[BEAM-70] More expressive UnboundedSource hierarchy and utilities

• Type: New Feature
• Status: Resolved
• Priority: P2
• Resolution: Won't Do
• Fix Version/s: Not applicable
• Component/s: sdk-java-core
• Labels: Done
• Assignee: Unassigned
• Reporter: Dan Halperin
• Created: 25/Feb/16 17:06
• Updated: 06/Oct/20 21:50
• Resolved: 01/Jun/19 03:51

Description

Right now, the UnboundedSource type hierarchy is 1 deep – UnboundedSource and then things like CountingSource or KafkaSource directly on top.

To ease implementors, we should have more abstract classes in the "common source types". Some examples may be:

• KeyRangeUnboundedSource – for things like PubSub, Bigtable, Kafka, Kinesis
• StreamSource – for reading from a socket or other stream.