t/helper/test-read-graph: implement bloom-filters mode

Implement a mode of the "read-graph" test helper to dump out the
hexadecimal contents of the Bloom filter(s) contained in a commit-graph.

Signed-off-by: Taylor Blau <[email protected]>
Signed-off-by: Jonathan Tan <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
Signed-off-by: Taylor Blau <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: ttaylorr

t/helper/test-read-graph.c

@@ -47,23 +47,55 @@ static void dump_graph_info(struct commit_graph *graph)
 	printf("\n");
 }
 
-int cmd__read_graph(int argc UNUSED, const char **argv UNUSED)
+static void dump_graph_bloom_filters(struct commit_graph *graph)
+{
+	uint32_t i;
+
+	for (i = 0; i < graph->num_commits + graph->num_commits_in_base; i++) {
+		struct bloom_filter filter = { 0 };
+		size_t j;
+
+		if (load_bloom_filter_from_graph(graph, &filter, i) < 0) {
+			fprintf(stderr, "missing Bloom filter for graph "
+				"position %"PRIu32"\n", i);
+			continue;
+		}
+
+		for (j = 0; j < filter.len; j++)
+			printf("%02x", filter.data[j]);
+		if (filter.len)
+			printf("\n");
+	}
+}
+
+int cmd__read_graph(int argc, const char **argv)
 {
 	struct commit_graph *graph = NULL;
 	struct object_directory *odb;
+	int ret = 0;
 
 	setup_git_directory();
 	odb = the_repository->objects->odb;
 
 	prepare_repo_settings(the_repository);
 
 	graph = read_commit_graph_one(the_repository, odb);
-	if (!graph)
-		return 1;
+	if (!graph) {
+		ret = 1;
+		goto done;
+	}
 
-	dump_graph_info(graph);
+	if (argc <= 1)
+		dump_graph_info(graph);
+	else if (!strcmp(argv[1], "bloom-filters"))
+		dump_graph_bloom_filters(graph);
+	else {
+		fprintf(stderr, "unknown sub-command: '%s'\n", argv[1]);
+		ret = 1;
+	}
 
+done:
 	UNLEAK(graph);
 
-	return 0;
+	return ret;
 }