BitLogger/docs/api/configured-logger-file-default-policy-or-none.md

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

name	group	category	update-time	description	key-word
configured-logger-file-default-policy-or-none	api	runtime	20260707	Read the default runtime file policy from a ConfiguredLogger only when it is actually file-backed.	logger runtime file truthful

Configured-logger-file-default-policy-or-none

Read the default runtime file policy from a ConfiguredLogger only when it is actually file-backed.

The returned FileSinkPolicy value is owned by src/file_model; this configured-logger surface is a facade over Logger[@runtime.RuntimeSink] and avoids fabricating that model on non-file variants.

This is the truthful companion to file_default_policy(). Prefer it when default-policy inspection should not fabricate a fallback object on non-file sinks.

Interface

pub fn ConfiguredLogger::file_default_policy_or_none(self : ConfiguredLogger) -> FileSinkPolicy? {}

input

• self : ConfiguredLogger - Config-driven runtime logger whose default file policy should be inspected.

output

• FileSinkPolicy? - Some(policy) when the configured sink is file-backed, otherwise None.

Explanation

Detailed rules explaining key parameters and behaviors

• File-backed sinks return Some(default_policy) through the wrapped RuntimeSink.
• Queued file sinks forward the wrapped inner file sink default policy as Some(default_policy).
• The wrapped value is the shared @file_model.FileSinkPolicy model, not a configured-logger-owned concrete type.
• Non-file sinks return None.
• This helper is useful when callers need to compare runtime drift or restore defaults without fabricating file semantics.

How to Use

Here are some specific examples provided.

When Need Truthful Baseline Policy Visibility

When tooling should inspect defaults only for real file-backed sinks:

let defaults = logger.file_default_policy_or_none()

In this example, None means the configured logger has no file default policy.

When Compare Current And Default Policy Truthfully

When diagnostics should avoid fallback policy objects:

match (logger.file_policy_or_none(), logger.file_default_policy_or_none()) {
  (Some(current), Some(defaults)) => ignore((current, defaults))
  _ => ()
}

In this example, comparisons happen only when real file semantics exist.

Error Case

e.g.:

• If the configured sink is not file-backed, the method returns None.

• If callers only need a drift boolean, file_policy_matches_default() remains simpler.

Notes

1. Prefer this helper over file_default_policy() for truthful runtime diagnostics.

2. file_default_policy() remains available as the compatibility fallback API.