Merge branch 'main' into experiment/name-parts

.github/workflows/ci.yml

@@ -35,6 +35,23 @@ jobs:
           override: true
     - name: Run Tests
       run: cargo test
+  docs:
+    runs-on: ubuntu-latest
+    env:
+      RUSTDOCFLAGS: -Dwarnings
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install Rust Nightly
+      uses: actions-rs/toolchain@v1
+      with:
+          toolchain: nightly
+          override: true
+          components: rust-docs
+    - name: Check docs
+      uses: actions-rs/cargo@v1
+      with:
+        command: doc
+        args: --workspace --no-deps
   bench:
     name: Bench ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
@@ -49,4 +66,7 @@ jobs:
           toolchain: 'stable'
           override: true
     - name: Run Benchmarks
-      run: cargo bench --all-features
+      uses: actions-rs/cargo@v1
+      with:
+        command: bench
+        args: --all-features

metrics-exporter-prometheus/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "metrics-exporter-prometheus"
-version = "0.1.0-alpha.6"
+version = "0.1.0-alpha.7"
 authors = ["Toby Lawrence <toby@nuclearfurnace.com>"]
 edition = "2018"
 
@@ -15,15 +15,21 @@ readme = "README.md"
 categories = ["development-tools::debugging"]
 keywords = ["metrics", "telemetry", "prometheus"]
 
+[features]
+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-util = { version = "0.4.0-alpha.1", path = "../metrics-util" }
 hdrhistogram = "7.1"
-hyper = { version = "0.13", default-features = false, features = ["tcp"] }
-tokio = { version = "0.2", features = ["rt-core", "tcp", "time", "macros"] }
 parking_lot = "0.11"
 thiserror = "1.0"
 
+# Optional
+hyper = { version = "0.13", default-features = false, features = ["tcp"], optional = true }
+tokio = { version = "0.2", features = ["rt-core", "tcp", "time", "macros"], optional = true }
+
 [dev-dependencies]
 quanta = "0.6"
 tracing = "0.1"

metrics-exporter-prometheus/src/lib.rs

@@ -3,6 +3,7 @@
 #![cfg_attr(docsrs, feature(doc_cfg), deny(broken_intra_doc_links))]
 use std::future::Future;
 
+#[cfg(feature = "tokio-exporter")]
 use hyper::{
     service::{make_service_fn, service_fn},
     {Body, Error as HyperError, Response, Server},
@@ -16,9 +17,11 @@ use std::io;
 use std::iter::FromIterator;
 use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::sync::Arc;
+#[cfg(feature = "tokio-exporter")]
 use std::thread;
 use std::{collections::HashMap, time::SystemTime};
 use thiserror::Error as ThisError;
+#[cfg(feature = "tokio-exporter")]
 use tokio::{pin, runtime, select};
 
 type PrometheusRegistry = Registry<CompositeKey, Handle>;
@@ -32,6 +35,7 @@ pub enum Error {
     Io(#[from] io::Error),
 
     /// Binding/listening to the given address did not succeed.
+    #[cfg(feature = "tokio-exporter")]
     #[error("failed to bind to given listen address: {0}")]
     Hyper(#[from] HyperError),
 
@@ -331,6 +335,13 @@ pub struct PrometheusRecorder {
 }
 
 impl PrometheusRecorder {
+    /// Gets a [`PrometheusHandle`] to this recorder.
+    pub fn handle(&self) -> PrometheusHandle {
+        PrometheusHandle {
+            inner: self.inner.clone(),
+        }
+    }
+
     fn add_description_if_missing(&self, key: &Key, description: Option<&'static str>) {
         if let Some(description) = description {
             let mut descriptions = self.inner.descriptions.write();
@@ -341,6 +352,20 @@ impl PrometheusRecorder {
     }
 }
 
+/// Handle to [`PrometheusRecorder`].
+///
+/// Useful for exposing a scrape endpoint on an existing HTTP/HTTPS server.
+pub struct PrometheusHandle {
+    inner: Arc<Inner>,
+}
+
+impl PrometheusHandle {
+    /// Returns the metrics in Prometheus accepted String format.
+    pub fn render(&self) -> String {
+        self.inner.render()
+    }
+}
+
 /// Builder for creating and installing a Prometheus recorder/exporter.
 pub struct PrometheusBuilder {
     listen_address: SocketAddr,
@@ -416,15 +441,16 @@ impl PrometheusBuilder {
     ///
     /// An error will be returned if there's an issue with creating the HTTP server or with
     /// installing the recorder as the global recorder.
+    #[cfg(feature = "tokio-exporter")]
     pub fn install(self) -> Result<(), Error> {
-        let (recorder, exporter) = self.build()?;
-        metrics::set_boxed_recorder(Box::new(recorder))?;
-
         let mut runtime = runtime::Builder::new()
             .basic_scheduler()
             .enable_all()
             .build()?;
 
+        let (recorder, exporter) = runtime.enter(|| self.build_with_exporter())?;
+        metrics::set_boxed_recorder(Box::new(recorder))?;
+
         thread::Builder::new()
             .name("metrics-exporter-prometheus-http".to_string())
             .spawn(move || {
@@ -441,13 +467,31 @@ impl PrometheusBuilder {
         Ok(())
     }
 
+    /// Builds the recorder and returns it.
+    /// This function is only enabled when default features are not set.
+    pub fn build(self) -> Result<PrometheusRecorder, Error> {
+        let inner = Arc::new(Inner {
+            registry: Registry::new(),
+            distributions: RwLock::new(HashMap::new()),
+            quantiles: self.quantiles.clone(),
+            buckets: self.buckets.clone(),
+            buckets_by_name: self.buckets_by_name,
+            descriptions: RwLock::new(HashMap::new()),
+        });
+
+        let recorder = PrometheusRecorder { inner };
+
+        Ok(recorder)
+    }
+
     /// Builds the recorder and exporter and returns them both.
     ///
     /// In most cases, users should prefer to use [`PrometheusBuilder::install`] to create and
     /// install the recorder and exporter automatically for them.  If a caller is combining
     /// recorders, or needs to schedule the exporter to run in a particular way, this method
     /// provides the flexibility to do so.
-    pub fn build(
+    #[cfg(feature = "tokio-exporter")]
+    pub fn build_with_exporter(
         self,
     ) -> Result<
         (

metrics/src/key.rs

@@ -87,7 +87,7 @@ impl fmt::Display for NameParts {
 
 /// Inner representation of [`Key`].
 ///
-/// While [`Key`] is the type that users will interact with via [`Recorder`][crate::Recorder`,
+/// While [`Key`] is the type that users will interact with via [`Recorder`][crate::Recorder],
 /// [`KeyData`] is responsible for the actual storage of the name and label data.
 #[derive(PartialEq, Eq, Hash, Clone, Debug)]
 pub struct KeyData {