1 files changed, 120 insertions, 0 deletions
diff --git a/third_party/rust/dashmap/src/mapref/multiple.rs b/third_party/rust/dashmap/src/mapref/multiple.rs
new file mode 100644
index 0000000000..4d30aee46f
--- /dev/null
+++ b/third_party/rust/dashmap/src/mapref/multiple.rs
@@ -0,0 +1,120 @@
+use crate::lock::{RwLockReadGuard, RwLockWriteGuard};
+use crate::HashMap;
+use core::hash::BuildHasher;
+use core::hash::Hash;
+use core::ops::{Deref, DerefMut};
+use std::collections::hash_map::RandomState;
+use std::sync::Arc;
+
+// -- Shared
+pub struct RefMulti<'a, K, V, S = RandomState> {
+    _guard: Arc<RwLockReadGuard<'a, HashMap<K, V, S>>>,
+    k: &'a K,
+    v: &'a V,
+}
+
+unsafe impl<'a, K: Eq + Hash + Send, V: Send, S: BuildHasher> Send for RefMulti<'a, K, V, S> {}
+
+unsafe impl<'a, K: Eq + Hash + Send + Sync, V: Send + Sync, S: BuildHasher> Sync
+    for RefMulti<'a, K, V, S>
+{
+}
+
+impl<'a, K: Eq + Hash, V, S: BuildHasher> RefMulti<'a, K, V, S> {
+    pub(crate) fn new(
+        guard: Arc<RwLockReadGuard<'a, HashMap<K, V, S>>>,
+        k: &'a K,
+        v: &'a V,
+    ) -> Self {
+        Self {
+            _guard: guard,
+            k,
+            v,
+        }
+    }
+
+    pub fn key(&self) -> &K {
+        self.k
+    }
+
+    pub fn value(&self) -> &V {
+        self.v
+    }
+
+    pub fn pair(&self) -> (&K, &V) {
+        (self.k, self.v)
+    }
+}
+
+impl<'a, K: Eq + Hash, V, S: BuildHasher> Deref for RefMulti<'a, K, V, S> {
+    type Target = V;
+
+    fn deref(&self) -> &V {
+        self.value()
+    }
+}
+
+// --
+// -- Unique
+pub struct RefMutMulti<'a, K, V, S = RandomState> {
+    _guard: Arc<RwLockWriteGuard<'a, HashMap<K, V, S>>>,
+    k: &'a K,
+    v: &'a mut V,
+}
+
+unsafe impl<'a, K: Eq + Hash + Send, V: Send, S: BuildHasher> Send for RefMutMulti<'a, K, V, S> {}
+
+unsafe impl<'a, K: Eq + Hash + Send + Sync, V: Send + Sync, S: BuildHasher> Sync
+    for RefMutMulti<'a, K, V, S>
+{
+}
+
+impl<'a, K: Eq + Hash, V, S: BuildHasher> RefMutMulti<'a, K, V, S> {
+    pub(crate) fn new(
+        guard: Arc<RwLockWriteGuard<'a, HashMap<K, V, S>>>,
+        k: &'a K,
+        v: &'a mut V,
+    ) -> Self {
+        Self {
+            _guard: guard,
+            k,
+            v,
+        }
+    }
+
+    pub fn key(&self) -> &K {
+        self.k
+    }
+
+    pub fn value(&self) -> &V {
+        self.v
+    }
+
+    pub fn value_mut(&mut self) -> &mut V {
+        self.v
+    }
+
+    pub fn pair(&self) -> (&K, &V) {
+        (self.k, self.v)
+    }
+
+    pub fn pair_mut(&mut self) -> (&K, &mut V) {
+        (self.k, self.v)
+    }
+}
+
+impl<'a, K: Eq + Hash, V, S: BuildHasher> Deref for RefMutMulti<'a, K, V, S> {
+    type Target = V;
+
+    fn deref(&self) -> &V {
+        self.value()
+    }
+}
+
+impl<'a, K: Eq + Hash, V, S: BuildHasher> DerefMut for RefMutMulti<'a, K, V, S> {
+    fn deref_mut(&mut self) -> &mut V {
+        self.value_mut()
+    }
+}
+
+// --