capybara/virtualenv/lib/python2.7/site-packages/pip/_vendor/cachecontrol/adapter.py
def build_response(self, request, response, from_cache=False):
        """
        Build a response by making a request or using the cache.

        This will end up calling send and returning a potentially
        cached response
        """
        if not from_cache and request.method == 'GET':

            # apply any expiration heuristics
            if response.status == 304:
                # We must have sent an ETag request. This could mean
                # that we've been expired already or that we simply
                # have an etag. In either case, we want to try and
                # update the cache if that is the case.
                cached_response = self.controller.update_cached_response(
                    request, response
                )

                if cached_response is not response:
                    from_cache = True

                # We are done with the server response, read a
                # possible response body (compliant servers will
                # not return one, but we cannot be 100% sure) and
                # release the connection back to the pool.
                response.read(decode_content=False)
                response.release_conn()

                response = cached_response

            # We always cache the 301 responses
            elif response.status == 301:
                self.controller.cache_response(request, response)
            else:
                # Check for any heuristics that might update headers
                # before trying to cache.
                if self.heuristic:
                    response = self.heuristic.apply(response)

                # Wrap the response file with a wrapper that will cache the
                #   response when the stream has been consumed.
                response._fp = CallbackFileWrapper(
                    response._fp,
                    functools.partial(
                        self.controller.cache_response,
                        request,
                        response,
                    )
                )

        resp = super(CacheControlAdapter, self).build_response(
            request, response
        )

        # See if we should invalidate the cache.
        if request.method in self.invalidating_methods and resp.ok:
            cache_url = self.controller.cache_url(request.url)
            self.cache.delete(cache_url)

        # Give the request a from_cache attr to let people use it
        resp.from_cache = from_cache

        return resp
def build_response(self, request, response, from_cache=False):
        """
        Build a response by making a request or using the cache.

        This will end up calling send and returning a potentially
        cached response
        """
        if not from_cache and request.method == 'GET':

            # apply any expiration heuristics
            if response.status == 304:
                # We must have sent an ETag request. This could mean
                # that we've been expired already or that we simply
                # have an etag. In either case, we want to try and
                # update the cache if that is the case.
                cached_response = self.controller.update_cached_response(
                    request, response
                )

                if cached_response is not response:
                    from_cache = True

                # We are done with the server response, read a
                # possible response body (compliant servers will
                # not return one, but we cannot be 100% sure) and
                # release the connection back to the pool.
                response.read(decode_content=False)
                response.release_conn()

                response = cached_response

            # We always cache the 301 responses
            elif response.status == 301:
                self.controller.cache_response(request, response)
            else:
                # Check for any heuristics that might update headers
                # before trying to cache.
                if self.heuristic:
                    response = self.heuristic.apply(response)

                # Wrap the response file with a wrapper that will cache the
                #   response when the stream has been consumed.
                response._fp = CallbackFileWrapper(
                    response._fp,
                    functools.partial(
                        self.controller.cache_response,
                        request,
                        response,
                    )
                )

        resp = super(CacheControlAdapter, self).build_response(
            request, response
        )

        # See if we should invalidate the cache.
        if request.method in self.invalidating_methods and resp.ok:
            cache_url = self.controller.cache_url(request.url)
            self.cache.delete(cache_url)

        # Give the request a from_cache attr to let people use it
        resp.from_cache = from_cache

        return resp
Build a response by making a request or using the cache.

        This will end up calling send and returning a potentially
        cached response