Method safeWrite

internal/buffer/save.go:356–400

safeWrite writes the buffer to a file in a "safe" way, preventing loss of the contents of the file if it fails to write the new contents. This means that the file is not overwritten directly but by writing to the backup file first.

(path string, withSudo bool, newFile bool)

// This means that the file is not overwritten directly but by writing to the
// backup file first.
func (b *SharedBuffer) safeWrite(path string, withSudo bool, newFile bool) (int, error) {
	file, err := openFile(path, withSudo)
	if err != nil {
		return 0, err
	}

	defer func() {
		if newFile && err != nil {
			os.Remove(path)
		}
	}()

	// Try to backup first before writing
	backupName, resolveName, err := b.writeBackup(path)
	if err != nil {
		file.Close()
		return 0, err
	}

	// Backup saved, so cancel pending periodic backup, if any
	delete(requestedBackups, b)

	b.forceKeepBackup = true
	size := 0
	{
		// If we failed to write or close, keep the backup we made
		size, err = file.Write(b)
		if err != nil {
			file.Close()
			return 0, util.OverwriteError{err, backupName}
		}

		err = file.Close()
		if err != nil {
			return 0, util.OverwriteError{err, backupName}
		}
	}
	b.forceKeepBackup = false

	if !b.keepBackup() {
		b.removeBackup(backupName, resolveName)
	}

	return size, err
}