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()), + } } +} - /// Set the value contained in the map for the type `T`. - /// This will override any previous value stored. - pub fn insert(&mut self, value: T) { - self.data.insert(TypeId::of::(), box value as Box); +impl<'a, V: Any> OccupiedEntry<'a, V> { + /// Gets a reference to the value in the entry + pub fn get(&self) -> &V { + unsafe { self.inner.get().downcast_ref_unchecked() } } - /// Remove the value for the type `T` if it existed. - pub fn remove(&mut self) { - self.data.remove(&TypeId::of::()); + /// Gets a mutable reference to the value in the entry + pub fn get_mut(&mut self) -> &mut V { + 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 collection itself + pub fn into_mut(self) -> &'a mut V { + unsafe { self.inner.into_mut().downcast_mut_unchecked() } } -} -impl Collection for AnyMap { - fn len(&self) -> uint { - self.data.len() + /// Sets the value of the entry, and returns the entry's old value + pub fn insert(&mut self, value: V) -> V { + unsafe { *self.inner.insert(Box::new(value)).downcast_unchecked() } } - fn is_empty(&self) -> bool { - self.data.is_empty() + /// Takes the value out of the entry, and returns it + pub fn remove(self) -> V { + unsafe { *self.inner.remove().downcast_unchecked() } } } -impl Mutable for AnyMap { - fn clear(&mut self) { - self.data.clear(); +impl<'a, V: Any> 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.inner.insert(Box::new(value)).downcast_mut_unchecked() } } } @@ -164,30 +292,95 @@ impl Mutable for AnyMap { fn bench_insertion(b: &mut ::test::Bencher) { b.iter(|| { let mut data = AnyMap::new(); - for _ in range(0, 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(0, 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(0, 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::() { + 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); + + + // 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 (remove) + match map.entry::() { + Entry::Vacant(_) => unreachable!(), + Entry::Occupied(view) => { + assert_eq!(view.remove(), C(30)); + } + } + assert_eq!(map.get::(), None); + assert_eq!(map.len(), 5); + + + // 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); +}