BitLogger/docs/api/patch-sink.md

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

name	group	category	update-time	description	key-word
patch-sink	api	sink	20260520	Create a sink that rewrites records with a patch before forwarding them.	sink patch record public

Patch-sink

Create a sink that rewrites each record with a RecordPatch before forwarding it to another sink. This helper is the sink-level counterpart to Logger::with_patch(...).

Interface

pub fn[S] patch_sink(sink : S, patch : RecordPatch) -> PatchSink[S] {

input

• sink : S - Wrapped sink receiving patched records.
• patch : RecordPatch - Record transformation applied before forwarding.

output

• PatchSink[S] - Patch-applying sink.

Explanation

Detailed rules explaining key parameters and behaviors

• Each record is transformed before it reaches the wrapped sink.
• This helper is useful for sink-first composition graphs and adapters.
• Use the logger-level helper when the patch should be attached after Logger::new(...) instead.

How to Use

Here are some specific examples provided.

When Need Record Rewriting At Sink Construction Time

When sanitization or target rewriting should happen before sink delivery:

let sink = patch_sink(console_sink(), prefix_message("[safe] "))
let logger = Logger::new(sink, target="auth")

In this example, records are patched before they are written to the wrapped sink.

Error Case

e.g.:

• If patching should be attached to an already-built logger, use with_patch(...) instead.

• Patch behavior is defined by the supplied function, so semantic mistakes come from patch logic rather than sink mechanics.

Notes

1. This helper is useful for explicit sink graphs.

2. It composes naturally with helpers such as compose_patches(...).