refactor api views inter their respecting apps

src/c3nav/mapdata/cache.py

@@ -0,0 +1,43 @@
+import base64
+
+from django.core.cache import cache
+from django.template.response import SimpleTemplateResponse
+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 request.META.get('HTTP_ACCEPT', '')
+
+    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:
+            if isinstance(response, SimpleTemplateResponse):
+                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))