BitLogger/docs/api/queued-sink-dropped-count.md

name, group, category, update-time, description, key-word

name	group	category	update-time	description	key-word
queued-sink-dropped-count	api	sink	20260613	Read the cumulative dropped-record count from a QueuedSink.	sink queue dropped public

Queued-sink-dropped-count

Read the cumulative dropped-record count from a QueuedSink[S]. This helper exposes the direct sink-level loss metric when a bounded queue overflows.

Interface

pub fn[S] QueuedSink::dropped_count(self : QueuedSink[S]) -> Int {

input

• self : QueuedSink[S] - Queued sink whose cumulative dropped-record metric should be inspected.

output

• Int - Number of dropped records reported by the queue wrapper.

Explanation

Detailed rules explaining key parameters and behaviors

• The counter value comes from self.dropped_count.val.
• It increases when the queue is full and an incoming record cannot be kept without applying overflow handling.
• The counter is cumulative for the lifetime of the concrete queued sink value.
• This helper does not explain why drops happened beyond exposing the count.

How to Use

Here are some specific examples provided.

When Need Direct Queue Loss Visibility

When a bounded queue may discard records under pressure:

if sink.dropped_count() > 0 {
  println("queue dropped records")
}

In this example, direct queue loss becomes visible without inspecting internal fields manually.

When Compare Overflow Tuning Changes

When queue capacity or overflow policy should be checked operationally:

ignore(sink.dropped_count())

In this example, callers can compare the cumulative drop metric across different queue settings.

Error Case

e.g.:

• If the queue never overflows, this counter remains 0.

• If callers need a higher-level wrapper around runtime-configured sinks, RuntimeSink::dropped_count() or ConfiguredLogger::dropped_count() may fit better.

Notes

1. This helper reports cumulative loss, not the exact overflow moment.

2. Pair it with pending_count(), drain(), and queue configuration when investigating pressure.