BitLogger/docs/api/runtime-sink-file-set-policy.md

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

name	group	category	update-time	description	key-word
runtime-sink-file-set-policy	api	runtime	20260707	Apply a bundled runtime file policy update to a file-backed RuntimeSink.	runtime sink file public

Runtime-sink-file-set-policy

Apply a bundled runtime file policy update to a RuntimeSink. This helper updates append mode, auto-flush, and rotation together through one runtime policy object on direct sink values.

Interface

pub fn RuntimeSink::file_set_policy(self : RuntimeSink, policy : FileSinkPolicy) -> Bool {

input

• self : RuntimeSink - Runtime sink whose file policy should change.
• policy : FileSinkPolicy - Bundled runtime file policy to apply.

output

• Bool - Whether the policy update was applied.

Explanation

Detailed rules explaining key parameters and behaviors

• Plain File runtime variants update append, auto-flush, and rotation together on the wrapped FileSink and return true.
• QueuedFile runtime variants forward the policy update to the wrapped inner FileSink only when no queued records are pending.
• Non-file runtime variants return false.
• This helper is broader than the single-setting setters because it updates the whole file policy in one call.
• If a queued file sink still has pending records, the update is rejected and returns false so already queued records are not later written under a different policy bundle than the one they were queued under.

How to Use

Here are some specific examples provided.

When Need Bundled Runtime Policy Changes

When append, flush, and rotation should change together:

ignore(sink.file_set_policy(FileSinkPolicy::new(
  append=true,
  auto_flush=false,
  rotation=Some(file_rotation(2048, max_backups=2)),
)))

In this example, runtime file behavior is updated as one policy change.

When Apply A Policy Snapshot

When a previously captured or computed policy should be restored:

let ok = sink.file_set_policy(policy)

In this example, callers can reapply a whole policy object without splitting it into separate setter calls.

Error Case

e.g.:

• If the runtime sink is not file-backed, the method returns false.

• If callers only need to change one setting, a narrower setter such as file_set_auto_flush(...) or file_set_rotation(...) may be clearer.

• If a queued file sink still has pending records, callers should flush or close it first before changing policy.

Notes

1. Use this helper when the runtime policy should be treated as one cohesive object.

2. On queued file sinks, clear pending records first so policy mutation does not retroactively affect already queued writes.