Bug #47574 for Win32-File: SetFileAttributes() doesn't support COMPRESS

xrmb via RT wrote: Show quoted text
I'd call it a lack of documentation - Set doesn't allow COMPRESS. Note 'Remarks' section of manual page: ---------------------------------------------------------------------------------------------- The SetFileAttributes function sets a file's attributes. BOOL SetFileAttributes ( LPCTSTR lpFileName, // address of filename DWORD dwFileAttributes // address of attributes to set ); Parameters lpFileName Points to a string that specifies the name of the file whose attributes are to be set. Windows 95: This string must not exceed MAX_PATH characters. Windows NT: There is a default string size limit for paths of MAX_PATH characters. This limit is related to how the SetFileAttributes function parses paths. An application can transcend this limit and send in paths longer than MAX_PATH characters by calling the wide (W) version of SetFileAttributes and prepending "\\?\" to the path. The "\\?\" tells the function to turn off path parsing; it lets paths longer than MAX_PATH be used with SetFileAttributesW. This also works with UNC names. The "\\?\" is ignored as part of the path. For example, "\\?\C:\myworld\private" is seen as "C:\myworld\private", and "\\?\UNC\bill_g_1\hotstuff\coolapps" is seen as "\\bill_g_1\hotstuff\coolapps". dwFileAttributes Specifies the file attributes to set for the file. This parameter can be a combination of the following values. However, all other values override FILE_ATTRIBUTE_NORMAL. Value Meaning FILE_ATTRIBUTE_ARCHIVE The file is an archive file. Applications use this value to mark files for backup or removal. FILE_ATTRIBUTE_NORMAL The file has no other attributes set. This value is valid only if used alone. FILE_ATTRIBUTE_HIDDEN The file is hidden. It is not included in an ordinary directory listing. FILE_ATTRIBUTE_READONLY The file is read-only. Applications can read the file but cannot write to it or delete it. FILE_ATTRIBUTE_SYSTEM The file is part of the operating system or is used exclusively by it. FILE_ATTRIBUTE_TEMPORARY The file is being used for temporary storage. File systems attempt to keep all of the data in memory for quicker access rather than flushing the data back to mass storage. A temporary file should be deleted by the application as soon as it is no longer needed. Return Value If the function succeeds, the return value is TRUE. If the function fails, the return value is FALSE. To get extended error information, call GetLastError. Remarks You cannot use the SetFileAttribute function to set a file's compression state. Setting FILE_ATTRIBUTE_COMPRESSED in the dwFileAttributes parameter does nothing. Use the DeviceIoControl function and the FSCTL_SET_COMPRESSION operation to set a file's compression state. ----------------------------------------------------------------------------------------------

Show quoted text

On Sun, 05 Jul 2009, Bill Luebkert wrote: Show quoted text
The SetFileAttributes() function in Windows indeed doesn't support it, but that doesn't mean that the Win32::SetFileAttributes() one can't. We could just implement it behind the scenes and have it work transparently instead of expecting the user to learn about and use another module to do this. The question then becomes: what is the complete set of missing functionality and can we implement it all using the existing interface? For example, setting the COMPRESSED attribute on a directory will not automatically compress all files stored in it. It will only cause *new* files added to the directory to be compressed. Therefore, would we also need an interface to actually compress/uncompress a whole directory tree? If yes, does this belong into Win32::File, and how should the interface look like? Cheers, -Jan