Re: Move backup-related code to xlogbackup.c/.h

On Wed, Oct 19, 2022 at 6:30 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> 0001 seems mostly OK, but I don't like some of these new function names.
> I see you've named them so that they are case-consistent with the name
> of the struct member that they affect, but I don't think that's a good
> criterion.  I propose
>
> SetrunningBackups -> XLogBackupSetRunning()
> ResetXLogBackupActivity -> XLogBackupNotRunning()
> // or maybe SetNotRunning, or ResetRunning?  I prefer the one above
> SetlastBackupStart -> XLogBackupSetLastStart()
>
> GetlastFpwDisableRecPtr -> XLogGetLastFPWDisableRecptr()
> GetminRecoveryPoint -> XLogGetMinRecoveryPoint()

XLogBackupResetRunning() seemed better. +1 for above function names.

> I wouldn't say in the xlog_internal.h comment that these new functions
> are for xlogbackup.c to use.  The API definition doesn't have to concern
> itself with that.  Maybe one day xlogrecovery.c or some other xlog*.c
> would like to call those functions, and then the comment becomes a lie;
> and what for?

Removed.

> 0002 is where the interesting stuff happens.  I have not reviewed that
> part with any care, but it appears that set_backup_state is pretty much
> useless.  Let's get rid of it instead of moving it.  Which also means
> that we shouldn't introduce reset_backup_status in 0001, I suppose.
> I think xlogfuncs.c is content with having just get_backup_status().

There's no set_backup_state() at all. We need get_backup_status() for
xlogfuncs.c and basebackup.c and we need reset_backup_status() for
XLogBackupResetRunning() sitting in xlog.c.

> Speaking of which -- I'm not sure we really want to do 0003.
> xlogfuncs.c is not a big file, the functions are not complex, and there
> are no interesting interactions in those functions with the internals
> (other than get_backup_status).  I see that Michael advised the same.
> I propose we keep those functions where they are.

I'm okay either way.

Please see the attached v8 patch set.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com