[SAGA-RG] missing(?) method reporting last modification time

[Thilo Kielmann]

Dear Sylvain,

interesting to hear! (It's a pity that you did not raise this issue
before...)

I have 2 questions:

1. Where exactly have you added getLastModified?
   In ns_entry/ns_directory? or in file/directory?
   Is there a good reason for one or the other place in the hierarchy?

2. Did you add anything else? I mean, did you find any other omissions?


Thilo

On Fri, May 29, 2009 at 03:54:05PM +0200, Sylvain Reynaud wrote:
> From: Sylvain Reynaud <Sylvain.Reynaud at in2p3.fr>
> To: Thilo Kielmann <kielmann at cs.vu.nl>
> CC: saga-rg at ogf.org
> Subject: Re: [SAGA-RG] missing(?) method reporting last modification time
> 
> A method "getLastModified" has already been added to our implementation 
> (JSAGA) of the SAGA specification in order to fulfil a user request, but 
> using it makes his code dependent on our implementation...
> 
> Consequently, I fully support your proposal.
> 
> Sylvain Reynaud
> 
> 
> Thilo Kielmann a écrit :
> >Folks,
> >
> >within our group we are currently delving into issues with accessing
> >remote file systems. What strikes us is that such access is SLOW.
> >As such, it would be very beneficial if one could find out when (and
> >thus whether) a remote file or directory has been modified.
> >
> >While returning this piece of information sounds to be "trivial", it 
> >strikes
> >us that the SAGA spec has no such call in the name space package (where 
> >files
> >reside).
> >
> >In POSIX terms, this is the info returned by the stat system call
> >(see: man 2 stat), with the st_mtime parameter.
> >
> >In Java, files have a method lastmodified().
> >
> >Both POSIX and Java report the time in milliseconds since 01/01/1970 
> >(epoch).
> >
> >
> >Of course, it looks like nobody has ever been thinking about such a use 
> >case,
> >but here we are! Our feeling is that the last modification time is very
> >essential meta data about files, so such a call should certainly be there.
> >With our current problem certainly not being the only use case for finding
> >out how old/new a given file or directory is...
> >
> >Our favourite proposal is to add a method that returns the last 
> >modification
> >time to both ns_entry and ns_directory as this makes sense with physical 
> >as well as with logical (replicated) files.
> >
> >
> >Any reactions/objections ???
> >
> >
> >Thilo Kielmann
> >  
> 



-- 
Thilo Kielmann                                 http://www.cs.vu.nl/~kielmann/