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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 std::sync::Arc;
use glean::traits::Counter;
use super::{CommonMetricData, MetricId};
use crate::ipc::{need_ipc, with_ipc_payload};
/// A counter metric.
///
/// Used to count things.
/// The value can only be incremented, not decremented.
#[derive(Clone)]
pub enum CounterMetric {
Parent {
/// The metric's ID.
///
/// **TEST-ONLY** - Do not use unless gated with `#[cfg(test)]`.
id: MetricId,
inner: Arc<glean::private::CounterMetric>,
},
Child(CounterMetricIpc),
}
#[derive(Clone, Debug)]
pub struct CounterMetricIpc(MetricId);
impl CounterMetric {
/// Create a new counter metric.
pub fn new(id: MetricId, meta: CommonMetricData) -> Self {
if need_ipc() {
CounterMetric::Child(CounterMetricIpc(id))
} else {
let inner = Arc::new(glean::private::CounterMetric::new(meta));
CounterMetric::Parent { id, inner }
}
}
/// Special-purpose ctor for use by codegen.
/// Only useful if the metric is:
/// * not disabled
/// * lifetime: ping
/// * and is sent in precisely one ping.
pub fn codegen_new(id: u32, category: &str, name: &str, ping: &str) -> Self {
if need_ipc() {
CounterMetric::Child(CounterMetricIpc(id.into()))
} else {
let inner = Arc::new(glean::private::CounterMetric::new(CommonMetricData {
category: category.into(),
name: name.into(),
send_in_pings: vec![ping.into()],
..Default::default()
}));
CounterMetric::Parent {
id: id.into(),
inner,
}
}
}
#[cfg(test)]
pub(crate) fn metric_id(&self) -> MetricId {
match self {
CounterMetric::Parent { id, .. } => *id,
CounterMetric::Child(c) => c.0,
}
}
#[cfg(test)]
pub(crate) fn child_metric(&self) -> Self {
match self {
CounterMetric::Parent { id, .. } => CounterMetric::Child(CounterMetricIpc(*id)),
CounterMetric::Child(_) => panic!("Can't get a child metric from a child metric"),
}
}
}
#[inherent]
impl Counter for CounterMetric {
/// Increase the counter by `amount`.
///
/// ## Arguments
///
/// * `amount` - The amount to increase by. Should be positive.
///
/// ## Notes
///
/// Logs an error if the `amount` is 0 or negative.
pub fn add(&self, amount: i32) {
match self {
CounterMetric::Parent { inner, .. } => {
inner.add(amount);
}
CounterMetric::Child(c) => {
with_ipc_payload(move |payload| {
if let Some(v) = payload.counters.get_mut(&c.0) {
*v += amount;
} else {
payload.counters.insert(c.0, amount);
}
});
}
}
}
/// **Test-only API.**
///
/// Get the currently stored value as an integer.
/// This doesn't clear the stored value.
///
/// ## Arguments
///
/// * `ping_name` - the storage name to look into.
///
/// ## Return value
///
/// Returns the stored value or `None` if nothing stored.
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 {
CounterMetric::Parent { inner, .. } => inner.test_get_value(ping_name),
CounterMetric::Child(c) => {
panic!("Cannot get test value for {:?} in non-parent process!", c.0)
}
}
}
/// **Test-only API.**
///
/// Gets the number of recorded errors for the given metric and error type.
///
/// # Arguments
///
/// * `error` - The type of error
/// * `ping_name` - represents the optional name of the ping to retrieve the
/// metric for. Defaults to the first value in `send_in_pings`.
///
/// # Returns
///
/// The number of errors reported.
pub fn test_get_num_recorded_errors(&self, error: glean::ErrorType) -> i32 {
match self {
CounterMetric::Parent { inner, .. } => inner.test_get_num_recorded_errors(error),
CounterMetric::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_counter_value_parent() {
let _lock = lock_test();
let metric = &metrics::test_only_ipc::a_counter;
metric.add(1);
assert_eq!(1, metric.test_get_value("store1").unwrap());
}
#[test]
fn sets_counter_value_child() {
let _lock = lock_test();
let parent_metric = &metrics::test_only_ipc::a_counter;
parent_metric.add(3);
{
let child_metric = parent_metric.child_metric();
// scope for need_ipc RAII
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!(
42 == *payload.counters.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(),
"Values from the 'processes' should be summed"
);
}
}