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Configured-logger-drain

Drain queued work from a ConfiguredLogger. This helper is the configured logger wrapper over RuntimeSink::drain(...) when config-driven queue wrapping should be advanced in a controlled, bounded way.

Interface

moonbit
pub fn ConfiguredLogger::drain(self : ConfiguredLogger, max_items~ : Int = -1) -> Int {}

input

  • self : ConfiguredLogger - Config-driven runtime logger whose queued work should be drained.
  • max_items : Int - Optional upper bound on how many queued items to drain. Negative values mean no explicit bound.

output

  • Int - Count returned by the wrapped RuntimeSink::drain(...) call.

Explanation

Detailed rules explaining key parameters and behaviors

  • This helper delegates directly to self.sink.drain(max_items=max_items).
  • Queue-wrapped sinks forward to the concrete queue sink's drain(...) behavior and may drain up to max_items records.
  • Plain file sinks fall back to FileSink::flush() behavior through RuntimeSink and return 1 or 0.
  • Plain console-style sinks return 0 because they do not own a drainable queue here.

How to Use

Here are some specific examples provided.

When Need Bounded Queue Progress

When queued output should be advanced in chunks:

moonbit
let drained = logger.drain(max_items=16)

In this example, callers limit how much queued work is processed in one step.

When Need Full Manual Drain

When the configured queue should be emptied explicitly:

moonbit
ignore(logger.drain())

In this example, the configured runtime logger drains without imposing an item cap.

Error Case

e.g.:

  • If the configured runtime sink is not queue-backed, draining may return 0 or follow the plain-file flush fallback.

  • If callers only need generic flush semantics, flush() may be the simpler API.

Notes

  1. Prefer this helper when queue progress should be bounded or observable.

  2. Use pending_count() to inspect remaining backlog after the drain call when the configured sink is queue-backed.

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