📝 document wrapper sink types

2026-07-24 00:42:18 +00:00 · 2026-06-13 21:47:40 +08:00
parent fd7defbb93
commit 27886e1eba
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@@ -0,0 +1,77 @@
+---
+name: buffered-sink-type
+group: api
+category: sink
+update-time: 20260613
+description: Public buffered sink type used for threshold-based synchronous batching over another sink.
+key-word:
+    - sink
+    - buffer
+    - type
+    - public
+---
+
+## Buffered-sink-type
+
+`BufferedSink[S]` is the public buffering sink type used for threshold-based synchronous batching over another sink. It is the concrete sink type returned by `buffered_sink(...)` and preserves the wrapped sink type in its type parameter.
+
+### Interface
+
+```moonbit
+pub struct BufferedSink[S] {
+  sink : S
+  buffer : Ref[Array[Record]]
+  flush_limit : Int
+}
+```
+
+#### output
+
+- `BufferedSink[S]` - Public synchronous sink type that buffers records before forwarding them to the wrapped sink.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This is a public root struct, not a type alias.
+- The current fields are `sink : S`, `buffer : Ref[Array[Record]]`, and `flush_limit : Int`.
+- `buffered_sink(...)` constructs this type directly from a wrapped sink and flush threshold.
+- The sink preserves the wrapped sink type `S`, which is useful when typed composition still matters after buffering is introduced.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need A Typed Buffered Sink Value
+
+When code should keep the concrete buffering sink type visible:
+```moonbit
+let sink : BufferedSink[ConsoleSink] = buffered_sink(console_sink(), flush_limit=2)
+```
+
+In this example, the sink value stays explicit and preserves the wrapped console sink type.
+
+#### When Need A Typed Logger With Synchronous Batching
+
+When logging should preserve the buffering sink type in the logger:
+```moonbit
+let logger : Logger[BufferedSink[ConsoleSink]] = Logger::new(
+  buffered_sink(console_sink(), flush_limit=2),
+  target="buffered",
+)
+```
+
+In this example, the concrete buffered sink remains part of the logger type.
+
+### Error Case
+
+e.g.:
+- `BufferedSink[S]` itself does not have a runtime failure mode.
+
+- Runtime behavior still depends on the wrapped sink `S`, and buffered records can remain pending if flushing never happens.
+
+### Notes
+
+1. Use `buffered_sink(...)` when you need a value of this type.
+
+2. Use `QueuedSink[S]` when overflow-aware queueing behavior is needed instead of simple buffering.
@@ -0,0 +1,75 @@
+---
+name: filter-sink-type
+group: api
+category: sink
+update-time: 20260613
+description: Public filter sink type used for predicate-based record forwarding over another sink.
+key-word:
+    - sink
+    - filter
+    - type
+    - public
+---
+
+## Filter-sink-type
+
+`FilterSink[S]` is the public predicate wrapper sink type used for forwarding only matching records to another sink. It is the concrete sink type returned by `filter_sink(...)` and preserves the wrapped sink type in its type parameter.
+
+### Interface
+
+```moonbit
+pub struct FilterSink[S] {
+  sink : S
+  predicate : (Record) -> Bool
+}
+```
+
+#### output
+
+- `FilterSink[S]` - Public synchronous sink type that forwards only predicate-matching records to the wrapped sink.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This is a public root struct, not a type alias.
+- The current fields are `sink : S` and `predicate : (Record) -> Bool`.
+- `filter_sink(...)` constructs this type directly from a wrapped sink and predicate.
+- The sink preserves the wrapped sink type `S`, which is useful when typed composition still matters after filtering is introduced.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need A Typed Predicate-filtering Sink Value
+
+When code should keep the concrete filter wrapper sink type visible:
+```moonbit
+let sink : FilterSink[ConsoleSink] = filter_sink(console_sink(), fn(rec) { rec.target == "kept" })
+```
+
+In this example, the sink value stays explicit and preserves the wrapped console sink type.
+
+#### When Need A Typed Logger With Sink-level Filtering
+
+When logging should preserve the filter wrapper sink type in the logger:
+```moonbit
+let logger : Logger[FilterSink[ConsoleSink]] = Logger::new(
+  filter_sink(console_sink(), fn(rec) { rec.level == Level::Warn }),
+)
+```
+
+In this example, the concrete filter sink remains part of the logger type.
+
+### Error Case
+
+e.g.:
+- `FilterSink[S]` itself does not have a runtime failure mode.
+
+- Runtime behavior still depends on the wrapped sink `S`, and record selection errors come from the supplied predicate rather than the type itself.
+
+### Notes
+
+1. Use `filter_sink(...)` when you need a value of this type.
+
+2. Use `PatchSink[S]` when records should be rewritten rather than accepted or rejected.
@@ -117,10 +117,14 @@ BitLogger API navigation.
