feat(problem-site): add file size limiting

dmoj/settings.py

@@ -215,6 +215,8 @@
 DMOJ_PROBLEM_MAX_TIME_LIMIT = 60  # seconds
 DMOJ_PROBLEM_MIN_MEMORY_LIMIT = 0  # kilobytes
 DMOJ_PROBLEM_MAX_MEMORY_LIMIT = 1048576  # kilobytes
+DMOJ_PROBLEM_MIN_FILE_SIZE_LIMIT = 0  # kilobytes
+DMOJ_PROBLEM_MAX_FILE_SIZE_LIMIT = 102400  # kilobytes (100 MB)
 DMOJ_PROBLEM_MIN_PROBLEM_POINTS = 0
 DMOJ_PROBLEM_HOT_PROBLEM_COUNT = 7
 

judge/admin/problem.py

@@ -64,7 +64,7 @@ class Meta:
 
 class LanguageLimitInline(admin.TabularInline):
     model = LanguageLimit
-    fields = ('language', 'time_limit', 'memory_limit')
+    fields = ('language', 'time_limit', 'memory_limit', 'file_size_limit')
     form = LanguageLimitInlineForm
 
 

judge/bridge/judge_handler.py

@@ -209,8 +209,13 @@ def get_related_submission_data(self, submission):
                                                date__lt=sub_date).exclude(status__in=('CE', 'IE')).count() + 1
 
         try:
-            time, memory = (LanguageLimit.objects.filter(problem__id=pid, language__id=lid)
-                            .values_list('time_limit', 'memory_limit').get())
+            lang_limit = LanguageLimit.objects.filter(problem__id=pid, language__id=lid).values_list(
+                'time_limit', 'memory_limit', 'file_size_limit').get()
+            time = lang_limit[0]
+            memory = lang_limit[1]
+            # Use problem-specific file size limit if set, otherwise fall back to language default
+            if lang_limit[2] is not None:
+                file_size_limit = lang_limit[2]
         except LanguageLimit.DoesNotExist:
             pass
 

judge/forms.py

@@ -153,7 +153,7 @@ def clean_time_limit(self):
 
     class Meta:
         model = LanguageLimit
-        fields = ('language', 'time_limit', 'memory_limit')
+        fields = ('language', 'time_limit', 'memory_limit', 'file_size_limit')
         widgets = {
             'language': Select2Widget(attrs={'style': 'width:200px'}),
         }
@@ -377,40 +377,65 @@ def clean(self):
         self.check_submission()
         return cleaned_data
 
