Re: Avoid overflow with simplehash

Hi,

I pushed changing i to uint32 and adding Tom's comment to 11-HEAD.


On 2023-07-06 14:01:55 -0300, Ranier Vilela wrote:
> > > then will it iterate forwards?
> >
> > No, it'd still iterate backwards, but starting from the wrong place - but
> > there is no correct place to start iterating from if there is no unused
> > element.
> >
> Thanks for the confirmation.
> 
> So I suppose we could have this in v1, attached.
> With comments added by Tom.


> diff --git a/src/include/lib/simplehash.h b/src/include/lib/simplehash.h
> index 48db837ec8..4fe627a921 100644
> --- a/src/include/lib/simplehash.h
> +++ b/src/include/lib/simplehash.h
> @@ -964,8 +964,8 @@ SH_DELETE_ITEM(SH_TYPE * tb, SH_ELEMENT_TYPE * entry)
>  SH_SCOPE void
>  SH_START_ITERATE(SH_TYPE * tb, SH_ITERATOR * iter)
>  {
> -	int			i;
> -	uint64		startelem = PG_UINT64_MAX;
> +	uint32		i;
> +	uint32		startelem = PG_UINT32_MAX;

The startelem type change doesn't strike me as a good idea.  Currently
PG_UINT32_MAX is a valid element.

Greetings,

Andres Freund