net/http: add request file upload benchmarks

This adds benchmarks to test file uploads using PUT requests.

It's designed to complement changes https://golang.org/cl/163599 and
https://golang.org/cl/163737, allowing an easy comparison of
performance before and after these changes are applied.

Updates #30377.

Co-authored-by: Emmanuel Odeke <emm.odeke@gmail.com>

src/net/http/request_test.go

@@ -8,12 +8,14 @@ import (
 	"bufio"
 	"bytes"
 	"context"
+	"crypto/rand"
 	"encoding/base64"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"mime/multipart"
 	. "net/http"
+	"net/http/httptest"
 	"net/url"
 	"os"
 	"reflect"
@@ -1046,3 +1048,92 @@ func BenchmarkReadRequestWrk(b *testing.B) {
 Host: localhost:8080
 `)
 }
+
+const (
+	withTLS = true
+	noTLS   = false
+)
+
+func BenchmarkFileAndServer_1KB(b *testing.B) {
+	benchmarkFileAndServer(b, 1<<10)
+}
+
+func BenchmarkFileAndServer_16MB(b *testing.B) {
+	benchmarkFileAndServer(b, 1<<24)
+}
+
+func BenchmarkFileAndServer_64MB(b *testing.B) {
+	benchmarkFileAndServer(b, 1<<26)
+}
+
+func benchmarkFileAndServer(b *testing.B, n int64) {
+	f, err := ioutil.TempFile(os.TempDir(), "go-bench-http-file-and-server")
+	if err != nil {
+		b.Fatalf("Failed to create temp file: %v", err)
+	}
+
+	defer func() {
+		f.Close()
+		os.RemoveAll(f.Name())
+	}()
+
+	if _, err := io.CopyN(f, rand.Reader, n); err != nil {
+		b.Fatalf("Failed to copy %d bytes: %v", n, err)
+	}
+
+	b.Run("NoTLS", func(b *testing.B) {
+		runFileAndServerBenchmarks(b, noTLS, f, n)
+	})
+
+	b.Run("TLS", func(b *testing.B) {
+		runFileAndServerBenchmarks(b, withTLS, f, n)
+	})
+}
+
+func runFileAndServerBenchmarks(b *testing.B, tlsOption bool, f *os.File, n int64) {
+	handler := HandlerFunc(func(rw ResponseWriter, req *Request) {
+		defer req.Body.Close()
+		nc, err := io.Copy(ioutil.Discard, req.Body)
+		if err != nil {
+			panic(err)
+		}
+
+		if nc != n {
+			panic(fmt.Errorf("Copied %d Wanted %d bytes", nc, n))
+		}
+	})
+
+	var cst *httptest.Server
+	if tlsOption == withTLS {
+		cst = httptest.NewTLSServer(handler)
+	} else {
+		cst = httptest.NewServer(handler)
+	}
+
+	defer cst.Close()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		// Perform some setup.
+		b.StopTimer()
+		if _, err := f.Seek(0, 0); err != nil {
+			b.Fatalf("Failed to seek back to file: %v", err)
+		}
+
+		b.StartTimer()
+		req, err := NewRequest("PUT", cst.URL, ioutil.NopCloser(f))
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		req.ContentLength = n
+		// Prevent mime sniffing by setting the Content-Type.
+		req.Header.Set("Content-Type", "application/octet-stream")
+		res, err := cst.Client().Do(req)
+		if err != nil {
+			b.Fatalf("Failed to make request to backend: %v", err)
+		}
+
+		res.Body.Close()
+		b.SetBytes(n)
+	}
+}