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Diffstat (limited to 'src/ptr_weak_key_hash_map.rs')
| -rw-r--r-- | src/ptr_weak_key_hash_map.rs | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/src/ptr_weak_key_hash_map.rs b/src/ptr_weak_key_hash_map.rs new file mode 100644 index 0000000..cd48809 --- /dev/null +++ b/src/ptr_weak_key_hash_map.rs @@ -0,0 +1,352 @@ +//! A hash map where the keys are held by weak pointers and compared by pointer. + +use std::collections::hash_map::RandomState; +use std::fmt::{self, Debug}; +use std::hash::BuildHasher; +use std::iter::FromIterator; +use std::ops::{Deref, Index, IndexMut}; + +use super::by_ptr::*; +use super::traits::*; +use super::weak_key_hash_map as base; + +pub use super::PtrWeakKeyHashMap; +pub use super::weak_key_hash_map::{Entry, Iter, IterMut, Keys, Values, ValuesMut, Drain, IntoIter}; + +impl <K: WeakElement, V> PtrWeakKeyHashMap<K, V, RandomState> + where K::Strong: Deref +{ + /// Creates an empty `PtrWeakKeyHashMap`. + pub fn new() -> Self { + PtrWeakKeyHashMap(base::WeakKeyHashMap::new()) + } + + /// Creates an empty `PtrWeakKeyHashMap` with the given capacity. + pub fn with_capacity(capacity: usize) -> Self { + PtrWeakKeyHashMap(base::WeakKeyHashMap::with_capacity(capacity)) + } +} + +impl <K: WeakElement, V, S: BuildHasher> PtrWeakKeyHashMap<K, V, S> + where K::Strong: Deref +{ + /// Creates an empty `PtrWeakKeyHashMap` with the given capacity and hasher. + pub fn with_hasher(hash_builder: S) -> Self { + PtrWeakKeyHashMap(base::WeakKeyHashMap::with_hasher(hash_builder)) + } + + /// Creates an empty `PtrWeakKeyHashMap` with the given capacity and hasher. + pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> Self { + PtrWeakKeyHashMap(base::WeakKeyHashMap::with_capacity_and_hasher(capacity, hash_builder)) + } + + /// Returns a reference to the map's `BuildHasher`. + pub fn hasher(&self) -> &S { + self.0.hasher() + } + + /// Returns the number of elements the map can hold without reallocating. + pub fn capacity(&self) -> usize { + self.0.capacity() + } + + /// Removes all mappings whose keys have expired. + pub fn remove_expired(&mut self) { + self.0.remove_expired() + } + + /// Reserves room for additional elements. + pub fn reserve(&mut self, additional_capacity: usize) { + self.0.reserve(additional_capacity) + } + + /// Shrinks the capacity to the minimum allowed to hold the current number of elements. + pub fn shrink_to_fit(&mut self) { + self.0.shrink_to_fit() + } + + /// Returns an over-approximation of the number of elements. + pub fn len(&self) -> usize { + self.0.len() + } + + /// Is the map known to be empty? + /// + /// This could answer `false` for an empty map whose keys have + /// expired but have yet to be collected. + pub fn is_empty(&self) -> bool { + self.len() == 0 + } + + /// The proportion of buckets that are used. + /// + /// This is an over-approximation because of expired keys. + pub fn load_factor(&self) -> f32 { + self.0.load_factor() + } + + /// Gets the requested entry. + pub fn entry(&mut self, key: K::Strong) -> Entry<ByPtr<K>, V> { + self.0.entry(key) + } + + /// Removes all associations from the map. + pub fn clear(&mut self) { + self.0.clear() + } + + /// Returns a reference to the value corresponding to the key. + pub fn