Fetch scrollback history independently of main loop (#39)

src/worker.rs

@@ -1,3 +1,4 @@
+use std::collections::HashMap;
 use std::convert::TryFrom;
 use std::fmt::{Debug, Formatter};
 use std::fs::File;
@@ -5,12 +6,12 @@ use std::io::BufWriter;
 use std::str::FromStr;
 use std::sync::mpsc::{sync_channel, Receiver, SyncSender};
 use std::sync::Arc;
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 use gethostname::gethostname;
 use tokio::sync::mpsc::{unbounded_channel, UnboundedReceiver, UnboundedSender};
 use tokio::task::JoinHandle;
-use tracing::error;
+use tracing::{error, warn};
 
 use matrix_sdk::{
     config::{RequestConfig, StoreConfig, SyncSettings},
@@ -44,6 +45,7 @@ use matrix_sdk::{
             tag::Tags,
             typing::SyncTypingEvent,
             AnyInitialStateEvent,
+            AnyMessageLikeEvent,
             AnyTimelineEvent,
             EmptyStateKey,
             InitialStateEvent,
@@ -56,6 +58,7 @@ use matrix_sdk::{
         OwnedRoomId,
         OwnedRoomOrAliasId,
         OwnedUserId,
+        RoomId,
         RoomVersionId,
     },
     Client,
@@ -68,12 +71,14 @@ use modalkit::editing::action::{EditInfo, InfoMessage, UIError};
 use crate::{
     base::{
         AsyncProgramStore,
+        ChatStore,
         CreateRoomFlags,
         CreateRoomType,
         EventLocation,
         IambError,
         IambResult,
         Receipts,
+        RoomFetchStatus,
         VerifyAction,
     },
     message::MessageFetchResult,
@@ -82,6 +87,7 @@ use crate::{
 
 const IAMB_DEVICE_NAME: &str = "iamb";
 const IAMB_USER_AGENT: &str = "iamb";
+const MIN_MSG_LOAD: u32 = 50;
 
 fn initial_devname() -> String {
     format!("{} on {}", IAMB_DEVICE_NAME, gethostname().to_string_lossy())
@@ -158,6 +164,113 @@ pub async fn create_room(
     return Ok(resp.room_id);
 }
 
