// zipInputFiles deterministically builds a zip archive out of input files and
// writes it to the writer. Files are written in the order given.
func zipInputFiles(files []File, w io.Writer, log logging.Logger) error {
writer := zip.NewWriter(w)
defer writer.Close()
// Reports zipping progress to the log each second.
lastReport := time.Time{}
progress := func(count int) {
if time.Since(lastReport) > time.Second {
lastReport = time.Now()
log.Infof("Zipping files: %d files left", len(files)-count)
}
}
for i, in := range files {
progress(i)
// Intentionally do not add timestamp or file mode to make zip archive
// deterministic. See also zip.FileInfoHeader() implementation.
fh := zip.FileHeader{
Name: in.Name(),
Method: zip.Deflate,
}
mode := os.FileMode(0600)
if in.Executable() {
mode |= 0100
}
if in.Symlink() {
mode |= os.ModeSymlink
}
fh.SetMode(mode)
dst, err := writer.CreateHeader(&fh)
if err != nil {
return err
}
if in.Symlink() {
err = zipSymlinkFile(dst, in)
} else {
err = zipRegularFile(dst, in)
}
if err != nil {
return err
}
}
return nil
}
