Make 'object save' fast again

'openstack object save' is critically slow to download big objects. While
we 'stream' (chunked download) the data, the default chunks_size
is 1 byte [1], which is terribly inefficient.

[1] : http://docs.python-requests.org/en/master/api/#requests.Response.iter_content

Closes-Bug: 1654645


Change-Id: I2223e5897346acd2f2c1fae638d1193cff833c19

openstackclient/api/object_store_v1.py

@@ -380,7 +380,7 @@ class APIv1(api.BaseAPI):
                 if len(os.path.dirname(file)) > 0:
                     os.makedirs(os.path.dirname(file))
             with open(file, 'wb') as f:
-                for chunk in response.iter_content():
+                for chunk in response.iter_content(64 * 1024):
                     f.write(chunk)
 
     def object_set(

releasenotes/notes/speedup-object-save-6bd59e678a31c3e8.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+     Makes ``openstack object save`` much faster when saving an object to disk.
+     [Bug `1654645 <https://bugs.launchpad.net/bugs/1654645>`_]