Re: Reversed sync check in pg_receivewal

On Tue, Apr 11, 2017 at 6:51 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Magnus Hagander <magnus(at)hagander(dot)net> writes:
> > Something like the attached?
>
> Not sure about
>
> + * All methods that have a failure path will set errno on failure.
>
> Given that you've got a getlasterror method, I don't think that's really
> the API invariant is it? If it were, you'd just have the callers doing
> strerror(errno) for themselves. I think maybe a more accurate statement
> would be
>

Hmm. You're right, this is what I get for rushing a patch before plane
departure :/

> * All methods that have a failure return indicator will set state
> * allowing the getlasterror() method to return a suitable message.
> * Commonly, errno is this state (or part of it); so callers must take
> * care not to clobber errno between a failed method call and use of
> * getlasterror() to retrieve the message.
>

Yeah, that's much better.

> Also:
>
> * the arguments of open_for_write() could stand to be explained
>
> * what's the return value of finish()?
>

Both fixed.

>
> * wouldn't it be better to declare getlasterror() as returning
> "const char *"?
>

Yeah, probably is. Will do and push.

Thanks!

--
Magnus Hagander
Me: https://www.hagander.net/ <http://www.hagander.net/>
Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>