Refactor memorelay as an EventStore

src/db/events.ts

@@ -354,8 +354,8 @@ function buildUserSearchContent(event: Event<0>): string {
 
 /** SQLite database storage adapter for Nostr events. */
 const eventsDB: EventStore = {
-  storeEvent,
   getEvents,
+  storeEvent,
   countEvents,
   deleteEvents,
 };

src/db/memorelay.test.ts

@@ -5,14 +5,12 @@ import event1 from '~/fixtures/events/event-1.json' assert { type: 'json' };
 import { memorelay } from './memorelay.ts';
 
 Deno.test('memorelay', async () => {
-  assertEquals(memorelay.hasEvent(event1), false);
-  assertEquals(memorelay.hasEventById(event1.id), false);
+  assertEquals(await memorelay.countEvents([{ ids: [event1.id] }]), 0);
 
-  memorelay.insertEvent(event1);
+  await memorelay.storeEvent(event1);
 
-  assertEquals(memorelay.hasEvent(event1), true);
-  assertEquals(memorelay.hasEventById(event1.id), true);
+  assertEquals(await memorelay.countEvents([{ ids: [event1.id] }]), 1);
 
-  const result = await memorelay.getFilters([{ ids: [event1.id] }]);
+  const result = await memorelay.getEvents([{ ids: [event1.id] }]);
   assertEquals(result[0], event1);
 });

src/db/memorelay.ts

@@ -1,5 +1,6 @@
 import { Debug, type Event, type Filter, LRUCache } from '@/deps.ts';
-import { getFilterId, type GetFiltersOpts, getMicroFilters, isMicrofilter } from '@/filter.ts';
+import { getFilterId, getMicroFilters, isMicrofilter } from '@/filter.ts';
+import { type EventStore, type GetEventsOpts } from '@/store.ts';
 
 const debug = Debug('ditto:memorelay');
 
@@ -10,7 +11,7 @@ const events = new LRUCache<string, Event>({
 });
 
 /** Get events from memory. */
-function getFilters<K extends number>(filters: Filter<K>[], opts: GetFiltersOpts = {}): Promise<Event<K>[]> {
+function getEvents<K extends number>(filters: Filter<K>[], opts: GetEventsOpts = {}): Promise<Event<K>[]> {
   if (opts.signal?.aborted) return Promise.resolve([]);
   if (!filters.length) return Promise.resolve([]);
   debug('REQ', JSON.stringify(filters));
@@ -30,7 +31,7 @@ function getFilters<K extends number>(filters: Filter<K>[], opts: GetFiltersOpts
 }
 
 /** Insert an event into memory. */
-function insertEvent(event: Event): void {
+function storeEvent(event: Event): Promise<void> {
   for (const microfilter of getMicroFilters(event)) {
     const filterId = getFilterId(microfilter);
     const existing = events.get(filterId);
@@ -38,32 +39,31 @@ function insertEvent(event: Event): void {
       events.set(filterId, event);
     }
   }
+  return Promise.resolve();
 }
 
-/** Check if an event is in memory. */
-function hasEvent(event: Event): boolean {
-  for (const microfilter of getMicroFilters(event)) {
-    const filterId = getFilterId(microfilter);
-    const existing = events.get(filterId);
-    if (existing) {
-      return true;
-    }
-  }
-  return false;
+/** Count events in memory for the filters. */
+async function countEvents(filters: Filter[]): Promise<number> {
+  const events = await getEvents(filters);
+  return events.length;
 }
 
-/** Check if an event is in memory by ID. */
-function hasEventById(eventId: string): boolean {
-  const filterId = getFilterId({ ids: [eventId] });
-  return events.has(filterId);
+/** Delete events from memory. */
+function deleteEvents(filters: Filter[]): Promise<void> {
+  for (const filter of filters) {
+    if (isMicrofilter(filter)) {
+      events.delete(getFilterId(filter));
+    }
+  }
+  return Promise.resolve();
 }
 
 /** In-memory data store for events using microfilters. */
-const memorelay = {
-  getFilters,
-  insertEvent,
-  hasEvent,
-  hasEventById,
+const memorelay: EventStore = {
+  getEvents,
+  storeEvent,
+  countEvents,
+  deleteEvents,
 };
 
 export { memorelay };

src/filter.ts

@@ -21,16 +21,6 @@ type AuthorMicrofilter = { kinds: [0]; authors: [Event['pubkey']] };
 /** Filter to get one specific event. */
 type MicroFilter = IdMicrofilter | AuthorMicrofilter;
 
