dovecot - Apr 2008 - using mysql from within a plugin

Hello,

I'm trying to access a mysql database in a plugin.

-What special compiler flags do I need? I discovered that when I don't
explicitly link lib-sql/libsql.a in, then I get an undefind symbol error
about sql_init when loading the plugin.

Shouldn't the imap process itself have sql support linked in, rather
than each plugin?

-It appears that I need to call sql_drivers_init() and
sql_drivers_register_all() before sql_init.

Again, shouldn't the imap process do this, instead of each plugin? It
should probably only be called once, so if one plugin already does it,
then the second one will create problems.

-When linking libsql.a in, and calling the functions mentioned above,
then I get this error when starting dovecot:

undefined symbol: mysql_ssl_set

I'm guessing it's part of the mysql library itself, not dovecot.

Can someone give me some hints on how to use dovecot's mysql library in
a plugin?

Thanks,

Alexander

On Sun, 2008-04-20 at 00:36 +0200, Alexander Prinsier
wrote:
> Hello,
> 
> I'm trying to access a mysql database in a plugin.
> 
> -What special compiler flags do I need? I discovered that when I don't
> explicitly link lib-sql/libsql.a in, then I get an undefind symbol error
> about sql_init when loading the plugin.
Right. Also you need the mysql libraries linked with it.
> Shouldn't the imap process itself have sql support linked in, rather
> than each plugin?
It could, but since IMAP normally doesn't need SQL it would just be
extra bloat and slower startup time for >99% of users. That's one of the
main reasons why dict-proxy exists, so that SQL support can be linked
only to dict process and used by IMAP plugins via the proxy.

I think it would be possible to create a SQL plugin though, which
contains lib-sql.a and the sql libraries linked to it as well. Although
that would require changes to lib-sql also so that it would build a .la
library out of it.

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