codekingpro/portable-devtools

1// Copyright 2018 The Go Authors. All rights reserved.2// Use of this source code is governed by a BSD-style3// license that can be found in the LICENSE file.4 5// This file provides a simple framework to add benchmarks6// based on generated input (source) files.7 8package format_test9 10import (11	"bytes"12	"flag"13	"fmt"14	"go/format"15	"os"16	"testing"17)18 19var debug = flag.Bool("debug", false, "write .src files containing formatting input; for debugging")20 21// array1 generates an array literal with n elements of the form:22//23//	var _ = [...]byte{24//		// 025//		0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,26//		0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,27//		0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,28//		0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,29//		0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,30//		// 4031//		0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,32//		0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,33//		...34func array1(buf *bytes.Buffer, n int) {35	buf.WriteString("var _ = [...]byte{\n")36	for i := 0; i < n; {37		if i%10 == 0 {38			fmt.Fprintf(buf, "\t// %d\n", i)39		}40		buf.WriteByte('\t')41		for j := 0; j < 8; j++ {42			fmt.Fprintf(buf, "0x%02x, ", byte(i))43			i++44		}45		buf.WriteString("\n")46	}47	buf.WriteString("}\n")48}49 50var tests = []struct {51	name string52	gen  func(*bytes.Buffer, int)53	n    int54}{55	{"array1", array1, 10000},56	// add new test cases here as needed57}58 59func BenchmarkFormat(b *testing.B) {60	var src bytes.Buffer61	for _, t := range tests {62		src.Reset()63		src.WriteString("package p\n")64		t.gen(&src, t.n)65		data := src.Bytes()66 67		if *debug {68			filename := t.name + ".src"69			err := os.WriteFile(filename, data, 0660)70			if err != nil {71				b.Fatalf("couldn't write %s: %v", filename, err)72			}73		}74 75		b.Run(fmt.Sprintf("%s-%d", t.name, t.n), func(b *testing.B) {76			b.SetBytes(int64(len(data)))77			b.ReportAllocs()78			b.ResetTimer()79			for i := 0; i < b.N; i++ {80				var err error81				sink, err = format.Source(data)82				if err != nil {83					b.Fatal(err)84				}85			}86		})87	}88}89 90var sink []byte91