Do not process old membership events.

src/bot/event_handlers.rs

@@ -4,7 +4,7 @@ use log::{debug, error, info, warn};
 use matrix_sdk::{
     self,
     events::{
-        room::member::{MemberEventContent, MembershipState},
+        room::member::{MemberEventContent, MembershipChange},
         room::message::{MessageEventContent, TextMessageEventContent},
         StrippedStateEvent, SyncMessageEvent, SyncStateEvent,
     },
@@ -16,6 +16,11 @@ use std::clone::Clone;
 use std::ops::Sub;
 use std::time::{Duration, SystemTime};
 
+fn check_age(timestamp: &SystemTime, how_far_back: u64) -> bool {
+    let oldest_timestamp = SystemTime::now().sub(Duration::new(how_far_back, 0));
+    timestamp > &oldest_timestamp
+}
+
 /// Check if a message is recent enough to actually process. If the
 /// message is within "oldest_message_age" seconds, this function
 /// returns true. If it's older than that, it returns false and logs a
@@ -77,31 +82,36 @@ async fn should_process<'a>(
 /// Originally adapted from the matrix-rust-sdk examples.
 #[async_trait]
 impl EventEmitter for DiceBot {
-    async fn on_room_member(
-        &self,
-        room: SyncRoom,
-        room_member: &SyncStateEvent<MemberEventContent>,
-    ) {
-        if let SyncRoom::Joined(room) = room {
+    async fn on_room_member(&self, room: SyncRoom, event: &SyncStateEvent<MemberEventContent>) {
+        if !check_age(&event.origin_server_ts, 2) {
+            debug!("Ignoring old event: {:#?}", event);
+            return;
+        }
+
+        if let SyncRoom::Joined(room) | SyncRoom::Left(room) = room {
             let event_affects_us = if let Some(our_user_id) = self.client.user_id().await {
-                room_member.state_key == our_user_id
+                event.state_key == our_user_id
             } else {
                 false
             };
 
-            let adding_user = match room_member.content.membership {
-                MembershipState::Join => true,
-                MembershipState::Leave | MembershipState::Ban => false,
+            use MembershipChange::*;
+            let adding_user = match event.membership_change() {
+                Joined => true,
+                Banned | Left | Kicked | KickedAndBanned => false,
                 _ => return,
             };
 
             //Clone to avoid holding lock.
             let room = room.read().await.clone();
-            let (room_id, username) = (room.room_id.as_str(), &room_member.state_key);
+            let (room_id, username) = (room.room_id.as_str(), &event.state_key);
 
             let result = if event_affects_us && !adding_user {
                 info!("Clearing all information for room ID {}", room_id);
                 self.db.rooms.clear_info(room_id)
+            } else if event_affects_us && adding_user {
+                info!("Joined room {}; recording user information", room_id);
+                Ok(())
             } 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)
@@ -109,7 +119,7 @@ impl EventEmitter for DiceBot {
                 info!("Removing user {} from room ID {}", username, room_id);
                 self.db.rooms.remove_user_from_room(username, room_id)
             } else {
-                debug!("Ignoring a room member event: {:#?}", room_member);
+                debug!("Ignoring a room member event: {:#?}", event);
                 Ok(())
             };