fix

announcement/views/oj.py

@@ -14,7 +14,7 @@ class AnnouncementAPI(APIView):
             except Announcement.DoesNotExist:
                 return self.error("Announcement does not exist")
 
-        announcements = Announcement.objects.filter(visible=True)
+        announcements = Announcement.objects.select_related("created_by").filter(visible=True)
         return self.success(
             self.paginate_data(request, announcements, AnnouncementListSerializer)
         )

contest/migrations/0002_acmcontestrank_acm_rank_order_idx_and_more.py

@@ -0,0 +1,23 @@
+# Generated by Django 6.0 on 2026-03-30 15:28
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contest', '0001_initial'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name='acmcontestrank',
+            index=models.Index(fields=['contest', 'accepted_number', 'total_time'], name='acm_rank_order_idx'),
+        ),
+        migrations.AddIndex(
+            model_name='oicontestrank',
+            index=models.Index(fields=['contest', 'total_score'], name='oi_rank_order_idx'),
+        ),
+    ]

contest/models.py

@@ -79,6 +79,10 @@ class ACMContestRank(AbstractContestRank):
     class Meta:
         db_table = "acm_contest_rank"
         unique_together = (("user", "contest"),)
+        indexes = [
+            models.Index(fields=["contest", "accepted_number", "total_time"],
+                         name="acm_rank_order_idx"),
+        ]
 
 
 class OIContestRank(AbstractContestRank):
@@ -90,6 +94,9 @@ class OIContestRank(AbstractContestRank):
     class Meta:
         db_table = "oi_contest_rank"
         unique_together = (("user", "contest"),)
+        indexes = [
+            models.Index(fields=["contest", "total_score"], name="oi_rank_order_idx"),
+        ]
 
 
 class ContestAnnouncement(models.Model):

contest/views/oj.py

@@ -169,15 +169,16 @@ class ContestRankAPI(APIView):
             cache_key = f"{CacheKey.contest_rank_cache}:{self.contest.id}"
             qs = cache.get(cache_key)
             if not qs:
-                qs = self.get_rank()
+                qs = list(self.get_rank())
                 cache.set(cache_key, qs)
 
         if download_csv:
             data = serializer(qs, many=True, is_contest_admin=is_contest_admin).data
-            contest_problems = Problem.objects.filter(
+            contest_problems = list(Problem.objects.filter(
                 contest=self.contest, visible=True
-            ).order_by("_id")
+            ).order_by("_id"))
-            problem_ids = [item.id for item in contest_problems]
+            # 预建 problem_id → 列索引 的字典，避免循环中 O(n) list.index()
+            problem_id_to_col = {p.id: i for i, p in enumerate(contest_problems)}
 
             f = io.BytesIO()
             workbook = xlsxwriter.Workbook(f)
@@ -187,11 +188,8 @@ class ContestRankAPI(APIView):
             worksheet.write("C1", "Real Name")
             if self.contest.rule_type == ContestRuleType.OI:
                 worksheet.write("D1", "Total Score")
-                for item in range(contest_problems.count()):
+                for i, p in enumerate(contest_problems):
-                    worksheet.write(
+                    worksheet.write(self.column_string(5 + i) + "1", p.title)
-                        self.column_string(5 + item) + "1",
-                        f"{contest_problems[item].title}",
-                    )
                 for index, item in enumerate(data):
                     worksheet.write_string(index + 1, 0, str(item["user"]["id"]))
                     worksheet.write_string(index + 1, 1, item["user"]["username"])
@@ -201,17 +199,14 @@ class ContestRankAPI(APIView):
                     worksheet.write_string(index + 1, 3, str(item["total_score"]))
                     for k, v in item["submission_info"].items():
                         worksheet.write_string(
-                            index + 1, 4 + problem_ids.index(int(k)), str(v)
+                            index + 1, 4 + problem_id_to_col[int(k)], str(v)
                         )
             else:
                 worksheet.write("D1", "AC")
                 worksheet.write("E1", "Total Submission")
                 worksheet.write("F1", "Total Time")
-                for item in range(contest_problems.count()):
+                for i, p in enumerate(contest_problems):
-                    worksheet.write(
+                    worksheet.write(self.column_string(7 + i) + "1", p.title)
-                        self.column_string(7 + item) + "1",
-                        f"{contest_problems[item].title}",
-                    )
 
