mirror of
https://github.com/Nanaloveyuki/BitLogger.git
synced 2026-07-24 08:52:35 +00:00
Nanaloveyuki
90 lines
3.3 KiB
Markdown
90 lines
3.3 KiB
Markdown
---
|
|
name: async-logger-run
|
|
group: api
|
|
category: async
|
|
update-time: 20260614
|
|
description: Start the async logger worker loop so queued records are drained to the underlying sink while lifecycle and failure state are reset and updated around execution.
|
|
key-word:
|
|
- async
|
|
- logger
|
|
- worker
|
|
- public
|
|
---
|
|
|
|
## Async-logger-run
|
|
|
|
Start the async logger worker loop. This is the core runtime API that drains queued records to the underlying sink and updates worker lifecycle state around that drain loop.
|
|
|
|
### Interface
|
|
|
|
```moonbit
|
|
pub async fn[S : @bitlogger.Sink] AsyncLogger::run(self : AsyncLogger[S]) -> Unit {}
|
|
```
|
|
|
|
#### input
|
|
|
|
- `self : AsyncLogger[S]` - Async logger whose queue should be drained by the worker loop.
|
|
|
|
#### output
|
|
|
|
- `Unit` - No return value. The method runs until the queue is closed or a worker failure occurs.
|
|
|
|
### Explanation
|
|
|
|
Detailed rules explaining key parameters and behaviors
|
|
|
|
- `run()` sets `is_running` to `true` before worker execution begins.
|
|
- Every invocation clears previous failure state first by setting `has_failed=false` and `last_error()` to an empty string once that `run()` call has actually started executing.
|
|
- The method then keeps draining records until `queue.get()` stops with `AsyncLoggerClosed` or a worker error escapes.
|
|
- On a normal queue-close exit, `run()` clears `is_running` and returns normally.
|
|
- On failure, the logger records `has_failed=true`, stores the error text in `last_error`, clears `is_running`, and then raises the error back out of `run()`.
|
|
- This helper does not enforce a single-worker guard by itself, so the public contract should be treated as application-controlled worker startup rather than an API that deduplicates repeated `run()` calls.
|
|
|
|
### How to Use
|
|
|
|
Here are some specific examples provided.
|
|
|
|
#### When Need Background Queue Drain
|
|
|
|
When async logging should be processed by a worker task:
|
|
```moonbit
|
|
let logger = async_logger(console_sink())
|
|
@async.with_task_group(group => {
|
|
group.spawn_bg(() => logger.run())
|
|
logger.info("started")
|
|
logger.shutdown()
|
|
})
|
|
```
|
|
|
|
In this example, `run()` is the worker loop that makes the async logger actually deliver queued records.
|
|
|
|
#### When Need Explicit Worker Lifetime Control
|
|
|
|
When worker execution should be started under application control:
|
|
```moonbit
|
|
group.spawn_bg(() => logger.run())
|
|
```
|
|
|
|
In this example, the application decides when the worker begins instead of hiding that lifecycle step.
|
|
|
|
### Error Case
|
|
|
|
e.g.:
|
|
- If the worker loop fails, `has_failed()` becomes `true`, `last_error()` stores the error text, and `run()` raises that failure to the caller.
|
|
|
|
- If `run()` is never started, accepted records may remain queued and not reach the sink.
|
|
|
|
- A later `run()` attempt starts from a fresh failure flag and empty `last_error()` string, even if an earlier run failed.
|
|
|
|
- Starting more than one `run()` task for the same logger is not prevented by this method and can produce application-level worker coordination bugs.
|
|
|
|
### Notes
|
|
|
|
1. `async_logger(...)` only constructs the logger; `run()` is what activates queue draining.
|
|
|
|
2. Pair this API with `shutdown()` for a complete worker lifecycle.
|
|
|
|
3. Pair it with `has_failed()`, `last_error()`, or `state()` when tests need to inspect how a worker exit affected logger health.
|
|
|
|
4. Start one deliberate worker task per logger unless your own code is intentionally coordinating a different pattern.
|