+    def _get_file_size_limit(self, language, problem):
+        """Get effective file size limit in KB (problem-specific or language default)"""
+        limit = language.file_size_limit
+        if problem and limit >= 0:
+            try:
+                lang_limit = LanguageLimit.objects.get(problem=problem, language=language)
+                if lang_limit.file_size_limit is not None:
+                    limit = lang_limit.file_size_limit
+            except LanguageLimit.DoesNotExist:
+                pass
+        return limit
+
     def check_submission(self):
         source = self.cleaned_data.get('source', '')
-        content = self.files.get('submission_file')
-        lang_obj = self.cleaned_data.get('language')
-
-        if lang_obj is not None:
-            if (source != '' and content is not None) or (source == '' and content is None) or \
-                    (source != '' and lang_obj.file_only) or (content == '' and not lang_obj.file_only):
-                raise forms.ValidationError(_('Source code/file is missing or redundant. Please try again'))
-
-            if content:
-                max_file_size = lang_obj.file_size_limit * 1024 * 1024
-                ext = os.path.splitext(content.name)[1][1:]
-
-                if ext.lower() != lang_obj.extension.lower():
-                    raise forms.ValidationError(_('Wrong file type for language %(lang)s, expected %(lang_ext)s'
-                                                ', found %(ext)s')
-                                                % {'lang': lang_obj, 'lang_ext': lang_obj.extension, 'ext': ext})
-
-                elif content.size > max_file_size:
-                    raise forms.ValidationError(_('File size is too big! Maximum file size is %s')
-                                                % filesizeformat(max_file_size))
-
-                if lang_obj.key == 'SCRATCH':
-                    try:
-                        archive = zipfile.ZipFile(content.file)
-                        info = archive.getinfo('project.json')
-                        if info.file_size > max_file_size:
-                            raise forms.ValidationError(_('project.json is too big! Maximum file size is %s')
-                                                        % filesizeformat(max_file_size))
-
-                        self.files['submission_file'].file = archive.open('project.json')
-                    except (zipfile.BadZipFile, KeyError):
-                        pass
+        content = self.files.get('submission_file', None)
+        language = self.cleaned_data.get('language', None)
+        lang_obj = Language.objects.get(name=language)
+
+        if (source != '' and content is not None) or (source == '' and content is None) or \
+                (source != '' and lang_obj.file_only) or (content == '' and not lang_obj.file_only):
+            raise forms.ValidationError(_('Source code/file is missing or redundant. Please try again'))
+
+        problem = self.instance.problem if self.instance and self.instance.problem else None
+        max_size_kb = self._get_file_size_limit(lang_obj, problem)
+
+        # Validate source code size
+        if source and max_size_kb > 0:
+            source_size_bytes = len(source.encode('utf-8'))
+            if source_size_bytes > max_size_kb * 1024:
+                raise forms.ValidationError(
+                    _('Source code is too large! Size: %(size)s, Maximum allowed: %(max)s') % {
+                        'size': filesizeformat(source_size_bytes),
+                        'max': filesizeformat(max_size_kb * 1024),
+                    },
+                )
+
+        # Validate file upload
+        if content:
+            ext = os.path.splitext(content.name)[1][1:]
+            if ext.lower() != lang_obj.extension.lower():
+                raise forms.ValidationError(_('Wrong file type for language %(lang)s, expected %(lang_ext)s'
+                                              ', found %(ext)s')
+                                            % {'lang': language, 'lang_ext': lang_obj.extension, 'ext': ext})
+
+            if max_size_kb > 0 and content.size > max_size_kb * 1024:
+                raise forms.ValidationError(_('File size is too big! Maximum file size is %s')
+                                            % filesizeformat(max_size_kb * 1024))
+
+            if lang_obj.key == 'SCRATCH':
+                try:
+                    archive = zipfile.ZipFile(content.file)
+                    info = archive.getinfo('project.json')
+                    if info.file_size > max_size_kb * 1024:
+                        raise forms.ValidationError(_('project.json is too big! Maximum file size is %s')
+                                                    % filesizeformat(max_size_kb * 1024))
+
+                    self.files['submission_file'].file = archive.open('project.json')
+                except (zipfile.BadZipFile, KeyError):
+                    pass
 
     def __init__(self, *args, judge_choices=(), **kwargs):
         super(ProblemSubmitForm, self).__init__(*args, **kwargs)

judge/migrations/0221_alter_language_file_size_limit_and_more.py

@@ -0,0 +1,24 @@
+# Generated by Django 4.2.25 on 2026-02-01 08:53
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('judge', '0220_languagelimit_file_size_limit_alter_contest_authors_and_more'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='language',
+            name='file_size_limit',
+            field=models.IntegerField(blank=True, default=0, help_text='Limit of file size (in KB) if allow submit via file', verbose_name='Limit of file size'),
+        ),
+        migrations.AlterField(
+            model_name='languagelimit',
+            name='file_size_limit',
+            field=models.IntegerField(blank=True, help_text='File size limit in kilobytes (KB) for this problem and language. Leave blank to use the default language limit.', null=True, validators=[django.core.validators.MinValueValidator(0), django.core.validators.MaxValueValidator(102400)], verbose_name='file size limit'),
+        ),
+    ]

judge/models/problem.py

@@ -659,6 +659,15 @@ class LanguageLimit(models.Model):
     memory_limit = models.IntegerField(verbose_name=_('memory limit'),
                                        validators=[MinValueValidator(settings.DMOJ_PROBLEM_MIN_MEMORY_LIMIT),
                                                    MaxValueValidator(settings.DMOJ_PROBLEM_MAX_MEMORY_LIMIT)])
+    file_size_limit = models.IntegerField(
+        verbose_name=_('file size limit'),
+        null=True,
+        blank=True,
+        validators=[MinValueValidator(settings.DMOJ_PROBLEM_MIN_FILE_SIZE_LIMIT),
+                    MaxValueValidator(settings.DMOJ_PROBLEM_MAX_FILE_SIZE_LIMIT)],
+        help_text=_('File size limit in kilobytes (KB) for this problem and language. '
+                    'Leave blank to use the default language limit.'),
+    )
 
