1 files changed, 94 insertions, 0 deletions
diff --git a/third_party/rust/glean-core/src/metrics/numerator.rs b/third_party/rust/glean-core/src/metrics/numerator.rs
new file mode 100644
index 0000000000..3c340cab1d
--- /dev/null
+++ b/third_party/rust/glean-core/src/metrics/numerator.rs
@@ -0,0 +1,94 @@
+// 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
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+use std::sync::Arc;
+
+use crate::common_metric_data::CommonMetricDataInternal;
+use crate::error_recording::ErrorType;
+use crate::metrics::MetricType;
+use crate::metrics::Rate;
+use crate::metrics::RateMetric;
+use crate::CommonMetricData;
+use crate::Glean;
+
+/// Developer-facing API for recording rate metrics with external denominators.
+///
+/// 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 struct NumeratorMetric(pub(crate) Arc<RateMetric>);
+
+impl MetricType for NumeratorMetric {
+    fn meta(&self) -> &CommonMetricDataInternal {
+        self.0.meta()
+    }
+}
+
+impl NumeratorMetric {
+    /// The public constructor used by automatically generated metrics.
+    pub fn new(meta: CommonMetricData) -> Self {
+        Self(Arc::new(RateMetric::new(meta)))
+    }
+
+    /// Increases the numerator by `amount`.
+    ///
+    /// # Arguments
+    ///
+    /// * `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) {
+        self.0.add_to_numerator_sync(glean, amount)
+    }
+
+    /// **Exported for test purposes.**
+    ///
+    /// Gets the currently stored value as a pair of integers.
+    ///
+    /// # Arguments
+    ///
+    /// * `ping_name` - the optional name of the ping to retrieve the metric
+    ///                 for. Defaults to the first value in `send_in_pings`.
+    ///
+    /// This doesn't clear the stored value.
+    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()))
+    }
+
+    #[doc(hidden)]
+    pub fn get_value<'a, S: Into<Option<&'a str>>>(
+        &self,
+        glean: &Glean,
+        ping_name: S,
+    ) -> Option<Rate> {
+        self.0.get_value(glean, ping_name)
+    }
+
+    /// **Exported for test purposes.**
+    ///
+    /// Gets the number of recorded errors for the given metric and error type.
+    ///
+    /// # Arguments
+    ///
+    /// * `error` - The type of error
+    /// * `ping_name` - 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: ErrorType) -> i32 {
+        self.0.test_get_num_recorded_errors(error)
+    }
+}