Files
snort/packages/app/src/Cache/FollowsFeed.ts

125 lines
3.9 KiB
TypeScript

import debug from "debug";
import { EventKind, RequestBuilder, SystemInterface, TaggedNostrEvent } from "@snort/system";
import { unixNow, unixNowMs } from "@snort/shared";
import { db } from "Db";
import { RefreshFeedCache, TWithCreated } from "./RefreshFeedCache";
import { LoginSession } from "Login";
import { Day, Hour } from "Const";
const WindowSize = Hour * 6;
const MaxCacheWindow = Day * 7;
export class FollowsFeedCache extends RefreshFeedCache<TaggedNostrEvent> {
#kinds = [EventKind.TextNote, EventKind.Repost, EventKind.Polls];
#oldest?: number;
constructor() {
super("FollowsFeedCache", db.followsFeed);
}
key(of: TWithCreated<TaggedNostrEvent>): string {
return of.id;
}
takeSnapshot(): TWithCreated<TaggedNostrEvent>[] {
return [...this.cache.values()];
}
buildSub(session: LoginSession, rb: RequestBuilder): void {
const since = this.newest();
rb.withFilter()
.kinds(this.#kinds)
.authors(session.follows.item)
.since(since === 0 ? unixNow() - WindowSize : since);
}
async onEvent(evs: readonly TaggedNostrEvent[]): Promise<void> {
const filtered = evs.filter(a => this.#kinds.includes(a.kind));
if (filtered.length > 0) {
await this.bulkSet(filtered);
this.notifyChange(filtered.map(a => this.key(a)));
}
}
override async preload() {
const start = unixNowMs();
const keys = (await this.table?.toCollection().primaryKeys()) ?? [];
this.onTable = new Set<string>(keys.map(a => a as string));
// load only latest 10 posts, rest can be loaded on-demand
const latest = await this.table?.orderBy("created_at").reverse().limit(50).toArray();
latest?.forEach(v => this.cache.set(this.key(v), v));
// cleanup older than 7 days
await this.table
?.where("created_at")
.below(unixNow() - MaxCacheWindow)
.delete();
const oldest = await this.table?.orderBy("created_at").first();
this.#oldest = oldest?.created_at ?? unixNow() - MaxCacheWindow;
this.notifyChange(latest?.map(a => this.key(a)) ?? []);
debug(this.name)(`Loaded %d/%d in %d ms`, latest?.length ?? 0, keys.length, (unixNowMs() - start).toLocaleString());
}
async loadMore(system: SystemInterface, session: LoginSession, before: number) {
if (this.#oldest && before <= this.#oldest) {
const rb = new RequestBuilder(`${this.name}-loadmore`);
rb.withFilter()
.kinds(this.#kinds)
.authors(session.follows.item)
.until(before)
.since(before - WindowSize);
await system.Fetch(rb, async evs => {
await this.bulkSet(evs);
});
} else {
const latest = await this.table
?.where("created_at")
.between(before - WindowSize, before)
.reverse()
.sortBy("created_at");
latest?.forEach(v => {
const k = this.key(v);
this.cache.set(k, v);
this.onTable.add(k);
});
this.notifyChange(latest?.map(a => this.key(a)) ?? []);
}
}
/**
* Backfill cache with new follows
*/
async backFill(system: SystemInterface, keys: Array<string>) {
if (keys.length === 0) return;
const rb = new RequestBuilder(`${this.name}-backfill`);
rb.withFilter()
.kinds(this.#kinds)
.authors(keys)
.until(unixNow())
.since(this.#oldest ?? unixNow() - MaxCacheWindow);
await system.Fetch(rb, async evs => {
await this.bulkSet(evs);
});
}
/**
* Backfill cache based on follows list
*/
async backFillIfMissing(system: SystemInterface, keys: Array<string>) {
const start = unixNowMs();
const everything = await this.table?.toArray();
if((everything?.length ?? 0) > 0) {
const allKeys = new Set(everything?.map(a => a.pubkey));
const missingKeys = keys.filter(a => !allKeys.has(a));
await this.backFill(system, missingKeys);
debug(this.name)(`Backfilled %d keys in %d ms`, missingKeys.length, (unixNowMs() - start).toLocaleString());
}
}
}