[Zope-dev] Re: AdaptableStorage

[Oliver Bleutgen]

Shane Hathaway wrote:
> Oliver Bleutgen wrote:
> 
>> Shane Hathaway wrote:
>>
>>> On the filesystem, the problem seems much more difficult, since there 
>>> are no transactions.  You'd like the kernel to send Zope a message 
>>> anytime someone modifies a file in a certain hierarchy, but that 
>>> would require kernel hacking.
>>
>>
>>
>> FWIW, since I had the same problem some time ago (which could be 
>> solved in another way),
>> I dug out an url, which might be of interest - probably you already 
>> know about it:
>>
>> FAM, used by the two major open source desktop envs:
>>
>> http://oss.sgi.com/projects/fam/
>>
>> It may at least help to make the whole problem more os independend.
>> They have a lot of related pointers on their homepage.
> 
> 
> I've seen it before, but I don't think FAM is able to monitor an entire 
> directory tree.  It only monitors individual files.  I'd really like to 
> be wrong. :-)

I think you are wrong, because the manpage (for IRIX) says otherwise.
Additionally, it wouldn't be of much use for kde etc. if it only could 
monitor files. I think a filemanager would mainly be interested in 
directory changes (files added/deleted).
Then there's also dnotify (also reference from the FAM site) - there's 
hope that the "d" isn't an acronym for "file" ;).
I remember someting about recent 2.4.x versions having the prerequisites 
to use that.

> 
>> Btw. windows (>=nt IIRC) already has the capability to notify on 
>> directory alteration events, without polling.
> 
> 
> Do you know what API?  That would sure help.

I don't have any expirience on win32, but just searched google.
There's Win32::ChangeNotify for perl, described here
http://www.xav.com/perl/site/lib/Win32/ChangeNotify.html

and this seems to use ReadDirectoryChangesW, decribed here:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/base/readdirectorychangesw.asp

cheers,
oliver