Cache Fixes, Django 4.0 Update

CHANGELOG.rst

@@ -1,6 +1,14 @@
 Changelog
 =========
 
+3.6 (master)
+------------
+
+- Added support for Python 3.9.
+- Added support for Python 3.10.
+- Removed cache headers for all views except 404. Due to that snippets can be
+  deleted, it's not trivial to have them removed from upstream caches.
+
 3.5 (2020-01-08)
 ----------------
 

dpaste/apps.py

@@ -2,6 +2,9 @@ from django.apps import AppConfig, apps
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _
 
+from logging import getLogger
+
+log = getLogger(__file__)
 
 class dpasteAppConfig(AppConfig):
     name = "dpaste"
@@ -610,12 +613,8 @@ class dpasteAppConfig(AppConfig):
             # ('zephir', 'Zephir')
         ]
 
-    # Whether to send out cache headers (Max-Age, Never-Cache, etc.).
-    CACHE_HEADER = True
-
-    # Defines how long pages are cached by upstream Proxies (Max-Age Header).
-    # This does not affect caching of snippets, their max-age limit is set
-    # to the expire date.
+    # Cache timeout for 404 and static pages. Snippets don't have an explicit
+    # Cache timeout set to avoid caching in upstream proxies.
     CACHE_TIMEOUT = 60 * 10
 
     @staticmethod

dpaste/urls/__init__.py

@@ -1,11 +1,11 @@
-from django.conf.urls import include, url
+from django.urls import include, re_path
 
 urlpatterns = [
-    url(r"^", include("dpaste.urls.dpaste_api")),
-    url(r"^", include("dpaste.urls.dpaste")),
-    url(r"^i18n/", include("django.conf.urls.i18n")),
+    re_path(r"^", include("dpaste.urls.dpaste_api")),
+    re_path(r"^", include("dpaste.urls.dpaste")),
+    re_path(r"^i18n/", include("django.conf.urls.i18n")),
 ]
 
 # Custom error handlers which load `dpaste/<code>.html` instead of `<code>.html`
-handler404 = "dpaste.views.page_not_found"
-handler500 = "dpaste.views.server_error"
+handler404 = "dpaste.views.handler404"
+handler500 = "dpaste.views.handler500"

dpaste/urls/dpaste.py

@@ -1,6 +1,6 @@
 from django.apps import apps
 from django.conf import settings
-from django.conf.urls import url
+from django.urls import re_path
 from django.views.decorators.cache import cache_control
 from django.views.decorators.clickjacking import xframe_options_exempt
 from django.views.generic import TemplateView
@@ -11,8 +11,8 @@ L = getattr(settings, "DPASTE_SLUG_LENGTH", 4)
 config = apps.get_app_config("dpaste")
 
 urlpatterns = [
-    url(r"^$", views.SnippetView.as_view(), name="snippet_new"),
-    url(
+    re_path(r"^$", views.SnippetView.as_view(), name="snippet_new"),
+    re_path(
         r"^about/$",
         cache_control(max_age=config.CACHE_TIMEOUT)(
             TemplateView.as_view(
@@ -22,18 +22,18 @@ urlpatterns = [
         ),
         name="dpaste_about",
     ),
-    url(r"^history/$", views.SnippetHistory.as_view(), name="snippet_history"),
-    url(
+    re_path(r"^history/$", views.SnippetHistory.as_view(), name="snippet_history"),
+    re_path(
         r"^(?P<snippet_id>[a-zA-Z0-9]{%d,})/?$" % L,
         views.SnippetDetailView.as_view(),
         name="snippet_details",
     ),
-    url(
+    re_path(
         r"^(?P<snippet_id>[a-zA-Z0-9]{%d,})/raw/?$" % L,
         views.SnippetRawView.as_view(),
         name="snippet_details_raw",
     ),
-    url(
+    re_path(
         r"^(?P<snippet_id>[a-zA-Z0-9]{%d,})/slim/?$" % L,
         xframe_options_exempt(
             views.SnippetDetailView.as_view(template_name="dpaste/details_slim.html")

dpaste/urls/dpaste_api.py

@@ -1,8 +1,8 @@
-from django.conf.urls import url
+from django.urls import re_path
 from django.views.decorators.csrf import csrf_exempt
 
 from ..views import APIView
 
 urlpatterns = [
-    url(r"^api/$", csrf_exempt(APIView.as_view()), name="dpaste_api_create_snippet",)
+    re_path(r"^api/$", csrf_exempt(APIView.as_view()), name="dpaste_api_create_snippet",)
 ]

