1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78

// Copyright 2019 Conflux Foundation. All rights reserved.
// Conflux is free software and distributed under GNU General Public License.
// See http://www.gnu.org/licenses/

use crate::{
    metrics::{is_enabled, Metric, ORDER},
    registry::{DEFAULT_GROUPING_REGISTRY, DEFAULT_REGISTRY},
};
use std::sync::{atomic::AtomicUsize, Arc};

pub trait Counter<T: Default>: Send + Sync {
    fn count(&self) -> T { T::default() }
    fn dec(&self, _delta: T) {}
    fn inc(&self, _delta: T) {}
}

struct NoopCounter;
impl<T: Default> Counter<T> for NoopCounter {}

#[macro_export]
macro_rules! construct_counter {
    ($name:ident, $value_type:ty, $data_type:ty) => {
        #[derive(Default)]
        pub struct $name {
            value: $value_type,
        }

        impl $name {
            pub fn register(name: &str) -> Arc<dyn Counter<$data_type>> {
                if !is_enabled() {
                    return Arc::new(NoopCounter);
                }

                let counter = Arc::new($name::default());
                DEFAULT_REGISTRY
                    .write()
                    .register(name.into(), counter.clone());

                counter
            }

            pub fn register_with_group(
                group: &str, name: &str,
            ) -> Arc<dyn Counter<$data_type>> {
                if !is_enabled() {
                    return Arc::new(NoopCounter);
                }

                let counter = Arc::new($name::default());
                DEFAULT_GROUPING_REGISTRY.write().register(
                    group.into(),
                    name.into(),
                    counter.clone(),
                );

                counter
            }
        }

        impl Counter<$data_type> for $name {
            fn count(&self) -> $data_type { self.value.load(ORDER) }

            fn dec(&self, delta: $data_type) {
                self.value.fetch_sub(delta, ORDER);
            }

            fn inc(&self, delta: $data_type) {
                self.value.fetch_add(delta, ORDER);
            }
        }

        impl Metric for $name {
            fn get_type(&self) -> &str { "Counter" }
        }
    };
}

construct_counter!(CounterUsize, AtomicUsize, usize);