                 for index, item in enumerate(data):
                     worksheet.write_string(index + 1, 0, str(item["user"]["id"]))
@@ -224,7 +219,7 @@ class ContestRankAPI(APIView):
                     worksheet.write_string(index + 1, 5, str(item["total_time"]))
                     for k, v in item["submission_info"].items():
                         worksheet.write_string(
-                            index + 1, 6 + problem_ids.index(int(k)), str(v["is_ac"])
+                            index + 1, 6 + problem_id_to_col[int(k)], str(v["is_ac"])
                         )
 
             workbook.close()

message/views/oj.py

@@ -13,7 +13,7 @@ class MessageAPI(APIView):
     @login_required
     def get(self, request):
         messages = Message.objects.select_related(
-            "recipient", "sender", "submission"
+            "recipient", "sender", "submission", "submission__problem"
         ).filter(recipient=request.user)
         return self.success(self.paginate_data(request, messages, MessageSerializer))
 

options/options.py

@@ -217,7 +217,7 @@ class _SysOptionsMeta(type):
     def website_footer(cls, value):
         cls._set_option(OptionKeys.website_footer, value)
 
-    @my_property
+    @my_property(ttl=DEFAULT_SHORT_TTL)
     def allow_register(cls):
         return cls._get_option(OptionKeys.allow_register)
 
@@ -249,7 +249,7 @@ class _SysOptionsMeta(type):
     def smtp_config(cls, value):
         cls._set_option(OptionKeys.smtp_config, value)
 
-    @my_property
+    @my_property(ttl=DEFAULT_SHORT_TTL)
     def judge_server_token(cls):
         return cls._get_option(OptionKeys.judge_server_token)
 
@@ -257,7 +257,7 @@ class _SysOptionsMeta(type):
     def judge_server_token(cls, value):
         cls._set_option(OptionKeys.judge_server_token, value)
 
-    @my_property
+    @my_property(ttl=DEFAULT_SHORT_TTL)
     def throttling(cls):
         return cls._get_option(OptionKeys.throttling)
 

problem/migrations/0006_problem_problem_contest_visible_idx.py

@@ -0,0 +1,20 @@
+# Generated by Django 6.0 on 2026-03-30 15:28
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contest', '0002_acmcontestrank_acm_rank_order_idx_and_more'),
+        ('problem', '0005_remove_spj_fields'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name='problem',
+            index=models.Index(fields=['contest', 'visible'], name='problem_contest_visible_idx'),
+        ),
+    ]

problem/models.py

@@ -93,6 +93,9 @@ class Problem(models.Model):
         db_table = "problem"
         unique_together = (("_id", "contest"),)
         ordering = ("create_time",)
+        indexes = [
+            models.Index(fields=["contest", "visible"], name="problem_contest_visible_idx"),
+        ]
 
     def add_submission_number(self):
         self.submission_number = models.F("submission_number") + 1

problem/views/oj.py

@@ -89,6 +89,7 @@ class ProblemAPI(APIView):
 
         problems = (
             Problem.objects.select_related("created_by")
+            .prefetch_related("tags")
             .filter(contest_id__isnull=True, visible=True)
             .order_by("-create_time")
         )
@@ -162,7 +163,7 @@ class ContestProblemAPI(APIView):
                 problem_data = ProblemSafeSerializer(problem).data
             return self.success(problem_data)
 
