Fix conflicts

.github/workflows/rust.yml

@@ -9,6 +9,8 @@ jobs:
     steps:
       - name: Install Protoc
         uses: arduino/setup-protoc@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
@@ -49,6 +51,8 @@ jobs:
     steps:
       - name: Install Protoc
         uses: arduino/setup-protoc@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
@@ -85,6 +89,8 @@ jobs:
     steps:
       - name: Install Protoc
         uses: arduino/setup-protoc@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
@@ -103,6 +109,8 @@ jobs:
     steps:
       - name: Install Protoc
         uses: arduino/setup-protoc@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
@@ -134,6 +142,8 @@ jobs:
     steps:
       - name: Install Protoc
         uses: arduino/setup-protoc@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:

CHANGELOG.md

@@ -4,9 +4,99 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.19.0] - unreleased
+## [0.20.0] [unreleased]
 
 ### Added
+
+- Introduce `Collector` abstraction allowing users to provide additional metrics
+  and their description on each scrape. See [PR 82].
+
+- Introduce a `#[prometheus(flatten)]` attribute which can be used when deriving `EncodeLabelSet`, allowing
+  a nested struct to be flattened during encoding. See [PR 118].
+
+  For example:
+
+  ```rust
+  #[derive(EncodeLabelSet, Hash, Clone, Eq, PartialEq, Debug)]
+  struct CommonLabels {
+      a: u64,
+      b: u64,
+  }
+  #[derive(EncodeLabelSet, Hash, Clone, Eq, PartialEq, Debug)]
+  struct Labels {
+      unique: u64,
+      #[prometheus(flatten)]
+      common: CommonLabels,
+  }
+  ```
+
+  Would be encoded as:
+
+  ```
+  my_metric{a="42",b="42",unique="42"} 42
+  ```
+
+[PR 82]: https://github.com/prometheus/client_rust/pull/82
+[PR 118]: https://github.com/prometheus/client_rust/pull/118
+
+## [0.19.0]
+
+This is a large release including multiple breaking changes. Major user-facing
+improvement of this release is support for the OpenMetrics Protobuf format.
+
+### Upgrade guide:
+
+- Don't box before registering.
+
+  ```diff
+    registry.register(
+        "my_metric",
+        "This is my metric",
+  -      Box::new(my_metric.clone()),
+  +      my_metric.clone(),
+    );
+  ```
+
+- Gauge uses `i64` instead of `u64`.
+
+  ```diff
+    my_gauge
+  -     .set(42u64);
+  +     .set(42i64);
+  ```
+
+- Derive `EncodeLabelSet` for `struct` and `EncodeLabelValue` for `enum` instead of just `Encode` for all and require `Debug`.
+
+  ```diff
+  - #[derive(Clone, Hash, PartialEq, Eq, Encode)]
+  + #[derive(Clone, Hash, PartialEq, Eq, EncodeLabelSet, Debug)]
+    struct Labels {
+        path: String,
+        method: Method,
+        some_number: u64,
+    }
+
+  - #[derive(Clone, Hash, PartialEq, Eq, Encode)]
+  + #[derive(Clone, Hash, PartialEq, Eq, EncodeLabelValue, Debug)]
+    enum Method {
+        Get,
+        #[allow(dead_code)]
+        Put,
+    }
+  ```
+
+- Encode as utf-8 and not as `[u8]`.
+
+  ```diff
+  - let mut buffer = vec![];
+  + let mut buffer = String::new();
+    encode(&mut buffer, &registry).unwrap();
+  ```
+
+For details on each of these, see changelog entries below.
+
+### Added
+
 - Added support for the OpenMetrics protobuf format. See [PR 83].
 - Added a `remove` method to `Family` to allow the removal of a specified label
   set from a family. See [PR 85].
@@ -16,11 +106,22 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
-- Move`Encode` trait from `prometheus_client::encoding::text` to `prometheus_client::encoding`. See [PR 83].
+- Always use dynamic dispatch on `Registry`, i.e. remove generic type parameter `M` from `Registry`. See [PR 105].
+- Refactor encoding. See [PR 105].
+  - Introducing separate traits to encode
+    - value (e.g. `EncodeCounterValue`)
+    - label set (`EncodeLabelSet`), derivable for structs via `prometheus-client-derive-encode`
+    - label (`EncodeLabel`)
+    - label key (`EncodeLabelKey`)
+    - label value (`EncodeLabelValue`), derivable for enums via `prometheus-client-derive-encode`
+  - Encode as UTF-8 strings, not bytes. I.e. use `std::fmt::Write` instead of `std::io::Write`.
+- Use signed integers for `Gauge` for compliance with OpenMetrics protobuf
+  format. See [PR 105].
 
