With-queue

Add a synchronous queue wrapper to an existing LoggerConfig. This preset helper is the config-side counterpart to Logger::with_queue(...), allowing queue behavior to be expressed before the runtime logger is built.

Interface

pub fn with_queue(
  config : LoggerConfig,
  max_pending~ : Int = 0,
  overflow~ : QueueOverflowPolicy = QueueOverflowPolicy::DropNewest,
) -> LoggerConfig {

input

• config : LoggerConfig - Base logger config to wrap.
• max_pending : Int - Maximum number of pending records allowed in the queue.
• overflow : QueueOverflowPolicy - Overflow behavior such as DropNewest or DropOldest.

output

• LoggerConfig - A copy of the input config with queue=Some(QueueConfig::new(...)).

Explanation

Detailed rules explaining key parameters and behaviors

• This helper preserves the original config's min_level, target, timestamp, and sink fields.
• Only the top-level queue field is added or replaced.
• The helper can be composed with any preset, including console(...), json_console(...), text_console(...), and file(...).

How to Use

Here are some specific examples provided.

When Need Config-side Queueing

When queue behavior should be configured before calling build_logger(...):

let config = with_queue(
  text_console(target="svc"),
  max_pending=32,
  overflow=QueueOverflowPolicy::DropOldest,
)

In this example, the text console preset is wrapped with a bounded queue config.

And sink-specific settings remain unchanged.

Error Case

e.g.:

• If max_pending is too small, burst traffic may trigger overflow handling sooner.

• If the wrapped runtime logger is never flushed or drained, queued records may remain pending depending on how the built sink is used.

Notes

1. This helper is config composition only; it does not build or run the logger.

2. Queue wrapping can be combined with with_file_rotation(...) when the base config is file-based.