move eventidshort_cache to service

src/service/rooms/short.rs

@@ -1,7 +1,7 @@
 use std::sync::{Arc, Mutex};
 
 use lru_cache::LruCache;
-use ruma::{events::StateEventType, EventId, RoomId};
+use ruma::{events::StateEventType, EventId, OwnedEventId, RoomId};
 
 use crate::{
     observability::{FoundIn, Lookup, METRICS},
@@ -38,18 +38,23 @@ pub(crate) use data::Data;
 pub(crate) struct Service {
     db: &'static dyn Data,
     shorteventid_cache: Mutex<LruCache<ShortEventId, Arc<EventId>>>,
+    eventidshort_cache: Mutex<LruCache<OwnedEventId, ShortEventId>>,
 }
 
 impl Service {
     pub(crate) fn new(
         db: &'static dyn Data,
         shorteventid_cache_size: usize,
+        eventidshort_cache_size: usize,
     ) -> Self {
         Self {
             db,
             shorteventid_cache: Mutex::new(LruCache::new(
                 shorteventid_cache_size,
             )),
+            eventidshort_cache: Mutex::new(LruCache::new(
+                eventidshort_cache_size,
+            )),
         }
     }
 
@@ -57,7 +62,29 @@ impl Service {
         &self,
         event_id: &EventId,
     ) -> Result<ShortEventId> {
-        self.db.get_or_create_shorteventid(event_id)
+        let lookup = Lookup::CreateEventIdToShort;
+
+        if let Some(short) =
+            self.eventidshort_cache.lock().unwrap().get_mut(event_id)
+        {
+            METRICS.record_lookup(lookup, FoundIn::Cache);
+            return Ok(*short);
+        }
+
+        let (short, created) = self.db.get_or_create_shorteventid(event_id)?;
+
+        if created {
+            METRICS.record_lookup(lookup, FoundIn::Nothing);
+        } else {
+            METRICS.record_lookup(lookup, FoundIn::Database);
+        }
+
+        self.eventidshort_cache
+            .lock()
+            .unwrap()
+            .insert(event_id.to_owned(), short);
+
+        Ok(short)
     }
 
     pub(crate) fn get_shortstatekey(