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-rw-r--r--third_party/rust/dashmap/src/iter.rs309
1 files changed, 309 insertions, 0 deletions
diff --git a/third_party/rust/dashmap/src/iter.rs b/third_party/rust/dashmap/src/iter.rs
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index 0000000000..e88c1cae1d
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+++ b/third_party/rust/dashmap/src/iter.rs
@@ -0,0 +1,309 @@
+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 std::collections::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>>,
+}
+
+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 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);
+ }
+}
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