prysm/beacon-chain/node/clear_db.go

package node

import (
	"bufio"
	"fmt"
	"os"
	"strings"

	"github.com/prysmaticlabs/prysm/beacon-chain/db"
)

func confirmDelete(d db.Database, path string, force bool) (db.Database, error) {
	var clearDB bool
	var err error
	reader := bufio.NewReader(os.Stdin)
  if force {
    clearDB = true
  } else {
    log.Warn("This will delete your beacon chain data base stored in your data directory. " +
      "Your database backups will not be removed - do you want to proceed? (Y/N)")

    for {
      fmt.Print(">> ")

      line, _, err := reader.ReadLine()
      if err != nil {
        return nil, err
      }
      trimmedLine := strings.TrimSpace(string(line))
      lineInput := strings.ToUpper(trimmedLine)
      if lineInput != "Y" && lineInput != "N" {
        log.Errorf("Invalid option of %s chosen, enter Y/N", line)
        continue
      }
      if lineInput == "Y" {
        clearDB = true
        break
      }
      log.Info("Not deleting chain database, the db will be initialized" +
        " with the current data directory.")
      break
    }
  }

	if clearDB {
	  log.Warning("Removing database")
		if err := d.ClearDB(); err != nil {
			return nil, err
		}
		d, err = db.NewDB(path)
		if err != nil {
			return nil, err
		}
	}
	return d, nil
}