fix

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)