大幅优化数据库查询, 升级django至1.11 LTS, 升级python至3.6.2

submission/migrations/0005_submission_username.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.4 on 2017-08-26 03:47
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('submission', '0004_auto_20170717_1324'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='submission',
+            name='username',
+            field=models.CharField(default="", max_length=30),
+            preserve_default=False,
+        ),
+    ]

submission/models.py

@@ -25,6 +25,7 @@ class Submission(models.Model):
     problem_id = models.IntegerField(db_index=True)
     create_time = models.DateTimeField(auto_now_add=True)
     user_id = models.IntegerField(db_index=True)
+    username = models.CharField(max_length=30)
     code = models.TextField()
     result = models.IntegerField(default=JudgeStatus.PENDING)
     # 判题结果的详细信息

submission/serializers.py

@@ -1,5 +1,4 @@
 from .models import Submission
-from account.models import User
 from utils.api import serializers
 from judge.languages import language_names
 
@@ -21,20 +20,14 @@ class SubmissionModelSerializer(serializers.ModelSerializer):
 
 # 不显示submission info详情的serializer
 class SubmissionSafeSerializer(serializers.ModelSerializer):
-    username = serializers.SerializerMethodField()
     statistic_info = serializers.JSONField()
 
     class Meta:
         model = Submission
         exclude = ("info", "contest_id")
 
-    @staticmethod
-    def get_username(obj):
-        return User.objects.get(id=obj.user_id).username
-
 
 class SubmissionListSerializer(serializers.ModelSerializer):
-    username = serializers.SerializerMethodField()
     statistic_info = serializers.JSONField()
     show_link = serializers.SerializerMethodField()
 
@@ -47,10 +40,7 @@ class SubmissionListSerializer(serializers.ModelSerializer):
         exclude = ("info", "contest_id", "code")
 
     def get_show_link(self, obj):
-        if self.user.id is None:
+        # 没传user或为匿名user
+        if self.user is None or self.user.id is None:
             return False
         return obj.check_user_permission(self.user)
-
-    @staticmethod
-    def get_username(obj):
-        return User.objects.get(id=obj.user_id).username

submission/views/oj.py

@@ -34,6 +34,7 @@ def _submit(response, user, problem_id, language, code, contest_id):
         return response.error("Problem not exist")
 
     submission = Submission.objects.create(user_id=user.id,
+                                           username=user.username,
                                            language=language,
                                            code=code,
                                            problem_id=problem._id,