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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::Counter;
use crate::ipc::{need_ipc, with_ipc_payload};
use crate::private::MetricId;
/// Developer-facing API for recording counter metrics that are acting as
/// external denominators for rate metrics.
///
/// 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 DenominatorMetric {
Parent {
/// The metric's ID.
///
/// **TEST-ONLY** - Do not use unless gated with `#[cfg(test)]`.
id: MetricId,
inner: glean::private::DenominatorMetric,
},
Child(DenominatorMetricIpc),
}
#[derive(Clone, Debug)]
pub struct DenominatorMetricIpc(MetricId);
impl DenominatorMetric {
/// The constructor used by automatically generated metrics.
pub fn new(id: MetricId, meta: CommonMetricData, numerators: Vec<CommonMetricData>) -> Self {
if need_ipc() {
DenominatorMetric::Child(DenominatorMetricIpc(id))
} else {
let inner = glean::private::DenominatorMetric::new(meta, numerators);
DenominatorMetric::Parent { id, inner }
}
}
#[cfg(test)]
pub(crate) fn metric_id(&self) -> MetricId {
match self {
DenominatorMetric::Parent { id, .. } => *id,
DenominatorMetric::Child(c) => c.0,
}
}
#[cfg(test)]
pub(crate) fn child_metric(&self) -> Self {
match self {
DenominatorMetric::Parent { id, .. } => {
DenominatorMetric::Child(DenominatorMetricIpc(*id))
}
DenominatorMetric::Child(_) => panic!("Can't get a child metric from a child metric"),
}
}
}
#[inherent]
impl Counter for DenominatorMetric {
pub fn add(&self, amount: i32) {
match self {
DenominatorMetric::Parent { inner, .. } => {
inner.add(amount);
}
DenominatorMetric::Child(c) => {
with_ipc_payload(move |payload| {
if let Some(v) = payload.denominators.get_mut(&c.0) {
*v += amount;
} else {
payload.denominators.insert(c.0, amount);
}
});
}
}
}
pub fn test_get_value<'a, S: Into<Option<&'a str>>>(&self, ping_name: S) -> Option<i32> {
let ping_name = ping_name.into().map(|s| s.to_string());
match self {
DenominatorMetric::Parent { inner, .. } => inner.test_get_value(ping_name),
DenominatorMetric::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 {
DenominatorMetric::Parent { inner, .. } => inner.test_get_num_recorded_errors(error),
DenominatorMetric::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_denominator_value_parent() {
let _lock = lock_test();
let metric = &metrics::test_only_ipc::an_external_denominator;
metric.add(1);
assert_eq!(1, metric.test_get_value("store1").unwrap());
}
#[test]
fn sets_denominator_value_child() {
let _lock = lock_test();
let parent_metric = &metrics::test_only_ipc::an_external_denominator;
parent_metric.add(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(42);
ipc::with_ipc_payload(move |payload| {
assert_eq!(
42,
*payload.denominators.get(&metric_id).unwrap(),
"Stored the correct value in the ipc payload"
);
});
}
assert_eq!(
false,
ipc::need_ipc(),
"RAII dropped, should not need ipc any more"
);
assert!(ipc::replay_from_buf(&ipc::take_buf().unwrap()).is_ok());
assert_eq!(
45,
parent_metric.test_get_value("store1").unwrap(),
"Values from the 'processes' should be summed"
);
}
}