Re: hash locate_matching_entry()

[Jason Stover]

On Wed, Oct 08, 2008 at 10:25:19AM -0400, Jason Stover wrote:
> I'm having some trouble getting a matching entry in my
> hash table. It looks like the problem is here:
> 
> /* Locates an entry matching TARGET.  Returns the index for the
>    entry, if found, or the index of an empty entry that indicates
>    where TARGET should go, otherwise. */
> static inline unsigned
> locate_matching_entry (struct hsh_table *h, const void *target)
> {
>   unsigned i = h->hash (target, h->aux);
> 
>   assert (h->hash_ordered);
>   for (;;)
>     {
>       void *entry;
>       i &= h->size - 1;
>       entry = h->entries[i];
>       if (entry == NULL || !h->compare (entry, target, h->aux))
>       return i;
>       i--;
>     }
> }
> 
> In my code, h->compare (entry, target, h->aux) returns 1 when
> entry and target match. So I would think locate_matching_entry()
> should return i, but it doesn't because of the !h->compare (...).
> Should this line be:
> 
>       if (entry == NULL || h->compare (entry, target, h->aux))

John just clarified over IRC that the return value here is supposed to be
strcmp-ish: 0 for a match. 

So disregard.

-Jason