Open Stack

On 08/13/2013 03:05 AM, Yee, Guang wrote:
> Passing the query parameters, whatever they are, into the driver if the
> given driver supports pagination and allowing the driver to override the
> manager default pagination functionality seem reasonable to me.

Please do use the standards that are supported in other OpenStack 
services already: limit, marker, sort_key and sort_dir.

Pagination is meaningless without a sort key and direction, so picking a 
sensible default for user/project records is good. I'd go with either 
created_at (what Glance/Nova/Cinder use..) or with the user/project UUID.

The Glance DB API pagination is well-documented and clean [1]. I highly 
recommend it as a starting point.

Nova uses the same marker/limit/sort_key/sort_dir options for queries 
that it allows pagination on. An example is the 
instance_get_all_by_filters() call [2].

Cinder uses the same marker/limit/sort_key/sort_dir options for query 
pagination as well. [3]

Finally, I'd consider supporting the standard change-since parameter for 
listing operations. Both Nova [4] and Glance [5] support the parameter, 
which is useful for tools that poll the APIs for "new" events/records.

In short, go with what is already a standard in the other projects...

Best,
-jay

[1] 
https://github.com/openstack/glance/blob/master/glance/db/sqlalchemy/api.py#L429
[2] 
https://github.com/openstack/nova/blob/master/nova/db/sqlalchemy/api.py#L1709
[3] 
https://github.com/openstack/cinder/blob/master/cinder/common/sqlalchemyutils.py#L33
[4] 
https://github.com/openstack/nova/blob/master/nova/db/sqlalchemy/api.py#L1766
[5] 
https://github.com/openstack/glance/blob/master/glance/db/sqlalchemy/api.py#L618