metrics-exporter-prometheus: switch methods to gain access to the inner data of the recorder (using a type alias)

metrics-exporter-prometheus/Cargo.toml

@@ -20,8 +20,8 @@ default = ["tokio-exporter"]
 tokio-exporter = ["hyper", "tokio"]
 
 [dependencies]
-metrics = { version = "0.13.0-alpha.1", path="../metrics" }
-metrics-util = { version = "0.4.0-alpha.1", path="../metrics-util" }
+metrics = { version = "0.13.0-alpha.1", path = "../metrics" }
+metrics-util = { version = "0.4.0-alpha.1", path = "../metrics-util" }
 hdrhistogram = "7.1"
 parking_lot = "0.11"
 thiserror = "1.0"

metrics-exporter-prometheus/src/lib.rs

@@ -26,6 +26,9 @@ use tokio::{pin, runtime, select};
 type PrometheusRegistry = Registry<CompositeKey, Handle>;
 type HdrHistogram = hdrhistogram::Histogram<u64>;
 
+/// A type wrapper around the Inner struct of the Prometheus recorder.
+pub type PrometheusHandle = Arc<Inner>;
+
 /// Errors that could occur while installing a Prometheus recorder/exporter.
 #[derive(ThisError, Debug)]
 pub enum Error {
@@ -65,7 +68,8 @@ struct Snapshot {
     pub distributions: HashMap<String, HashMap<Vec<String>, Distribution>>,
 }
 
-struct Inner {
+/// Inner contains all of the data stored by the Prometheus Recorder.
+pub struct Inner {
     registry: PrometheusRegistry,
     distributions: RwLock<HashMap<String, HashMap<Vec<String>, Distribution>>>,
     quantiles: Vec<Quantile>,
@@ -75,6 +79,7 @@ struct Inner {
 }
 
 impl Inner {
+    /// Returns a reference to the [`PrometheusRegistry`] this struct uses.
     pub fn registry(&self) -> &PrometheusRegistry {
         &self.registry
     }
@@ -165,6 +170,7 @@ impl Inner {
         }
     }
 
+    /// Returns the metrics in Prometheus accepted String format.
     pub fn render(&self) -> String {
         let mut sorted_overrides = self
             .buckets_by_name
@@ -334,9 +340,9 @@ pub struct PrometheusRecorder {
 }
 
 impl PrometheusRecorder {
-    /// Renders the Prometheus metrics in string format.
-    pub fn render(&self) -> String {
-        self.inner.render()
+    ///Returns a [`PrometheusHandle`] from the inner struct of this recorder.
+    pub fn handle(&self) -> PrometheusHandle {
+        self.inner.clone()
     }
 
     fn add_description_if_missing(&self, key: &Key, description: Option<&'static str>) {