Fixing dokan support discussion...

[apocalypse2012]

Python 2.7.9 64 bit and 32 bit
Dokan 0.7.4
FS 0.5.4
Windows 8.1

from fs.memoryfs import MemoryFS
from fs.expose import dokan
fs = MemoryFS()
mp = dokan.mount(fs,"Q")
Traceback (most recent call last):
File "", line 1, in
File "C:\Python27\lib\site-packages\fs\expose\dokan__init__.py", line 936, in mount
check_ready(mp)
File "C:\Python27\lib\site-packages\fs\expose\dokan__init__.py", line 913, in check_ready
raise OSError("dokan mount process seems to be hung")
OSError: dokan mount process seems to be hung

dokan.mount(fs,"Q",foreground=True)
Traceback (most recent call last):
File "", line 1, in
File "C:\Python27\lib\site-packages\fs\expose\dokan__init__.py", line 929, in mount
raise OSError("Dokan failed with error: %d" % (res,))
OSError: Dokan failed with error: -5

I tried the newer versions before I realized that 8.0 was API breaking. I've read through all the message boards I can find with no apparent 'fix'. Dokan 0.6.0 no longer appears to be available on the Dokan project page at Github. I

[lurch]

Somebody started working on updated Dokan support (#241 and #236) but I dunno if they ever got any further :-/
Ping @zommuter

See also https://github.com/PyFilesystem/pyfilesystem/search?q=dokan&state=open&type=Issues

[zommuter]

Thanks for the ping, @lurch. Unfortunately that is currently at the very bottom of my TODO list, and lacking more experience with Dokan I doubt I can fix this on my own :(

[Liryna]

👍 I am willing to help on this !
@arekbulski I seen you forked pyfilesystem, did you plan to update dokan implentation ?

I will try to take a look at it in the next days and see what changes should be made.
Dokan 1.0.0 should be implemented since it is near to be release stable.

[lurch]

It would be great to see working Dokan support in pyfilesystem again :-)

[arekbulski]

I am willing to review pyfilesystem, especially documentation. But I am also looking forward to seeing Dokan working with pyfilesystem, tell me how can I help. @Liryna

[Liryna]

@arekbulski Ok, I just wanted to know if you planned to update the wrapper yourself.

I began to update most of the natives commandes https://github.com/Liryna/pyfilesystem without implementing it

from ctypes import *

try:
    DokanMain = windll.Dokan.DokanMain
    DokanVersion = windll.Dokan.DokanVersion
except AttributeError:
    raise ImportError("Dokan DLL not found")

Where does the dllimport happen ? How to set library name ?

[arekbulski]

You import windll from ctypes, which is a library loader. Member name is used as library name that is DLL name to be loaded. And for the library object, member name is used as function name. Simple example:

In [13]: ctypes.windll
Out[13]: <ctypes.LibraryLoader at 0x247b7dcdc88>
In [11]: ctypes.windll.msvcrt
Out[11]: <WinDLL 'msvcrt', handle 7ff829220000 at 0x247b8359f98>
In [12]: ctypes.windll.msvcrt.memset
Out[12]: <_FuncPtr object at 0x00000247B829FEE8>

In your code Dokan is the library name, DokanMain/DokanVersion are imported functions. You might limit it to from ctypes import windll if you choose.

[Liryna]

Thank you for your answer @arekbulski ❤️
So windll.dokan1 should load dokan1.dll ?

[arekbulski]

I think so, one way to know for sure.

[Liryna]

Yes I will make the test 😃
I don't have access to my dev environment so I am just reviewing the code for now.

[Liryna]

I am currently able to start the mount of a dokan device with my last changes https://github.com/Liryna/pyfilesystem
I see that Mounted operation is called, the python is correctly called but I get the error run-time check failure the value of ESP directly when the function return here: https://github.com/Liryna/pyfilesystem/blob/master/fs/expose/dokan/__init__.py#L805
I understood that this error means that the mapping python <-> C is not correct but I am unable to find what I did wrong. :( (first time I do this 😄 )

If someone could guide me, it would be nice !

https://github.com/dokan-dev/dokany/blob/master/dokan/dokan.h#L111
https://github.com/Liryna/pyfilesystem/blob/master/fs/expose/dokan/libdokan.py#L112

[arekbulski]

Throw it at Stack Overflow. I am not familiar enough with it.

I do not understand why USHORT is not taken from c_ushort.

[Liryna]

Probably in case USHORT was not define in earliest version of ctypes.
I removed it and forced c_ushort, same behaviour 😢
@lurch @zommuter are you familiar with ctypes ?

[arekbulski]

Not surprised. There is no point in supporting dinosaur-old versions of Python.

[Liryna]

My bad, I found that all call work with dokan1.dll in Release mode and not in Debug as I was doing.
Now I get proper call from dokan.

CreateFile fail here https://github.com/Liryna/pyfilesystem/blob/master/fs/expose/dokan/__init__.py#L453 when \ directory is requested

execpt Path contains invalid characters: \

I am not familiar with fs api and the code seems to not have been updated since 3 years (dokan part). It there one of the pyfilesystem that could help me to review fs api calls ?