Reuse canisters of deleted empty and dormant users (#6046)

backend/canisters/local_user_index/CHANGELOG.md

@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Added
 
 - Support gates with multiple verifiable credentials ([#6029](https://github.com/open-chat-labs/open-chat/pull/6029))
+- Reuse canisters of deleted empty and dormant users ([#6046](https://github.com/open-chat-labs/open-chat/pull/6046))
 
 ### Changed
 

backend/canisters/local_user_index/impl/src/jobs/delete_users.rs

@@ -3,16 +3,17 @@ use ic_cdk_timers::TimerId;
 use std::cell::Cell;
 use std::time::Duration;
 use tracing::trace;
-use types::Empty;
+use types::{Empty, Milliseconds};
 use user_index_canister::{Event, UserDeleted};
+use utils::time::SECOND_IN_MS;
 
 thread_local! {
     static TIMER_ID: Cell<Option<TimerId>> = Cell::default();
 }
 
-pub(crate) fn start_job_if_required(state: &RuntimeState) -> bool {
+pub(crate) fn start_job_if_required(state: &RuntimeState, delay: Option<Milliseconds>) -> bool {
     if TIMER_ID.get().is_none() && !state.data.users_to_delete_queue.is_empty() {
-        let timer_id = ic_cdk_timers::set_timer(Duration::ZERO, run);
+        let timer_id = ic_cdk_timers::set_timer(Duration::from_millis(delay.unwrap_or_default()), run);
         TIMER_ID.set(Some(timer_id));
         true
     } else {
@@ -42,7 +43,7 @@ async fn process_user(user: UserToDelete) {
         match user_canister_c2c_client::c2c_is_empty_and_dormant(canister_id, &Empty {}).await {
             Ok(true) => {}
             Ok(false) => {
-                read_state(start_job_if_required);
+                read_state(|state| start_job_if_required(state, None));
                 return;
             }
             Err(_) => error = true,
@@ -60,6 +61,7 @@ async fn process_user(user: UserToDelete) {
 
             if !user.triggered_by_user {
                 state.push_event_to_user_index(Event::UserDeleted(Box::new(UserDeleted { user_id })));
+                state.data.canister_pool.push(canister_id);
             }
         } else if user.attempt < 50 {
             state.data.users_to_delete_queue.push_back(UserToDelete {
@@ -69,6 +71,6 @@ async fn process_user(user: UserToDelete) {
             });
         }
 
-        start_job_if_required(state);
+        start_job_if_required(state, error.then_some(30 * SECOND_IN_MS));
     })
 }

backend/canisters/local_user_index/impl/src/jobs/mod.rs

@@ -8,7 +8,7 @@ pub mod topup_canister_pool;
 pub mod upgrade_canisters;
 
 pub(crate) fn start(state: &RuntimeState) {
-    delete_users::start_job_if_required(state);
+    delete_users::start_job_if_required(state, None);
     make_btc_miami_payments::start_job_if_required(state);
     sync_events_to_user_canisters::start_job_if_required(state);
     sync_events_to_user_index_canister::start_job_if_required(state);

backend/canisters/local_user_index/impl/src/updates/c2c_notify_user_index_events.rs

@@ -171,7 +171,7 @@ fn handle_event(event: Event, state: &mut RuntimeState) {
                     triggered_by_user: ev.triggered_by_user,
                     attempt: 0,
                 });
-                jobs::delete_users::start_job_if_required(state);
+                jobs::delete_users::start_job_if_required(state, None);
             } else {
                 state.data.global_users.remove(&ev.user_id);
             }

backend/canisters/user/CHANGELOG.md

@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Added lots more achievements to enum ([#6020](https://github.com/open-chat-labs/open-chat/pull/6020))
 - Added support for a bunch more achievements ([#6033](https://github.com/open-chat-labs/open-chat/pull/6033))
 - Store `unique_person_proof` in User canisters ([#6029](https://github.com/open-chat-labs/open-chat/pull/6029))
+- Re-enable notifying of user accounts that are empty and dormant ([#6046](https://github.com/open-chat-labs/open-chat/pull/6046))
 
