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Diffstat (limited to 'vendor/dashmap/src/iter.rs')
-rw-r--r-- | vendor/dashmap/src/iter.rs | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/vendor/dashmap/src/iter.rs b/vendor/dashmap/src/iter.rs new file mode 100644 index 000000000..cc2f12ea8 --- /dev/null +++ b/vendor/dashmap/src/iter.rs @@ -0,0 +1,315 @@ +use super::mapref::multiple::{RefMulti, RefMutMulti}; +use super::util; +use crate::lock::{RwLockReadGuard, RwLockWriteGuard}; +use crate::t::Map; +use crate::util::SharedValue; +use crate::{DashMap, HashMap}; +use core::hash::{BuildHasher, Hash}; +use core::mem; +use hashbrown::hash_map; +use std::collections::hash_map::RandomState; +use std::sync::Arc; + +/// Iterator over a DashMap yielding key value pairs. +/// +/// # Examples +/// +/// ``` +/// use dashmap::DashMap; +/// +/// let map = DashMap::new(); +/// map.insert("hello", "world"); +/// map.insert("alex", "steve"); +/// let pairs: Vec<(&'static str, &'static str)> = map.into_iter().collect(); +/// assert_eq!(pairs.len(), 2); +/// ``` +pub struct OwningIter<K, V, S = RandomState> { + map: DashMap<K, V, S>, + shard_i: usize, + current: Option<GuardOwningIter<K, V>>, +} + +impl<K: Eq + Hash, V, S: BuildHasher + Clone> OwningIter<K, V, S> { + pub(crate) fn new(map: DashMap<K, V, S>) -> Self { + Self { + map, + shard_i: 0, + current: None, + } + } +} + +type GuardOwningIter<K, V> = hash_map::IntoIter<K, SharedValue<V>>; + +impl<K: Eq + Hash, V, S: BuildHasher + Clone> Iterator for OwningIter<K, V, S> { + type Item = (K, V); + + fn next(&mut self) -> Option<Self::Item> { + loop { + if let Some(current) = self.current.as_mut() { + if let Some((k, v)) = current.next() { + return Some((k, v.into_inner())); + } + } + + if self.shard_i == self.map._shard_count() { + return None; + } + + //let guard = unsafe { self.map._yield_read_shard(self.shard_i) }; + let mut shard_wl = unsafe { self.map._yield_write_shard(self.shard_i) }; + + let hasher = self.map._hasher(); + + let map = mem::replace(&mut *shard_wl, HashMap::with_hasher(hasher)); + + drop(shard_wl); + + let iter = map.into_iter(); + + //unsafe { ptr::write(&mut self.current, Some((arcee, iter))); } + self.current = Some(iter); + + self.shard_i += 1; + } + } +} + +unsafe impl<K, V, S> Send for OwningIter<K, V, S> +where + K: Eq + Hash + Send, + V: Send, + S: BuildHasher + Clone + Send, +{ +} + +unsafe impl<K, V, S> Sync for OwningIter<K, V, S> +where + K: Eq + Hash + Sync, + V: Sync, + S: BuildHasher + Clone + Sync, +{ +} + +type GuardIter<'a, K, V, S> = ( + Arc<RwLockReadGuard<'a, HashMap<K, V, S>>>, + hash_map::Iter<'a, K, SharedValue<V>>, +); + +type GuardIterMut<'a, K, V, S> = ( + Arc<RwLockWriteGuard<'a, HashMap<K, V, S>>>, + hash_map::IterMut<'a, K, SharedValue<V>>, +); + +/// Iterator over a DashMap yielding immutable references. +/// +/// # Examples +/// +/// ``` +/// use dashmap::DashMap; +/// +/// let map = DashMap::new(); +/// map.insert("hello", "world"); +/// assert_eq!