private void CreateDirectory(
AbstractDownloadsDirectory directory)
{
if (_fileSystem.Directory.Exists(directory) is false)
{
_logger.LogInformation($"Creating {directory} directory.");
}
/* If DownloadPath directory already exists this line does nothing. */
_fileSystem.Directory.CreateDirectory(directory);
}
/// <summary>
/// Naive way to check if we can create files in DownloadPath. Standard .NET tools to perform such check are
/// currently only available on Windows. So we just try to create a random file and delete it - we'll get
/// an exception if that's not permitted. It is an unrecoverable situation so an exception is appropriate
/// here, as it will terminate the app.
/// </summary>
private void AssertDownloadPathHasWriteAccess(
AbstractDownloadsDirectory directory)
{
var testFilePath =
_fileSystem.Path.Combine(
directory,
$"downloaderPermissionsTest.{Guid.NewGuid()}");
using (_fileSystem.File.Create(testFilePath))
{
/* Close and dispose the stream */
}
_fileSystem.File.Delete(testFilePath);
}
private void CreateDirectoryIfNotExistsAndCheckPermissions(
AbstractDownloadsDirectory directory)
{
try
{
CreateDirectory(directory);
}
catch (UnauthorizedAccessException)
{
throw new DownloadPathAccessDeniedException(
$"'{directory}' directory cannot be created");
}
try
{
AssertDownloadPathHasWriteAccess(directory);
}
catch (UnauthorizedAccessException)
{
throw new DownloadPathAccessDeniedException(
$"'{directory}' directory is not writable");
}
}