-/** Additional options to apply to the whole subscription. */
-interface GetFiltersOpts {
-  /** Signal to abort the request. */
-  signal?: AbortSignal;
-  /** Event limit for the whole subscription. */
-  limit?: number;
-  /** Relays to use, if applicable. */
-  relays?: WebSocket['url'][];
-}
-
 function matchDittoFilter(filter: DittoFilter, event: Event, data: EventData): boolean {
   if (filter.local && !(data.user || event.pubkey === Conf.pubkey)) {
     return false;
@@ -97,7 +87,6 @@ export {
   type DittoFilter,
   eventToMicroFilter,
   getFilterId,
-  type GetFiltersOpts,
   getMicroFilters,
   type IdMicrofilter,
   isMicrofilter,

src/pipeline.ts

@@ -26,7 +26,7 @@ const debug = Debug('ditto:pipeline');
 async function handleEvent(event: Event): Promise<void> {
   if (!(await verifySignatureWorker(event))) return;
   const wanted = reqmeister.isWanted(event);
-  if (encounterEvent(event)) return;
+  if (await encounterEvent(event)) return;
   debug(`Event<${event.kind}> ${event.id}`);
   const data = await getEventData(event);
 
@@ -43,9 +43,9 @@ async function handleEvent(event: Event): Promise<void> {
 }
 
 /** Encounter the event, and return whether it has already been encountered. */
-function encounterEvent(event: Event): boolean {
-  const preexisting = memorelay.hasEvent(event);
-  memorelay.insertEvent(event);
+async function encounterEvent(event: Event): Promise<boolean> {
+  const preexisting = (await memorelay.countEvents([{ ids: [event.id] }])) > 0;
+  memorelay.storeEvent(event);
   reqmeister.encounter(event);
   return preexisting;
 }
@@ -142,7 +142,7 @@ function fetchRelatedEvents(event: Event, data: EventData) {
     reqmeister.req({ kinds: [0], authors: [event.pubkey] }).catch(() => {});
   }
   for (const [name, id, relay] of event.tags) {
-    if (name === 'e' && !memorelay.hasEventById(id)) {
+    if (name === 'e' && !memorelay.countEvents([{ ids: [id] }])) {
       reqmeister.req({ ids: [id] }, { relays: [relay] }).catch(() => {});
     }
   }

src/queries.ts

@@ -22,7 +22,7 @@ const getEvent = async <K extends number = number>(
   const { kind, relations, signal = AbortSignal.timeout(1000) } = opts;
   const microfilter: IdMicrofilter = { ids: [id] };
 
-  const [memoryEvent] = await memorelay.getFilters([microfilter], opts) as DittoEvent<K>[];
+  const [memoryEvent] = await memorelay.getEvents([microfilter], opts) as DittoEvent<K>[];
 
   if (memoryEvent && !relations) {
     return memoryEvent;
@@ -39,14 +39,14 @@ const getEvent = async <K extends number = number>(
   // TODO: make this DRY-er.
 
   if (dbEvent && !dbEvent.author) {
-    const [author] = await memorelay.getFilters([{ kinds: [0], authors: [dbEvent.pubkey] }], opts);
+    const [author] = await memorelay.getEvents([{ kinds: [0], authors: [dbEvent.pubkey] }], opts);
     dbEvent.author = author;
   }
 
   if (dbEvent) return dbEvent;
 
   if (memoryEvent && !memoryEvent.author) {
-    const [author] = await memorelay.getFilters([{ kinds: [0], authors: [memoryEvent.pubkey] }], opts);
+    const [author] = await memorelay.getEvents([{ kinds: [0], authors: [memoryEvent.pubkey] }], opts);
     memoryEvent.author = author;
   }
 
@@ -60,7 +60,7 @@ const getAuthor = async (pubkey: string, opts: GetEventOpts<0> = {}): Promise<Ev
   const { relations, signal = AbortSignal.timeout(1000) } = opts;
   const microfilter: AuthorMicrofilter = { kinds: [0], authors: [pubkey] };
 
-  const [memoryEvent] = await memorelay.getFilters([microfilter], opts);
+  const [memoryEvent] = await memorelay.getEvents([microfilter], opts);
 
   if (memoryEvent && !relations) {
     return memoryEvent;