1 files changed, 32 insertions, 6 deletions

diff --git a/third_party/rust/glean-core/src/metrics/custom_distribution.rs b/third_party/rust/glean-core/src/metrics/custom_distribution.rs
index 929e4863ec..c7f3fbc56f 100644
--- a/third_party/rust/glean-core/src/metrics/custom_distribution.rs
+++ b/third_party/rust/glean-core/src/metrics/custom_distribution.rs
@@ -84,14 +84,33 @@ impl CustomDistributionMetric {
     /// for each of them.
     pub fn accumulate_samples(&self, samples: Vec<i64>) {
         let metric = self.clone();
-        crate::launch_with_glean(move |glean| metric.accumulate_samples_sync(glean, samples))
+        crate::launch_with_glean(move |glean| metric.accumulate_samples_sync(glean, &samples))
+    }
+
+    /// Accumulates precisely one signed sample and appends it to the metric.
+    ///
+    /// Signed is required so that the platform-specific code can provide us with a
+    /// 64 bit signed integer if no `u64` comparable type is available. This
+    /// will take care of filtering and reporting errors.
+    ///
+    /// # Arguments
+    ///
+    /// - `sample` - The singular sample to be recorded by the metric.
+    ///
+    /// ## Notes
+    ///
+    /// Discards any negative value of `sample` and reports an
+    /// [`ErrorType::InvalidValue`](crate::ErrorType::InvalidValue).
+    pub fn accumulate_single_sample(&self, sample: i64) {
+        let metric = self.clone();
+        crate::launch_with_glean(move |glean| metric.accumulate_samples_sync(glean, &[sample]))
     }
 
     /// Accumulates the provided sample in the metric synchronously.
     ///
     /// See [`accumulate_samples`](Self::accumulate_samples) for details.
     #[doc(hidden)]
-    pub fn accumulate_samples_sync(&self, glean: &Glean, samples: Vec<i64>) {
+    pub fn accumulate_samples_sync(&self, glean: &Glean, samples: &[i64]) {
         if !self.should_record(glean) {
             return;
         }
@@ -132,7 +151,7 @@ impl CustomDistributionMetric {
                             self.bucket_count as usize,
                         )
                     };
-                    accumulate(&samples, hist, Metric::CustomDistributionLinear)
+                    accumulate(samples, hist, Metric::CustomDistributionLinear)
                 }
                 HistogramType::Exponential => {
                     let hist = if let Some(Metric::CustomDistributionExponential(hist)) = old_value
@@ -145,7 +164,7 @@ impl CustomDistributionMetric {
                             self.bucket_count as usize,
                         )
                     };
-                    accumulate(&samples, hist, Metric::CustomDistributionExponential)
+                    accumulate(samples, hist, Metric::CustomDistributionExponential)
                 }
             };
 
@@ -194,6 +213,15 @@ impl CustomDistributionMetric {
     /// 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<DistributionData> {
         crate::block_on_dispatcher();
         crate::core::with_glean(|glean| self.get_value(glean, ping_name.as_deref()))
@@ -206,8 +234,6 @@ impl CustomDistributionMetric {
     /// # Arguments
     ///
     /// * `error` - The type of error
-    /// * `ping_name` - represents the optional name of the ping to retrieve the
-    ///   metric for. inner to the first value in `send_in_pings`.
     ///
     /// # Returns
     ///