name-rev: use commit-slab for rev-name instead of commit->util

It's done so that commit->util can be removed. See more explanation in
the commit that removes commit->util.

Signed-off-by: Junio C Hamano <[email protected]>

Author: pclouds

builtin/name-rev.c

@@ -6,6 +6,7 @@
 #include "refs.h"
 #include "parse-options.h"
 #include "sha1-lookup.h"
+#include "commit-slab.h"
 
 #define CUTOFF_DATE_SLOP 86400 /* one day */
 
@@ -17,11 +18,26 @@ typedef struct rev_name {
 	int from_tag;
 } rev_name;
 
+define_commit_slab(commit_rev_name, struct rev_name *);
+
 static timestamp_t cutoff = TIME_MAX;
+static struct commit_rev_name rev_names;
 
 /* How many generations are maximally preferred over _one_ merge traversal? */
 #define MERGE_TRAVERSAL_WEIGHT 65535
 
+static struct rev_name *get_commit_rev_name(struct commit *commit)
+{
+	struct rev_name **slot = commit_rev_name_peek(&rev_names, commit);
+
+	return slot ? *slot : NULL;
+}
+
+static void set_commit_rev_name(struct commit *commit, struct rev_name *name)
+{
+	*commit_rev_name_at(&rev_names, commit) = name;
+}
+
 static int is_better_name(struct rev_name *name,
 			  const char *tip_name,
 			  timestamp_t taggerdate,
@@ -65,7 +81,7 @@ static void name_rev(struct commit *commit,
 		int generation, int distance, int from_tag,
 		int deref)
 {
-	struct rev_name *name = (struct rev_name *)commit->util;
+	struct rev_name *name = get_commit_rev_name(commit);
 	struct commit_list *parents;
 	int parent_number = 1;
 	char *to_free = NULL;
@@ -84,7 +100,7 @@ static void name_rev(struct commit *commit,
 
 	if (name == NULL) {
 		name = xmalloc(sizeof(rev_name));
-		commit->util = name;
+		set_commit_rev_name(commit, name);
 		goto copy_data;
 	} else if (is_better_name(name, tip_name, taggerdate,
 				  generation, distance, from_tag)) {
@@ -296,7 +312,7 @@ static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 	if (o->type != OBJ_COMMIT)
 		return get_exact_ref_match(o);
 	c = (struct commit *) o;
-	n = c->util;
+	n = get_commit_rev_name(c);
 	if (!n)
 		return NULL;
 
@@ -413,6 +429,7 @@ int cmd_name_rev(int argc, const char **argv, const char *prefix)
 		OPT_END(),
 	};
 
+	init_commit_rev_name(&rev_names);
 	git_config(git_default_config, NULL);
 	argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 	if (all + transform_stdin + !!argc > 1) {