//! Definitions for dealing with a [`prometheus::Error`].
#[doc(inline)]
pub use self::strategy::Strategy;
/// Possible actions on an encountered [`prometheus::Error`] inside
/// [`metrics::Recorder`] methods.
#[derive(Clone, Copy, Debug)]
pub enum Action {
/// Return a no-op metric implementation (see [`metrics::Counter::noop()`]
/// for example).
NoOp,
/// Panic with the encountered [`prometheus::Error`].
Panic,
}
/// Strategies for dealing with a [`prometheus::Error`].
pub mod strategy {
use super::Action;
/// Strategy deciding which [`Action`] should be performed on an encountered
/// [`prometheus::Error`] inside [`metrics::Recorder`] methods.
pub trait Strategy {
/// Inspects the encountered [`prometheus::Error`] and returns the
/// [`Action`] to be performed.
fn decide(&self, res: &prometheus::Error) -> Action;
}
/// [`Strategy`] returning always [`Action::NoOp`].
#[derive(Clone, Copy, Debug, Default)]
pub struct NoOp;
impl Strategy for NoOp {
fn decide(&self, _: &prometheus::Error) -> Action {
Action::NoOp
}
}
/// [`Strategy`] returning always [`Action::Panic`].
#[derive(Clone, Copy, Debug, Default)]
pub struct Panic;
impl Strategy for Panic {
fn decide(&self, _: &prometheus::Error) -> Action {
Action::Panic
}
}
/// [`Strategy`] returning an [`Action::Panic`] in debug mode, and
/// [`Action::NoOp`] in release mode.
#[derive(Clone, Copy, Debug, Default)]
pub struct PanicInDebugNoOpInRelease;
impl Strategy for PanicInDebugNoOpInRelease {
fn decide(&self, _: &prometheus::Error) -> Action {
#[cfg(debug_assertions)]
{
Action::Panic
}
#[cfg(not(debug_assertions))]
{
Action::NoOp
}
}
}
}