Functions for storing RoomInfo in db. Refactor bot joins room event.

Add get/insert functions for RoomInfo in the rooms db.

Move 'bot joins room' code to single method, so we can also record a
RoomInfo struct into the database.

src/bot/event_handlers.rs

@@ -92,6 +92,21 @@ fn should_process_event(db: &Database, room_id: &str, event_id: &str) -> bool {
         })
 }
 
+async fn record_users_in_room(
+    client: &matrix_sdk::Client,
+    db: &crate::db::Database,
+    room: &matrix_sdk::Room,
+    our_username: &str,
+) -> Result<(), crate::db::errors::DataError> {
+    let room_id_str = room.room_id.as_str();
+    let usernames = matrix::get_users_in_room(&client, &room.room_id).await;
+    usernames
+        .into_iter()
+        .filter(|username| username != our_username)
+        .map(|username| db.rooms.add_user_to_room(&username, room_id_str))
+        .collect() //Make use of collect impl on Result.
+}
+
 /// This event emitter listens for messages with dice rolling commands.
 /// Originally adapted from the matrix-rust-sdk examples.
 #[async_trait]
@@ -124,12 +139,7 @@ impl EventEmitter for DiceBot {
                 self.db.rooms.clear_info(room_id)
             } else if event_affects_us && adding_user {
                 info!("Joined room {}; recording user information", room_id);
-                let usernames = matrix::get_users_in_room(&self.client, &room.room_id).await;
-                usernames
-                    .into_iter()
-                    .filter(|username| username != &event.state_key)
-                    .map(|username| self.db.rooms.add_user_to_room(&username, room_id))
-                    .collect() //Make use of collect impl on Result.
+                record_users_in_room(&self.client, &self.db, &room, &event.state_key).await
             } else if !event_affects_us && adding_user {
                 info!("Adding user {} to room ID {}", username, room_id);
                 self.db.rooms.add_user_to_room(username, room_id)

src/db/rooms.rs

@@ -1,5 +1,6 @@
 use crate::db::errors::DataError;
 use crate::db::schema::convert_u64;
+use crate::models::RoomInfo;
 use byteorder::BigEndian;
 use log::{debug, error, log_enabled};
 use sled::transaction::TransactionalTree;
@@ -14,7 +15,8 @@ use zerocopy::AsBytes;
 
 #[derive(Clone)]
 pub struct Rooms {
-    /// Room ID -> RoomInfo struct (single entries)
+    /// Room ID -> RoomInfo struct (single entries).
+    /// Key is just room ID as bytes.
     pub(in crate::db) roomid_roominfo: Tree,
 
     /// Room ID -> list of usernames in room.
@@ -225,6 +227,24 @@ impl Rooms {
         }
     }
 
+    pub fn insert_room_info(&self, info: &RoomInfo) -> Result<(), DataError> {
+        let key = info.room_id.as_bytes();
+        let serialized = bincode::serialize(&info)?;
+        self.roomid_roominfo.insert(key, serialized)?;
+        Ok(())
+    }
+
+    pub fn get_room_info(&self, info: &RoomInfo) -> Result<Option<RoomInfo>, DataError> {
+        let key = info.room_id.as_bytes();
+
+        //swap/flatten Result<Option<Result>> down into the return type.
+        self.roomid_roominfo
+            .get(key)
+            .map(|bytes| bytes.map(|b| bincode::deserialize::<RoomInfo>(&b)))?
+            .transpose()
+            .map_err(|e| e.into())
+    }
+
     pub fn get_rooms_for_user(&self, username: &str) -> Result<HashSet<String>, DataError> {
         hashset_tree::get_set(&self.username_roomids, username.as_bytes())
     }

src/models.rs

@@ -1,4 +1,7 @@
+use serde::{Deserialize, Serialize};
+
 /// RoomInfo has basic metadata about a room: its name, ID, etc.
+#[derive(Serialize, Deserialize, Clone, Debug)]
 pub struct RoomInfo {
     pub room_id: String,
     pub room_name: String,