From e5e737faae58a470e7f1fa8675ed2025bd427d59 Mon Sep 17 00:00:00 2001
From: Alex Gleason <alex@alexgleason.me>
Date: Tue, 26 Dec 2023 16:23:24 -0600
Subject: [PATCH] Reqmeister: add a jsdoc

---
 src/reqmeister.ts                             |   1 +
 tringifyStable from npm:fast-stable-stringify | 307 ++++++++++++++++++
 2 files changed, 308 insertions(+)
 create mode 100644 tringifyStable from npm:fast-stable-stringify

diff --git a/src/reqmeister.ts b/src/reqmeister.ts
index 960151f..7830b84 100644
--- a/src/reqmeister.ts
+++ b/src/reqmeister.ts
@@ -10,6 +10,7 @@ interface ReqmeisterOpts {
 
 type ReqmeisterQueueItem = [string, MicroFilter, WebSocket['url'][]];
 
+/** Batches requests to Nostr relays using microfilters. */
 class Reqmeister extends EventEmitter<{ [filterId: string]: (event: Event) => any }> {
   #opts: ReqmeisterOpts;
   #queue: ReqmeisterQueueItem[] = [];
diff --git a/tringifyStable from npm:fast-stable-stringify b/tringifyStable from npm:fast-stable-stringify
new file mode 100644
index 0000000..edb0958
--- /dev/null
+++ b/tringifyStable from npm:fast-stable-stringify	
@@ -0,0 +1,307 @@
+diff --git a/src/client.ts b/src/client.ts
+index 970a077..3cf2e8a 100644
+--- a/src/client.ts
++++ b/src/client.ts
+@@ -14,7 +14,7 @@ function getFilters<K extends number>(filters: Filter<K>[], opts: GetFiltersOpts
+ 
+     const unsub = pool.subscribe(
+       filters,
+-      activeRelays,
++      opts.relays ?? activeRelays,
+       (event: Event | null) => {
+         if (event && matchFilters(filters, event)) {
+           pipeline.handleEvent(event).catch(() => {});
+diff --git a/src/common.ts b/src/common.ts
+new file mode 100644
+index 0000000..0424b52
+--- /dev/null
++++ b/src/common.ts
+@@ -0,0 +1,9 @@
++import { Reqmeister } from '@/reqmeister.ts';
++import { Time } from '@/utils/time.ts';
++
++const reqmeister = new Reqmeister({
++  delay: Time.seconds(1),
++  signal: AbortSignal.timeout(Time.seconds(1)),
++});
++
++export { reqmeister };
+diff --git a/src/deps.ts b/src/deps.ts
+index b9db9e2..4a9314b 100644
+--- a/src/deps.ts
++++ b/src/deps.ts
+@@ -81,5 +81,7 @@ export { Machina } from 'https://gitlab.com/soapbox-pub/nostr-machina/-/raw/08a1
+ export * as Sentry from 'https://deno.land/x/sentry@7.78.0/index.js';
+ export { sentry as sentryMiddleware } from 'npm:@hono/sentry@^1.0.0';
+ export * as Comlink from 'npm:comlink@^4.4.1';
++export { EventEmitter } from 'npm:tseep@^1.1.3';
++export { default as stringifyStable } from 'npm:fast-stable-stringify@^1.0.0';
+ 
+ export type * as TypeFest from 'npm:type-fest@^4.3.0';
+diff --git a/src/filter.ts b/src/filter.ts
+index fb43251..38fcff7 100644
+--- a/src/filter.ts
++++ b/src/filter.ts
+@@ -1,5 +1,5 @@
+ import { Conf } from '@/config.ts';
+-import { type Event, type Filter, matchFilters } from '@/deps.ts';
++import { type Event, type Filter, matchFilters, stringifyStable } from '@/deps.ts';
+ 
+ import type { EventData } from '@/types.ts';
+ 
+@@ -14,12 +14,17 @@ interface DittoFilter<K extends number = number> extends Filter<K> {
+   relations?: Relation[];
+ }
+ 
++/** Filter to get one specific event. */
++type MicroFilter = { ids: [Event['id']] } | { kinds: [0]; authors: [Event['pubkey']] };
++
+ /** 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 {
+@@ -44,4 +49,33 @@ function matchDittoFilters(filters: DittoFilter[], event: Event, data: EventData
+   return false;
+ }
+ 
+-export { type DittoFilter, type GetFiltersOpts, matchDittoFilters, type Relation };
++/** Get deterministic ID for a microfilter. */
++function getFilterId(filter: MicroFilter): string {
++  if ('ids' in filter) {
++    return stringifyStable({ ids: [filter.ids] });
++  } else {
++    return stringifyStable({
++      kinds: [filter.kinds[0]],
++      authors: [filter.authors[0]],
