From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Novodvorsky <nidd@altlinux.ru>
To: gnats-devel@sources.redhat.com
Subject: modular database backends
Date: Sun, 27 May 2001 11:32:00 -0000
Message-id: <7xr8xaac5q.fsf@lambda.novdv.ru>
X-SW-Source: 2001-q2/msg00114.html

Hello!

        I always thought about BTS as database and tools to work with
it. And these things are different. In gnats I see opposite thing: database,
tools and servers share one source and tools sometimes do too much.

        So I've began work on making database backends to gnats modular. 
Just now, gnats has two "backends", network (gnatsd) and filsystem. If
we make system of backends modular we could have SQL backend, etc., etc.

        Second thing I don't like in  GNATS, it doesn't has ACLs. This
modular framework should support them.  Here is the header file that
will briefly describe what I mean:

struct _gnats_database {
  URI *U;
  
  FILE *serv_read;
  FILE *serv_write;

  void *module_handle;

  int (* init) (ErrorDesc *err, gnats_database);
  int (* add_pr) (ErrorDesc *err, gnats_database, PR);
  int (* update_pr) (ErrorDesc *err, gnats_database, PR);
  int (* query_pr) (ErrorDesc *err, gnats_database, QueryExpr);
  int (* disconnect) (ErrorDesc *err, gnats_database);
};

typedef struct _gnats_database *gnats_database;

gnats_database gnats_new_database (ErrorDesc *err, URI *U);
int gnats_destroy_database (gnats_database db);

        module_handle is object handle that is returned by dlopen.
URI is:

struct _URI
{
  char *scheme;
  char *host;
  char *user;
  char *pwd;
  char *path;
  unsigned int port;
};

typedef struct _URI URI;

        And there is a function

URI *gnats_parse_uri (const char *gnats_uri, int length);

that takes URI (for example 
gnatsd4x://nidd:pwd@nidd.debian.net:1529/database_name) and converts
it in such structure (gnatsd4x is 4.0 gnatsd protocol).

        I'm currently implementing gnatsd4x backend. After this I'll
make query-pr, pr-edit, gnatsd and other tools to work with this model.
And then I'll begin to make SQL backend.

        If everything will be OK in the end following will be possible:

           user -> client -> gnatsd -> SQL server (MySQL, Postgres)

        What do you think of this crazy idea?

                                                Thanks,
-- 
Peter Novodvorsky     http://www.altlinux.ru/    AltLinux Team, Russia
Debian.Org                                       http://debian.org/~nidd
            Debian  ---  no need to  wait for tomorrow.