dpaste/views.py

@@ -1,5 +1,6 @@
 import datetime
 import difflib
+import ipaddress
 import json
 
 from django.apps import apps
@@ -14,19 +15,22 @@ from django.shortcuts import get_object_or_404, render
 from django.urls import reverse
 from django.utils import timezone
 from django.utils.cache import add_never_cache_headers, patch_cache_control
-from django.utils.http import http_date
-from django.utils.translation import ugettext
+from django.utils.translation import gettext
 from django.views.generic import FormView
 from django.views.generic.base import TemplateView, View
 from django.views.generic.detail import DetailView
 from pygments.lexers import get_lexer_for_filename
 from pygments.util import ClassNotFound
+from ratelimit.decorators import ratelimit
+from ratelimit.exceptions import Ratelimited
 
 from dpaste import highlight
 from dpaste.forms import SnippetForm, get_expire_values
 from dpaste.highlight import PygmentsHighlighter
 from dpaste.models import Snippet
 
+from django.conf import settings
+
 config = apps.get_app_config("dpaste")
 
 
@@ -45,8 +49,6 @@ class SnippetView(FormView):
 
     def get(self, request, *args, **kwargs):
         response = super().get(request, *args, **kwargs)
-        if config.CACHE_HEADER:
-            patch_cache_control(response, max_age=config.CACHE_TIMEOUT)
         return response
 
     def get_form_kwargs(self):
@@ -111,18 +113,7 @@ class SnippetDetailView(DetailView, FormView):
         snippet.view_count += 1
         snippet.save(update_fields=["view_count"])
 
-        response = super().get(request, *args, **kwargs)
-
-        # Set the Max-Age header up until the snippet would expire
-        if config.CACHE_HEADER:
-            if snippet.expire_type == Snippet.EXPIRE_KEEP:
-                patch_cache_control(response, max_age=config.CACHE_TIMEOUT)
-            if snippet.expire_type == Snippet.EXPIRE_ONETIME:
-                add_never_cache_headers(response)
-            if snippet.expire_type == Snippet.EXPIRE_TIME and snippet.expires:
-                response["Expires"] = http_date(snippet.expires.timestamp())
-
-        return response
+        return super().get(request, *args, **kwargs)
 
     def get_initial(self):
         snippet = self.get_object()
@@ -153,8 +144,8 @@ class SnippetDetailView(DetailView, FormView):
         d = difflib.unified_diff(
             snippet.parent.content.splitlines(),
             snippet.content.splitlines(),
-            ugettext("Previous Snippet"),
-            ugettext("Current Snippet"),
+            gettext("Previous Snippet"),
+            gettext("Current Snippet"),
             n=1,
         )
         diff_code = "\n".join(d).strip()
@@ -188,7 +179,7 @@ class SnippetRawView(SnippetDetailView):
     def dispatch(self, request, *args, **kwargs):
         if not config.RAW_MODE_ENABLED:
             return HttpResponseForbidden(
-                ugettext("This dpaste installation has Raw view mode disabled.")
+                gettext("This dpaste installation has Raw view mode disabled.")
             )
         return super().dispatch(request, *args, **kwargs)
 
@@ -332,7 +323,10 @@ class APIView(View):
             expire_type = Snippet.EXPIRE_TIME
 
         snippet = Snippet.objects.create(
-            content=content, lexer=lexer, expires=expires, expire_type=expire_type,
+            content=content,
+            lexer=lexer,
+            expires=expires,
+            expire_type=expire_type,
         )
 
         # Custom formatter for the API response
@@ -349,17 +343,15 @@ class APIView(View):
 # handle them here.
 # -----------------------------------------------------------------------------
 
-
-def page_not_found(request, exception=None, template_name="dpaste/404.html"):
+def handler404(request, exception=None, template_name="dpaste/404.html"):
     context = {}
     context.update(config.extra_template_context)
     response = render(request, template_name, context, status=404)
-    if config.CACHE_HEADER:
-        patch_cache_control(response, max_age=config.CACHE_TIMEOUT)
+    patch_cache_control(response, max_age=config.CACHE_TIMEOUT)
     return response
 
 
-def server_error(request, template_name="dpaste/500.html"):
+def handler500(request, template_name="dpaste/500.html"):
     context = {}
     context.update(config.extra_template_context)
     response = render(request, template_name, context, status=500)

tox.ini

@@ -4,7 +4,8 @@ skip_missing_interpreters=True
 envlist=
     readme
     coverage_setup
-    py{36,37,38}-django-{22,30,31}
+    py{36,37,38,39,310}-django-{22,30,31,32}
+    py{38,39,310}-django-{40}
     coverage_report
 
 [testenv]
@@ -18,6 +19,8 @@ deps=
     django-22: django>=2.2,<3.0
     django-30: django>=3.0,<3.1
     django-31: django>=3.1,<3.2
+    django-32: django>=3.2,<4.0
+    django-40: django>=4.0,<4.1
 
 [testenv:coverage_setup]
 skip_install = True