1 files changed, 39 insertions, 0 deletions
diff --git a/webapp/django/middleware/gzip.py b/webapp/django/middleware/gzip.py
new file mode 100644
index 0000000000..3b849801da
--- /dev/null
+++ b/webapp/django/middleware/gzip.py
@@ -0,0 +1,39 @@
+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