使用来自请求的参数绑定基于缓存 Django class 的视图响应

Question

我想缓存我的 API 响应并将其与 GET 请求中存在的参数绑定。 请求如下所示：

GET /products?producent=some_company

这是我的简化 class：

class ProductsListCreate(generics.ListCreateAPIView):

    def list(self, request, *args, **kwargs):
        producent = request.query_params.get("producent")
        cached_response = cache.get(f"response-products-{producent}", None)
        if not cached_response:
            queryset = self.filter_queryset(self.get_queryset())
            page = self.paginate_queryset(queryset)
            serializer = self.get_serializer(page)
            response = self.get_paginated_response(serializer.data)

            cache.set(f"response-products-{producent}", response , timeout=20)
            return response

        return cached_response 

但是当我尝试缓存响应时，我收到错误：

django.template.response.ContentNotRenderedError: The response content must be rendered before it can be pickled.

你对我有什么建议吗？ 当我试图弄清楚这一点时，我在这里搜索https://docs.djangoproject.com/en/3.2/topics/cache/ 。 起初我尝试使用@cache_page的方法，但它不允许我使用请求中的参数，所以我猜go 的方法是低级缓存API。

Answer 1

错误消息实际上非常具有描述性。 在尝试将其腌制为可缓存格式之前，您必须在响应上调用render() 。 问题是：这将导致您进入一个兔子洞来解构响应并从缓存的数据中重建。 IMO，你最好缓存查询集。 然而，这就是它的样子：

class ProductsListCreate(generics.ListCreateAPIView):

    def list(self, request, *args, **kwargs):
        producent = request.query_params.get("producent")
        response_triple = cache.get(f"response-products-{producent}", None)
        if not response_triple:
            queryset = self.filter_queryset(self.get_queryset())
            page = self.paginate_queryset(queryset)
            serializer = self.get_serializer(page)
            response = self.get_paginated_response(serializer.data)

            response.render()

            if not response.status_code >= 400:
                # django 3.0 has no .items() method, django 3.2 has no ._headers
                if hasattr(response, '_headers'):
                    headers = response._headers.copy()
                else:
                    headers = {k: (k, v) for k, v in response.items()}
                response_triple = (
                    response.rendered_content,
                    response.status_code,
                    headers
                )
                cache.set(f"response-products-{producent}", response_triple, timeout=20)
        else:
            # build smaller Django HttpResponse
            content, status, headers = response_triple
            response = HttpResponse(content=content, status=status)
            for k, v in headers.values():
                response[k] = v
        if not hasattr(response, '_closable_objects'):
            response._closable_objects = []

        return response

取自： https://github.com/chibisov/drf-extensions/blob/ecdf3a95d7f18ccf9cffa55809635c3715179605/rest_framework_extensions/cache/decorators.py#L63