cache api responses

src/c3nav/api/views/cache.py

@@ -0,0 +1,41 @@
+import base64
+
+from django.core.cache import cache
+from django.utils.cache import patch_vary_headers
+
+from ..permissions import get_unlocked_packages
+
+
+class CachedViewSetMixin:
+    def get_cache_key(self, request):
+        cache_key = ('api__' + ('OPTIONS' if request.method == 'OPTIONS' else 'GET') + '_' +
+                     base64.b64encode(self.get_cache_params(request).encode()).decode() + '_' +
+                     request.path + '?' + request.META['QUERY_STRING'])
+        return cache_key
+
+    def get_cache_params(self, request):
+        return ''
+
+    def dispatch(self, request, *args, **kwargs):
+        do_cache = request.method in ('GET', 'HEAD', 'OPTIONS')
+        if do_cache:
+            cache_key = self.get_cache_key(request)
+            if cache_key in cache:
+                return cache.get(cache_key)
+        response = super().dispatch(request, *args, **kwargs)
+        patch_vary_headers(response, ['Cookie'])
+        if do_cache:
+            response.render()
+            cache.set(cache_key, response, 60)
+        return response
+
+    @property
+    def default_response_headers(self):
+        headers = super().default_response_headers
+        headers['Vary'] += ', Cookie'
+        return headers
+
+
+class AccessCachedViewSetMixin(CachedViewSetMixin):
+    def get_cache_params(self, request):
+        return super().get_cache_params(request)+'___'+'___'.join(get_unlocked_packages(request))

src/c3nav/api/views/mapdata.py

@@ -11,9 +11,10 @@ from rest_framework.viewsets import ReadOnlyModelViewSet
 from ...mapdata.models import Level, Package, Source
 from ..permissions import filter_source_queryset
 from ..serializers import LevelSerializer, PackageSerializer, SourceSerializer
+from .cache import AccessCachedViewSetMixin, CachedViewSetMixin
 
 
-class LevelViewSet(ReadOnlyModelViewSet):
+class LevelViewSet(CachedViewSetMixin, ReadOnlyModelViewSet):
     """
     Returns a list of all levels on the map.
     """
@@ -26,7 +27,7 @@ class LevelViewSet(ReadOnlyModelViewSet):
     search_fields = ('name',)
 
 
-class PackageViewSet(ReadOnlyModelViewSet):
+class PackageViewSet(AccessCachedViewSetMixin, ReadOnlyModelViewSet):
     """
     Returns a list of all packages the map consists of.
     """
@@ -39,7 +40,7 @@ class PackageViewSet(ReadOnlyModelViewSet):
     search_fields = ('name',)
 
 
-class SourceViewSet(ReadOnlyModelViewSet):
+class SourceViewSet(AccessCachedViewSetMixin, ReadOnlyModelViewSet):
     """
     Returns a list of source images (to use as a drafts).
     Call /sources/{name}/image to get the image.