# 0.2.21 (September 12, 2021) This release introduces the [`Filter`] trait, a new API for [per-layer filtering][plf]. This allows controlling which spans and events are recorded by various layers individually, rather than globally. In addition, it adds a new [`Targets`] filter, which provides a lighter-weight version of the filtering provided by [`EnvFilter`], as well as other smaller API improvements and fixes. ### Deprecated - **registry**: `SpanRef::parent_id`, which cannot properly support per-layer filtering. Use `.parent().map(SpanRef::id)` instead. ([#1523]) ### Fixed - **layer** `Context` methods that are provided when the `Subscriber` implements `LookupSpan` no longer require the "registry" feature flag ([#1525]) - **layer** `fmt::Debug` implementation for `Layered` no longer requires the `S` type parameter to implement `Debug` ([#1528]) ### Added - **registry**: `Filter` trait, `Filtered` type, `Layer::with_filter` method, and other APIs for per-layer filtering ([#1523]) - **filter**: `FilterFn` and `DynFilterFn` types that implement global (`Layer`) and per-layer (`Filter`) filtering for closures and function pointers ([#1523]) - **filter**: `Targets` filter, which implements a lighter-weight form of `EnvFilter`-like filtering ([#1550]) - **env-filter**: Added support for filtering on floating-point values ([#1507]) - **layer**: `Layer::on_layer` callback, called when layering the `Layer` onto a `Subscriber` ([#1523]) - **layer**: `Layer` implementations for `Box<L>` and `Arc<L>` where `L: Layer` ([#1536]) - **layer**: `Layer` implementations for `Box<dyn Layer<S> + Send + Sync + 'static>` and `Arc<dyn Layer<S> + Send + Sync + 'static>` ([#1536]) - A number of small documentation fixes and improvements ([#1553], [#1544], [#1539], [#1524]) Special thanks to new contributors @jsgf and @maxburke for contributing to this release! [`Filter`]: https://docs.rs/tracing-subscriber/0.2.21/tracing_subscriber/layer/trait.Filter.html [`plf`]: https://docs.rs/tracing-subscriber/0.2.21/tracing_subscriber/layer/index.html#per-layer-filtering [`Targets`]: https://docs.rs/tracing-subscriber/0.2.21/tracing_subscriber/filter/struct.Targets.html [`EnvFilter`]: https://docs.rs/tracing-subscriber/0.2.21/tracing_subscriber/filter/struct.EnvFilter.html [#1507]: #1507 [#1523]: #1523 [#1524]: #1524 [#1525]: #1525 [#1528]: #1528 [#1539]: #1539 [#1544]: #1544 [#1550]: #1550 [#1553]: #1553

Commits

Commits on Sep 12, 2021

tiny docs fix

add linky

subscriber: prepare to release 0.2.21

Merge branch 'v0.1.x' into eliza/subscriber-0.2.21