Can't do 'Transfer-Encoding: chunked'

Large objects are never sent using chunked transfers because response.content_length is always set.

FWIW I'm using gluster's version with their plug-ins patched in. I don't believe that affects this issue.

Looking at the rest of the swift code and .../site-packages/eventlet/wsgi.py it's apparent that if response.content_length is not set on large objects the result will be to send using chunked transfer.

This was found in 1.4.8 but looking at 1.6.0 source I can see the bug appears to exist there as well.

With the following change large objects are sent using chunked transfer (verified both with and without using tcpdump)

I chose to keep things simple and do chunk transfers at the disk_chunk_size, but an option in the config file would be okay too.

*** swift/obj/server.py.orig 2012-08-28 14:04:11.896008684 -0400
--- swift/obj/server.py 2012-09-05 10:32:38.788003438 -0400
***************
*** 720,730 ****
                  response.headers[key] = value
          response.etag = file.metadata['ETag']
          response.last_modified = float(file.metadata['X-Timestamp'])
! response.content_length = file_size
! if response.content_length < KEEP_CACHE_SIZE and \
! 'X-Auth-Token' not in request.headers and \
! 'X-Storage-Token' not in request.headers:
! file.keep_cache = True
          if 'Content-Encoding' in file.metadata:
              response.content_encoding = file.metadata['Content-Encoding']
          response.headers['X-Timestamp'] = file.metadata['X-Timestamp']
--- 720,731 ----
                  response.headers[key] = value
          response.etag = file.metadata['ETag']
          response.last_modified = float(file.metadata['X-Timestamp'])
! if file_size <= self.disk_chunk_size:
! response.content_length = file_size
! if response.content_length < KEEP_CACHE_SIZE and \
! 'X-Auth-Token' not in request.headers and \
! 'X-Storage-Token' not in request.headers:
! file.keep_cache = True
          if 'Content-Encoding' in file.metadata:
              response.content_encoding = file.metadata['Content-Encoding']
          response.headers['X-Timestamp'] = file.metadata['X-Timestamp']