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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 glean::traits::Quantity;
use super::CommonMetricData;
use crate::ipc::need_ipc;
use crate::private::MetricId;
/// A quantity metric.
///
/// Records a single numeric value of a specific unit.
#[derive(Clone)]
pub enum QuantityMetric {
Parent(glean::private::QuantityMetric),
Child(QuantityMetricIpc),
}
#[derive(Clone, Debug)]
pub struct QuantityMetricIpc;
impl QuantityMetric {
/// Create a new quantity metric.
pub fn new(_id: MetricId, meta: CommonMetricData) -> Self {
if need_ipc() {
QuantityMetric::Child(QuantityMetricIpc)
} else {
QuantityMetric::Parent(glean::private::QuantityMetric::new(meta))
}
}
#[cfg(test)]
pub(crate) fn child_metric(&self) -> Self {
match self {
QuantityMetric::Parent(_) => QuantityMetric::Child(QuantityMetricIpc),
QuantityMetric::Child(_) => panic!("Can't get a child metric from a child metric"),
}
}
}
#[inherent]
impl Quantity for QuantityMetric {
/// Set the value. Must be non-negative.
///
/// # Arguments
///
/// * `value` - The value. Must be non-negative.
///
/// ## Notes
///
/// Logs an error if the `value` is negative.
pub fn set(&self, value: i64) {
match self {
QuantityMetric::Parent(p) => {
p.set(value);
}
QuantityMetric::Child(_) => {
log::error!("Unable to set quantity metric in non-main process. This operation will be ignored.");
// If we're in automation we can panic so the instrumentor knows they've gone wrong.
// This is a deliberate violation of Glean's "metric APIs must not throw" design.
assert!(!crate::ipc::is_in_automation(), "Attempted to set quantity metric in non-main process, which is forbidden. This panics in automation.");
// TODO: Record an error.
}
}
}
/// **Test-only API.**
///
/// Get the currently stored value.
/// 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<i64> {
let ping_name = ping_name.into().map(|s| s.to_string());
match self {
QuantityMetric::Parent(p) => p.test_get_value(ping_name),
QuantityMetric::Child(_) => {
panic!("Cannot get test value for quantity metric in non-main process!",)
}
}
}
/// **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 {
QuantityMetric::Parent(p) => p.test_get_num_recorded_errors(error),
QuantityMetric::Child(_) => panic!(
"Cannot get the number of recorded errors for quantity metric in non-main process!"
),
}
}
}
#[cfg(test)]
mod test {
use crate::{common_test::*, ipc, metrics};
#[test]
fn sets_quantity_metric() {
let _lock = lock_test();
let metric = &metrics::test_only_ipc::a_quantity;
metric.set(14);
assert_eq!(14, metric.test_get_value("store1").unwrap());
}
#[test]
fn quantity_ipc() {
// QuantityMetric doesn't support IPC.
let _lock = lock_test();
let parent_metric = &metrics::test_only_ipc::a_quantity;
parent_metric.set(15);
{
let child_metric = parent_metric.child_metric();
// scope for need_ipc RAII
let _raii = ipc::test_set_need_ipc(true);
// Instrumentation calls do not panic.
child_metric.set(30);
// (They also shouldn't do anything,
// but that's not something we can inspect in this test)
}
assert!(ipc::replay_from_buf(&ipc::take_buf().unwrap()).is_ok());
assert_eq!(15, parent_metric.test_get_value(None).unwrap());
}
}