+async fn load_plan(store: &AsyncProgramStore) -> HashMap<OwnedRoomId, Option<String>> {
+    let mut locked = store.lock().await;
+    let ChatStore { need_load, rooms, .. } = &mut locked.application;
+    let mut plan = HashMap::new();
+
+    for room_id in std::mem::take(need_load).into_iter() {
+        let info = rooms.get_or_default(room_id.clone());
+
+        if info.recently_fetched() || info.fetching {
+            need_load.insert(room_id);
+            continue;
+        } else {
+            info.fetch_last = Instant::now().into();
+            info.fetching = true;
+        }
+
+        let fetch_id = match &info.fetch_id {
+            RoomFetchStatus::Done => continue,
+            RoomFetchStatus::HaveMore(fetch_id) => Some(fetch_id.clone()),
+            RoomFetchStatus::NotStarted => None,
+        };
+
+        plan.insert(room_id, fetch_id);
+    }
+
+    return plan;
+}
+
+async fn load_older_one(
+    client: Client,
+    room_id: &RoomId,
+    fetch_id: Option<String>,
+    limit: u32,
+) -> MessageFetchResult {
+    if let Some(room) = client.get_room(room_id) {
+        let mut opts = match &fetch_id {
+            Some(id) => MessagesOptions::backward().from(id.as_str()),
+            None => MessagesOptions::backward(),
+        };
+        opts.limit = limit.into();
+
+        let Messages { end, chunk, .. } = room.messages(opts).await.map_err(IambError::from)?;
+
+        let msgs = chunk.into_iter().filter_map(|ev| {
+            match ev.event.deserialize() {
+                Ok(AnyTimelineEvent::MessageLike(msg)) => Some(msg),
+                Ok(AnyTimelineEvent::State(_)) => None,
+                Err(_) => None,
+            }
+        });
+
+        Ok((end, msgs.collect()))
+    } else {
+        Err(IambError::UnknownRoom(room_id.to_owned()).into())
+    }
+}
+
+async fn load_insert(room_id: OwnedRoomId, res: MessageFetchResult, store: AsyncProgramStore) {
+    let mut locked = store.lock().await;
+    let ChatStore { need_load, presences, rooms, .. } = &mut locked.application;
+    let info = rooms.get_or_default(room_id.clone());
+    info.fetching = false;
+
+    match res {
+        Ok((fetch_id, msgs)) => {
+            for msg in msgs.into_iter() {
+                let sender = msg.sender().to_owned();
+                let _ = presences.get_or_default(sender);
+
+                match msg {
+                    AnyMessageLikeEvent::RoomMessage(msg) => {
+                        info.insert(msg);
+                    },
+                    AnyMessageLikeEvent::Reaction(ev) => {
+                        info.insert_reaction(ev);
+                    },
+                    _ => continue,
+                }
+            }
+
+            info.fetch_id = fetch_id.map_or(RoomFetchStatus::Done, RoomFetchStatus::HaveMore);
+        },
+        Err(e) => {
+            warn!(room_id = room_id.as_str(), err = e.to_string(), "Failed to load older messages");
+
+            // Wait and try again.
+            need_load.insert(room_id);
+        },
+    }
+}
+
+async fn load_older(client: &Client, store: &AsyncProgramStore) {
+    let limit = MIN_MSG_LOAD;
+    let plan = load_plan(store).await;
+
+    // Fetch each room separately, so they don't block each other.
+    for (room_id, fetch_id) in plan.into_iter() {
+        let client = client.clone();
+        let store = store.clone();
+
+        tokio::spawn(async move {
+            let res = load_older_one(client, room_id.as_ref(), fetch_id, limit).await;
+            load_insert(room_id, res, store).await;
+        });
+    }
+}
+
 #[derive(Debug)]
 pub enum LoginStyle {
     SessionRestore(Session),
@@ -216,7 +329,6 @@ pub enum WorkerTask {
     ActiveRooms(ClientReply<Vec<FetchedRoom>>),
     DirectMessages(ClientReply<Vec<FetchedRoom>>),
     Init(AsyncProgramStore, ClientReply<()>),
-    LoadOlder(OwnedRoomId, Option<String>, u32, ClientReply<MessageFetchResult>),
     Login(LoginStyle, ClientReply<IambResult<EditInfo>>),
     GetInviter(Invited, ClientReply<IambResult<Option<RoomMember>>>),
     GetRoom(OwnedRoomId, ClientReply<IambResult<FetchedRoom>>),
@@ -246,14 +358,6 @@ impl Debug for WorkerTask {
                     .field(&format_args!("_"))
                     .finish()
             },
-            WorkerTask::LoadOlder(room_id, from, n, _) => {
-                f.debug_tuple("WorkerTask::LoadOlder")
-                    .field(room_id)
-                    .field(from)
-                    .field(n)
-                    .field(&format_args!("_"))
-                    .finish()
-            },
             WorkerTask::Login(style, _) => {
                 f.debug_tuple("WorkerTask::Login")
                     .field(style)
@@ -325,21 +429,6 @@ impl Requester {
         return response.recv();
     }
 
-    pub fn load_older(
-        &self,
-        room_id: OwnedRoomId,
-        fetch_id: Option<String>,
-        limit: u32,
-    ) -> MessageFetchResult {
-        let (reply, response) = oneshot();
-
-        self.tx
-            .send(WorkerTask::LoadOlder(room_id, fetch_id, limit, reply))
-            .unwrap();
-
-        return response.recv();
-    }
-
     pub fn login(&self, style: LoginStyle) -> IambResult<EditInfo> {
         let (reply, response) = oneshot();
 
