Optimize problem feed DB query

chat_box/models.py

@@ -58,6 +58,7 @@ class UserRoom(models.Model):
     class Meta:
         unique_together = ("user", "room")
 
+
 class Ignore(models.Model):
     user = models.OneToOneField(
         Profile,

dmoj/decorators.py

@@ -1,14 +0,0 @@
-import time
-
-
-def timeit(method):
-    def timed(*args, **kw):
-        ts = time.time()
-        result = method(*args, **kw)
-        te = time.time()
-        if "log_time" in kw:
-            name = kw.get("log_name", method.__name__.upper())
-            kw["log_time"][name] = int((te - ts) * 1000)
-        return result
-
-    return timed

dmoj/urls.py

@@ -1090,6 +1090,7 @@ urlpatterns = [
             ]
         ),
     ),
+    # url("__debug__/", include("debug_toolbar.urls")), # debug_toolbar use
 ] + url_static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)
 
 favicon_paths = [

judge/ml/collab_filter.py

@@ -1,7 +1,6 @@
 import numpy as np
 from django.conf import settings
 import os
-from dmoj.decorators import timeit
 
 
 class CollabFilter:
@@ -9,7 +8,6 @@ class CollabFilter:
     COSINE = "cosine"
 
     # name = 'collab_filter' or 'collab_filter_time'
-    @timeit
     def __init__(self, name, **kwargs):
         embeddings = np.load(
             os.path.join(settings.ML_OUTPUT_PATH, name + "/embeddings.npz"),
@@ -38,7 +36,6 @@ class CollabFilter:
         scores = u.dot(V.T)
         return scores
 
-    @timeit
     def user_recommendations(self, user, problems, measure=DOT, limit=None, **kwargs):
         uid = user.id
         if uid >= len(self.user_embeddings):
@@ -48,10 +45,10 @@ class CollabFilter:
         )
 
         res = []  # [(score, problem)]
-        for problem in problems:
-            pid = problem.id
+        for pid in problems:
+            # pid = problem.id
             if pid < len(scores):
-                res.append((scores[pid], problem))
+                res.append((scores[pid], pid))
 
         res.sort(reverse=True, key=lambda x: x[0])
         return res[:limit]

judge/views/problem.py

@@ -115,7 +115,6 @@ class ProblemMixin(object):
         try:
             return super(ProblemMixin, self).get(request, *args, **kwargs)
         except Http404 as e:
-            print(e)
             return self.no_such_problem()
 
 
@@ -558,7 +557,6 @@ class ProblemList(QueryStringSortMixin, TitleMixin, SolvedProblemMixin, ListView
             )
         if self.org_query:
             self.org_query = self.get_org_query(self.org_query)
-            print(self.org_query)
             queryset = queryset.filter(
                 Q(organizations__in=self.org_query)
                 | Q(contests__contest__organizations__in=self.org_query)
@@ -782,9 +780,6 @@ class ProblemList(QueryStringSortMixin, TitleMixin, SolvedProblemMixin, ListView
         return HttpResponseRedirect(request.get_full_path())
 
 
-cf_logger = logging.getLogger("judge.ml.collab_filter")
-
-
 class ProblemFeed(ProblemList):
     model = Problem
     context_object_name = "problems"
@@ -859,56 +854,49 @@ class ProblemFeed(ProblemList):
         if not settings.ML_OUTPUT_PATH or not user:
             return queryset.order_by("?")
 
-        # Logging
-        log_data = {
-            "user": self.request.user.username,
-            "cf": {
-                "dot": {},
-                "cosine": {},
-            },
-            "cf_time": {"dot": {}, "cosine": {}},
-        }
+        cf_model = CollabFilter("collab_filter")
+        cf_time_model = CollabFilter("collab_filter_time")
 
-        cf_model = CollabFilter("collab_filter", log_time=log_data["cf"])
-        cf_time_model = CollabFilter("collab_filter_time", log_time=log_data["cf_time"])
+        queryset = queryset.values_list("id", flat=True)
         hot_problems_recommendations = [
-            problem
+            problem.id
             for problem in hot_problems(timedelta(days=7), 20)
-            if problem in queryset
+            if problem.id in set(queryset)
         ]
 
         q = self.merge_recommendation(
             [
-                cf_model.user_recommendations(
-                    user, queryset, cf_model.DOT, 100, log_time=log_data["cf"]["dot"]
-                ),
+                cf_model.user_recommendations(user, queryset, cf_model.DOT, 100),
                 cf_model.user_recommendations(
                     user,
                     queryset,
                     cf_model.COSINE,
                     100,
-                    log_time=log_data["cf"]["cosine"],
                 ),
                 cf_time_model.user_recommendations(
                     user,
                     queryset,
                     cf_time_model.COSINE,
                     100,
-                    log_time=log_data["cf_time"]["cosine"],
                 ),
                 cf_time_model.user_recommendations(
                     user,
                     queryset,
                     cf_time_model.DOT,
                     100,
-                    log_time=log_data["cf_time"]["dot"],
                 ),
                 hot_problems_recommendations,
             ]
         )
+        queryset = Problem.objects.filter(id__in=q)
+        queryset = queryset.add_i18n_name(self.request.LANGUAGE_CODE)
 
-        cf_logger.info(log_data)
-        return q
+        # Reorder results from database to correct positions
+        res = [None for _ in range(len(q))]
+        position_in_q = {i: idx for idx, i in enumerate(q)}
+        for problem in queryset:
+            res[position_in_q[problem.id]] = problem
+        return res
 
     def get_context_data(self, **kwargs):
         context = super(ProblemFeed, self).get_context_data(**kwargs)

templates/problem/feed.html

@@ -26,7 +26,7 @@
         <div class="blog-box">
             <h3 class="problem-feed-name">
                 <a href="{{ url('problem_detail', problem.code) }}">
-                    {{ problem.name }}
+                    {{ problem.i18n_name }}
                 </a>
                 {% if problem.id in completed_problem_ids %}
                     <i class="solved-problem-color fa fa-check-circle"></i>