util.go

package pget

import (
	"fmt"
	"os"
	"path/filepath"
)

func getPartialDirname(targetDir, filename string, procs int) string {
	if targetDir == "" {
		return fmt.Sprintf("_%s.%d", filename, procs)
	}
	return filepath.Join(targetDir, fmt.Sprintf("_%s.%d", filename, procs))
}

// getPartialFilePath returns the path of the partial file
func getPartialFilePath(targetDir, filename string, id, procs int) string {
	return filepath.Join(
		targetDir,
		fmt.Sprintf("%s.%d.%d", filename, procs, id),
	)
}

// checkProgress In order to confirm the degree of progress
func checkProgress(dirname string) (int64, error) {
	return subDirsize(dirname)
}

func subDirsize(dirname string) (int64, error) {
	var size int64
	err := filepath.Walk(dirname, func(_ string, info os.FileInfo, err error) error {
		if !info.IsDir() {
			size += info.Size()
		}
		return err
	})

	return size, err
}

func makeRange(i, procs int, rangeSize, contentLength int64) Range {
	low := rangeSize * int64(i)
	if i == procs-1 {
		return Range{
			low:  low,
			high: contentLength,
		}
	}
	return Range{
		low:  low,
		high: low + rangeSize - 1,
	}
}

func (r Range) BytesRange() string {
	return fmt.Sprintf("bytes=%d-%d", r.low, r.high)
}