 - [split-sink-type.md](./split-sink-type.md)
 - [split-by-level.md](./split-by-level.md)
 - [buffered-sink.md](./buffered-sink.md)
+- [buffered-sink-type.md](./buffered-sink-type.md)
 - [queued-sink.md](./queued-sink.md)
+- [queued-sink-type.md](./queued-sink-type.md)
 - [queue-overflow-policy.md](./queue-overflow-policy.md)
 - [filter-sink.md](./filter-sink.md)
+- [filter-sink-type.md](./filter-sink-type.md)
 - [patch-sink.md](./patch-sink.md)
+- [patch-sink-type.md](./patch-sink-type.md)
 - [file-sink.md](./file-sink.md)
 - [native-files-supported.md](./native-files-supported.md)
 - [file-rotation.md](./file-rotation.md)
@@ -0,0 +1,75 @@
+---
+name: patch-sink-type
+group: api
+category: sink
+update-time: 20260613
+description: Public patch sink type used for record-rewriting forwarding over another sink.
+key-word:
+    - sink
+    - patch
+    - type
+    - public
+---
+
+## Patch-sink-type
+
+`PatchSink[S]` is the public record-rewriting sink type used for forwarding patched records to another sink. It is the concrete sink type returned by `patch_sink(...)` and preserves the wrapped sink type in its type parameter.
+
+### Interface
+
+```moonbit
+pub struct PatchSink[S] {
+  sink : S
+  patch : RecordPatch
+}
+```
+
+#### output
+
+- `PatchSink[S]` - Public synchronous sink type that rewrites records before forwarding them to the wrapped sink.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This is a public root struct, not a type alias.
+- The current fields are `sink : S` and `patch : RecordPatch`.
+- `patch_sink(...)` constructs this type directly from a wrapped sink and patch function.
+- The sink preserves the wrapped sink type `S`, which is useful when typed composition still matters after record rewriting is introduced.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need A Typed Record-rewriting Sink Value
+
+When code should keep the concrete patch wrapper sink type visible:
+```moonbit
+let sink : PatchSink[ConsoleSink] = patch_sink(console_sink(), prefix_message("[safe] "))
+```
+
+In this example, the sink value stays explicit and preserves the wrapped console sink type.
+
+#### When Need A Typed Logger With Sink-level Patching
+
+When logging should preserve the patch wrapper sink type in the logger:
+```moonbit
+let logger : Logger[PatchSink[ConsoleSink]] = Logger::new(
+  patch_sink(console_sink(), set_target("audit")),
+)
+```
+
+In this example, the concrete patch sink remains part of the logger type.
+
+### Error Case
+
+e.g.:
+- `PatchSink[S]` itself does not have a runtime failure mode.
+
+- Runtime behavior still depends on the wrapped sink `S`, and semantic rewrite mistakes come from the supplied patch function rather than the type itself.
+
+### Notes
+
+1. Use `patch_sink(...)` when you need a value of this type.
+
+2. Use `FilterSink[S]` when records should be conditionally dropped rather than rewritten.
@@ -0,0 +1,79 @@
+---
+name: queued-sink-type
+group: api
+category: sink
+update-time: 20260613
+description: Public queued sink type used for explicit synchronous queueing over another sink.
+key-word:
+    - sink
+    - queue
+    - type
+    - public
+---
+
+## Queued-sink-type
+
+`QueuedSink[S]` is the public queue wrapper sink type used for explicit synchronous queueing over another sink. It is the concrete sink type returned by `queued_sink(...)` and preserves the wrapped sink type in its type parameter.
+
+### Interface
+
+```moonbit
+pub struct QueuedSink[S] {
+  sink : S
+  queue : @queue.Queue[Record]
+  max_pending : Int
+  overflow : QueueOverflowPolicy
+  dropped_count : Ref[Int]
+}
+```
+
+#### output
+
+- `QueuedSink[S]` - Public synchronous sink type that queues records before they are drained to the wrapped sink.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This is a public root struct, not a type alias.
+- The current fields are `sink : S`, `queue : @queue.Queue[Record]`, `max_pending : Int`, `overflow : QueueOverflowPolicy`, and `dropped_count : Ref[Int]`.
+- `queued_sink(...)` constructs this type directly from a wrapped sink and queue policy.
+- The sink preserves the wrapped sink type `S`, which is useful when typed composition still matters after queueing is introduced.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need A Typed Queued Sink Value
+
+When code should keep the concrete queue wrapper sink type visible:
+```moonbit
+let sink : QueuedSink[ConsoleSink] = queued_sink(console_sink(), max_pending=4)
+```
+
+In this example, the sink value stays explicit and preserves the wrapped console sink type.
+
+#### When Need A Typed Logger With Explicit Queueing
+
+When logging should preserve the queue wrapper sink type in the logger:
+```moonbit
+let logger : Logger[QueuedSink[ConsoleSink]] = Logger::new(
+  queued_sink(console_sink(), max_pending=2, overflow=QueueOverflowPolicy::DropOldest),
+  target="queue",
+)
+```
+
+In this example, the concrete queued sink remains part of the logger type.
+
+### Error Case
+
+e.g.:
+- `QueuedSink[S]` itself does not have a runtime failure mode.
+
+- Runtime behavior still depends on the wrapped sink `S`, and records may be dropped when the queue reaches the configured bound.
+
+### Notes
+
+1. Use `queued_sink(...)` when you need a value of this type.
+
+2. Use `BufferedSink[S]` when simple threshold buffering is enough and overflow policy is unnecessary.