From 0bd4795cfd44ab887d93332878a8123e32bc0c5d Mon Sep 17 00:00:00 2001
From: rahulpa <rahulpa@google.com>
Date: Mon, 7 Oct 2019 22:14:12 -0700
Subject: [PATCH] add benchmark test.

---
 propagation/benchmark_b3_propagator_test.go | 127 ++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 propagation/benchmark_b3_propagator_test.go

diff --git a/propagation/benchmark_b3_propagator_test.go b/propagation/benchmark_b3_propagator_test.go
new file mode 100644
index 00000000000..0eae3eb59eb
--- /dev/null
+++ b/propagation/benchmark_b3_propagator_test.go
@@ -0,0 +1,127 @@
+// Copyright 2019, OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package propagation_test
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"go.opentelemetry.io/api/trace"
+	mocktrace "go.opentelemetry.io/internal/trace"
+	"go.opentelemetry.io/propagation"
+)
+
+func BenchmarkExtractB3(b *testing.B) {
+	testGroup := []struct {
+		singleHeader bool
+		name         string
+		tests        []extractTest
+	}{
+		{
+			singleHeader: false,
+			name:         "multiple headers",
+			tests:        extractMultipleHeaders,
+		},
+		{
+			singleHeader: true,
+			name:         "single headers",
+			tests:        extractSingleHeader,
+		},
+		{
+			singleHeader: false,
+			name:         "invalid multiple headers",
+			tests:        extractInvalidB3MultipleHeaders,
+		},
+		{
+			singleHeader: true,
+			name:         "invalid single headers",
+			tests:        extractInvalidB3SingleHeader,
+		},
+	}
+	trace.SetGlobalTracer(&mocktrace.MockTracer{})
+
+	for _, tg := range testGroup {
+		propagator := propagation.HttpB3Propagator(tg.singleHeader)
+		for _, tt := range tg.tests {
+			traceBenchmark(tg.name+"/"+tt.name, b, func(b *testing.B) {
+				ctx := context.Background()
+				req, _ := http.NewRequest("GET", "http://example.com", nil)
+				for h, v := range tt.headers {
+					req.Header.Set(h, v)
+				}
+
+				b.ResetTimer()
+				_ = propagator.Extract(ctx, req.Header)
+			})
+		}
+	}
+}
+
+func BenchmarkInjectB3(b *testing.B) {
+	var id uint64
+	testGroup := []struct {
+		singleHeader bool
+		name         string
+		tests        []injectTest
+	}{
+		{
+			singleHeader: false,
+			name:         "multiple headers",
+			tests:        injectB3MultipleHeader,
+		},
+		{
+			singleHeader: true,
+			name:         "single headers",
+			tests:        injectB3SingleleHeader,
+		},
+	}
+
+	mockTracer := &mocktrace.MockTracer{
+		Sampled:     false,
+		StartSpanId: &id,
+	}
+	trace.SetGlobalTracer(mockTracer)
+
+	for _, tg := range testGroup {
+		id = 0
+		propagator := propagation.HttpB3Propagator(tg.singleHeader)
+		for _, tt := range tg.tests {
+			traceBenchmark(tg.name+"/"+tt.name, b, func(b *testing.B) {
+				req, _ := http.NewRequest("GET", "http://example.com", nil)
+				ctx := context.Background()
+				if tt.parentSc.IsValid() {
+					ctx, _ = mockTracer.Start(ctx, "inject", trace.ChildOf(tt.parentSc))
+				} else {
+					ctx, _ = mockTracer.Start(ctx, "inject")
+				}
+
+				b.ResetTimer()
+				propagator.Inject(ctx, req.Header)
+			})
+		}
+	}
+}
+
+func traceBenchmark(name string, b *testing.B, fn func(*testing.B)) {
+	b.Run(name, func(b *testing.B) {
+		b.ReportAllocs()
+		fn(b)
+	})
+	b.Run(name, func(b *testing.B) {
+		b.ReportAllocs()
+		fn(b)
+	})
+}