diff --git a/packages/hydrojudge/package.json b/packages/hydrojudge/package.json
index f228ad49c..228e68cbc 100644
--- a/packages/hydrojudge/package.json
+++ b/packages/hydrojudge/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@hydrooj/hydrojudge",
-    "version": "2.0.4",
+    "version": "2.0.5",
     "main": "package.json",
     "author": "masnn",
     "os": [
diff --git a/packages/hydrojudge/service.ts b/packages/hydrojudge/src/service.ts
similarity index 97%
rename from packages/hydrojudge/service.ts
rename to packages/hydrojudge/src/service.ts
index d999d2163..a727e5b2c 100644
--- a/packages/hydrojudge/service.ts
+++ b/packages/hydrojudge/src/service.ts
@@ -11,13 +11,13 @@ import { homedir, tmpdir } from 'os';
 async function postInit() {
     // Only start a single daemon
     if (!cluster.isFirstWorker) return;
-    const { compilerText } = require('./src/utils');
-    const tmpfs = require('./src/tmpfs');
-    const { FormatError, CompileError, SystemError } = require('./src/error');
+    const { compilerText } = require('./utils');
+    const tmpfs = require('./tmpfs');
+    const { FormatError, CompileError, SystemError } = require('./error');
     const { STATUS_COMPILE_ERROR, STATUS_SYSTEM_ERROR } = global.Hydro.model.builtin.STATUS;
-    const readYamlCases = require('./src/cases');
-    const judge = require('./src/judge');
-    const sysinfo = require('./src/sysinfo');
+    const readYamlCases = require('./cases');
+    const judge = require('./judge');
+    const sysinfo = require('./sysinfo');
 
     const { problem, file, task } = global.Hydro.model;
     const _judge = global.Hydro.handler.judge as any;
diff --git a/packages/hydrojudge/tsconfig.json b/packages/hydrojudge/tsconfig.json
index ee0b5120f..6c06cb233 100644
--- a/packages/hydrojudge/tsconfig.json
+++ b/packages/hydrojudge/tsconfig.json
@@ -2,8 +2,8 @@
     "compilerOptions": {
         "target": "es2018",
         "module": "commonjs",
-        "outDir": ".",
-        "rootDir": ".",
+        "outDir": "dist",
+        "rootDir": "src",
         "moduleResolution": "node",
         "declaration": true,
         "sourceMap": true,
@@ -12,13 +12,7 @@
         "resolveJsonModule": true
     },
     "include": [
-        "service.ts",
         "src"
     ],
-    "paths": {
-        "src/*": [
-            "dist/*"
-        ]
-    },
     "exclude": []
 }
\ No newline at end of file
diff --git a/packages/hydrooj/TODO b/packages/hydrooj/TODO
index 47ce4524f..a8c8931e2 100644
--- a/packages/hydrooj/TODO
+++ b/packages/hydrooj/TODO
@@ -4,6 +4,4 @@ SETTINGS_PRIVACY.allowRegisteredUsers
 model.setting.ui.name
 pdoc.secretConfig?
 message.markAsRead
-Handle OAuth Map   !important
-基于document的model难以lint，建议拆分
-写test!   !important
\ No newline at end of file
+基于document的model难以lint，建议拆分
\ No newline at end of file
diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index d0565d52a..8198e8bab 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.12.17",
+    "version": "2.12.18",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",
diff --git a/packages/hydrooj/src/handler/user.ts b/packages/hydrooj/src/handler/user.ts
index 5be8b8e27..bcb6b2fe2 100644
--- a/packages/hydrooj/src/handler/user.ts
+++ b/packages/hydrooj/src/handler/user.ts
@@ -8,6 +8,7 @@ import {
     Route, Handler, Types, param,
 } from '../service/server';
 import * as user from '../model/user';
+import * as oauth from '../model/oauth';
 import * as token from '../model/token';
 import * as record from '../model/record';
 import * as problem from '../model/problem';
@@ -227,10 +228,9 @@ class OauthCallbackHandler extends Handler {
         let r;
         if (global.Hydro.lib[`oauth_${args.type}`]) r = await global.Hydro.lib[`oauth_${args.type}`].callback.call(this, args);
         else throw new UserFacingError('Oauth type');
-        const udoc = await user.getByEmail('system', r.email);
-        if (udoc) {
-            this.session.uid = udoc._id;
-        } else {
+        const uid = await oauth.get(r._id);
+        if (uid) this.session.uid = uid;
+        else {
             this.checkPriv(PRIV.PRIV_REGISTER_USER);
             let username = '';
             r.uname = r.uname || [];
@@ -243,7 +243,7 @@ class OauthCallbackHandler extends Handler {
                     break;
                 }
             }
-            const uid = await user.create(
+            const _id = await user.create(
                 r.email, username, String.random(32),
                 undefined, this.request.ip,
             );
@@ -252,8 +252,11 @@ class OauthCallbackHandler extends Handler {
             };
             if (r.bio) $set.bio = r.bio;
             if (r.viewLang) $set.viewLang = r.viewLang;
-            await user.setById(uid, $set);
-            this.session.uid = uid;
+            await Promise.all([
+                user.setById(_id, $set),
+                oauth.set(r.email, _id),
+            ]);
+            this.session.uid = _id;
         }
     }
 }
