✨ Add file policy snapshot helpers

bitlogger/BitLogger_test.mbt

@@ -330,9 +330,13 @@ test "configured logger file setters update file sink policy state" {
       queue=Some(QueueConfig::new(2, overflow=QueueOverflowPolicy::DropNewest)),
     ),
   )
+  let default_policy = logger.file_default_policy()
   inspect(logger.file_append_mode(), content="true")
   inspect(logger.file_auto_flush(), content="true")
   inspect(logger.file_rotation_enabled(), content="false")
+  inspect(default_policy.append, content="true")
+  inspect(default_policy.auto_flush, content="true")
+  inspect(default_policy.rotation is None, content="true")
   inspect(logger.file_set_append_mode(false), content="true")
   inspect(logger.file_append_mode(), content="false")
   inspect(logger.file_set_auto_flush(false), content="true")
@@ -352,9 +356,13 @@ test "configured logger file setters update file sink policy state" {
   inspect(logger.file_reopen(), content=if logger.file_available() { "true" } else { "false" })
   inspect(logger.file_append_mode(), content="false")
   let state = logger.file_state()
+  let policy = logger.file_policy()
   inspect(state.append, content="false")
   inspect(state.auto_flush, content="false")
   inspect(state.rotation is None, content="true")
+  inspect(policy.append, content="false")
+  inspect(policy.auto_flush, content="false")
+  inspect(policy.rotation is None, content="true")
   inspect(logger.file_reset_policy(), content="true")
   inspect(logger.file_append_mode(), content="true")
   inspect(logger.file_auto_flush(), content="true")
@@ -374,6 +382,9 @@ test "configured logger reset policy restores configured file defaults" {
       ),
     ),
   )
+  let default_policy = logger.file_default_policy()
+  inspect(default_policy.append, content="false")
+  inspect(default_policy.auto_flush, content="false")
   inspect(logger.file_set_append_mode(true), content="true")
   inspect(logger.file_set_auto_flush(true), content="true")
   inspect(logger.file_clear_rotation(), content="true")
@@ -393,6 +404,8 @@ test "configured logger reset policy restores configured file defaults" {
 test "configured non-file logger cannot reset file policy" {
   let logger = build_logger(LoggerConfig::new(sink=SinkConfig::new(kind=SinkKind::Console)))
   inspect(logger.file_reset_policy(), content="false")
+  inspect(logger.file_policy().append, content="false")
+  inspect(logger.file_default_policy().append, content="false")
 }
 
 test "configured logger can reopen built file sink" {

bitlogger/BitLogger_wbtest.mbt

@@ -130,9 +130,13 @@ test "file sink rotation config normalizes invalid inputs" {
 
 test "file sink setters update auto flush and rotation state" {
   let sink = file_sink("bitlogger-setters.log")
+  let default_policy = sink.default_policy()
   inspect(sink.append_mode(), content="true")
   inspect(sink.auto_flush_enabled(), content="true")
   inspect(sink.rotation_enabled(), content="false")
+  inspect(default_policy.append, content="true")
+  inspect(default_policy.auto_flush, content="true")
+  inspect(default_policy.rotation is None, content="true")
   sink.set_append_mode(false)
   inspect(sink.append_mode(), content="false")
   sink.set_auto_flush(false)
@@ -152,9 +156,13 @@ test "file sink setters update auto flush and rotation state" {
   inspect(sink.reopen(), content=if sink.is_available() { "true" } else { "false" })
   inspect(sink.append_mode(), content="false")
   let state = sink.state()
+  let policy = sink.policy()
   inspect(state.append, content="false")
   inspect(state.auto_flush, content="false")
   inspect(state.rotation is None, content="true")
+  inspect(policy.append, content="false")
+  inspect(policy.auto_flush, content="false")
+  inspect(policy.rotation is None, content="true")
   sink.reset_policy()
   inspect(sink.append_mode(), content="true")
   inspect(sink.auto_flush_enabled(), content="true")
@@ -171,6 +179,9 @@ test "file sink reset policy restores configured defaults" {
   sink.set_append_mode(true)
   sink.set_auto_flush(true)
   sink.clear_rotation()
+  let default_policy = sink.default_policy()
+  inspect(default_policy.append, content="false")
+  inspect(default_policy.auto_flush, content="false")
   sink.reset_policy()
   inspect(sink.append_mode(), content="false")
   inspect(sink.auto_flush_enabled(), content="false")

