convert hashmap comparison functions to oideq()

The comparison functions used for hashmaps don't care about
strict ordering; they only want to compare entries for
equality. Let's use the oideq() function instead, which can
potentially be better optimized. Note that unlike the
previous patches mass-converting calls like "!oidcmp()",
this patch could actually provide an improvement even with
the current implementation. Those comparison functions are
passed around as function pointers, so at compile-time the
compiler cannot realize that the caller (which is in another
file completely) will treat the return value as a boolean.

Note that this does change the return values in quite a
subtle way (it's still an int, but now the sign bit is
irrelevant for ordering). Because of their funny
hashmap-specific signature, it's unlikely that any of these
static functions would be reused for more generic ordering.
But to be double-sure, let's stop using "cmp" in their
names.

Calling them "eq" doesn't quite work either, because the
hashmap convention is actually _inverted_. "0" means "same",
and non-zero means "different". So I've called them "neq" by
convention here.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/builtin/describe.c b/builtin/describe.c
index 1e7c75b..22c0541 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -62,7 +62,7 @@ static const char *prio_names[] = {
 	N_("head"), N_("lightweight"), N_("annotated"),
 };
 
-static int commit_name_cmp(const void *unused_cmp_data,
+static int commit_name_neq(const void *unused_cmp_data,
 			   const void *entry,
 			   const void *entry_or_key,
 			   const void *peeled)
@@ -70,7 +70,7 @@ static int commit_name_cmp(const void *unused_cmp_data,
 	const struct commit_name *cn1 = entry;
 	const struct commit_name *cn2 = entry_or_key;
 
-	return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
+	return !oideq(&cn1->peeled, peeled ? peeled : &cn2->peeled);
 }
 
 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
@@ -596,7 +596,7 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 		return cmd_name_rev(args.argc, args.argv, prefix);
 	}
 
-	hashmap_init(&names, commit_name_cmp, NULL, 0);
+	hashmap_init(&names, commit_name_neq, NULL, 0);
 	for_each_rawref(get_name, NULL);
 	if (!hashmap_get_size(&names) && !always)
 		die(_("No names found, cannot describe anything."));