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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 crate::common_metric_data::CommonMetricDataInternal;
use crate::error_recording::{record_error, test_get_num_recorded_errors, ErrorType};
use crate::metrics::CounterMetric;
use crate::metrics::Metric;
use crate::metrics::MetricType;
use crate::metrics::RateMetric;
use crate::storage::StorageManager;
use crate::CommonMetricData;
use crate::Glean;
/// A Denominator metric (a kind of count shared among Rate metrics).
///
/// Used to count things.
/// The value can only be incremented, not decremented.
// This is essentially a counter metric,
// which additionally forwards increments to the denominator to a list of associated rates.
// The numerator is incremented through the corresponding `NumeratorMetric`.
#[derive(Clone, Debug)]
pub struct DenominatorMetric {
counter: CounterMetric,
numerators: Vec<RateMetric>,
}
impl MetricType for DenominatorMetric {
fn meta(&self) -> &CommonMetricDataInternal {
self.counter.meta()
}
}
impl DenominatorMetric {
/// Creates a new denominator metric.
pub fn new(meta: CommonMetricData, numerators: Vec<CommonMetricData>) -> Self {
Self {
counter: CounterMetric::new(meta),
numerators: numerators.into_iter().map(RateMetric::new).collect(),
}
}
/// Increases the denominator by `amount`.
///
/// # Arguments
///
/// * `glean` - The Glean instance this metric belongs to.
/// * `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) {
let metric = self.clone();
crate::launch_with_glean(move |glean| metric.add_sync(glean, amount))
}
#[doc(hidden)]
pub fn add_sync(&self, glean: &Glean, amount: i32) {
if !self.should_record(glean) {
return;
}
if amount <= 0 {
record_error(
glean,
self.meta(),
ErrorType::InvalidValue,
format!("Added negative or zero value {}", amount),
None,
);
return;
}
for num in &self.numerators {
num.add_to_denominator_sync(glean, amount);
}
glean
.storage()
.record_with(glean, self.counter.meta(), |old_value| match old_value {
Some(Metric::Counter(old_value)) => {
Metric::Counter(old_value.saturating_add(amount))
}
_ => Metric::Counter(amount),
})
}
/// **Test-only API (exported for FFI purposes).**
///
/// Gets the currently stored value as an integer.
///
/// This doesn't clear the stored value.
///
/// # Arguments
///
/// * `ping_name` - the optional name of the ping to retrieve the metric
/// for. Defaults to the first value in `send_in_pings`.
///
/// # Returns
///
/// The stored value or `None` if nothing stored.
pub fn test_get_value(&self, ping_name: Option<String>) -> Option<i32> {
crate::block_on_dispatcher();
crate::core::with_glean(|glean| self.get_value(glean, ping_name.as_deref()))
}
#[doc(hidden)]
pub fn get_value<'a, S: Into<Option<&'a str>>>(
&self,
glean: &Glean,
ping_name: S,
) -> Option<i32> {
let queried_ping_name = ping_name
.into()
.unwrap_or_else(|| &self.meta().inner.send_in_pings[0]);
match StorageManager.snapshot_metric_for_test(
glean.storage(),
queried_ping_name,
&self.meta().identifier(glean),
self.meta().inner.lifetime,
) {
Some(Metric::Counter(i)) => Some(i),
_ => None,
}
}
/// **Exported for test purposes.**
///
/// Gets the number of recorded errors for the given metric and error type.
///
/// # Arguments
///
/// * `error` - The type of error
///
/// # Returns
///
/// The number of errors reported.
pub fn test_get_num_recorded_errors(&self, error: ErrorType) -> i32 {
crate::block_on_dispatcher();
crate::core::with_glean(|glean| {
test_get_num_recorded_errors(glean, self.meta(), error).unwrap_or(0)
})
}
}