bitlogger/README.mbt.md

@@ -242,6 +242,7 @@ test {
 - `path()` and `auto_flush_enabled()` expose core file sink policy state / `path()` 与 `auto_flush_enabled()` 可读取 file sink 的基础策略状态
 - `rotation_enabled()` and `rotation_config()` expose whether rotation is active and which settings are currently applied / `rotation_enabled()` 与 `rotation_config()` 可读取 rotation 是否启用及当前配置参数
 - `state()` exposes a single file-sink snapshot including path, availability, append policy, auto-flush, rotation config, and failure counters / `state()` 可一次性读取包含 path、availability、append、auto-flush、rotation 配置与失败计数的 file sink 快照
+- `policy()` and `default_policy()` expose the current runtime policy and the sink's original defaults separately / `policy()` 与 `default_policy()` 可分别读取当前运行期策略与 sink 初始默认策略
 - `reset_failure_counters()` clears the open/write/flush/rotation counters after diagnostics or recovery / `reset_failure_counters()` 可在排障或恢复后清空 open/write/flush/rotation 失败计数
 - `reset_policy()` restores append, auto-flush, and rotation back to the sink's original defaults / `reset_policy()` 可将 append、auto-flush、rotation 恢复到 sink 初始默认策略
 - `file_sink_state_to_json(...)` / `stringify_file_sink_state(...)` and `runtime_file_state_to_json(...)` / `stringify_runtime_file_state(...)` export snapshots as JSON / `file_sink_state_to_json(...)` / `stringify_file_sink_state(...)` 与 `runtime_file_state_to_json(...)` / `stringify_runtime_file_state(...)` 可将快照直接导出为 JSON
@@ -249,6 +250,7 @@ test {
 - `open_failures()`、`write_failures()`、`flush_failures()`、`rotation_failures()` expose basic sink health counters / `open_failures()`、`write_failures()`、`flush_failures()`、`rotation_failures()` 可用于观察基础 sink 健康状态
 - `ConfiguredLogger` also forwards file reopen, flush, close, append-mode, path, auto-flush, rotation-config, state snapshot, append setter, policy setter, and failure-counter helpers for config-built file sinks / `ConfiguredLogger` 也会为配置生成的 file sink 转发 reopen、flush、close、append-mode、path、auto-flush、rotation 配置、state 快照、append setter、策略 setter 与失败计数访问器
 - `ConfiguredLogger::file_runtime_state()` also reports whether a file sink is queue-wrapped and exposes the outer queue pending/drop counters together with the inner file snapshot / `ConfiguredLogger::file_runtime_state()` 还可报告 file sink 是否被 queue 包装，并将外层 queue 的 pending/drop 计数与内层 file 快照一起返回
+- `ConfiguredLogger::file_policy()` and `ConfiguredLogger::file_default_policy()` also expose current runtime policy and initial config policy separately / `ConfiguredLogger::file_policy()` 与 `ConfiguredLogger::file_default_policy()` 也可分别读取当前运行期策略与初始配置策略
 - `ConfiguredLogger::file_reset_failure_counters()` also clears file failure counters through the config-built control surface / `ConfiguredLogger::file_reset_failure_counters()` 也可通过配置式控制面清空 file 失败计数
 - `ConfiguredLogger::file_reset_policy()` also restores runtime file policy back to the initial config values / `ConfiguredLogger::file_reset_policy()` 也可将运行期 file 策略恢复到初始配置值
 - current scope is observability-first, not a full self-healing sink runtime / 当前定位仍以可观测性优先，不是完整自愈型 sink runtime

bitlogger/config.mbt

@@ -498,6 +498,22 @@ pub fn RuntimeSink::file_reset_policy(self : RuntimeSink) -> Bool {
   }
 }
 
+pub fn RuntimeSink::file_policy(self : RuntimeSink) -> FileSinkPolicy {
+  match self {
+    File(sink) => sink.policy()
+    QueuedFile(sink) => sink.sink.policy()
+    _ => FileSinkPolicy::new(append=false, auto_flush=false, rotation=None)
+  }
+}
+
+pub fn RuntimeSink::file_default_policy(self : RuntimeSink) -> FileSinkPolicy {
+  match self {
+    File(sink) => sink.default_policy()
+    QueuedFile(sink) => sink.sink.default_policy()
+    _ => FileSinkPolicy::new(append=false, auto_flush=false, rotation=None)
+  }
+}
+
 pub fn RuntimeSink::file_state(self : RuntimeSink) -> FileSinkState {
   match self {
     File(sink) => sink.state()
@@ -644,6 +660,14 @@ pub fn ConfiguredLogger::file_reset_policy(self : ConfiguredLogger) -> Bool {
   self.sink.file_reset_policy()
 }
 
+pub fn ConfiguredLogger::file_policy(self : ConfiguredLogger) -> FileSinkPolicy {
+  self.sink.file_policy()
+}
+
+pub fn ConfiguredLogger::file_default_policy(self : ConfiguredLogger) -> FileSinkPolicy {
+  self.sink.file_default_policy()
+}
+
 pub fn ConfiguredLogger::file_state(self : ConfiguredLogger) -> FileSinkState {
   self.sink.file_state()
 }

bitlogger/sinks.mbt

@@ -77,6 +77,20 @@ pub struct FileSinkState {
   rotation_failures : Int
 }
 
+pub struct FileSinkPolicy {
+  append : Bool
+  auto_flush : Bool
+  rotation : FileRotation?
+}
+
+pub fn FileSinkPolicy::new(
+  append~ : Bool = true,
+  auto_flush~ : Bool = true,
+  rotation~ : FileRotation? = None,
+) -> FileSinkPolicy {
+  { append, auto_flush, rotation }
+}
+
 pub fn FileSinkState::new(
   path : String,
   available~ : Bool = false,
@@ -232,6 +246,22 @@ pub fn FileSink::reset_policy(self : FileSink) -> Unit {
   self.rotation.val = self.default_rotation
 }
 
+pub fn FileSink::policy(self : FileSink) -> FileSinkPolicy {
+  FileSinkPolicy::new(
+    append=self.append.val,
+    auto_flush=self.auto_flush.val,
+    rotation=self.rotation.val,
+  )
+}
+
+pub fn FileSink::default_policy(self : FileSink) -> FileSinkPolicy {
+  FileSinkPolicy::new(
+    append=self.default_append,
+    auto_flush=self.default_auto_flush,
+    rotation=self.default_rotation,
+  )
+}
+
 pub fn FileSink::state(self : FileSink) -> FileSinkState {
   {
     path: self.path,