📝 补充runtime文档

docs/api/configured-logger-flush-progress.md

@@ -0,0 +1,78 @@
+---
+name: configured-logger-flush-progress
+group: api
+category: runtime
+update-time: 20260707
+description: Return a structured generic flush progress snapshot for a ConfiguredLogger through RuntimeSink without collapsing queue and plain-file fallback semantics into one Int.
+key-word:
+    - logger
+    - runtime
+    - flush
+    - public
+---
+
+## Configured-logger-flush-progress
+
+Return a structured generic flush progress snapshot for a `ConfiguredLogger`. This is the recommended configured runtime wrapper over `RuntimeSink::flush_progress(...)` when code wants truthful generic progress instead of the compatibility `Int` returned by `flush()`.
+
+### Interface
+
+```moonbit
+pub fn ConfiguredLogger::flush_progress(self : ConfiguredLogger) -> RuntimeSinkProgress {}
+```
+
+#### input
+
+- `self : ConfiguredLogger` - Config-driven runtime logger whose generic flush progress should be observed.
+
+#### output
+
+- `RuntimeSinkProgress` - Structured progress snapshot returned by the wrapped `RuntimeSink::flush_progress(...)` call.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This helper delegates directly to `self.sink.flush_progress()`.
+- Queue-wrapped sinks report queue advancement through `queue_advanced_count`.
+- Plain file sinks report the generic fallback flush step through `file_flush_step_count`.
+- Plain console-style sinks return a zeroed snapshot.
+- This helper is the configured-logger entry point for the truthful generic progress surface introduced alongside the older compatibility `flush()` path.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need Recommended Generic Flush Progress On A Config-built Logger
+
+When config-built runtime code should inspect flush progress explicitly:
+```moonbit
+let progress = logger.flush_progress()
+```
+
+In this example, the configured runtime logger reports structured progress without collapsing runtime-shape semantics.
+
+#### When Need To Branch On Queue-backed Versus Plain-file Generic Progress
+
+When application code should keep the config-built facade but still distinguish progress meaning:
+```moonbit
+let progress = logger.flush_progress()
+if progress.queue_backed {
+  println(progress.queue_advanced_count)
+}
+```
+
+In this example, queue advancement remains explicit even though the logger was built from config.
+
+### Error Case
+
+e.g.:
+- If the configured runtime sink shape has no flushable state, the snapshot simply reports zero counts.
+
+- If callers need file-specific success semantics on a file-backed logger, `file_flush()` is the better API.
+
+### Notes
+
+1. Prefer `flush_progress()` over `flush()` in new configured-runtime code.
+
+2. `flush()` is still available for compatibility with older code that expects one numeric count.