apache_beam.runners.direct.watermark_manager module
Manages watermarks of PCollections and AppliedPTransforms.
- class apache_beam.runners.direct.watermark_manager.WatermarkManager(clock, root_transforms, value_to_consumers, transform_keyed_states)[source]
- Bases: - object- For internal use only; no backwards-compatibility guarantees. - Tracks and updates watermarks for all AppliedPTransforms. - WATERMARK_POS_INF = Timestamp(9223372036854.775000)
 - WATERMARK_NEG_INF = Timestamp(-9223372036854.775000)
 - get_watermarks(applied_ptransform: AppliedPTransform) _TransformWatermarks[source]
- Gets the input and output watermarks for an AppliedPTransform. - If the applied_ptransform has not processed any elements, return a watermark with minimum value. - Parameters:
- applied_ptransform – AppliedPTransform to get the watermarks for. 
- Returns:
- A snapshot (TransformWatermarks) of the input watermark and output watermark for the provided transform.