reload.rs

#![cfg(feature = "env-filter")]
use criterion::{criterion_group, criterion_main, Criterion};
use tracing_subscriber::{
    filter::LevelFilter,
    fmt::{
        format::{DefaultFields, Format, Full},
        Collector, CollectorBuilder,
    },
    EnvFilter,
};

mod support;
use support::NoWriter;

/// Prepare a real-world-inspired collector and use it to  measure the performance impact of
/// reloadable collectors.
fn mk_builder() -> CollectorBuilder<DefaultFields, Format<Full>, EnvFilter, fn() -> NoWriter> {
    let filter = EnvFilter::default()
        .add_directive("this=off".parse().unwrap())
        .add_directive("also=off".parse().unwrap())
        .add_directive("this_too=off".parse().unwrap())
        .add_directive("stuff=warn".parse().unwrap())
        .add_directive("moar=warn".parse().unwrap())
        .add_directive(LevelFilter::INFO.into());

    Collector::builder()
        .with_env_filter(filter)
        .with_writer(NoWriter::new as _)
        .with_ansi(true)
        .with_target(true)
        .with_level(true)
        .with_thread_names(true)
}

fn bench_reload(c: &mut Criterion) {
    let mut group = c.benchmark_group("reload");
    group.bench_function("complex-collector", |b| {
        let builder = mk_builder();
        let collector = builder.finish();
        tracing::collect::with_default(collector, || {
            b.iter(|| {
                tracing::info!(target: "this", "hi");
                tracing::debug!(target: "enabled", "hi");
                tracing::warn!(target: "hepp", "hi");
                tracing::trace!(target: "stuff", "hi");
            })
        });
    });
    group.bench_function("complex-collector-reloadable", |b| {
        let builder = mk_builder().with_filter_reloading();
        let _handle = builder.reload_handle();
        let collector = builder.finish();
        tracing::collect::with_default(collector, || {
            b.iter(|| {
                tracing::info!(target: "this", "hi");
                tracing::debug!(target: "enabled", "hi");
                tracing::warn!(target: "hepp", "hi");
                tracing::trace!(target: "stuff", "hi");
            })
        });
    });
    group.finish();
}
criterion_group!(benches, bench_reload);
criterion_main!(benches);