get(&self, key: &K::Strong) -> Option<&V> { + self.0.get(&(key.deref() as *const _)) + } + + /// Returns true if the map contains the specified key. + pub fn contains_key(&self, key:&K::Strong) -> bool { + self.0.contains_key(&(key.deref() as *const _)) + } + + /// Returns a mutable reference to the value corresponding to the key. + pub fn get_mut(&mut self, key: &K::Strong) -> Option<&mut V> { + self.0.get_mut(&(key.deref() as *const _)) + } + + /// Unconditionally inserts the value, returning the old value if already present. Does not + /// replace the key. + pub fn insert(&mut self, key: K::Strong, value: V) -> Option<V> { + self.0.insert(key, value) + } + + /// Removes the entry with the given key, if it exists, and returns the value. + pub fn remove(&mut self, key: &K::Strong) -> Option<V> { + self.0.remove(&(key.deref() as *const _)) + } + + /// Removes all mappings not satisfying the given predicate. + /// + /// Also removes any expired mappings. + pub fn retain<F>(&mut self, f: F) + where F: FnMut(K::Strong, &mut V) -> bool + { + self.0.retain(f) + } + + /// Is this map a submap of the other, using the given value comparison. + /// + /// In particular, all the keys of self must be in other and the values must compare true with + /// value_equal. + pub fn submap_with<F, S1, V1>(&self, other: &PtrWeakKeyHashMap<K, V1, S1>, value_equal: F) -> bool + where F: FnMut(&V, &V1) -> bool, + S1: BuildHasher + { + self.0.is_submap_with(&other.0, value_equal) + } + + /// Is self a submap of other? + pub fn is_submap<V1, S1>(&self, other: &PtrWeakKeyHashMap<K, V1, S1>) -> bool + where V: PartialEq<V1>, + S1: BuildHasher + { + self.0.is_submap(&other.0) + } + + /// Are the keys of self a subset of the keys of other? + pub fn domain_is_subset<V1, S1>(&self, other: &PtrWeakKeyHashMap<K, V1, S1>) -> bool + where S1: BuildHasher + { + self.0.domain_is_subset(&other.0) + } +} + +impl<K: WeakElement, V, S> PtrWeakKeyHashMap<K, V, S> + where K::Strong: Deref +{ + /// Gets an iterator over the keys and values. + pub fn iter(&self) -> Iter<ByPtr<K>, V> { + self.0.iter() + } + + /// Gets an iterator over the keys. + pub fn keys(&self) -> Keys<ByPtr<K>, V> { + self.0.keys() + } + + /// Gets an iterator over the values. + pub fn values(&self) -> Values<ByPtr<K>, V> { + self.0.values() + } + + /// Gets an iterator over the keys and mutable values. + pub fn iter_mut(&mut self) -> IterMut<ByPtr<K>, V> { + self.0.iter_mut() + } + + /// Gets an iterator over the mutable values. + pub fn values_mut(&mut self) -> ValuesMut<ByPtr<K>, V> { + self.0.values_mut() + } + + /// Gets a draining iterator, which removes all the values but retains the storage. + pub fn drain(&mut self) -> Drain<ByPtr<K>, V> { + self.0.drain() + } +} + +impl<K, V, V1, S, S1> PartialEq<PtrWeakKeyHashMap<K, V1, S1>> + for PtrWeakKeyHashMap<K, V, S> + where K: WeakElement, + K::Strong: Deref, + V: PartialEq<V1>, + S: BuildHasher, + S1: BuildHasher +{ + fn eq(&self, other: &PtrWeakKeyHashMap<K, V1, S1>) -> bool { + self.0 == other.0 + } +} + +impl<K: WeakElement, V: Eq, S: BuildHasher> Eq for PtrWeakKeyHashMap<K, V, S> + where K::Strong: Deref +{ } + +impl<K: WeakElement, V, S: BuildHasher + Default> Default for PtrWeakKeyHashMap<K, V, S> + where K::Strong: Deref +{ + fn default() -> Self { + PtrWeakKeyHashMap(base::WeakKeyHashMap::<ByPtr<K>, V, S>::default()) + } +} + +impl<'a, K, V, S> Index<&'a K::Strong> for PtrWeakKeyHashMap<K, V, S> + where K: WeakElement, + K::Strong: Deref, + S: BuildHasher +{ + type Output = V; + + fn index(&self, index: &'a K::Strong) -> &Self::Output { + self.0.index(&(index.deref() as *const _)) + } +} + +impl<'a, K, V, S> IndexMut<&'a K::Strong> for PtrWeakKeyHashMap<K, V, S> + where + K: WeakElement, + K::Strong: Deref, + S: BuildHasher +{ + fn index_mut(&mut self, index: &'a K::Strong) -> &mut Self::Output { + self.0.index_mut(&(index.deref() as *const _)) + } +} + +impl<K, V, S> FromIterator<(K::Strong, V)> for PtrWeakKeyHashMap<K, V, S> + where K: WeakElement, + K::Strong: Deref, + S: BuildHasher + Default +{ + fn from_iter<T: IntoIterator<Item=(K::Strong, V)>>(iter: T) -> Self { + PtrWeakKeyHashMap(base::WeakKeyHashMap::<ByPtr<K>, V, S>::from_iter(iter)) + } +} + +impl<K, V, S> Extend<(K::Strong, V)> for PtrWeakKeyHashMap<K, V, S> + where K: WeakElement, + K::Strong: Deref, + S: BuildHasher +{ + fn extend<T: IntoIterator<Item=(K::Strong, V)>>(&mut self, iter: T) { + self.0.extend(iter) + } +} + +impl<'a, K, V, S> Extend<(&'a K::Strong, &'a V)> for PtrWeakKeyHashMap<K, V, S> + where K: 'a + WeakElement, + K::Strong: Clone + Deref, + V: 'a + Clone, + S: BuildHasher +{ + fn extend<T: IntoIterator<Item=(&'a K::Strong, &'a V)>>(&mut self, iter: T) { + self.0.extend(iter) + } +} + +impl<K, V: Debug, S> Debug for PtrWeakKeyHashMap<K, V, S> + where K: WeakElement, + K::Strong: Debug +{ + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + self.0.fmt(f) + } +} + +impl<K: WeakElement, V, S> IntoIterator for PtrWeakKeyHashMap<K, V, S> { + type Item = (K::Strong, V); + type IntoIter = IntoIter<ByPtr<K>, V>; + + fn into_iter(self) -> Self::IntoIter { + self.0.into_iter() + } +} + +impl<'a, K: WeakElement, V, S> IntoIterator for &'a PtrWeakKeyHashMap<K, V, S> { + type Item = (K::Strong, &'a V); + type IntoIter = Iter<'a, ByPtr<K>, V>; + + fn into_iter(self) -> Self::IntoIter { + (&self.0).into_iter() + } +} + +impl<'a, K: WeakElement, V, S> IntoIterator for &'a mut PtrWeakKeyHashMap<K, V, S> { + type Item = (K::Strong, &'a mut V); + type IntoIter = IterMut<'a, ByPtr<K>, V>; + + fn into_iter(self) -> Self::IntoIter { + (&mut self.0).into_iter() + } +} + +#[cfg(test)] +mod test +{ + use crate::PtrWeakKeyHashMap; + use crate::weak_key_hash_map::Entry; + use std::rc::{Rc, Weak}; + +// fn show_me(weakmap: &PtrWeakKeyHashMap<Weak<u32>, f32>) { +// for (key, _) in weakmap { +// eprint!(" {:2}", *key); +// } +// eprintln!(); +// } + + // From https://github.com/tov/weak-table-rs/issues/1#issuecomment-461858060 + #[test] + fn insert_and_check() { + let mut rcs: Vec<Rc<u32>> = Vec::new(); + + for i in 0 .. 200 { + rcs.push(Rc::new(i)); + } + + let mut weakmap: PtrWeakKeyHashMap<Weak<u32>, f32> = PtrWeakKeyHashMap::new(); + + for item in rcs.iter().cloned() { + let f = *item as f32 + 0.1; + weakmap.insert(item, f); + } + + let mut count = 0; + + for item in &rcs { + assert!(weakmap.contains_key(item)); + + match weakmap.entry(Rc::clone(item)) { + Entry::Occupied(_) => count += 1, + Entry::Vacant(_) => eprintln!("PointerWeakKeyHashMap: missing: {}", *item), + } + } + + assert_eq!( count, rcs.len() ); + } +} |