(map.iter().count(), 1); +/// ``` +pub struct Iter<'a, K, V, S = RandomState, M = DashMap<K, V, S>> { + map: &'a M, + shard_i: usize, + current: Option<GuardIter<'a, K, V, S>>, +} + +impl<'a, 'i, K: Clone + Hash + Eq, V: Clone, S: Clone + BuildHasher> Clone for Iter<'i, K, V, S> { + fn clone(&self) -> Self { + Iter::new(self.map) + } +} + +unsafe impl<'a, 'i, K, V, S, M> Send for Iter<'i, K, V, S, M> +where + K: 'a + Eq + Hash + Send, + V: 'a + Send, + S: 'a + BuildHasher + Clone, + M: Map<'a, K, V, S>, +{ +} + +unsafe impl<'a, 'i, K, V, S, M> Sync for Iter<'i, K, V, S, M> +where + K: 'a + Eq + Hash + Sync, + V: 'a + Sync, + S: 'a + BuildHasher + Clone, + M: Map<'a, K, V, S>, +{ +} + +impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>> Iter<'a, K, V, S, M> { + pub(crate) fn new(map: &'a M) -> Self { + Self { + map, + shard_i: 0, + current: None, + } + } +} + +impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>> Iterator + for Iter<'a, K, V, S, M> +{ + type Item = RefMulti<'a, K, V, S>; + + fn next(&mut self) -> Option<Self::Item> { + loop { + if let Some(current) = self.current.as_mut() { + if let Some((k, v)) = current.1.next() { + let guard = current.0.clone(); + + return unsafe { Some(RefMulti::new(guard, k, v.get())) }; + } + } + + if self.shard_i == self.map._shard_count() { + return None; + } + + let guard = unsafe { self.map._yield_read_shard(self.shard_i) }; + + let sref: &HashMap<K, V, S> = unsafe { util::change_lifetime_const(&*guard) }; + + let iter = sref.iter(); + + self.current = Some((Arc::new(guard), iter)); + + self.shard_i += 1; + } + } +} + +/// Iterator over a DashMap yielding mutable references. +/// +/// # Examples +/// +/// ``` +/// use dashmap::DashMap; +/// +/// let map = DashMap::new(); +/// map.insert("Johnny", 21); +/// map.iter_mut().for_each(|mut r| *r += 1); +/// assert_eq!(*map.get("Johnny").unwrap(), 22); +/// ``` +pub struct IterMut<'a, K, V, S = RandomState, M = DashMap<K, V, S>> { + map: &'a M, + shard_i: usize, + current: Option<GuardIterMut<'a, K, V, S>>, +} + +unsafe impl<'a, 'i, K, V, S, M> Send for IterMut<'i, K, V, S, M> +where + K: 'a + Eq + Hash + Send, + V: 'a + Send, + S: 'a + BuildHasher + Clone, + M: Map<'a, K, V, S>, +{ +} + +unsafe impl<'a, 'i, K, V, S, M> Sync for IterMut<'i, K, V, S, M> +where + K: 'a + Eq + Hash + Sync, + V: 'a + Sync, + S: 'a + BuildHasher + Clone, + M: Map<'a, K, V, S>, +{ +} + +impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>> + IterMut<'a, K, V, S, M> +{ + pub(crate) fn new(map: &'a M) -> Self { + Self { + map, + shard_i: 0, + current: None, + } + } +} + +impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>> Iterator + for IterMut<'a, K, V, S, M> +{ + type Item = RefMutMulti<'a, K, V, S>; + + fn next(&mut self) -> Option<Self::Item> { + loop { + if let Some(current) = self.current.as_mut() { + if let Some((k, v)) = current.1.next() { + let guard = current.0.clone(); + + unsafe { + let k = util::change_lifetime_const(k); + + let v = &mut *v.as_ptr(); + + return Some(RefMutMulti::new(guard, k, v)); + } + } + } + + if self.shard_i == self.map._shard_count() { + return None; + } + + let mut guard = unsafe { self.map._yield_write_shard(self.shard_i) }; + + let sref: &mut HashMap<K, V, S> = unsafe { util::change_lifetime_mut(&mut *guard) }; + + let iter = sref.iter_mut(); + + self.current = Some((Arc::new(guard), iter)); + + self.shard_i += 1; + } + } +} + +#[cfg(test)] +mod tests { + use crate::DashMap; + + #[test] + fn iter_mut_manual_count() { + let map = DashMap::new(); + + map.insert("Johnny", 21); + + assert_eq!(map.len(), 1); + + let mut c = 0; + + for shard in map.shards() { + c += shard.write().iter_mut().count(); + } + + assert_eq!(c, 1); + } + + #[test] + fn iter_mut_count() { + let map = DashMap::new(); + + map.insert("Johnny", 21); + + assert_eq!(map.len(), 1); + + assert_eq!(map.iter_mut().count(), 1); + } + + #[test] + fn iter_count() { + let map = DashMap::new(); + + map.insert("Johnny", 21); + + assert_eq!(map.len(), 1); + + assert_eq!(map.iter().count(), 1); + } +} |