vortex_metrics/
gauge.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use std::sync::Arc;
5use std::sync::atomic::AtomicU64;
6use std::sync::atomic::Ordering;
7
8/// A gauge metric that can increase or decrease, representing a single value at the point of sampling.
9#[derive(Clone)]
10pub struct Gauge(Arc<AtomicU64>);
11
12impl std::fmt::Debug for Gauge {
13    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
14        f.debug_tuple("Gauge").field(&self.value()).finish()
15    }
16}
17
18impl Gauge {
19    pub(crate) fn new() -> Self {
20        Self(Default::default())
21    }
22
23    /// Increment the gauge by value.
24    pub fn increment(&self, value: f64) {
25        loop {
26            if self
27                .0
28                .fetch_update(Ordering::AcqRel, Ordering::Relaxed, |current| {
29                    let input = f64::from_bits(current);
30                    Some((input + value).to_bits())
31                })
32                .is_ok()
33            {
34                break;
35            }
36        }
37    }
38
39    /// Decrement the gauge by value.
40    pub fn decrement(&self, value: f64) {
41        loop {
42            if self
43                .0
44                .fetch_update(Ordering::AcqRel, Ordering::Relaxed, |current| {
45                    let input = f64::from_bits(current);
46                    Some((input - value).to_bits())
47                })
48                .is_ok()
49            {
50                break;
51            }
52        }
53    }
54
55    /// Sets the gauge to a specific value.
56    pub fn set(&self, value: f64) {
57        // We use `swap` with `AcqRel` ordering to make sure we get
58        // consistent ordering across operations.
59        _ = self.0.swap(value.to_bits(), Ordering::AcqRel);
60    }
61
62    /// Returns the current value of the gauge.
63    pub fn value(&self) -> f64 {
64        let value = self.0.load(Ordering::Acquire);
65        f64::from_bits(value)
66    }
67}
vortex_metrics/gauge.rs

vortex_metrics/
gauge.rs