@@ -437,8 +526,9 @@ pub struct ClientWorker {
     initialized: bool,
     settings: ApplicationSettings,
     client: Client,
-    sync_handle: Option<JoinHandle<()>>,
+    load_handle: Option<JoinHandle<()>>,
     rcpt_handle: Option<JoinHandle<()>>,
+    sync_handle: Option<JoinHandle<()>>,
 }
 
 impl ClientWorker {
@@ -476,8 +566,9 @@ impl ClientWorker {
             initialized: false,
             settings,
             client: client.clone(),
-            sync_handle: None,
+            load_handle: None,
             rcpt_handle: None,
+            sync_handle: None,
         };
 
         tokio::spawn(async move {
@@ -535,10 +626,6 @@ impl ClientWorker {
                 assert!(self.initialized);
                 reply.send(self.active_rooms().await);
             },
-            WorkerTask::LoadOlder(room_id, fetch_id, limit, reply) => {
-                assert!(self.initialized);
-                reply.send(self.load_older(room_id, fetch_id, limit).await);
-            },
             WorkerTask::Login(style, reply) => {
                 assert!(self.initialized);
                 reply.send(self.login_and_sync(style).await);
@@ -811,17 +898,34 @@ impl ClientWorker {
             },
         );
 
-        let client = self.client.clone();
+        self.rcpt_handle = tokio::spawn({
+            let store = store.clone();
+            let client = self.client.clone();
 
-        self.rcpt_handle = tokio::spawn(async move {
-            // Update the displayed read receipts ever 5 seconds.
-            let mut interval = tokio::time::interval(Duration::from_secs(5));
+            async move {
+                // Update the displayed read receipts every 5 seconds.
+                let mut interval = tokio::time::interval(Duration::from_secs(5));
 
-            loop {
-                interval.tick().await;
+                loop {
+                    interval.tick().await;
 
-                let receipts = update_receipts(&client).await;
-                store.lock().await.application.set_receipts(receipts).await;
+                    let receipts = update_receipts(&client).await;
+                    store.lock().await.application.set_receipts(receipts).await;
+                }
+            }
+        })
+        .into();
+
+        self.load_handle = tokio::spawn({
+            let client = self.client.clone();
+
+            async move {
+                // Load older messages every 2 seconds.
+                let mut interval = tokio::time::interval(Duration::from_secs(2));
+                loop {
+                    interval.tick().await;
+                    load_older(&client, &store).await;
+                }
             }
         })
         .into();
@@ -991,35 +1095,6 @@ impl ClientWorker {
         return rooms;
     }
 
-    async fn load_older(
-        &mut self,
-        room_id: OwnedRoomId,
-        fetch_id: Option<String>,
-        limit: u32,
-    ) -> MessageFetchResult {
-        if let Some(room) = self.client.get_room(room_id.as_ref()) {
-            let mut opts = match &fetch_id {
-                Some(id) => MessagesOptions::backward().from(id.as_str()),
-                None => MessagesOptions::backward(),
-            };
-            opts.limit = limit.into();
-
-            let Messages { end, chunk, .. } = room.messages(opts).await.map_err(IambError::from)?;
-
-            let msgs = chunk.into_iter().filter_map(|ev| {
-                match ev.event.deserialize() {
-                    Ok(AnyTimelineEvent::MessageLike(msg)) => Some(msg),
-                    Ok(AnyTimelineEvent::State(_)) => None,
-                    Err(_) => None,
-                }
-            });
-
-            Ok((end, msgs.collect()))
-        } else {
-            Err(IambError::UnknownRoom(room_id).into())
-        }
-    }
-
     async fn members(&mut self, room_id: OwnedRoomId) -> IambResult<Vec<RoomMember>> {
         if let Some(room) = self.client.get_room(room_id.as_ref()) {
             Ok(room.active_members().await.map_err(IambError::from)?)