Re: Why assignment before return?

On Fri, Aug 20, 2010 at 15:10, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Magnus Hagander <magnus(at)hagander(dot)net> writes:
>> This code-pattern appears many times in pgstatfuncs.c:
>> Datum
>> pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS)
>> {
>>       Oid                     relid = PG_GETARG_OID(0);
>>       int64           result;
>>       PgStat_StatTabEntry *tabentry;
>
>>       if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
>>               result = 0;
>>       else
>>               result = (int64) (tabentry->blocks_fetched);
>
>>       PG_RETURN_INT64(result);
>> }
>
>
> I see nothing wrong with that style.  Reducing it as you propose
> probably wouldn't change the emitted code at all, and what it would
> do is reduce flexibility.  For instance, if we ever needed to add
> additional operations just before the RETURN (releasing a lock on
> the tabentry, perhaps) we'd just have to undo the "improvement".

I'm not saying it's wrong, I'm just trying to figure out why it's
there since I wanted to add other functions and it looked.. Odd. I'll
change my new functions to look like this for consistency, but I was
curious if there was some specific reason why it was better to do it
this way.

I see your answer as "no, not really any reason, but also not worth
changing", which is fine by me :-)

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