Move Prometheus adapter to an external module (#4)

Author: vearutop

.github/workflows/bench.yml

@@ -13,7 +13,7 @@ jobs:
   bench:
     strategy:
       matrix:
-        go-version: [ 1.15.x ]
+        go-version: [ 1.16.x ]
     runs-on: ubuntu-latest
     steps:
       - name: Install Go

.github/workflows/golangci-lint.yml

@@ -14,16 +14,25 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@v2.3.0
+        uses: golangci/golangci-lint-action@v2.5.1
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
-          version: v1.34.1
+          version: v1.37.1
+
+          # Optional: working directory, useful for monorepos
+          # working-directory: somedir
 
           # Optional: golangci-lint command line arguments.
-          # args: ./the-only-dir-to-analyze/...
+          # args: --issues-exit-code=0
+
+          # Optional: show only new issues if it's a pull request. The default value is `false`.
+          # only-new-issues: true
+
+          # Optional: if set to true then the action will use pre-installed Go.
+          # skip-go-installation: true
+
+          # Optional: if set to true then the action don't cache or restore ~/go/pkg.
+          # skip-pkg-cache: true
 
-          # Required: the token is used for fetching a list of releases of golangci-lint.
-          # The secret `GITHUB_TOKEN` is automatically created by GitHub,
-          # no need to create it manually.
-          # https://help.github.com/en/actions/configuring-and-managing-workflows/authenticating-with-the-github_token#about-the-github_token-secret
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+          # Optional: if set to true then the action don't cache or restore ~/.cache/go-build.
+          # skip-build-cache: true

.github/workflows/test-unit.yml

@@ -11,7 +11,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [ 1.13.x, 1.14.x, 1.15.x ]
+        go-version: [ 1.13.x, 1.14.x, 1.15.x, 1.16.x ]
     runs-on: ubuntu-latest
     steps:
       - name: Install Go
@@ -52,7 +52,7 @@ jobs:
         if: ${{ github.ref == 'refs/heads/master' || github.ref == 'refs/heads/main' }}
         run: cp unit.txt unit-base.txt
       - name: Comment Test Coverage
-        if: matrix.go-version == '1.15.x'
+        if: matrix.go-version == '1.16.x'
         uses: marocchino/sticky-pull-request-comment@v2
         with:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -68,7 +68,7 @@ jobs:
             </details>
 
       - name: Upload code coverage
-        if: matrix.go-version == '1.15.x'
+        if: matrix.go-version == '1.16.x'
         uses: codecov/codecov-action@v1
         with:
           file: ./unit.coverprofile

README.md

@@ -13,8 +13,8 @@ This library provides context-driven stats tracker.
 
 * Loosely coupled with underlying implementation.
 * Context-driven labels control.
-* Zero allocation implementation for Prometheus client.
-* Simple interface with variadic number of key-value pairs for labels.
+* Zero allocation implementation for [Prometheus client](https://github.com/bool64/prom-stats).
+* A simple interface with variadic number of key-value pairs for labels.
 * Easily mockable interface free from 3rd party dependencies.
 
 ## Example
@@ -49,25 +49,9 @@ tr.Add(ctx, "my_latency_seconds", 1.23)
 tr.Set(ctx, "temperature", 33.3)
 ```
 
-## Performance
+## Versioning
 
-Sample benchmark result with Dell XPS 7590 i9-9980HK on Ubuntu 19 and go1.14.2.
+This project adheres to [Semantic Versioning](https://semver.org/#semantic-versioning-200).
 
-```
-name              time/op
-Tracker_Add-16    814ns ± 6%
-RawPrometheus-16  801ns ± 1%
-
-name              alloc/op
-Tracker_Add-16    0.00B     
-RawPrometheus-16   336B ± 0%
-
-name              allocs/op
-Tracker_Add-16     0.00     
-RawPrometheus-16   2.00 ± 0%
-```
-
-## Caveats
-
-Prometheus client does not support metrics with same name and different label sets. 
-If you add a label to context, make sure you have it in all cases, at least with empty value `""`.
+Before version `1.0.0`, breaking changes are tagged with `MINOR` bump, features and fixes are tagged with `PATCH` bump.
+After version `1.0.0`, breaking changes are tagged with `MAJOR` bump.

context_test.go

@@ -0,0 +1,41 @@
+package stats_test
+
+import (
+	"context"
+	"github.com/bool64/stats"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestAddKeysAndValues(t *testing.T) {
+	ctx := stats.AddKeysAndValues(context.Background(), "k1", "one", "k2", "two")
+	assert.Equal(t, []string{"k1", "one", "k2", "two"}, stats.KeysAndValues(ctx))
+
+	ctx2 := stats.AddKeysAndValues(ctx, "k3", "three")
+	assert.Equal(t, []string{"k1", "one", "k2", "two", "k3", "three"}, stats.KeysAndValues(ctx2))
+
+	ctx3 := stats.AddKeysAndValues(ctx2, "k4", "four")
+	assert.Equal(t, []string{"k1", "one", "k2", "two", "k3", "three", "k4", "four"}, stats.KeysAndValues(ctx3))
+
+	ctx4 := stats.AddKeysAndValues(ctx2, "k4a", "four-a")
+	assert.Equal(t, []string{"k1", "one", "k2", "two", "k3", "three", "k4a", "four-a"}, stats.KeysAndValues(ctx4))
+
+	assert.Equal(t, []string{"k1", "one", "k2", "two", "k3", "three", "k4", "four"}, stats.KeysAndValues(ctx3))
+}
+
+func BenchmarkAddKeysAndValues(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		ctx := stats.AddKeysAndValues(context.Background(), "k1", "one", "k2", "two")
+		_ = stats.KeysAndValues(ctx)
+
+		ctx2 := stats.AddKeysAndValues(ctx, "k3", "three")
+		_ = stats.KeysAndValues(ctx2)
+
+		ctx3 := stats.AddKeysAndValues(ctx2, "k4", "four")
+		_ = stats.KeysAndValues(ctx3)
+
+		ctx4 := stats.AddKeysAndValues(ctx2, "k4a", "four-a")
+		_ = stats.KeysAndValues(ctx4)
+	}
+}

go.mod

@@ -3,10 +3,6 @@ module github.com/bool64/stats
 go 1.13
 
 require (
-	github.com/bool64/dev v0.1.12
-	github.com/kr/pretty v0.2.0 // indirect
-	github.com/prometheus/client_golang v1.9.0
-	github.com/stretchr/testify v1.5.1
-	golang.org/x/sys v0.0.0-20210108172913-0df2131ae363 // indirect
-	google.golang.org/protobuf v1.25.0 // indirect
+	github.com/bool64/dev v0.1.20
+	github.com/stretchr/testify v1.4.0
 )