 [PR 83]: https://github.com/prometheus/client_rust/pull/83
 [PR 85]: https://github.com/prometheus/client_rust/pull/85
 [PR 96]: https://github.com/prometheus/client_rust/pull/96
+[PR 105]: https://github.com/prometheus/client_rust/pull/105
 
 ## [0.18.1]
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "prometheus-client"
-version = "0.19.0"
+version = "0.20.0"
 authors = ["Max Inden <[email protected]>"]
 edition = "2021"
 description = "Open Metrics client library allowing users to natively instrument applications."
@@ -11,7 +11,8 @@ homepage = "https://github.com/prometheus/client_rust"
 documentation = "https://docs.rs/prometheus-client"
 
 [features]
-protobuf = ["dep:prost", "dep:prost-types", "dep:prost-build", "dep:void", "prometheus-client-derive-encode/protobuf"]
+default = []
+protobuf = ["dep:prost", "dep:prost-types", "dep:prost-build"]
 
 [workspace]
 members = ["derive-encode"]
@@ -20,17 +21,16 @@ members = ["derive-encode"]
 dtoa = "1.0"
 itoa = "1.0"
 parking_lot = "0.12"
-prometheus-client-derive-encode = { version = "0.3.0", path = "derive-encode" }
+prometheus-client-derive-encode = { version = "0.4.1", path = "derive-encode" }
 prost = { version = "0.11.0", optional = true }
 prost-types = { version = "0.11.0", optional = true }
-void = { version = "1.0", optional = true }
 quantiles = "0.7.1"
 
 [dev-dependencies]
 async-std = { version = "1", features = ["attributes"] }
 criterion = "0.4"
 http-types = "2"
-pyo3 = "0.17"
+pyo3 = "0.18"
 quickcheck = "1"
 rand = "0.8.4"
 tide = "0.16"

benches/encoding/proto.rs

@@ -2,82 +2,80 @@
 // 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::proto::{encode, EncodeMetric};
-use prometheus_client::encoding::Encode;
+use prometheus_client::encoding::protobuf;
 use prometheus_client::metrics::counter::Counter;
 use prometheus_client::metrics::family::Family;
 use prometheus_client::metrics::histogram::{exponential_buckets, Histogram};
 use prometheus_client::registry::Registry;
-use std::fmt::{Display, Formatter};
+use prometheus_client_derive_encode::{EncodeLabelSet, EncodeLabelValue};
 
 pub fn proto(c: &mut Criterion) {
     c.bench_function("encode", |b| {
-        #[derive(Clone, Hash, PartialEq, Eq, Encode)]
-        struct Labels {
+        #[derive(Clone, Hash, PartialEq, Eq, EncodeLabelSet, Debug)]
+        struct CounterLabels {
             path: String,
             method: Method,
             some_number: u64,
         }
 
-        #[derive(Clone, Hash, PartialEq, Eq, Encode)]
+        #[derive(Clone, Hash, PartialEq, Eq, EncodeLabelValue, Debug)]
         enum Method {
             Get,
             #[allow(dead_code)]
             Put,
         }
 
-        impl Display for Method {
-            fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-                match self {
-                    Method::Get => write!(f, "Get"),
-                    Method::Put => write!(f, "Put"),
-                }
-            }
+        #[derive(Clone, Hash, PartialEq, Eq, EncodeLabelSet, Debug)]
+        struct HistogramLabels {
+            region: Region,
         }
 
-        #[derive(Clone, Hash, PartialEq, Eq, Encode)]
+        #[derive(Clone, Hash, PartialEq, Eq, EncodeLabelValue, Debug)]
         enum Region {
             Africa,
             #[allow(dead_code)]
             Asia,
         }
 
-        let mut registry = Registry::<Box<dyn EncodeMetric>>::default();
+        let mut registry = Registry::default();
 
         for i in 0..100 {
-            let counter_family = Family::<Labels, Counter>::default();
-            let histogram_family = Family::<Region, Histogram>::new_with_constructor(|| {
-                Histogram::new(exponential_buckets(1.0, 2.0, 10))
-            });
+            let counter_family = Family::<CounterLabels, Counter>::default();
+            let histogram_family =
+                Family::<HistogramLabels, Histogram>::new_with_constructor(|| {
+                    Histogram::new(exponential_buckets(1.0, 2.0, 10))
+                });
 
             registry.register(
                 format!("my_counter{}", i),
                 "My counter",
-                Box::new(counter_family.clone()),
+                counter_family.clone(),
             );
             registry.register(
                 format!("my_histogram{}", i),
                 "My histogram",
-                Box::new(histogram_family.clone()),
+                histogram_family.clone(),
             );
 
             for j in 0_u32..100 {
                 counter_family
-                    .get_or_create(&Labels {
+                    .get_or_create(&CounterLabels {
                         path: format!("/path/{}", i),
                         method: Method::Get,
                         some_number: j.into(),
                     })
                     .inc();
 
                 histogram_family
-                    .get_or_create(&Region::Africa)
+                    .get_or_create(&HistogramLabels {
+                        region: Region::Africa,
+                    })
                     .observe(j.into());
             }
         }
 
         b.iter(|| {
-            let metric_set = encode(&registry);
+            let metric_set = protobuf::encode(&registry).unwrap();
             black_box(metric_set);
         })
     });