[NEMO-259] Implement ReadyCheckingSideInputReader

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.1
• Assignee: Unassigned
• Reporter: Tae-Geon Um
• Created: 02/Nov/18 01:26
• Updated: 11/Dec/18 04:02
• Resolved: 22/Nov/18 00:21

Description

Beam's ReadyCheckingSideInputReader allows us to check whether the current side input of a window is available or not.  By implementing the ReadyCheckingSideInputHandler, we can push back main elements if the side input of a window is not available. We also don't have to emit empty side inputs in CreateViewTransform. Instead, we can return empty side inputs in the ReadyCheckingSideInputHandler if the side input of a window is available but no data are received in the window. 

Issue Links

• is a child of: NEMO-216 Support side inputs and windowing
• links to: PR#159