📝 document file sink reopen methods

2026-07-31 07:24:31 +00:00 · 2026-06-13 22:26:05 +08:00
parent e34065441f
commit afce0c7ce2
5 changed files with 301 additions and 0 deletions
@@ -0,0 +1,74 @@
+---
+name: file-sink-reopen-with-current-policy
+group: api
+category: sink
+update-time: 20260613
+description: Reopen a FileSink using its currently stored runtime policy.
+key-word:
+    - file
+    - sink
+    - reopen
+    - public
+---
+
+## File-sink-reopen-with-current-policy
+
+Reopen a `FileSink` using the currently stored runtime policy. This helper is useful when direct recovery should happen without supplying a one-off append override.
+
+### Interface
+
+```moonbit
+pub fn FileSink::reopen_with_current_policy(self : FileSink) -> Bool {
+```
+
+#### input
+
+- `self : FileSink` - File sink that should be reopened with current policy.
+
+#### output
+
+- `Bool` - Whether reopen succeeded.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This helper reuses the sink's currently stored append policy.
+- It differs from `reopen(...)` because it does not accept a per-call append override.
+- Existing handle state is handled through the underlying `reopen(...)` behavior.
+- On failure, the sink remains unavailable and `open_failures` is updated by the reopen path.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need Policy-preserving Recovery
+
+When a file sink should be reopened without changing runtime append behavior:
+```moonbit
+ignore(sink.reopen_with_current_policy())
+```
+
+In this example, recovery reuses the runtime policy already stored on the sink.
+
+#### When Separate Recovery From Policy Mutation
+
+When append mode should be controlled elsewhere:
+```moonbit
+let ok = sink.reopen_with_current_policy()
+```
+
+In this example, reopen is explicit while policy mutation stays separate.
+
+### Error Case
+
+e.g.:
+- If callers want to change append behavior during reopen, `reopen(...)`, `reopen_append()`, or `reopen_truncate()` are better APIs.
+
+- This helper still depends on the underlying file backend being able to reopen the path successfully.
+
+### Notes
+
+1. Use this helper when recovery should respect the currently stored runtime policy.
+
+2. It is clearer than passing no override through a more general reopen API.