     class Meta:
         unique_together = ('problem', 'language')

judge/models/runtime.py

@@ -49,7 +49,7 @@ class Language(models.Model):
                                     help_text=_('If this language is submitted using file or not'))
 
     file_size_limit = models.IntegerField(verbose_name=_('Limit of file size'), default=0, blank=True,
-                                          help_text=_('Limit of file size (in MB) if allow submit via file'))
+                                          help_text=_('Limit of file size (in KB) if allow submit via file'))
 
     include_in_problem = models.BooleanField(verbose_name=_('Include in problems'), default=False,
                                              help_text=_('If true, this language will be added to all problems'))

judge/views/problem.py

@@ -29,7 +29,7 @@
 from judge.comments import CommentedDetailView
 from judge.forms import LanguageLimitFormSet, ProblemCloneForm, ProblemEditForm, ProblemEditTypeGroupForm, \
     ProblemImportPolygonForm, ProblemImportPolygonStatementFormSet, ProblemSubmitForm, ProposeProblemSolutionFormSet
-from judge.models import ContestSubmission, Judge, Language, Problem, ProblemGroup, \
+from judge.models import ContestSubmission, Judge, Language, LanguageLimit, Problem, ProblemGroup, \
     ProblemTranslation, ProblemType, RuntimeVersion, Solution, Submission, SubmissionSource
 from judge.tasks import on_new_problem
 from judge.template_context import misc_config
@@ -791,10 +791,32 @@ def get_title(self):
     def get_form(self, form_class=None):
         return self.get_submit_form()
 
+    def _get_file_size_limit(self, language, problem):
+        """Get effective file size limit in KB (problem-specific or language default)"""
+        limit = language.file_size_limit
+        try:
+            lang_limit = LanguageLimit.objects.get(problem=problem, language=language)
+            if lang_limit.file_size_limit is not None:
+                limit = lang_limit.file_size_limit
+        except LanguageLimit.DoesNotExist:
+            pass
+        return limit
+
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
-        context.update(self.get_submit_context())
-        context['no_judges'] = not context['form'].fields['language'].queryset if context.get('form') else True
+        context['langs'] = Language.objects.all()
+        context['no_judges'] = not context['form'].fields['language'].queryset
+        context['submission_limit'] = self.contest_problem and self.contest_problem.max_submissions
+        context['submissions_left'] = self.remaining_submission_count
+        context['ACE_URL'] = settings.ACE_URL
+        context['default_lang'] = self.default_language
+
+        # Build map of language ID to effective file size limit
+        context['lang_file_size_limits'] = {
+            lang.id: self._get_file_size_limit(lang, self.object)
+            for lang in context['form'].fields['language'].queryset
+        }
+
         return context
 
     def form_valid(self, form):

templates/problem/editor.html

@@ -71,13 +71,14 @@
 {% macro form_as_row(form) -%}
     {% if form.non_field_errors() %}
     <tr>
-        <td colspan="6">{{ form.non_field_errors() }}</td>
+        <td colspan="7">{{ form.non_field_errors() }}</td>
     </tr>
     {% endif %}
     <tr>
         <td>{{ form.id }} {{ form.language.errors }}{{ form.language }}</td>
         <td>{{ form.time_limit.errors }}{{ form.time_limit }}</td>
         <td>{{ form.memory_limit.errors }}{{ form.memory_limit }}</td>
+        <td>{{ form.file_size_limit.errors }}{{ form.file_size_limit }}</td>
         <td>
         {% if lang_limit_formset.can_delete and form.instance.pk %}
             {{ form.DELETE }}
@@ -119,6 +120,7 @@ <h3 id="lang_limit_title">{{ _('Language-specific resource limit') }} <i class="
                     <th style="width: 20em;"> {{ _('Language') }} </th>
                     <th> {{ _('Time limit (seconds)') }} </th>
                     <th> {{ _('Memory limit (KiB)') }} </th>
+                    <th> {{ _('File size limit (KB)') }} </th>
                     <th> {{ _('Delete') }} </th>
                 </tr>
             </thead>