turbo_tasks/
task_statistics.rs

1use std::sync::{Arc, OnceLock};
2
3use serde::{Serialize, Serializer, ser::SerializeMap};
4
5use crate::{FxDashMap, macro_helpers::NativeFunction};
6
7/// An API for optionally enabling, updating, and reading aggregated statistics.
8#[derive(Default)]
9pub struct TaskStatisticsApi {
10    inner: OnceLock<Arc<TaskStatistics>>,
11}
12
13impl TaskStatisticsApi {
14    pub fn enable(&self) -> &Arc<TaskStatistics> {
15        self.inner.get_or_init(|| {
16            Arc::new(TaskStatistics {
17                inner: FxDashMap::with_hasher(Default::default()),
18            })
19        })
20    }
21
22    // Calls `func` if statistics have been enabled (via
23    // [`TaskStatisticsApi::enable`]).
24    pub fn map<T>(&self, func: impl FnOnce(&Arc<TaskStatistics>) -> T) -> Option<T> {
25        self.get().map(func)
26    }
27
28    // Returns the statistics if they have been enabled (via
29    // [`TaskStatisticsApi::enable`]).
30    pub fn get(&self) -> Option<&Arc<TaskStatistics>> {
31        self.inner.get()
32    }
33}
34
35/// A type representing the enabled state of [`TaskStatisticsApi`]. Implements [`serde::Serialize`].
36pub struct TaskStatistics {
37    inner: FxDashMap<&'static NativeFunction, TaskFunctionStatistics>,
38}
39
40impl TaskStatistics {
41    pub fn increment_cache_hit(&self, native_fn: &'static NativeFunction) {
42        self.with_task_type_statistics(native_fn, |stats| stats.cache_hit += 1)
43    }
44
45    pub fn increment_cache_miss(&self, native_fn: &'static NativeFunction) {
46        self.with_task_type_statistics(native_fn, |stats| stats.cache_miss += 1)
47    }
48
49    pub fn increment_execution_duration(
50        &self,
51        native_fn: &'static NativeFunction,
52        duration: std::time::Duration,
53    ) {
54        self.with_task_type_statistics(native_fn, |stats| {
55            stats.executions += 1;
56            stats.duration += duration
57        })
58    }
59
60    fn with_task_type_statistics(
61        &self,
62        native_fn: &'static NativeFunction,
63        func: impl Fn(&mut TaskFunctionStatistics),
64    ) {
65        func(self.inner.entry(native_fn).or_default().value_mut())
66    }
67
68    pub fn get(&self, f: &'static NativeFunction) -> TaskFunctionStatistics {
69        self.inner.get(f).unwrap().value().clone()
70    }
71}
72
73/// Statistics for an individual function.
74#[derive(Default, Serialize, Clone)]
75pub struct TaskFunctionStatistics {
76    pub cache_hit: u32,
77    pub cache_miss: u32,
78    // Generally executions == cache_miss, however they can diverge when there are invalidations.
79    // The caller gets one cache miss but we might execute multiple times.
80    pub executions: u32,
81    pub duration: std::time::Duration,
82}
83
84impl Serialize for TaskStatistics {
85    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
86    where
87        S: Serializer,
88    {
89        let mut map = serializer.serialize_map(Some(self.inner.len()))?;
90        for entry in &self.inner {
91            map.serialize_entry(entry.key().global_name, entry.value())?;
92        }
93        map.end()
94    }
95}
turbo_tasks/task_statistics.rs

turbo_tasks/
task_statistics.rs
