[saga-rg] Re: Final Call Issue 15: The URL Problem

[Andre Merzky]

Hi group, 

no negative response, so I put the proposal below in the
spec, and call issue 15 resolved.  Hurray!

A.

Quoting [Andre Merzky] (Feb 16 2006):
> 
> Hi group(s), 
> 
> We discussed issue 15 in Athens, but could not come to
> consensus.  I further discussed the issue with Thilo,
> Wolfgang Ziegler, and some Unicore guys (Philip and Achim).
> 
> In order to settle the issue for the SAGA-CORE-API (NOT
> forever), I want to propose the following solution.  If no
> reply comes within a week, I assume its accepted :-)
> 
> 
>   - A URL utility class seems useful, but would increase
>     the syntactic load on the current set of methods (either
>     allow all methods with strings _and_ urls, or require
>     transformation from strings to urls _always_ - both
>     seems suboptimal).
> 
>   - hence NO URL utility class is mandated.
> 
>   - a NSEntry utility call is introduced:
> 
>       convert (in  string target, 
>                out string new_url);
> 
>     Usage examples:
> 
>     saga::file  f ("ftp://ftp.net.org/pub/data/file.txt");
>     std::string n1 = f.convert ("ftp://ftp.net.org:123/");
>     std::string n2 = f.convert ("ftp://alias.net.org/data/");
>     std::string n3 = f.convert ("http://www.net.org");
> 
>   - that call tries to translate URLs, and if unsuccessfull
>     returns an empty string.
> 
> I know that is 'somewhat' of a compromise.  A full fledged
> URL class certainly would be useful, and Java for example
> already has it.  I would expect that most SAGA
> implementations will provide one anyway.  But as we could
> not reach consensus on that, the topic seems to need more
> discussion, and more time which I wthink we don't have for
> stabilizing the API.
> 
> The convert method could be implemented as follows (all
> services hosted on same resource):
> 
>   Known: 1  host:  ftp.net.org
>             proto: ftp
>             root:  /var/www/htdocs/ftp_store/
> 
>          2  host:  ftp.net.org
>             proto: ftp:123
>             root:  /var/ftp_test/
> 
>          3  host:  www.net.org
>             proto: http
>             root:  /var/www/htdocs/
> 
>   input: url: ftp://ftp.net.org/pub/data/file.txt
>          tgt: http
>   with 1 translates into absolute path
>          abs: /var/www/htdocs/ftp_store/pub/data/file.txt
>   with 3 translates into 
>          out: http://www.net.org/ftp_store/pub/data/file.txt
> 
> Cheers, Andre.
-- 
"So much time, so little to do..."  -- Garfield