On Mon, Nov 02, 2020 at 06:55:10PM +0000, Elijah Newren via GitGitGadget wrote:
> +int strset_check_and_add(struct strset *set, const char *str)
> +{
> + if (strset_contains(set, str))
> + return 1;
> + strset_add(set, str);
> + return 0;
> +}
With this implementation, I wonder if it is worth having such a
specialized function. The value of an atomic check-and-add operation is
that it can reuse the effort to hash the string for both operations (it
could also reuse any open-table probing effort, but for a chained hash
like our implementation, it's cheap to add a new entry to the front of
the list).
I doubt it matters all that much for the use case in shortlog. Perhaps
we should just open-code it there for now, and we can revisit it if
another user comes up.
> --- a/strmap.h
> +++ b/strmap.h
> @@ -28,6 +28,10 @@ int cmp_strmap_entry(const void *hashmap_cmp_fn_data,
> .map.strdup_strings = 1, \
> .default_value = 0, \
> }
> +#define STRSET_INIT { \
> + .map.map = HASHMAP_INIT(cmp_strmap_entry, NULL), \
> + .map.strdup_strings = 1, \
> + }
As with strint, this could be:
#define STRSET_INIT { .map = STRMAP_INIT }
-Peff
