Measure heap with pprof

main.go

package main

import (
	"log"
	"os"
	"path/filepath"
	"runtime/pprof"

	"time"

	"github.com/otiai10/gosseract"
)

const (
	repeat = 500
)

func main() {

	f, err := os.Create(time.Now().Format("0102_150405"))
	if err != nil {
		panic(err)
	}

	var count int

	var clients []*gosseract.Client

	sample := filepath.Join(os.Getenv("GOPATH"), "src/github.com/otiai10/gosseract/test/data", "001-helloworld.png")

	log.Println("01")
	for _ = range time.Tick(time.Millisecond * 1) {
		client := gosseract.NewClient()

		client.SetImage(sample)
		_, _ = client.Text()
		_, _ = client.HOCRText()
		// fmt.Println(text)
		// Hello, World!
		count++

		clients = append(clients, client)

		if count >= repeat {
			break
		}

		if count%100 == 0 {
			log.Println(count)
		}
	}

	log.Println("02")
	for _ = range time.Tick(time.Millisecond * 1) {
		count--
		if count == 0 {
			break
		}
	}

	for _, c := range clients {
		(*c).Close()
	}

	log.Println("03")
	for _ = range time.Tick(time.Millisecond * 1) {
		if count > repeat {
			break
		}
		count++
	}

	log.Println("04")
	if err := pprof.WriteHeapProfile(f); err != nil {
		panic(err)
	}

	log.Println("05")
	f.Close()
}

% go run main.go
2018/05/01 18:10:36 01
2018/05/01 18:11:06 100
2018/05/01 18:11:36 200
2018/05/01 18:12:06 300
2018/05/01 18:12:36 400
2018/05/01 18:13:07 02
2018/05/01 18:13:13 03
2018/05/01 18:13:14 04
2018/05/01 18:13:14 05
% ls
0501_181036	main.go
% go tool pprof 0501_181036
Entering interactive mode (type "help" for commands)
(pprof) png
Generating report in profile001.png
(pprof)
%
% ls
0501_181036	main.go		profile001.png
%