Switch back to send_file and add a bit of gzip buffering

endpoints/verbs.py

@@ -58,9 +58,6 @@ def get_squashed_tag(namespace, repository, tag, headers):
         yield current_image_stream
 
     stream = GzipWrap(StreamLayerMerger(get_next_layer).get_generator())
-    return app.response_class(wrap_file(request.environ, stream, 1024 * 16),
+    return send_file(stream)
-                              mimetype='application/octet-stream',
-                              direct_passthrough=True)
-    
 
   abort(403)

util/gzipwrap.py

@@ -18,13 +18,21 @@ class GzipWrap(object):
     while True:
       # Attempt to retrieve the next bytes to write.
       is_done = False
-      try:
-        s = self.input.next()
-        self.zipper.write(s)
-      except StopIteration:
-        is_done = True
 
-      if len(self.buffer) < size or is_done:
+      input_size = 0
+      input_buffer = ''
+      while input_size < 1024 * 256:  # 256K buffer to Gzip
+        try:
+          s = self.input.next()
+          input_buffer += s
+          input_size = input_size + len(s)
+        except StopIteration:
+          is_done = True
+          break
+        
+      self.zipper.write(input_buffer)
+
+      if is_done:
         self.zipper.flush()
 
       if len(self.buffer) >= size or is_done: