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// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
package utils
import (
"bytes"
"fmt"
"io"
"net/http"
"os"
"path/filepath"
"strconv"
)
var _ = fmt.Print
type ReportFunc = func(done, total uint64) error
type write_counter struct {
done, total uint64
report ReportFunc
}
func (self *write_counter) Write(p []byte) (int, error) {
n := len(p)
self.done += uint64(n)
if self.report != nil {
err := self.report(self.done, self.total)
if err != nil {
return 0, err
}
}
return n, nil
}
func DownloadToWriter(url string, dest io.Writer, progress_callback ReportFunc) error {
resp, err := http.Get(url)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return fmt.Errorf("The server responded with the HTTP error: %s", resp.Status)
}
wc := write_counter{report: progress_callback}
cl, err := strconv.Atoi(resp.Header.Get("Content-Length"))
if err == nil {
wc.total = uint64(cl)
}
_, err = io.Copy(dest, io.TeeReader(resp.Body, &wc))
if err != nil {
return err
}
return nil
}
func DownloadAsSlice(url string, progress_callback ReportFunc) (data []byte, err error) {
b := bytes.Buffer{}
b.Grow(4096)
err = DownloadToWriter(url, &b, progress_callback)
if err == nil {
return b.Bytes(), nil
}
return nil, err
}
func DownloadToFile(destpath, url string, progress_callback ReportFunc, temp_file_path_callback func(string)) error {
destpath, err := filepath.EvalSymlinks(destpath)
if err != nil {
return err
}
dest, err := os.CreateTemp(filepath.Dir(destpath), filepath.Base(destpath)+".partial-download.")
if err != nil {
return err
}
if temp_file_path_callback != nil {
temp_file_path_callback(dest.Name())
}
dest_removed := false
defer func() {
dest.Close()
if !dest_removed {
os.Remove(dest.Name())
}
}()
err = DownloadToWriter(url, dest, progress_callback)
if err != nil {
return err
}
dest.Close()
fi, err := os.Stat(destpath)
if err == nil {
err = os.Chmod(dest.Name(), fi.Mode().Perm())
if err != nil {
return err
}
}
if err != nil {
return err
}
err = os.Rename(dest.Name(), destpath)
if err != nil {
return err
}
dest_removed = true
return nil
}
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