++    });
++  }
++}
++
++/** Get a microfilter from a Nostr event. */
++function eventToMicroFilter(event: Event): MicroFilter {
++  if (event.kind === 0) {
++    return { kinds: [0], authors: [event.pubkey] };
++  } else {
++    return { ids: [event.id] };
++  }
++}
++
++export {
++  type DittoFilter,
++  eventToMicroFilter,
++  getFilterId,
++  type GetFiltersOpts,
++  matchDittoFilters,
++  type MicroFilter,
++  type Relation,
++};
+diff --git a/src/pipeline.ts b/src/pipeline.ts
+index adf8a84..923bf4e 100644
+--- a/src/pipeline.ts
++++ b/src/pipeline.ts
+@@ -1,3 +1,4 @@
++import { reqmeister } from '@/common.ts';
+ import { Conf } from '@/config.ts';
+ import * as eventsDB from '@/db/events.ts';
+ import { addRelays } from '@/db/relays.ts';
+@@ -23,15 +24,17 @@ import type { EventData } from '@/types.ts';
+  */
+ async function handleEvent(event: Event): Promise<void> {
+   if (!(await verifySignatureWorker(event))) return;
++  const wanted = reqmeister.isWanted(event);
+   if (encounterEvent(event)) return;
+   console.info(`pipeline: Event<${event.kind}> ${event.id}`);
+   const data = await getEventData(event);
+ 
+   await Promise.all([
+-    storeEvent(event, data),
++    storeEvent(event, data, { force: wanted }),
+     processDeletions(event),
+     trackRelays(event),
+     trackHashtags(event),
++    fetchRelatedEvents(event, data),
+     processMedia(event, data),
+     streamOut(event, data),
+     broadcast(event, data),
+@@ -39,13 +42,14 @@ async function handleEvent(event: Event): Promise<void> {
+ }
+ 
+ /** Tracks encountered events to skip duplicates, improving idempotency and performance. */
+-const encounters = new LRUCache<string, boolean>({ max: 1000 });
++const encounters = new LRUCache<Event['id'], true>({ max: 1000 });
+ 
+ /** Encounter the event, and return whether it has already been encountered. */
+-function encounterEvent(event: Event) {
++function encounterEvent(event: Event): boolean {
+   const result = encounters.get(event.id);
+   encounters.set(event.id, true);
+-  return result;
++  reqmeister.encounter(event);
++  return !!result;
+ }
+ 
+ /** Preload data that will be useful to several tasks. */
+@@ -57,11 +61,16 @@ async function getEventData({ pubkey }: Event): Promise<EventData> {
+ /** Check if the pubkey is the `DITTO_NSEC` pubkey. */
+ const isAdminEvent = ({ pubkey }: Event): boolean => pubkey === Conf.pubkey;
+ 
++interface StoreEventOpts {
++  force?: boolean;
++}
++
+ /** Maybe store the event, if eligible. */
+-async function storeEvent(event: Event, data: EventData): Promise<void> {
++async function storeEvent(event: Event, data: EventData, opts: StoreEventOpts = {}): Promise<void> {
+   if (isEphemeralKind(event.kind)) return;
++  const { force = false } = opts;
+ 
+-  if (data.user || isAdminEvent(event) || await isLocallyFollowed(event.pubkey)) {
++  if (force || data.user || isAdminEvent(event) || await isLocallyFollowed(event.pubkey)) {
+     const [deletion] = await mixer.getFilters(
+       [{ kinds: [5], authors: [event.pubkey], '#e': [event.id], limit: 1 }],
+       { limit: 1, signal: AbortSignal.timeout(Time.seconds(1)) },
+@@ -129,6 +138,18 @@ function trackRelays(event: Event) {
+   return addRelays([...relays]);
+ }
+ 
++/** Queue related events to fetch. */
++function fetchRelatedEvents(event: Event, data: EventData) {
++  if (!data.user) {
++    reqmeister.req({ kinds: [0], authors: [event.pubkey] }).catch(() => {});
++  }
++  for (const [name, id, relay] of event.tags) {
++    if (name === 'e' && !encounters.has(id)) {
++      reqmeister.req({ ids: [id] }, [relay]).catch(() => {});
++    }
++  }
++}
++
+ /** Delete unattached media entries that are attached to the event. */
+ function processMedia({ tags, pubkey }: Event, { user }: EventData) {
