| import re |
| |
| from django.utils.text import compress_string |
| from django.utils.cache import patch_vary_headers |
| |
| re_accepts_gzip = re.compile(r'\bgzip\b') |
| |
| class GZipMiddleware(object): |
| """ |
| This middleware compresses content if the browser allows gzip compression. |
| It sets the Vary header accordingly, so that caches will base their storage |
| on the Accept-Encoding header. |
| """ |
| def process_response(self, request, response): |
| # It's not worth compressing non-OK or really short responses. |
| if response.status_code != 200 or len(response.content) < 200: |
| return response |
| |
| patch_vary_headers(response, ('Accept-Encoding',)) |
| |
| # Avoid gzipping if we've already got a content-encoding. |
| if response.has_header('Content-Encoding'): |
| return response |
| |
| # Older versions of IE have issues with gzipped pages containing either |
| # Javascript and PDF. |
| if "msie" in request.META.get('HTTP_USER_AGENT', '').lower(): |
| ctype = response.get('Content-Type', '').lower() |
| if "javascript" in ctype or ctype == "application/pdf": |
| return response |
| |
| ae = request.META.get('HTTP_ACCEPT_ENCODING', '') |
| if not re_accepts_gzip.search(ae): |
| return response |
| |
| response.content = compress_string(response.content) |
| response['Content-Encoding'] = 'gzip' |
| response['Content-Length'] = str(len(response.content)) |
| return response |