 ### Removed
 

backend/canisters/user/impl/src/lifecycle/post_upgrade.rs

@@ -1,6 +1,6 @@
 use crate::lifecycle::{init_env, init_state};
 use crate::memory::get_upgrades_memory;
-use crate::{mutate_state, Data};
+use crate::{read_state, Data};
 use canister_logger::LogEntry;
 use canister_tracing_macros::trace;
 use ic_cdk::post_upgrade;
@@ -12,7 +12,6 @@ use user_canister::post_upgrade::Args;
 use utils::time::DAY_IN_MS;
 
 const SIX_MONTHS: Milliseconds = 183 * DAY_IN_MS;
-const NOTIFY_IF_EMPTY: bool = false;
 
 #[post_upgrade]
 #[trace]
@@ -29,22 +28,19 @@ fn post_upgrade(args: Args) {
 
     info!(version = %args.wasm_version, "Post-upgrade complete");
 
-    // Disable this for now until all existing empty users have been deleted
-    if NOTIFY_IF_EMPTY {
-        mutate_state(|state| {
-            if state.data.user_created + SIX_MONTHS < state.env.now()
-                && state.data.direct_chats.len() <= 1
-                && state.data.group_chats.len() == 0
-                && state.data.communities.len() == 0
-            {
-                ic_cdk_timers::set_timer(Duration::ZERO, mark_user_canister_empty);
-            }
-        });
-    }
+    read_state(|state| {
+        if state.data.user_created + SIX_MONTHS < state.env.now()
+            && state.data.direct_chats.len() <= 1
+            && state.data.group_chats.len() == 0
+            && state.data.communities.len() == 0
+        {
+            ic_cdk_timers::set_timer(Duration::ZERO, mark_user_canister_empty);
+        }
+    });
 }
 
 fn mark_user_canister_empty() {
-    mutate_state(|state| {
+    read_state(|state| {
         let user_index_canister_id = state.data.user_index_canister_id;
         state.data.fire_and_forget_handler.send(
             user_index_canister_id,

backend/canisters/user_index/CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 - Sync userIds to Identity canister ([#6027](https://github.com/open-chat-labs/open-chat/pull/6027))
 - Add `is_unique_person` field to user responses ([#6040](https://github.com/open-chat-labs/open-chat/pull/6040))
+- Auto delete users who get flagged as being empty and dormant ([#6046](https://github.com/open-chat-labs/open-chat/pull/6046))
 
 ## [[2.0.1235](https://github.com/open-chat-labs/open-chat/releases/tag/v2.0.1235-user_index)] - 2024-07-11
 

backend/canisters/user_index/impl/src/updates/c2c_mark_user_canister_empty.rs

@@ -1,6 +1,7 @@
 use crate::{mutate_state, RuntimeState};
 use canister_api_macros::update;
 use canister_tracing_macros::trace;
+use local_user_index_canister::{DeleteUser, Event};
 use user_index_canister::c2c_mark_user_canister_empty::{Response::*, *};
 
 #[update(msgpack = true)]
@@ -13,6 +14,13 @@ fn c2c_mark_user_canister_empty_impl(state: &mut RuntimeState) -> Response {
     let user_id = state.env.caller().into();
     if state.data.users.get_by_user_id(&user_id).is_some() {
         state.data.empty_users.insert(user_id);
+        state.push_event_to_all_local_user_indexes(
+            Event::DeleteUser(DeleteUser {
+                user_id,
+                triggered_by_user: false,
+            }),
+            None,
+        );
     }
     Success
 }

backend/libraries/utils/src/canister/pool.rs

@@ -29,6 +29,10 @@ impl Pool {
         self.canister_ids.len() >= self.target_size as usize
     }
 
+    pub fn contains(&self, canister_id: &CanisterId) -> bool {
+        self.canister_ids.contains(canister_id)
+    }
+
     pub fn push(&mut self, canister_id: CanisterId) {
         self.canister_ids.push_back(canister_id);
     }