Function prepare_commit_graph

commit-graph.c:738–779

* Return 1 if commit_graph is non-NULL, and 0 otherwise. * * On the first invocation, this function attempts to load the commit * graph if the repository is configured to have one. */

 * graph if the repository is configured to have one.
 */
static struct commit_graph *prepare_commit_graph(struct repository *r)
{
	struct odb_source *source;

	/*
	 * Early return if there is no object database or if the commit graph is
	 * disabled.
	 *
	 * This must come before the "already attempted?" check below, because
	 * we want to disable even an already-loaded graph file.
	 */
	if (!r->objects || r->commit_graph_disabled)
		return NULL;

	if (r->objects->commit_graph_attempted)
		return r->objects->commit_graph;
	r->objects->commit_graph_attempted = 1;

	prepare_repo_settings(r);

	if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
	    r->settings.core_commit_graph != 1)
		/*
		 * This repository is not configured to use commit graphs, so
		 * do not load one. (But report commit_graph_attempted anyway
		 * so that commit graph loading is not attempted again for this
		 * repository.)
		 */
		return NULL;

	if (!commit_graph_compatible(r))
		return NULL;

	odb_prepare_alternates(r->objects);
	for (source = r->objects->sources; source; source = source->next) {
		r->objects->commit_graph = read_commit_graph_one(source);
		if (r->objects->commit_graph)
			break;
	}

	return r->objects->commit_graph;
}

int generation_numbers_enabled(struct repository *r)
{