refactor: RequestBuilder

packages/app/src/System/ProfileCache.ts

@@ -0,0 +1,100 @@
+import { EventKind, HexKey, TaggedRawEvent } from "@snort/nostr";
+import { ProfileCacheExpire } from "Const";
+import { mapEventToProfile, MetadataCache } from "State/Users";
+import { UserCache } from "State/Users/UserCache";
+import { PubkeyReplaceableNoteStore, RequestBuilder, System } from "System";
+import { unixNowMs } from "Util";
+
+class ProfileCache {
+  /**
+   * List of pubkeys to fetch metadata for
+   */
+  WantsMetadata: Set<HexKey> = new Set();
+
+  constructor() {
+    this.#FetchMetadata();
+  }
+
+  /**
+   * Request profile metadata for a set of pubkeys
+   */
+  TrackMetadata(pk: HexKey | Array<HexKey>) {
+    for (const p of Array.isArray(pk) ? pk : [pk]) {
+      if (p.length > 0) {
+        this.WantsMetadata.add(p);
+      }
+    }
+  }
+
+  /**
+   * Stop tracking metadata for a set of pubkeys
+   */
+  UntrackMetadata(pk: HexKey | Array<HexKey>) {
+    for (const p of Array.isArray(pk) ? pk : [pk]) {
+      if (p.length > 0) {
+        this.WantsMetadata.delete(p);
+      }
+    }
+  }
+
+  async #FetchMetadata() {
+    const missingFromCache = await UserCache.buffer([...this.WantsMetadata]);
+
+    const expire = unixNowMs() - ProfileCacheExpire;
+    const expired = [...this.WantsMetadata]
+      .filter(a => !missingFromCache.includes(a))
+      .filter(a => (UserCache.get(a)?.loaded ?? 0) < expire);
+    const missing = new Set([...missingFromCache, ...expired]);
+    if (missing.size > 0) {
+      console.debug(`Wants profiles: ${missingFromCache.length} missing, ${expired.length} expired`);
+
+      const sub = new RequestBuilder(`profiles`);
+      sub
+        .withFilter()
+        .kinds([EventKind.SetMetadata])
+        .authors([...missing]);
+
+      const q = System.Query<PubkeyReplaceableNoteStore>(PubkeyReplaceableNoteStore, sub);
+      // never release this callback, it will stop firing anyway after eose
+      q.onEvent(async ev => {
+        for (const e of ev) {
+          const profile = mapEventToProfile(e);
+          if (profile) {
+            await UserCache.update(profile);
+          }
+        }
+      });
+      const results = await new Promise<Readonly<Array<TaggedRawEvent>>>(resolve => {
+        let timeout: ReturnType<typeof setTimeout> | undefined = undefined;
+        const release = q.hook(() => {
+          if (!q.loading) {
+            clearTimeout(timeout);
+            resolve(q.getSnapshotData() ?? []);
+          }
+          release();
+        });
+        timeout = setTimeout(() => {
+          release();
+          resolve(q.getSnapshotData() ?? []);
+        }, 5_000);
+      });
+
+      const couldNotFetch = [...missing].filter(a => !results.some(b => b.pubkey === a));
+      if (couldNotFetch.length > 0) {
+        console.debug("No profiles: ", couldNotFetch);
+        const empty = couldNotFetch.map(a =>
+          UserCache.update({
+            pubkey: a,
+            loaded: unixNowMs() - ProfileCacheExpire + 5_000, // expire in 5s
+            created: 69,
+          } as MetadataCache)
+        );
+        await Promise.all(empty);
+      }
+    }
+
+    setTimeout(() => this.#FetchMetadata(), 500);
+  }
+}
+
+export const ProfileLoader = new ProfileCache();