feat(core): implement message tasks

includes:
- acknowledgements
- last_message_id
- embeds
- web push

crates/core/database/src/tasks/ack.rs

@@ -0,0 +1,122 @@
+// Queue Type: Debounced
+use crate::Database;
+
+use deadqueue::limited::Queue;
+use once_cell::sync::Lazy;
+use std::{collections::HashMap, time::Duration};
+
+use super::DelayedTask;
+
+/// Enumeration of possible events
+#[derive(Debug, Eq, PartialEq)]
+pub enum AckEvent {
+    /// Add mentions for a user in a channel
+    AddMention {
+        /// Message IDs
+        ids: Vec<String>,
+    },
+
+    /// Acknowledge message in a channel for a user
+    AckMessage {
+        /// Message ID
+        id: String,
+    },
+}
+
+/// Task information
+struct Data {
+    /// Channel to ack
+    channel: String,
+    /// User to ack for
+    user: String,
+    /// Event
+    event: AckEvent,
+}
+
+#[derive(Debug)]
+struct Task {
+    event: AckEvent,
+}
+
+static Q: Lazy<Queue<Data>> = Lazy::new(|| Queue::new(10_000));
+
+/// Queue a new task for a worker
+pub async fn queue(channel: String, user: String, event: AckEvent) {
+    Q.try_push(Data {
+        channel,
+        user,
+        event,
+    })
+    .ok();
+
+    info!("Queue is using {} slots from {}.", Q.len(), Q.capacity());
+}
+
+/// Start a new worker
+pub async fn worker(db: Database) {
+    let mut tasks = HashMap::<(String, String), DelayedTask<Task>>::new();
+    let mut keys = vec![];
+
+    loop {
+        // Find due tasks.
+        for (key, task) in &tasks {
+            if task.should_run() {
+                keys.push(key.clone());
+            }
+        }
+
+        // Commit any due tasks to the database.
+        for key in &keys {
+            if let Some(task) = tasks.remove(key) {
+                let Task { event } = task.data;
+                let (user, channel) = key;
+
+                if let Err(err) = match &event {
+                    #[allow(clippy::disallowed_methods)] // event is sent by higher level function
+                    AckEvent::AckMessage { id } => db.acknowledge_message(channel, user, id).await,
+                    AckEvent::AddMention { ids } => {
+                        db.add_mention_to_unread(channel, user, ids).await
+                    }
+                } {
+                    error!("{err:?} for {event:?}. ({user}, {channel})");
+                } else {
+                    info!("User {user} ack in {channel} with {event:?}");
+                }
+            }
+        }
+
+        // Clear keys
+        keys.clear();
+
+        // Queue incoming tasks.
+        while let Some(Data {
+            channel,
+            user,
+            mut event,
+        }) = Q.try_pop()
+        {
+            let key = (user, channel);
+            if let Some(task) = tasks.get_mut(&key) {
+                task.delay();
+
+                match &mut event {
+                    AckEvent::AddMention { ids } => {
+                        if let AckEvent::AddMention { ids: existing } = &mut task.data.event {
+                            existing.append(ids);
+                        } else {
+                            task.data.event = event;
+                        }
+                    }
+                    AckEvent::AckMessage { .. } => {
+                        task.data.event = event;
+                    }
+                }
+            } else {
+                tasks.insert(key, DelayedTask::new(Task { event }));
+            }
+        }
+
+        // Sleep for an arbitrary amount of time.
+        async_std::task::sleep(Duration::from_secs(1)).await;
+    }
+}