Rename Store to ConnectionPool

crates/collab/src/rpc/connection_pool.rs

@@ -0,0 +1,93 @@
+use crate::db::UserId;
+use anyhow::{anyhow, Result};
+use collections::{BTreeMap, HashSet};
+use rpc::ConnectionId;
+use serde::Serialize;
+use tracing::instrument;
+
+#[derive(Default, Serialize)]
+pub struct ConnectionPool {
+    connections: BTreeMap<ConnectionId, Connection>,
+    connected_users: BTreeMap<UserId, ConnectedUser>,
+}
+
+#[derive(Default, Serialize)]
+struct ConnectedUser {
+    connection_ids: HashSet<ConnectionId>,
+}
+
+#[derive(Serialize)]
+pub struct Connection {
+    pub user_id: UserId,
+    pub admin: bool,
+}
+
+impl ConnectionPool {
+    #[instrument(skip(self))]
+    pub fn add_connection(&mut self, connection_id: ConnectionId, user_id: UserId, admin: bool) {
+        self.connections
+            .insert(connection_id, Connection { user_id, admin });
+        let connected_user = self.connected_users.entry(user_id).or_default();
+        connected_user.connection_ids.insert(connection_id);
+    }
+
+    #[instrument(skip(self))]
+    pub fn remove_connection(&mut self, connection_id: ConnectionId) -> Result<()> {
+        let connection = self
+            .connections
+            .get_mut(&connection_id)
+            .ok_or_else(|| anyhow!("no such connection"))?;
+
+        let user_id = connection.user_id;
+        let connected_user = self.connected_users.get_mut(&user_id).unwrap();
+        connected_user.connection_ids.remove(&connection_id);
+        if connected_user.connection_ids.is_empty() {
+            self.connected_users.remove(&user_id);
+        }
+        self.connections.remove(&connection_id).unwrap();
+        Ok(())
+    }
+
+    pub fn connections(&self) -> impl Iterator<Item = &Connection> {
+        self.connections.values()
+    }
+
+    pub fn user_connection_ids(&self, user_id: UserId) -> impl Iterator<Item = ConnectionId> + '_ {
+        self.connected_users
+            .get(&user_id)
+            .into_iter()
+            .map(|state| &state.connection_ids)
+            .flatten()
+            .copied()
+    }
+
+    pub fn is_user_online(&self, user_id: UserId) -> bool {
+        !self
+            .connected_users
+            .get(&user_id)
+            .unwrap_or(&Default::default())
+            .connection_ids
+            .is_empty()
+    }
+
+    #[cfg(test)]
+    pub fn check_invariants(&self) {
+        for (connection_id, connection) in &self.connections {
+            assert!(self
+                .connected_users
+                .get(&connection.user_id)
+                .unwrap()
+                .connection_ids
+                .contains(connection_id));
+        }
+
+        for (user_id, state) in &self.connected_users {
+            for connection_id in &state.connection_ids {
+                assert_eq!(
+                    self.connections.get(connection_id).unwrap().user_id,
+                    *user_id
+                );
+            }
+        }
+    }
+}