vendor/tracing-subscriber-0.3.3/tests/reload.rs

   1 #![cfg(feature = "reload")]
   2 use std::sync::atomic::{AtomicUsize, Ordering};
   3 use tracing_core::{
   4     span::{Attributes, Id, Record},
   5     subscriber::Interest,
   6     Event, Metadata, Subscriber,
   7 };
   8 use tracing_subscriber::{layer, prelude::*, reload::*};
   9
  10 pub struct NopSubscriber;
  11
  12 impl Subscriber for NopSubscriber {
  13     fn register_callsite(&self, _: &'static Metadata<'static>) -> Interest {
  14         Interest::never()
  15     }
  16
  17     fn enabled(&self, _: &Metadata<'_>) -> bool {
  18         false
  19     }
  20
  21     fn new_span(&self, _: &Attributes<'_>) -> Id {
  22         Id::from_u64(1)
  23     }
  24
  25     fn record(&self, _: &Id, _: &Record<'_>) {}
  26     fn record_follows_from(&self, _: &Id, _: &Id) {}
  27     fn event(&self, _: &Event<'_>) {}
  28     fn enter(&self, _: &Id) {}
  29     fn exit(&self, _: &Id) {}
  30 }
  31
  32 #[test]
  33 fn reload_handle() {
  34     static FILTER1_CALLS: AtomicUsize = AtomicUsize::new(0);
  35     static FILTER2_CALLS: AtomicUsize = AtomicUsize::new(0);
  36
  37     enum Filter {
  38         One,
  39         Two,
  40     }
  41
  42     impl<S: Subscriber> tracing_subscriber::Layer<S> for Filter {
  43         fn register_callsite(&self, m: &Metadata<'_>) -> Interest {
  44             println!("REGISTER: {:?}", m);
  45             Interest::sometimes()
  46         }
  47
  48         fn enabled(&self, m: &Metadata<'_>, _: layer::Context<'_, S>) -> bool {
  49             println!("ENABLED: {:?}", m);
  50             match self {
  51                 Filter::One => FILTER1_CALLS.fetch_add(1, Ordering::SeqCst),
  52                 Filter::Two => FILTER2_CALLS.fetch_add(1, Ordering::SeqCst),
  53             };
  54             true
  55         }
  56     }
  57     fn event() {
  58         tracing::trace!("my event");
  59     }
  60
  61     let (layer, handle) = Layer::new(Filter::One);
  62
  63     let subscriber = tracing_core::dispatcher::Dispatch::new(layer.with_subscriber(NopSubscriber));
  64
  65     tracing_core::dispatcher::with_default(&subscriber, || {
  66         assert_eq!(FILTER1_CALLS.load(Ordering::SeqCst), 0);
  67         assert_eq!(FILTER2_CALLS.load(Ordering::SeqCst), 0);
  68
  69         event();
  70
  71         assert_eq!(FILTER1_CALLS.load(Ordering::SeqCst), 1);
  72         assert_eq!(FILTER2_CALLS.load(Ordering::SeqCst), 0);
  73
  74         handle.reload(Filter::Two).expect("should reload");
  75
  76         event();
  77
  78         assert_eq!(FILTER1_CALLS.load(Ordering::SeqCst), 1);
  79         assert_eq!(FILTER2_CALLS.load(Ordering::SeqCst), 1);
  80     })
  81 }