public static FileAttributes GetAttributes(string fullPath, bool backupMode = false)
{
int flags = backupMode ? Win32Api.Kernel32.FileOperations.FILE_FLAG_BACKUP_SEMANTICS : 0;
Win32Api.Kernel32.WIN32_FILE_ATTRIBUTE_DATA data = new Win32Api.Kernel32.WIN32_FILE_ATTRIBUTE_DATA();
int errorCode = FillAttributeInfo(fullPath, ref data, returnErrorOnNotFound: true);
if (errorCode != 0)
{
throw PalWin32FileStream.GetExceptionForWin32Error(errorCode, fullPath);
}
return((FileAttributes)data.dwFileAttributes);
}
public static int FillAttributeInfo(string path, ref Win32Api.Kernel32.WIN32_FILE_ATTRIBUTE_DATA data, bool returnErrorOnNotFound)
{
int errorCode = Win32Api.Errors.ERROR_SUCCESS;
// Neither GetFileAttributes or FindFirstFile like trailing separators
path = Win32PathInternal.TrimEndingDirectorySeparator(path);
using (Win32Api.Win32DisableMediaInsertionPrompt.Create())
{
if (!Win32Api.Kernel32.GetFileAttributesEx(path, Win32Api.Kernel32.GET_FILEEX_INFO_LEVELS.GetFileExInfoStandard, ref data))
{
errorCode = Marshal.GetLastWin32Error();
if (errorCode != Win32Api.Errors.ERROR_FILE_NOT_FOUND &&
errorCode != Win32Api.Errors.ERROR_PATH_NOT_FOUND &&
errorCode != Win32Api.Errors.ERROR_NOT_READY &&
errorCode != Win32Api.Errors.ERROR_INVALID_NAME &&
errorCode != Win32Api.Errors.ERROR_BAD_PATHNAME &&
errorCode != Win32Api.Errors.ERROR_BAD_NETPATH &&
errorCode != Win32Api.Errors.ERROR_BAD_NET_NAME &&
errorCode != Win32Api.Errors.ERROR_INVALID_PARAMETER &&
errorCode != Win32Api.Errors.ERROR_NETWORK_UNREACHABLE &&
errorCode != Win32Api.Errors.ERROR_NETWORK_ACCESS_DENIED &&
errorCode != Win32Api.Errors.ERROR_INVALID_HANDLE // eg from \\.\CON
)
{
// Assert so we can track down other cases (if any) to add to our test suite
Debug.Assert(errorCode == Win32Api.Errors.ERROR_ACCESS_DENIED || errorCode == Win32Api.Errors.ERROR_SHARING_VIOLATION,
$"Unexpected error code getting attributes {errorCode}");
// Files that are marked for deletion will not let you GetFileAttributes,
// ERROR_ACCESS_DENIED is given back without filling out the data struct.
// FindFirstFile, however, will. Historically we always gave back attributes
// for marked-for-deletion files.
//
// Another case where enumeration works is with special system files such as
// pagefile.sys that give back ERROR_SHARING_VIOLATION on GetAttributes.
//
// Ideally we'd only try again for known cases due to the potential performance
// hit. The last attempt to do so baked for nearly a year before we found the
// pagefile.sys case. As such we're probably stuck filtering out specific
// cases that we know we don't want to retry on.
var findData = new Win32Api.Kernel32.WIN32_FIND_DATA();
using (Win32Api.SafeFindHandle handle = Win32Api.Kernel32.FindFirstFile(path, ref findData))
{
if (handle.IsInvalid)
{
errorCode = Marshal.GetLastWin32Error();
}
else
{
errorCode = Win32Api.Errors.ERROR_SUCCESS;
data.PopulateFrom(ref findData);
}
}
}
}
}
if (errorCode != Win32Api.Errors.ERROR_SUCCESS && !returnErrorOnNotFound)
{
switch (errorCode)
{
case Win32Api.Errors.ERROR_FILE_NOT_FOUND:
case Win32Api.Errors.ERROR_PATH_NOT_FOUND:
case Win32Api.Errors.ERROR_NOT_READY: // Removable media not ready
// Return default value for backward compatibility
data.dwFileAttributes = -1;
return(Win32Api.Errors.ERROR_SUCCESS);
}
}
return(errorCode);
}