-        contest_problems = Problem.objects.select_related("created_by").filter(
+        contest_problems = Problem.objects.select_related("created_by").prefetch_related("tags").filter(
             contest=self.contest, visible=True
         )
         if self.contest.problem_details_permission(request.user):
@@ -229,7 +230,9 @@ class SimilarProblemAPI(APIView):
             exclude_ids.extend(ac_display_ids)
 
         similar = (
-            Problem.objects.filter(tags__in=tag_ids, visible=True, contest__isnull=True)
+            Problem.objects.select_related("created_by")
+            .prefetch_related("tags")
+            .filter(tags__in=tag_ids, visible=True, contest__isnull=True)
             .exclude(_id__in=exclude_ids)
             .distinct()
             .order_by("difficulty")[:5]
@@ -240,9 +243,8 @@ class SimilarProblemAPI(APIView):
 class ProblemAuthorAPI(APIView):
     def get(self, request):
         show_all = request.GET.get("all", "0") == "1"
-        cached_data = cache.get(
+        cache_key = f"{CacheKey.problem_authors}{'_all' if show_all else '_only_visible'}"
-            f"{CacheKey.problem_authors}{'_all' if show_all else '_only_visible'}"
+        cached_data = cache.get(cache_key)
-        )
         if cached_data:
             return self.success(cached_data)
 
@@ -264,5 +266,5 @@ class ProblemAuthorAPI(APIView):
             for author in authors
         ]
 
-        cache.set(CacheKey.problem_authors, result, 7200)
+        cache.set(cache_key, result, 7200)
         return self.success(result)

problemset/models.py

@@ -170,15 +170,15 @@ class ProblemSetProgress(models.Model):
         )
         self.total_problems_count = problemset_problems.count()
 
-        # 获取当前题单中所有题目的ID集合
+        # 获取当前题单中所有题目的ID集合（直接用 problem_id FK 字段，无需额外查询）
-        current_problem_ids = {str(psp.problem.id) for psp in problemset_problems}
+        current_problem_ids = {str(psp.problem_id) for psp in problemset_problems}
-        
+
         # 清理已删除题目的进度记录
         progress_detail_to_remove = []
         for problem_id in self.progress_detail.keys():
             if problem_id not in current_problem_ids:
                 progress_detail_to_remove.append(problem_id)
-        
+
         for problem_id in progress_detail_to_remove:
             del self.progress_detail[problem_id]
 
@@ -187,7 +187,7 @@ class ProblemSetProgress(models.Model):
         total_score = 0
 
         for psp in problemset_problems:
-            problem_id = str(psp.problem.id)
+            problem_id = str(psp.problem_id)
             if problem_id in self.progress_detail:
                 problem_progress = self.progress_detail[problem_id]
                 completed_count += 1

problemset/serializers.py

@@ -183,16 +183,18 @@ class ProblemSetProblemSerializer(serializers.ModelSerializer):
     def get_is_completed(self, obj):
         """获取当前用户是否已完成该题目"""
         request = self.context.get("request")
-        if request and request.user.is_authenticated:
+        if not (request and request.user.is_authenticated):
+            return False
+        # 优先使用 view 层预取的进度对象，避免 N+1
+        progress = self.context.get("user_progress")
+        if progress is None:
             try:
                 progress = ProblemSetProgress.objects.get(
                     problemset=obj.problemset, user=request.user
                 )
-                problem_id = str(obj.problem.id)
-                return problem_id in progress.progress_detail
             except ProblemSetProgress.DoesNotExist:
                 return False
-        return False
+        return str(obj.problem.id) in progress.progress_detail
 
 
 class AddProblemToSetSerializer(serializers.Serializer):

problemset/views/oj.py

@@ -137,11 +137,23 @@ class ProblemSetProblemAPI(APIView):
         except ProblemSet.DoesNotExist:
             return self.error("题单不存在")
 
