core: deprecate export =

packages/hydrooj/src/service/db.ts

@@ -1,9 +1,10 @@
 /* eslint-disable no-await-in-loop */
 import {
-    Collection, Db, IndexDescription, MongoClient,
+    Collection, Db, FindCursor, IndexDescription, MongoClient,
 } from 'mongodb';
 import mongoUri from 'mongodb-uri';
 import { Time } from '@hydrooj/utils';
+import { ValidationError } from '../error';
 import { Logger } from '../logger';
 import { load } from '../options';
 import * as bus from './bus';
@@ -102,6 +103,44 @@ class MongoService {
         }
     }
 
+    async paginate<T>(
+        cursor: FindCursor<T>, page: number, pageSize: number,
+    ): Promise<[docs: T[], numPages: number, count: number]> {
+        if (page <= 0) throw new ValidationError('page');
+        let filter = {};
+        for (const key of Object.getOwnPropertySymbols(cursor)) {
+            if (key.toString() !== 'Symbol(filter)') continue;
+            filter = cursor[key];
+            break;
+        }
+        const coll = this.db.collection(cursor.namespace.collection as any);
+        const [count, pageDocs] = await Promise.all([
+            Object.keys(filter).length ? coll.count(filter) : coll.countDocuments(filter),
+            cursor.skip((page - 1) * pageSize).limit(pageSize).toArray(),
+        ]);
+        const numPages = Math.floor((count + pageSize - 1) / pageSize);
+        return [pageDocs, numPages, count];
+    }
+
+    async ranked<T extends Record<string, any>>(cursor: FindCursor<T>, equ: (a: T, b: T) => boolean): Promise<[number, T][]> {
+        let last = null;
+        let r = 0;
+        let count = 0;
+        const results = [];
+        const docs = await cursor.toArray();
+        for (const doc of docs) {
+            if ((doc as any).unrank) {
+                results.push([0, doc]);
+                continue;
+            }
+            count++;
+            if (!last || !equ(last, doc)) r = count;
+            last = doc;
+            results.push([r, doc]);
+        }
+        return results;
+    }
+
     public async apply(ctx) {
         await this.start();
         ctx.on('dispose', () => this.client.close());

packages/hydrooj/src/service/server.ts

@@ -11,13 +11,13 @@ import { errorMessage, Time } from '@hydrooj/utils';
 import { Context } from '../context';
 import { PermissionError, PrivilegeError } from '../error';
 import type { DomainDoc } from '../interface';
-import paginate from '../lib/paginate';
 import { Logger } from '../logger';
 import { PERM, PRIV } from '../model/builtin';
 import * as opcount from '../model/opcount';
 import * as OplogModel from '../model/oplog';
 import * as system from '../model/system';
 import { builtinConfig } from '../settings';
+import db from './db';
 import baseLayer from './layers/base';
 import domainLayer from './layers/domain';
 import userLayer from './layers/user';
@@ -228,7 +228,7 @@ export async function apply(ctx: Context) {
                 return res;
             },
             paginate<T>(cursor: FindCursor<T>, page: number, key: string) {
-                return paginate(cursor, page, this.ctx.setting.get(`pagination.${key}`));
+                return db.paginate(cursor, page, this.ctx.setting.get(`pagination.${key}`));
             },
             checkPerm(...args: bigint[]) {
                 if (!this.user.hasPerm(...args)) {