diff --git a/packages/hydrooj/src/model/oauth.ts b/packages/hydrooj/src/model/oauth.ts
new file mode 100644
index 000000000..f0f0c9b8f
--- /dev/null
+++ b/packages/hydrooj/src/model/oauth.ts
@@ -0,0 +1,36 @@
+import Lru from 'lru-cache';
+import { Collection } from 'mongodb';
+import * as db from '../service/db';
+
+interface OauthMap {
+    _id: string, // source openId
+    uid: number, // target uid
+}
+
+const coll: Collection<OauthMap> = db.collection('oauth');
+const cache = new Lru({
+    maxAge: 5000,
+});
+
+export async function get(_id: string) {
+    const res = cache.get(_id);
+    if (res !== undefined) return res;
+    const doc = await coll.findOne({ _id });
+    if (doc) return doc.uid;
+    return null;
+}
+
+export async function set(_id: string, value: number) {
+    cache.set(_id, value);
+    const res = await coll.findOneAndUpdate(
+        { _id },
+        { $set: { value } },
+        { upsert: true, returnOriginal: false },
+    );
+    return res.value.uid;
+}
+
+global.Hydro.model.oauth = {
+    get,
+    set,
+};
diff --git a/packages/login-with-github/lib.ts b/packages/login-with-github/lib.ts
index 5124c5250..816773056 100644
--- a/packages/login-with-github/lib.ts
+++ b/packages/login-with-github/lib.ts
@@ -46,6 +46,7 @@ async function callback({ state, code }) {
         .set('User-Agent', 'Hydro-OAuth')
         .set('Authorization', `token ${t}`);
     const ret = {
+        _id: `${userInfo.body.id}@github.local`,
         email: userInfo.body.email,
         bio: userInfo.body.bio,
         uname: [userInfo.body.name, userInfo.body.login],
diff --git a/packages/login-with-github/package.json b/packages/login-with-github/package.json
index 494341e8e..6aeeb79cc 100644
--- a/packages/login-with-github/package.json
+++ b/packages/login-with-github/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@hydrooj/login-with-github",
-    "version": "0.0.4",
+    "version": "0.0.5",
     "main": "package.json",
     "repository": "git@github.com:hydro-dev/Hydro.git",
     "author": "undefined <masnn0@outlook.com>",
diff --git a/packages/login-with-google/lib.ts b/packages/login-with-google/lib.ts
index c3c3a0ddc..e787bc4d2 100644
--- a/packages/login-with-google/lib.ts
+++ b/packages/login-with-google/lib.ts
@@ -43,6 +43,8 @@ async function callback({
     await token.del(state, token.TYPE_OAUTH);
     this.response.redirect = s.redirect;
     return {
+        // TODO use openid
+        _id: payload.email,
         email: payload.email,
         uname: [payload.given_name, payload.name, payload.family_name],
         viewLang: payload.locale.replace('-', '_'),
diff --git a/packages/login-with-google/package.json b/packages/login-with-google/package.json
index 6e82d29da..bf05200e8 100644
--- a/packages/login-with-google/package.json
+++ b/packages/login-with-google/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@hydrooj/login-with-google",
-    "version": "0.0.4",
+    "version": "0.0.5",
     "main": "package.json",
     "repository": "git@github.com:hydro-dev/Hydro.git",
     "author": "undefined <masnn0@outlook.com>",
diff --git a/packages/login-with-osu/lib.ts b/packages/login-with-osu/lib.ts
index ff1bd311a..f7510f89f 100644
--- a/packages/login-with-osu/lib.ts
+++ b/packages/login-with-osu/lib.ts
@@ -51,6 +51,7 @@ async function callback({ state, code }) {
         .set('User-Agent', 'Hydro-OAuth')
         .set('Authorization', `Bearer ${t}`);
     const ret = {
+        _id: `${userInfo.body.id}@osu.local`,
         email: `${userInfo.body.id}@osu.local`,
         bio: '',
         uname: [userInfo.body.username],
diff --git a/packages/login-with-osu/package.json b/packages/login-with-osu/package.json
index 93b874015..1fea35676 100644
--- a/packages/login-with-osu/package.json
+++ b/packages/login-with-osu/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@hydrooj/login-with-osu",
-    "version": "0.0.4",
+    "version": "0.0.5",
     "main": "package.json",
     "repository": "git@github.com:hydro-dev/Hydro.git",
     "author": "undefined <masnn0@outlook.com>",
diff --git a/packages/login-with-qq/lib.ts b/packages/login-with-qq/lib.ts
index 2c2b72e6f..40f64e3be 100644
--- a/packages/login-with-qq/lib.ts
+++ b/packages/login-with-qq/lib.ts
@@ -20,6 +20,7 @@ async function callback({ state }) {
     const s = await token.get(state, token.TYPE_OAUTH);
     if (!s || !s.email) throw new InvalidTokenError(state);
     const ret = {
+        _id: s.email,
         email: s.email,
         bio: '',
         uname: [s.username],
diff --git a/packages/login-with-qq/package.json b/packages/login-with-qq/package.json
index 58ab94a0c..e7a3d8c48 100644
--- a/packages/login-with-qq/package.json
+++ b/packages/login-with-qq/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@hydrooj/login-with-qq",
-    "version": "0.0.1",
+    "version": "0.0.2",
     "main": "package.json",
     "repository": "git@github.com:hydro-dev/Hydro.git",
     "author": "undefined <masnn0@outlook.com>",