Re: [PATCH] hash: Remove useless init_hash()

On Tue, Jul 27, 2010 at 19:49, Jeff King [off-list ref] wrote:

On Tue, Jul 27, 2010 at 10:36:09AM +0000, Ævar Arnfjörð Bjarmason wrote:

quoted

quoted

quoted

-static inline void init_hash(struct hash_table *table)
-{
-     table->size = 0;
-     table->nr = 0;
-     table->array = NULL;
-}

*This* could be replaced by memset.

No it couldn't? The second argument to memset is just an int, so
setting the memory area to 0 isn't portable to systems where the
representation of NULL isn't "0".

(It's early so I may be misremembering my C..)

You're remembering your C correctly. It isn't portable, but it is so
unlikely on modern machines that we simply don't care (and you will see
memsets zero-ing pointers like this all through the git code, so this is
certainly not introducing anything new).

Thanks for the confirmation. I was aware that NULL != 0 only occured
on long-dead architechtures, but I suspected that some compiler out
there would whine if it could statically determine that you were
reading in a memzero'd area and using it as NULL. Evidently not, or at
least nobody's complained.

That being said, I agree with the comments that removing init_hash
actually makes the code _less_ readable. You could just replace these
three lines with a memset, but why? It's just code churn.

Yeah, and for the record it also missed this part in hash.c:

    void free_hash(struct hash_table *table)
    {
    	free(table->array);
    	table->array = NULL;
    	table->size = 0;
    	table->nr = 0;
    }

Have fun everyone :)