DAV storage methods

crates/utils/src/bimap.rs

@@ -0,0 +1,52 @@
+/*
+ * SPDX-FileCopyrightText: 2020 Stalwart Labs Ltd <hello@stalw.art>
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ */
+
+use std::{borrow::Borrow, rc::Rc};
+
+use ahash::AHashMap;
+
+#[derive(Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+#[repr(transparent)]
+struct StringRef(Rc<String>);
+
+#[derive(Debug, Default)]
+pub struct IdBimap {
+    id_to_uri: AHashMap<u32, Rc<String>>,
+    uri_to_id: AHashMap<StringRef, u32>,
+}
+
+impl IdBimap {
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self {
+            id_to_uri: AHashMap::with_capacity(capacity),
+            uri_to_id: AHashMap::with_capacity(capacity),
+        }
+    }
+
+    pub fn insert(&mut self, id: u32, uri: impl Into<String>) {
+        let uri = Rc::new(uri.into());
+        self.id_to_uri.insert(id, uri.clone());
+        self.uri_to_id.insert(StringRef(uri), id);
+    }
+
+    pub fn by_name(&self, uri: &str) -> Option<u32> {
+        self.uri_to_id.get(uri).copied()
+    }
+
+    pub fn by_id(&self, id: u32) -> Option<&str> {
+        self.id_to_uri.get(&id).map(|x| x.as_str())
+    }
+}
+
+// SAFETY: Safe because Rc<> are never returned from the struct
+unsafe impl Send for IdBimap {}
+unsafe impl Sync for IdBimap {}
+
+impl Borrow<str> for StringRef {
+    fn borrow(&self) -> &str {
+        &self.0
+    }
+}

crates/utils/src/lib.rs

@@ -6,6 +6,7 @@
 
 use std::{fmt::Display, sync::Arc};
 
+pub mod bimap;
 pub mod cache;
 pub mod codec;
 pub mod config;