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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::Metric;
use crate::metrics::MetricType;
use crate::storage::StorageManager;
use crate::CommonMetricData;
use crate::Glean;
/// A rate value as given by its numerator and denominator.
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Rate {
/// A rate's numerator
pub numerator: i32,
/// A rate's denominator
pub denominator: i32,
}
impl From<(i32, i32)> for Rate {
fn from((num, den): (i32, i32)) -> Self {
Self {
numerator: num,
denominator: den,
}
}
}
/// A rate metric.
///
/// Used to determine the proportion of things via two counts:
/// * A numerator defining the amount of times something happened,
/// * A denominator counting the amount of times someting could have happened.
///
/// Both numerator and denominator can only be incremented, not decremented.
#[derive(Clone, Debug)]
pub struct RateMetric {
meta: CommonMetricDataInternal,
}
impl MetricType for RateMetric {
fn meta(&self) -> &CommonMetricDataInternal {
&self.meta
}
}
// IMPORTANT:
//
// When changing this implementation, make sure all the operations are
// also declared in the related trait in `../traits/`.
impl RateMetric {
/// Creates a new rate metric.
pub fn new(meta: CommonMetricData) -> Self {
Self { meta: meta.into() }
}
/// Increases the numerator by `amount`.
///
/// # Arguments
///
/// * `glean` - The Glean instance this metric belongs to.
/// * `amount` - The amount to increase by. Should be non-negative.
///
/// ## Notes
///
/// Logs an error if the `amount` is negative.
pub fn add_to_numerator(&self, amount: i32) {
let metric = self.clone();
crate::launch_with_glean(move |glean| metric.add_to_numerator_sync(glean, amount))
}
#[doc(hidden)]
pub fn add_to_numerator_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 value {} to numerator", amount),
None,
);
return;
}
glean
.storage()
.record_with(glean, &self.meta, |old_value| match old_value {
Some(Metric::Rate(num, den)) => Metric::Rate(num.saturating_add(amount), den),
_ => Metric::Rate(amount, 0), // Denominator will show up eventually. Probably.
});
}
/// Increases the denominator by `amount`.
///
/// # Arguments
///
/// * `glean` - The Glean instance this metric belongs to.
/// * `amount` - The amount to increase by. Should be non-negative.
///
/// ## Notes
///
/// Logs an error if the `amount` is negative.
pub fn add_to_denominator(&self, amount: i32) {
let metric = self.clone();
crate::launch_with_glean(move |glean| metric.add_to_denominator_sync(glean, amount))
}
#[doc(hidden)]
pub fn add_to_denominator_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 value {} to denominator", amount),
None,
);
return;
}
glean
.storage()
.record_with(glean, &self.meta, |old_value| match old_value {
Some(Metric::Rate(num, den)) => Metric::Rate(num, den.saturating_add(amount)),
_ => Metric::Rate(0, amount),
});
}
/// **Test-only API (exported for FFI purposes).**
///
/// Gets the currently stored value as a pair of integers.
///
/// 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<Rate> {
crate::block_on_dispatcher();
crate::core::with_glean(|glean| self.get_value(glean, ping_name.as_deref()))
}
/// Get current value
#[doc(hidden)]
pub fn get_value<'a, S: Into<Option<&'a str>>>(
&self,
glean: &Glean,
ping_name: S,
) -> Option<Rate> {
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::Rate(n, d)) => Some((n, d).into()),
_ => 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)
})
}
}