Terminal debug sink that prints every incoming message of any stream t to standard output, prefixed with a per-process sequence index, so a backend stage's output can be inspected during development. Consumes the stream; nothing flows past it.
Typical backends
A live image source is tapped so each received frame's contents are echoed to the log while the backend runs.
A throttled stream is logged to confirm the pacing stage emits at the expected cadence before the rest of the graph is wired up.
Caveats
- I/O contractThis is a terminal sink: messages stop here and there is no output, so branch the wire upstream if the same data is also needed elsewhere.
- State lifetimeThe printed index is process-local and restarts from zero every time the backend is (re)started.
- CompatibilityLines are written to standard output; whether they are retained depends on the deployment's log-capture setup.
- CostLarge payloads such as images or tensors are serialised inline and produce very long lines, and a high message rate can flood the log, so pace the stream upstream when volume is high.
- LimitationBehaviour is fully fixed; there is nothing to configure.