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// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
use inherent::inherent;
use super::CommonMetricData;
use glean::traits::Numerator;
use glean::Rate;
use crate::ipc::{need_ipc, with_ipc_payload};
use crate::private::MetricId;
/// Developer-facing API for recording rate metrics with external denominators.
///
/// Instances of this class type are automatically generated by the parsers
/// at build time, allowing developers to record values that were previously
/// registered in the metrics.yaml file.
#[derive(Clone)]
pub enum NumeratorMetric {
Parent {
/// The metric's ID.
///
/// **TEST-ONLY** - Do not use unless gated with `#[cfg(test)]`.
id: MetricId,
inner: glean::private::NumeratorMetric,
},
Child(NumeratorMetricIpc),
}
#[derive(Clone, Debug)]
pub struct NumeratorMetricIpc(MetricId);
impl NumeratorMetric {
/// The public constructor used by automatically generated metrics.
pub fn new(id: MetricId, meta: CommonMetricData) -> Self {
if need_ipc() {
NumeratorMetric::Child(NumeratorMetricIpc(id))
} else {
let inner = glean::private::NumeratorMetric::new(meta);
NumeratorMetric::Parent { id, inner }
}
}
#[cfg(test)]
pub(crate) fn metric_id(&self) -> MetricId {
match self {
NumeratorMetric::Parent { id, .. } => *id,
NumeratorMetric::Child(c) => c.0,
}
}
#[cfg(test)]
pub(crate) fn child_metric(&self) -> Self {
match self {
NumeratorMetric::Parent { id, .. } => NumeratorMetric::Child(NumeratorMetricIpc(*id)),
NumeratorMetric::Child(_) => panic!("Can't get a child metric from a child metric"),
}
}
}
#[inherent]
impl Numerator for NumeratorMetric {
pub fn add_to_numerator(&self, amount: i32) {
match self {
NumeratorMetric::Parent { inner, .. } => {
inner.add_to_numerator(amount);
}
NumeratorMetric::Child(c) => {
with_ipc_payload(move |payload| {
if let Some(v) = payload.numerators.get_mut(&c.0) {
*v += amount;
} else {
payload.numerators.insert(c.0, amount);
}
});
}
}
}
pub fn test_get_value<'a, S: Into<Option<&'a str>>>(&self, ping_name: S) -> Option<Rate> {
let ping_name = ping_name.into().map(|s| s.to_string());
match self {
NumeratorMetric::Parent { inner, .. } => inner.test_get_value(ping_name),
NumeratorMetric::Child(c) => {
panic!("Cannot get test value for {:?} in non-parent process!", c.0);
}
}
}
pub fn test_get_num_recorded_errors(&self, error: glean::ErrorType) -> i32 {
match self {
NumeratorMetric::Parent { inner, .. } => inner.test_get_num_recorded_errors(error),
NumeratorMetric::Child(c) => {
panic!(
"Cannot get the number of recorded errors for {:?} in non-parent process!",
c.0
);
}
}
}
}
#[cfg(test)]
mod test {
use crate::{common_test::*, ipc, metrics};
#[test]
fn sets_numerator_value_parent() {
let _lock = lock_test();
let metric = &metrics::test_only_ipc::rate_with_external_denominator;
metric.add_to_numerator(1);
assert_eq!(1, metric.test_get_value("store1").unwrap().numerator);
}
#[test]
fn sets_numerator_value_child() {
let _lock = lock_test();
let parent_metric = &metrics::test_only_ipc::rate_with_external_denominator;
parent_metric.add_to_numerator(3);
{
// scope for need_ipc RAII
let child_metric = parent_metric.child_metric();
let _raii = ipc::test_set_need_ipc(true);
let metric_id = child_metric.metric_id();
child_metric.add_to_numerator(42);
ipc::with_ipc_payload(move |payload| {
assert!(
42 == *payload.numerators.get(&metric_id).unwrap(),
"Stored the correct value in the ipc payload"
);
});
}
assert!(
false == ipc::need_ipc(),
"RAII dropped, should not need ipc any more"
);
assert!(ipc::replay_from_buf(&ipc::take_buf().unwrap()).is_ok());
assert!(
45 == parent_metric.test_get_value("store1").unwrap().numerator,
"Values from the 'processes' should be summed"
);
}
}