diff --git a/CHANGELOG.md b/CHANGELOG.md index 945d128..685c8b6 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -34,9 +34,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0 - Supoort `Arc` for `EncodeLabelValue`. See [PR 217]. +- Added `get` method to `Family`. + See [PR 234]. + [PR 173]: https://github.com/prometheus/client_rust/pull/173 [PR 216]: https://github.com/prometheus/client_rust/pull/216 [PR 217]: https://github.com/prometheus/client_rust/pull/217 +[PR 234]: https://github.com/prometheus/client_rust/pull/234 ### Fixed diff --git a/src/metrics/family.rs b/src/metrics/family.rs index 2f23b19..1a76cf8 100644 --- a/src/metrics/family.rs +++ b/src/metrics/family.rs @@ -226,9 +226,7 @@ impl> Family MappedRwLockReadGuard { - if let Ok(metric) = - RwLockReadGuard::try_map(self.metrics.read(), |metrics| metrics.get(label_set)) - { + if let Some(metric) = self.get(label_set) { return metric; } @@ -247,6 +245,23 @@ impl> Family, Counter>::default(); + /// + /// if let Some(metric) = family.get(&vec![("method".to_owned(), "GET".to_owned())]) { + /// metric.inc(); + /// }; + /// ``` + pub fn get(&self, label_set: &S) -> Option> { + RwLockReadGuard::try_map(self.metrics.read(), |metrics| metrics.get(label_set)).ok() + } + /// Remove a label set from the metric family. /// /// Returns a bool indicating if a label set was removed or not. @@ -452,4 +467,47 @@ mod tests { .get() ); } + + #[test] + fn test_get() { + let family = Family::, Counter>::default(); + + // Test getting a non-existent metric. + let non_existent = family.get(&vec![("method".to_string(), "GET".to_string())]); + assert!(non_existent.is_none()); + + // Create a metric. + family + .get_or_create(&vec![("method".to_string(), "GET".to_string())]) + .inc(); + + // Test getting an existing metric. + let existing = family.get(&vec![("method".to_string(), "GET".to_string())]); + assert!(existing.is_some()); + assert_eq!(existing.unwrap().get(), 1); + + // Test getting a different non-existent metric. + let another_non_existent = family.get(&vec![("method".to_string(), "POST".to_string())]); + assert!(another_non_existent.is_none()); + + // Test modifying the metric through the returned reference. + if let Some(metric) = family.get(&vec![("method".to_string(), "GET".to_string())]) { + metric.inc(); + } + + // Verify the modification. + let modified = family.get(&vec![("method".to_string(), "GET".to_string())]); + assert_eq!(modified.unwrap().get(), 2); + + // Test with a different label set type. + let string_family = Family::::default(); + string_family.get_or_create(&"test".to_string()).inc(); + + let string_metric = string_family.get(&"test".to_string()); + assert!(string_metric.is_some()); + assert_eq!(string_metric.unwrap().get(), 1); + + let non_existent_string = string_family.get(&"non_existent".to_string()); + assert!(non_existent_string.is_none()); + } }