Extrach PGconn* form $dbh (perl)

[Dmitry A Jackovlev <hobbut(at)orionet(dot)ru>]

Hello.

      Sorry for my bad English.

I need to extract PGconn*-type variable from perl $dbh (e.g.
magicfunction(dbh)) to use it in my XS-function, but I can't
understand how  to get PGconn from my function using DBH (I send dbh
to my function and need to get PGconn variable as returned value from my function).

Please help me to write PGconn *magicfunction(SV*) function.

      for example:
      
parser.pl:
...
my $dbh= DBI->connect("dbi:Pg:dbname=some_db","user","pass");
my $h=myfunction($dbh, "filename");
...

myfunction.xs:
HV *
myfunction( DBH, filename )
        SV *DBH
        char *filename
    CODE:
         HV *hash=newHV(); // some hash
         PGconn *myconnection=magicfunction( DBH );
         processfile ( hash, filename ); //fill hash from file.
         writehash ( hash, myconnection );
         RETVAL=hash;
    OUTPUT:
         RETVAL


-- 
WBR,
 Dmitry                          mailto:hobbut(at)orionet(dot)ru