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-rw-r--r--vendor/tracing/benches/shared.rs160
1 files changed, 160 insertions, 0 deletions
diff --git a/vendor/tracing/benches/shared.rs b/vendor/tracing/benches/shared.rs
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+++ b/vendor/tracing/benches/shared.rs
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+#![allow(dead_code)]
+use criterion::{black_box, measurement::WallTime, Bencher};
+use tracing::{field, span, Event, Id, Metadata};
+
+use std::{
+ fmt::{self, Write},
+ sync::{Mutex, MutexGuard},
+};
+
+pub fn for_all_recording(
+ group: &mut criterion::BenchmarkGroup<'_, WallTime>,
+ mut iter: impl FnMut(&mut Bencher<'_, WallTime>),
+) {
+ // first, run benchmarks with no subscriber
+ group.bench_function("none", &mut iter);
+
+ // then, run benchmarks with a scoped default subscriber
+ tracing::subscriber::with_default(EnabledSubscriber, || {
+ group.bench_function("scoped", &mut iter)
+ });
+
+ let subscriber = VisitingSubscriber(Mutex::new(String::from("")));
+ tracing::subscriber::with_default(subscriber, || {
+ group.bench_function("scoped_recording", &mut iter);
+ });
+
+ // finally, set a global default subscriber, and run the benchmarks again.
+ tracing::subscriber::set_global_default(EnabledSubscriber)
+ .expect("global default should not have already been set!");
+ let _ = log::set_logger(&NOP_LOGGER);
+ log::set_max_level(log::LevelFilter::Trace);
+ group.bench_function("global", &mut iter);
+}
+
+pub fn for_all_dispatches(
+ group: &mut criterion::BenchmarkGroup<'_, WallTime>,
+ mut iter: impl FnMut(&mut Bencher<'_, WallTime>),
+) {
+ // first, run benchmarks with no subscriber
+ group.bench_function("none", &mut iter);
+
+ // then, run benchmarks with a scoped default subscriber
+ tracing::subscriber::with_default(EnabledSubscriber, || {
+ group.bench_function("scoped", &mut iter)
+ });
+
+ // finally, set a global default subscriber, and run the benchmarks again.
+ tracing::subscriber::set_global_default(EnabledSubscriber)
+ .expect("global default should not have already been set!");
+ let _ = log::set_logger(&NOP_LOGGER);
+ log::set_max_level(log::LevelFilter::Trace);
+ group.bench_function("global", &mut iter);
+}
+
+const NOP_LOGGER: NopLogger = NopLogger;
+
+struct NopLogger;
+
+impl log::Log for NopLogger {
+ fn enabled(&self, _metadata: &log::Metadata) -> bool {
+ true
+ }
+
+ fn log(&self, record: &log::Record) {
+ if self.enabled(record.metadata()) {
+ let mut this = self;
+ let _ = write!(this, "{}", record.args());
+ }
+ }
+
+ fn flush(&self) {}
+}
+
+impl Write for &NopLogger {
+ fn write_str(&mut self, s: &str) -> std::fmt::Result {
+ black_box(s);
+ Ok(())
+ }
+}
+
+/// Simulates a subscriber that records span data.
+struct VisitingSubscriber(Mutex<String>);
+
+struct Visitor<'a>(MutexGuard<'a, String>);
+
+impl<'a> field::Visit for Visitor<'a> {
+ fn record_debug(&mut self, _field: &field::Field, value: &dyn fmt::Debug) {
+ let _ = write!(&mut *self.0, "{:?}", value);
+ }
+}
+
+impl tracing::Subscriber for VisitingSubscriber {
+ fn new_span(&self, span: &span::Attributes<'_>) -> Id {
+ let mut visitor = Visitor(self.0.lock().unwrap());
+ span.record(&mut visitor);
+ Id::from_u64(0xDEAD_FACE)
+ }
+
+ fn record(&self, _span: &Id, values: &span::Record<'_>) {
+ let mut visitor = Visitor(self.0.lock().unwrap());
+ values.record(&mut visitor);
+ }
+
+ fn event(&self, event: &Event<'_>) {
+ let mut visitor = Visitor(self.0.lock().unwrap());
+ event.record(&mut visitor);
+ }
+
+ fn record_follows_from(&self, span: &Id, follows: &Id) {
+ let _ = (span, follows);
+ }
+
+ fn enabled(&self, metadata: &Metadata<'_>) -> bool {
+ let _ = metadata;
+ true
+ }
+
+ fn enter(&self, span: &Id) {
+ let _ = span;
+ }
+
+ fn exit(&self, span: &Id) {
+ let _ = span;
+ }
+}
+
+/// A subscriber that is enabled but otherwise does nothing.
+struct EnabledSubscriber;
+
+impl tracing::Subscriber for EnabledSubscriber {
+ fn new_span(&self, span: &span::Attributes<'_>) -> Id {
+ let _ = span;
+ Id::from_u64(0xDEAD_FACE)
+ }
+
+ fn event(&self, event: &Event<'_>) {
+ let _ = event;
+ }
+
+ fn record(&self, span: &Id, values: &span::Record<'_>) {
+ let _ = (span, values);
+ }
+
+ fn record_follows_from(&self, span: &Id, follows: &Id) {
+ let _ = (span, follows);
+ }
+
+ fn enabled(&self, metadata: &Metadata<'_>) -> bool {
+ let _ = metadata;
+ true
+ }
+
+ fn enter(&self, span: &Id) {
+ let _ = span;
+ }
+
+ fn exit(&self, span: &Id) {
+ let _ = span;
+ }
+}