-        problems = ProblemSetProblem.objects.filter(problemset=problem_set).order_by(
+        problems = (
-            "order"
+            ProblemSetProblem.objects.filter(problemset=problem_set)
+            .select_related("problem__created_by")
+            .prefetch_related("problem__tags")
+            .order_by("order")
         )
+        # 预取当前用户的题单进度，供 get_is_completed 使用，避免 N+1
+        user_progress = None
+        if request.user.is_authenticated:
+            try:
+                user_progress = ProblemSetProgress.objects.get(
+                    problemset=problem_set, user=request.user
+                )
+            except ProblemSetProgress.DoesNotExist:
+                pass
         serializer = ProblemSetProblemSerializer(
-            problems, many=True, context={"request": request}
+            problems, many=True, context={"request": request, "user_progress": user_progress}
         )
         return self.success(serializer.data)
 

submission/serializers.py

@@ -1,4 +1,5 @@
 from django.db import models
+from django.db.models import F
 from django.utils import timezone
 
 from .models import Submission
@@ -7,6 +8,33 @@ from utils.serializers import LanguageNameChoiceField
 from problemset.models import ProblemSetProgress
 
 
+def bulk_fetch_problemset_progress(user, problem_ids):
+    """一次 IN 查询获取该用户对多个题目的题单进度，返回 {problem_id: ProblemSetProgress|None}"""
+    if not problem_ids:
+        return {}
+    rows = (
+        ProblemSetProgress.objects.filter(
+            user=user,
+            problemset__status="active",
+            problemset__problemsetproblem__problem_id__in=problem_ids,
+        )
+        .filter(
+            models.Q(problemset__end_time__isnull=True)
+            | models.Q(problemset__end_time__gt=timezone.now())
+        )
+        .annotate(matched_problem_id=F("problemset__problemsetproblem__problem_id"))
+        .only("join_time", "progress_detail")
+    )
+    cache = {}
+    for row in rows:
+        pid = row.matched_problem_id
+        if pid not in cache:
+            cache[pid] = row
+    for pid in problem_ids:
+        cache.setdefault(pid, None)
+    return cache
+
+
 class CreateSubmissionSerializer(serializers.Serializer):
     problem_id = serializers.IntegerField()
     language = LanguageNameChoiceField()
@@ -44,7 +72,10 @@ class SubmissionListSerializer(serializers.ModelSerializer):
 
     def __init__(self, *args, **kwargs):
         self.user = kwargs.pop("user", None)
+        preloaded = kwargs.pop("problemset_progress_cache", None)
         super().__init__(*args, **kwargs)
+        if preloaded is not None:
+            self._problemset_progress_cache = preloaded
 
     class Meta:
         model = Submission

submission/views/oj.py

@@ -18,7 +18,7 @@ from ..serializers import (
     SubmissionModelSerializer,
     ShareSubmissionSerializer,
 )
-from ..serializers import SubmissionSafeModelSerializer, SubmissionListSerializer
+from ..serializers import SubmissionSafeModelSerializer, SubmissionListSerializer, bulk_fetch_problemset_progress
 
 
 class SubmissionAPI(APIView):
@@ -193,8 +193,14 @@ class SubmissionListAPI(APIView):
             )
 
         data = self.paginate_data(request, submissions)
+        results = data["results"]
+        if request.user.is_authenticated and request.user.is_regular_user():
+            problem_ids = list({s.problem_id for s in results})
+            progress_cache = bulk_fetch_problemset_progress(request.user, problem_ids)
+        else:
+            progress_cache = {}
         data["results"] = SubmissionListSerializer(
-            data["results"], many=True, user=request.user
+            results, many=True, user=request.user, problemset_progress_cache=progress_cache
         ).data
         return self.success(data)
 
@@ -241,8 +247,14 @@ class ContestSubmissionListAPI(APIView):
                 submissions = submissions.filter(user_id=request.user.id)
 
         data = self.paginate_data(request, submissions)
+        results = data["results"]
+        if request.user.is_authenticated and request.user.is_regular_user():
+            problem_ids = list({s.problem_id for s in results})
+            progress_cache = bulk_fetch_problemset_progress(request.user, problem_ids)
+        else:
+            progress_cache = {}
         data["results"] = SubmissionListSerializer(
-            data["results"], many=True, user=request.user
+            results, many=True, user=request.user, problemset_progress_cache=progress_cache
         ).data
         return self.success(data)