refactor: make Metric fields private

Author: josecelano

packages/metrics/src/metric.rs

@@ -7,13 +7,14 @@ use super::label_set::LabelSet;
 use super::prometheus::PrometheusSerializable;
 use super::sample::Sample;
 use super::sample_collection::SampleCollection;
+use crate::gauge::Gauge;
 
 #[derive(Debug, Clone, Default, PartialEq, Serialize)]
 pub struct Metric<T> {
     name: MetricName,
 
     #[serde(rename = "samples")]
-    pub sample_collection: SampleCollection<T>,
+    sample_collection: SampleCollection<T>,
 }
 
 impl<T> Metric<T> {
@@ -42,6 +43,12 @@ impl Metric<Counter> {
     }
 }
 
+impl Metric<Gauge> {
+    pub fn set(&mut self, labels: &LabelSet, value: f64, time: DurationSinceUnixEpoch) {
+        self.sample_collection.set(labels, value, time);
+    }
+}
+
 impl<T: PrometheusSerializable> PrometheusSerializable for Metric<T> {
     fn to_prometheus(&self) -> String {
         let mut output = String::new();

packages/metrics/src/metric_collection.rs

@@ -9,7 +9,6 @@ use super::gauge::Gauge;
 use super::label_set::LabelSet;
 use super::metric::{Metric, MetricName};
 use super::prometheus::PrometheusSerializable;
-use super::sample::Sample;
 use crate::sample_collection::SampleCollection;
 
 #[derive(Debug, Clone, Default, PartialEq)]
@@ -160,11 +159,11 @@ impl MetricKindCollection<Counter> {
     ///
     /// # Panics
     ///
-    /// Panics if the metric name already exists in the collection.
+    /// Panics if the metric does not exist and it could not be created.
     pub fn increment(&mut self, name: &MetricName, labels: &LabelSet, time: DurationSinceUnixEpoch) {
         self.crate_metric_if_does_not_exist(name);
 
-        let metric = self.metrics.get_mut(name).unwrap();
+        let metric = self.metrics.get_mut(name).expect("Counter metric should exist");
 
         metric.increment(labels, time);
     }
@@ -179,29 +178,19 @@ impl MetricKindCollection<Counter> {
 }
 
 impl MetricKindCollection<Gauge> {
+    /// Sets the gauge for the given metric name and labels.
+    ///
+    /// If the metric name does not exist, it will be created.
+    ///
     /// # Panics
     ///
-    /// Panics if the metric name already exists in the collection.
+    /// Panics if the metric does not exist and it could not be created.
     pub fn set(&mut self, name: &MetricName, labels: &LabelSet, value: f64, time: DurationSinceUnixEpoch) {
         self.crate_metric_if_does_not_exist(name);
 
-        let metric = self.metrics.get_mut(name).unwrap();
+        let metric = self.metrics.get_mut(name).expect("Gauge metric should exist");
 
-        // Use entry API to handle existing or new sample
-        match metric.sample_collection.samples.entry(labels.clone()) {
-            std::collections::hash_map::Entry::Occupied(mut entry) => {
-                let sample = entry.get_mut();
-                sample.value.set(value);
-                sample.update_at = time;
-            }
-            std::collections::hash_map::Entry::Vacant(entry) => {
-                entry.insert(Sample {
-                    value: Gauge::new(value),
-                    update_at: time,
-                    labels: labels.clone(),
-                });
-            }
-        }
+        metric.set(labels, value, time);
     }
 
     #[must_use]