// Unless explicitly stated otherwise all files in this repository are licensed
// under the Apache License Version 2.0.
// This product includes software developed at Datadog (https://www.datadoghq.com/).
// Copyright 2021 Datadog, Inc.

// NOTE(fg): To run this benchmark you have to drop the ".disabled" suffix from
// the filename. This is done to avoid the panicparse library ending up in the
// go.mod file of this package. If anybody has better ideas, please let me know
// : ).

package gostackparse

import (
	"bytes"
	"io"
	"io/ioutil"
	"path/filepath"
	"testing"
	"time"

	"github.com/maruel/panicparse/v2/stack"
	"github.com/stretchr/testify/require"
)

func BenchmarkPanicparse(b *testing.B) {
	data, err := ioutil.ReadFile(filepath.Join("test-fixtures", "waitsince.txt"))
	require.NoError(b, err)

	b.ResetTimer()
	b.ReportAllocs()

	start := time.Now()
	parsedBytes := 0
	for i := 0; i < b.N; i++ {
		parsedBytes += len(data)
		s, _, err := stack.ScanSnapshot(bytes.NewReader(data), io.Discard, stack.DefaultOpts())
		if err != nil && err != io.EOF {
			b.Fatal(err)
		} else if l := len(s.Goroutines); l != 9 {
			b.Fatal(l)
		}
	}

	mbPerSec := float64(parsedBytes) / time.Since(start).Seconds() / 1024 / 1024
	b.ReportMetric(mbPerSec, "MiB/s")
}