builtin/repo: find commit with most parents

Complex merge events may produce an octopus merge where the resulting
merge commit has more than two parents. While iterating through objects
in the repository for git-repo-structure, identify the commit with the
most parents and display it in the output.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/builtin/repo.c b/builtin/repo.c
index ea7f5acd3e..047f5e098d 100644
--- a/builtin/repo.c
+++ b/builtin/repo.c
@@ -1,6 +1,7 @@
 #define USE_THE_REPOSITORY_VARIABLE
 
 #include "builtin.h"
+#include "commit.h"
 #include "environment.h"
 #include "hash.h"
 #include "hex.h"
@@ -208,6 +209,8 @@ struct largest_objects {
 	struct object_data commit_size;
 	struct object_data tree_size;
 	struct object_data blob_size;
+
+	struct object_data parent_count;
 };
 
 struct ref_stats {
@@ -318,6 +321,27 @@ static void stats_table_count_addf(struct stats_table *table, size_t value,
 	va_end(ap);
 }
 
+static void stats_table_object_count_addf(struct stats_table *table,
+					  struct object_id *oid, size_t value,
+					  const char *format, ...)
+{
+	struct stats_table_entry *entry;
+	va_list ap;
+
+	CALLOC_ARRAY(entry, 1);
+	humanise_count(value, &entry->value, &entry->unit);
+
+	/*
+	 * A NULL OID should not have a table annotation.
+	 */
+	if (!is_null_oid(oid))
+		entry->oid = oid;
+
+	va_start(ap, format);
+	stats_table_vaddf(table, entry, format, ap);
+	va_end(ap);
+}
+
 static void stats_table_size_addf(struct stats_table *table, size_t value,
 				  const char *format, ...)
 {
@@ -425,6 +449,10 @@ static void stats_table_setup_structure(struct stats_table *table,
 				     &objects->largest.commit_size.oid,
 				     objects->largest.commit_size.value,
 				     "    * %s", _("Maximum size"));
+	stats_table_object_count_addf(table,
+				      &objects->largest.parent_count.oid,
+				      objects->largest.parent_count.value,
+				      "    * %s", _("Maximum parents"));
 	stats_table_addf(table, "  * %s", _("Trees"));
 	stats_table_object_size_addf(table,
 				     &objects->largest.tree_size.oid,
@@ -595,6 +623,9 @@ static void structure_keyvalue_print(struct repo_structure *stats,
 	print_object_data("objects.tags.max_size", key_delim,
 			  &stats->objects.largest.tag_size, value_delim);
 
+	print_object_data("objects.commits.max_parents", key_delim,
+			  &stats->objects.largest.parent_count, value_delim);
+
 	fflush(stdout);
 }
 
@@ -682,16 +713,24 @@ static int count_objects(const char *path UNUSED, struct oid_array *oids,
 	for (size_t i = 0; i < oids->nr; i++) {
 		struct object_info oi = OBJECT_INFO_INIT;
 		unsigned long inflated;
+		struct commit *commit;
+		struct object *obj;
+		void *content;
 		off_t disk;
+		int eaten;
 
 		oi.sizep = &inflated;
 		oi.disk_sizep = &disk;
+		oi.contentp = &content;
 
 		if (odb_read_object_info_extended(data->odb, &oids->oid[i], &oi,
 						  OBJECT_INFO_SKIP_FETCH_OBJECT |
 						  OBJECT_INFO_QUICK) < 0)
 			continue;
 
+		obj = parse_object_buffer(the_repository, &oids->oid[i], type,
+					  inflated, content, &eaten);
+
 		switch (type) {
 		case OBJ_TAG:
 			stats->type_counts.tags++;
@@ -701,11 +740,14 @@ static int count_objects(const char *path UNUSED, struct oid_array *oids,
 				      inflated);
 			break;
 		case OBJ_COMMIT:
+			commit = object_as_type(obj, OBJ_COMMIT, 0);
 			stats->type_counts.commits++;
 			stats->inflated_sizes.commits += inflated;
 			stats->disk_sizes.commits += disk;
 			check_largest(&stats->largest.commit_size, &oids->oid[i],
 				      inflated);
+			check_largest(&stats->largest.parent_count, &oids->oid[i],
+				      commit_list_count(commit->parents));
 			break;
 		case OBJ_TREE:
 			stats->type_counts.trees++;
@@ -724,6 +766,9 @@ static int count_objects(const char *path UNUSED, struct oid_array *oids,
 		default:
 			BUG("invalid object type");
 		}
+
+		if (!eaten)
+			free(content);
 	}
 
 	object_count = get_total_object_values(&stats->type_counts);