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, 4 insertions, 4 deletions

diff --git a/patch-ids.c b/patch-ids.c
index 8f7c25d..960ea24 100644
--- a/patch-ids.c
+++ b/patch-ids.c
@@ -28,14 +28,14 @@ int commit_patch_id(struct commit *commit, struct diff_options *options,
 /*
  * When we cannot load the full patch-id for both commits for whatever
  * reason, the function returns -1 (i.e. return error(...)). Despite
- * the "cmp" in the name of this function, the caller only cares about
+ * the "neq" in the name of this function, the caller only cares about
  * the return value being zero (a and b are equivalent) or non-zero (a
  * and b are different), and returning non-zero would keep both in the
  * result, even if they actually were equivalent, in order to err on
  * the side of safety.  The actual value being negative does not have
  * any significance; only that it is non-zero matters.
  */
-static int patch_id_cmp(const void *cmpfn_data,
+static int patch_id_neq(const void *cmpfn_data,
 			const void *entry,
 			const void *entry_or_key,
 			const void *unused_keydata)
@@ -53,7 +53,7 @@ static int patch_id_cmp(const void *cmpfn_data,
 	    commit_patch_id(b->commit, opt, &b->patch_id, 0))
 		return error("Could not get patch ID for %s",
 			oid_to_hex(&b->commit->object.oid));
-	return oidcmp(&a->patch_id, &b->patch_id);
+	return !oideq(&a->patch_id, &b->patch_id);
 }
 
 int init_patch_ids(struct patch_ids *ids)
@@ -63,7 +63,7 @@ int init_patch_ids(struct patch_ids *ids)
 	ids->diffopts.detect_rename = 0;
 	ids->diffopts.flags.recursive = 1;
 	diff_setup_done(&ids->diffopts);
-	hashmap_init(&ids->patches, patch_id_cmp, &ids->diffopts, 256);
+	hashmap_init(&ids->patches, patch_id_neq, &ids->diffopts, 256);
 	return 0;
 }