Re: pgsql: Rethink the way walreceiver is linked into the backend. Instead

On Wed, Jan 20, 2010 at 6:16 PM, Heikki Linnakangas
<heikki@postgresql.org> wrote:
> Log Message:
> -----------
> Rethink the way walreceiver is linked into the backend. Instead than shoving
> walreceiver as whole into a dynamically loaded module, split the
> libpq-specific parts of it into dynamically loaded module and keep the rest
> in the main backend binary.
>
> Although Tom fixed the Windows compilation problems with the old walreceiver
> module already, this is a cleaner division of labour and makes the code
> more readable. There's also the prospect of adding new transport methods
> as pluggable modules in the future, which this patch makes easier, though for
> now the API between libpqwalreceiver and walreceiver process should be
> considered private.
>
> The libpq-specific module is now in src/backend/replication/libpqwalreceiver,
> and the part linked with postgres binary is in
> src/backend/replication/walreceiver.c.

This commit is pretty cool! Thanks!

And I found the small bug. Could you fix it?

src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
> _PG_init(void)
> {
>     /* Tell walreceiver how to reach us */
>     if (walrcv_connect != NULL || walrcv_receive != NULL || walrcv_disconnect)
>         elog(ERROR, "libpqwalreceiver already loaded");

In the above branch on condition, the "walrcv_disconnect" should be compared
with "NULL".

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center