+   if (user) {
+diff --git a/src/queries.ts b/src/queries.ts
+index fc7365a..1ecff7b 100644
+--- a/src/queries.ts
++++ b/src/queries.ts
+@@ -2,6 +2,7 @@ import * as eventsDB from '@/db/events.ts';
+ import { type Event, findReplyTag } from '@/deps.ts';
+ import { type DittoFilter, type Relation } from '@/filter.ts';
+ import * as mixer from '@/mixer.ts';
++import { reqmeister } from '@/common.ts';
+ 
+ interface GetEventOpts<K extends number> {
+   /** Signal to abort the request. */
+@@ -30,10 +31,10 @@ const getEvent = async <K extends number = number>(
+ const getAuthor = async (pubkey: string, opts: GetEventOpts<0> = {}): Promise<Event<0> | undefined> => {
+   const { relations, signal = AbortSignal.timeout(1000) } = opts;
+ 
+-  const [event] = await mixer.getFilters(
++  const event = await eventsDB.getFilters(
+     [{ authors: [pubkey], relations, kinds: [0], limit: 1 }],
+     { limit: 1, signal },
+-  );
++  ).then(([event]) => event) || await reqmeister.req({ kinds: [0], authors: [pubkey] }).catch(() => {});
+ 
+   return event;
+ };
+diff --git a/src/reqmeister.ts b/src/reqmeister.ts
+new file mode 100644
+index 0000000..960151f
+--- /dev/null
++++ b/src/reqmeister.ts
+@@ -0,0 +1,88 @@
++import * as client from '@/client.ts';
++import { type Event, EventEmitter, type Filter } from '@/deps.ts';
++
++import { eventToMicroFilter, getFilterId, type MicroFilter } from '@/filter.ts';
++
++interface ReqmeisterOpts {
++  delay?: number;
++  signal?: AbortSignal;
++}
++
++type ReqmeisterQueueItem = [string, MicroFilter, WebSocket['url'][]];
++
++class Reqmeister extends EventEmitter<{ [filterId: string]: (event: Event) => any }> {
++  #opts: ReqmeisterOpts;
++  #queue: ReqmeisterQueueItem[] = [];
++  #promise!: Promise<void>;
++  #resolve!: () => void;
++
++  constructor(opts: ReqmeisterOpts = {}) {
++    super();
++    this.#opts = opts;
++    this.#cycle();
++    this.#perform();
++  }
++
++  #cycle() {
++    this.#resolve?.();
++    this.#promise = new Promise((resolve) => {
++      this.#resolve = resolve;
++    });
++  }
++
++  async #perform() {
++    const { delay } = this.#opts;
++    await new Promise((resolve) => setTimeout(resolve, delay));
++
++    const queue = this.#queue;
++    this.#queue = [];
++
++    const wantedEvents = new Set<Event['id']>();
++    const wantedAuthors = new Set<Event['pubkey']>();
++
++    // TODO: batch by relays.
++    for (const [_filterId, filter, _relays] of queue) {
++      if ('ids' in filter) {
++        filter.ids.forEach((id) => wantedEvents.add(id));
++      } else {
++        wantedAuthors.add(filter.authors[0]);
++      }
++    }
++
++    const filters: Filter[] = [];
++
++    if (wantedEvents.size) filters.push({ ids: [...wantedEvents] });
++    if (wantedAuthors.size) filters.push({ kinds: [0], authors: [...wantedAuthors] });
++
++    const events = await client.getFilters(filters, { signal: this.#opts.signal });
++
++    for (const event of events) {
++      this.encounter(event);
++    }
++
++    this.#cycle();
++    this.#perform();
++  }
++
++  req(filter: MicroFilter, relays: WebSocket['url'][] = []): Promise<Event> {
++    const filterId = getFilterId(filter);
++    this.#queue.push([filterId, filter, relays]);
++    return new Promise<Event>((resolve, reject) => {
++      this.once(filterId, resolve);
++      this.#promise.finally(reject);
++    });
++  }
++
++  encounter(event: Event): void {
++    const filterId = getFilterId(eventToMicroFilter(event));
++    this.#queue = this.#queue.filter(([id]) => id !== filterId);
++    this.emit(filterId, event);
++  }
++
++  isWanted(event: Event): boolean {
++    const filterId = getFilterId(eventToMicroFilter(event));
++    return this.#queue.some(([id]) => id === filterId);
++  }
++}
++
++export { Reqmeister };