8661e914a5
# Objective Current way to wire `Layer`s together using `layer.with(new_layer)` in the `bevy_log` plugin is brittle and not flexible. As #17722 demonstrated, the current solution makes it very hard to do any kind of advanced wiring, as the type system of `tracing::Subscriber` gets in the way very quickly (the type of each new layer depends on the type of the previous ones). We want to make it easier to have more complex wiring of `Layers`. It would be hard to solve #19085 without it ## Solution It aims to be functionally equivalent. - Replace of using `layer.with(new_layer)` . We now add `layer.boxed()` to a `Vec<BoxedLayer>`. It is a solution recommended by `tracing_subscriber::Layer` for complex wiring cases (See https://docs.rs/tracing-subscriber/latest/tracing_subscriber/layer/index.html#runtime-configuration-with-layers) - Do some refactoring and clean up that is now enabled by the new solution ## Testing - Ran CI locally on Linux - Ran the logs examples - Need people familiar with the features `trace`, `tracing-chrome`, `tracing-tracy` to check that it still works as expected - Need people with access to `ios`, `android` and `wasm` to check it as well. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
74 lines
2.2 KiB
Rust
74 lines
2.2 KiB
Rust
//! This example illustrates how to add custom log layers in bevy.
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use bevy::{
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log::{
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tracing::{self, Subscriber},
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tracing_subscriber::Layer,
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BoxedLayer,
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},
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prelude::*,
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};
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struct CustomLayer;
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impl<S: Subscriber> Layer<S> for CustomLayer {
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fn on_event(
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&self,
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event: &tracing::Event<'_>,
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_ctx: bevy::log::tracing_subscriber::layer::Context<'_, S>,
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) {
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println!("Got event!");
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println!(" level={}", event.metadata().level());
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println!(" target={}", event.metadata().target());
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println!(" name={}", event.metadata().name());
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}
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}
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// We don't need App for this example, as we are just printing log information.
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// For an example that uses App, see log_layers_ecs.
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fn custom_layer(_app: &mut App) -> Option<BoxedLayer> {
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// You can provide multiple layers like this, since Vec<Layer> is also a layer:
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Some(Box::new(vec![
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bevy::log::tracing_subscriber::fmt::layer()
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.with_file(true)
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.boxed(),
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CustomLayer.boxed(),
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]))
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}
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// While `custom_layer` allows you to add _additional_ layers, it won't allow you to override the
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// default `tracing_subscriber::fmt::Layer` added by `LogPlugin`. To do that, you can use the
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// `fmt_layer` option.
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//
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// In this example, we're disabling the timestamp in the log output.
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fn fmt_layer(_app: &mut App) -> Option<BoxedLayer> {
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Some(
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bevy::log::tracing_subscriber::fmt::Layer::default()
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.without_time()
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.with_writer(std::io::stderr)
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.boxed(),
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)
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}
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins.set(bevy::log::LogPlugin {
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custom_layer,
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fmt_layer,
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..default()
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}))
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.add_systems(Update, log_system)
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.run();
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}
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fn log_system() {
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// here is how you write new logs at each "log level" (in "most important" to
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// "least important" order)
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error!("something failed");
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warn!("something bad happened that isn't a failure, but thats worth calling out");
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info!("helpful information that is worth printing by default");
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debug!("helpful for debugging");
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trace!("very noisy");
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}
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