[FLINK-12587] Add pure-API Watermark class

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Abandoned
• Component/s: API / DataStream
• Assignee: Aljoscha Krettek
• Reporter: Aljoscha Krettek
• Created: 22/May/19 08:34
• Updated: 09/Jun/20 10:47
• Resolved: 09/Jun/20 10:47

Description

Currently, Watermark extends StreamElement, which comes with a lot of transitive dependencies to classes and modules that are runtime code and shouldn't be in an API package. In the future, we want to more clearly separate API packages from runtime packages. The first instance of this is trying to put TableSources into flink-table-common, which will require our source-like interfaces to be clean of runtime dependencies. This means that we have to put SourceFunction into flink-core, which has Watermark in its interface, which we therefore have to untangle from runtime classes.

Issue Links

• is depended upon by: FLINK-12606 Move SourceFunction to flink-core