Preemptive anti-database-bloat measures

phoebe-main/src/main.rs

@@ -37,13 +37,16 @@ async fn handle_events(
                     )
                 }
 
-                if let Err(e) = link_messages(&mut conn, &message.origin, &resulting_messages).await
+                if !resulting_messages.is_empty() {
+                    if let Err(e) =
+                        link_messages(&mut conn, &message.origin, &resulting_messages).await
                     {
                         tracing::error!("Failed to link messages: {e}");
                     }
                 }
             }
         }
+    }
 }
 
 #[tokio::main]

phoebe/src/lib.rs

@@ -74,12 +74,10 @@ pub async fn link_messages(
     Ok(())
 }
 
-pub async fn get_linked_messages<'a>(
-    conn: &'a mut SqliteConnection,
-    dyn_service: DynServiceLookup,
+pub async fn get_message_link_id(
+    conn: &mut SqliteConnection,
     message: &ChatMessageReference,
-) -> sqlx::Result<BoxStream<'a, ChatMessageReference>> {
-    let link_id = {
+) -> sqlx::Result<i64> {
     let service = &message.channel.service;
     let channel = &message.channel.id;
     let message_id = &message.message_id;
@@ -89,9 +87,16 @@ pub async fn get_linked_messages<'a>(
         channel,
         message_id
     );
-        query.fetch_one(&mut *conn).await
-    }?
-    .link_id;
+    let r = query.fetch_one(&mut *conn).await?;
+    Ok(r.link_id)
+}
+
+pub async fn get_linked_messages<'a>(
+    conn: &'a mut SqliteConnection,
+    dyn_service: DynServiceLookup,
+    message: &ChatMessageReference,
+) -> sqlx::Result<BoxStream<'a, ChatMessageReference>> {
+    let link_id = get_message_link_id(&mut *conn, message).await?;
 
     let stream = sqlx::query("SELECT * FROM messages WHERE link_id = ?")
         .bind(link_id)

services/phoebe-discord/src/handler.rs

@@ -1,4 +1,4 @@
-use phoebe::{mid_chat::*, prelude::*};
+use phoebe::{get_message_link_id, mid_chat::*, prelude::*};
 use serenity::{
     client::{Context, EventHandler},
     model::prelude::*,
@@ -50,6 +50,13 @@ impl EventHandler for DiscordHandler {
     async fn message(&self, ctx: Context, message: Message) {
         let origin = ChatMessageReference::new(discord_reference(message.channel_id), message.id);
 
+        // skip messages linked to ones we have already seen
+        if let Ok(mut conn) = self.core_db.acquire().await {
+            if get_message_link_id(&mut conn, &origin).await.is_ok() {
+                return;
+            }
+        }
+
         let author = self.get_author(&ctx, &message).await;
 
         let content = discord_message_format::parse(&message.content);