Retain old 'protobuf' feature, make explicit types

Signed-off-by: John Howard <john.howard@solo.io>

Author: howardjohn

CHANGELOG.md

@@ -14,11 +14,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Updated `prost`, `prost-build`, and `prost-types` dependencies to `v0.14`.
-- The `protobuf` feature now generates and encodes Prometheus
+- The `prometheus_protobuf` feature generates and encodes Prometheus
   `io.prometheus.client` protobuf messages from `metrics.proto` rather than the
-  OpenMetrics protobuf data model. This is a breaking change for users of the `protobuf` feature.
+  OpenMetrics protobuf data model.
   See [Issue](https://github.com/prometheus/OpenMetrics/issues/296) for more context.
-  The `legacy_protobuf` feature retains the old, deprecated, OpenMetrics protobuf support which will
+  The `protobuf` and `openmetrics_protobuf` features retain the old, deprecated, OpenMetrics protobuf support which will
   be removed in a future release.
 
 ## [0.24.1]

Cargo.toml

@@ -12,9 +12,10 @@ documentation = "https://docs.rs/prometheus-client"
 
 [features]
 default = []
-protobuf = ["dep:prost", "dep:prost-types", "dep:prost-build"]
-legacy_protobuf = ["dep:prost", "dep:prost-types", "dep:prost-build"]
-protobuf-protox = ["protobuf", "dep:protox"]
+prometheus_protobuf = ["dep:prost", "dep:prost-types", "dep:prost-build"]
+openmetrics_protobuf = ["dep:prost", "dep:prost-types", "dep:prost-build"]
+protobuf = ["openmetrics_protobuf"]
+protobuf-protox = ["dep:protox"]
 
 # This feature provides additional APIs for testing downstream code using
 # `prometheus-client`.
@@ -76,7 +77,7 @@ required-features = []
 name = "proto"
 path = "benches/encoding/proto.rs"
 harness = false
-required-features = ["protobuf"]
+required-features = ["prometheus_protobuf"]
 
 # Passing arguments to the docsrs builder in order to properly document cfg's.
 # More information: https://docs.rs/about/builds#cross-compiling

benches/encoding/proto.rs

@@ -2,7 +2,7 @@
 // https://github.com/tikv/rust-prometheus/blob/ab1ca7285d3463504381a5025ae1951e020d6796/benches/text_encoder.rs:write
 
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
-use prometheus_client::encoding::protobuf;
+use prometheus_client::encoding::prometheus_protobuf;
 use prometheus_client::metrics::counter::Counter;
 use prometheus_client::metrics::family::Family;
 use prometheus_client::metrics::histogram::{exponential_buckets, Histogram};
@@ -75,7 +75,7 @@ pub fn proto(c: &mut Criterion) {
         }
 
         b.iter(|| {
-            let metric_set = protobuf::encode(&registry).unwrap();
+            let metric_set = prometheus_protobuf::encode(&registry).unwrap();
             black_box(metric_set);
         })
     });

build.rs

@@ -1,20 +1,20 @@
 use std::error::Error;
 
 fn main() -> Result<(), Box<dyn Error>> {
-    #[cfg(any(feature = "protobuf", feature = "legacy_protobuf"))]
+    #[cfg(any(feature = "prometheus_protobuf", feature = "openmetrics_protobuf"))]
     compile_protos()?;
 
     Ok(())
 }
 
 #[allow(clippy::vec_init_then_push)] // False positive due to feature flags
-#[cfg(any(feature = "protobuf", feature = "legacy_protobuf"))]
+#[cfg(any(feature = "prometheus_protobuf", feature = "openmetrics_protobuf"))]
 fn compile_protos() -> Result<(), Box<dyn Error>> {
     let mut protos = Vec::new();
 
-    #[cfg(feature = "protobuf")]
+    #[cfg(feature = "prometheus_protobuf")]
     protos.push("src/encoding/proto/metrics.proto");
-    #[cfg(feature = "legacy_protobuf")]
+    #[cfg(feature = "openmetrics_protobuf")]
     protos.push("src/encoding/proto/openmetrics_data_model.proto");
 
     let includes = ["src/encoding/proto/"];

derive-encode/Cargo.toml

@@ -17,7 +17,7 @@ quote = "1"
 syn = "2"
 
 [dev-dependencies]
-prometheus-client = { path = "../", features = ["protobuf"] }
+prometheus-client = { path = "../", features = ["prometheus_protobuf"] }
 trybuild = "1"
 
 [lib]

derive-encode/tests/lib.rs

@@ -47,8 +47,8 @@ fn basic_flow() {
 
 mod protobuf {
     use crate::{Labels, Method};
-    use prometheus_client::encoding::protobuf::encode;
-    use prometheus_client::encoding::protobuf::prometheus_data_model;
+    use prometheus_client::encoding::prometheus_protobuf::encode;
+    use prometheus_client::encoding::prometheus_protobuf::prometheus_data_model;
     use prometheus_client::metrics::counter::Counter;
     use prometheus_client::metrics::family::Family;
     use prometheus_client::registry::Registry;