int git_tree_create_updated()

in src/tree.c [1129:1297]

• 126 lines of code
• 31 McCabe index (conditional complexity)

int git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseline, size_t nupdates, const git_tree_update *updates)
{
	git_array_t(tree_stack_entry) stack = GIT_ARRAY_INIT;
	tree_stack_entry *root_elem;
	git_vector entries;
	int error;
	size_t i;
	git_buf component = GIT_BUF_INIT;

	if ((error = git_vector_init(&entries, nupdates, compare_entries)) < 0)
		return error;

	/* Sort the entries for treversal */
	for (i = 0 ; i < nupdates; i++)	{
		if ((error = git_vector_insert_sorted(&entries, (void *) &updates[i], on_dup_entry)) < 0)
			goto cleanup;
	}

	root_elem = git_array_alloc(stack);
	GIT_ERROR_CHECK_ALLOC(root_elem);
	memset(root_elem, 0, sizeof(*root_elem));

	if (baseline && (error = git_tree_dup(&root_elem->tree, baseline)) < 0)
		goto cleanup;

	if ((error = git_treebuilder_new(&root_elem->bld, repo, root_elem->tree)) < 0)
		goto cleanup;

	for (i = 0; i < nupdates; i++) {
		const git_tree_update *last_update = i == 0 ? NULL : git_vector_get(&entries, i-1);
		const git_tree_update *update = git_vector_get(&entries, i);
		size_t common_prefix = 0, steps_up, j;
		const char *path;

		/* Figure out how much we need to change from the previous tree */
		if (last_update)
			common_prefix = git_path_common_dirlen(last_update->path, update->path);

		/*
		 * The entries are sorted, so when we find we're no
		 * longer in the same directory, we need to abandon
		 * the old tree (steps up) and dive down to the next
		 * one.
		 */
		steps_up = last_update == NULL ? 0 : count_slashes(&last_update->path[common_prefix]);

		for (j = 0; j < steps_up; j++) {
			tree_stack_entry *current, *popped = git_array_pop(stack);
			assert(popped);

			current = git_array_last(stack);
			assert(current);

			if ((error = create_popped_tree(current, popped, &component)) < 0)
				goto cleanup;
		}

		/* Now that we've created the trees we popped from the stack, let's go back down */
		path = &update->path[common_prefix];
		while (next_component(&component, path)) {
			tree_stack_entry *last, *new_entry;
			const git_tree_entry *entry;

			last = git_array_last(stack);
			entry = last->tree ? git_tree_entry_byname(last->tree, component.ptr) : NULL;
			if (!entry)
				entry = treebuilder_get(last->bld, component.ptr);

			if (entry && git_tree_entry_type(entry) != GIT_OBJECT_TREE) {
				git_error_set(GIT_ERROR_TREE, "D/F conflict when updating tree");
				error = -1;
				goto cleanup;
			}

			new_entry = git_array_alloc(stack);
			GIT_ERROR_CHECK_ALLOC(new_entry);
			memset(new_entry, 0, sizeof(*new_entry));

			new_entry->tree = NULL;
			if (entry && (error = git_tree_lookup(&new_entry->tree, repo, git_tree_entry_id(entry))) < 0)
				goto cleanup;

			if ((error = git_treebuilder_new(&new_entry->bld, repo, new_entry->tree)) < 0)
				goto cleanup;

			new_entry->name = git__strdup(component.ptr);
			GIT_ERROR_CHECK_ALLOC(new_entry->name);

			/* Get to the start of the next component */
			path += component.size + 1;
		}

		/* After all that, we're finally at the place where we want to perform the update */
		switch (update->action) {
			case GIT_TREE_UPDATE_UPSERT:
			{
				/* Make sure we're replacing something of the same type */
				tree_stack_entry *last = git_array_last(stack);
				char *basename = git_path_basename(update->path);
				const git_tree_entry *e = git_treebuilder_get(last->bld, basename);
				if (e && git_tree_entry_type(e) != git_object__type_from_filemode(update->filemode)) {
					git__free(basename);
					git_error_set(GIT_ERROR_TREE, "cannot replace '%s' with '%s' at '%s'",
						   git_object_type2string(git_tree_entry_type(e)),
						   git_object_type2string(git_object__type_from_filemode(update->filemode)),
						   update->path);
					error = -1;
					goto cleanup;
				}

				error = git_treebuilder_insert(NULL, last->bld, basename, &update->id, update->filemode);
				git__free(basename);
				break;
			}
			case GIT_TREE_UPDATE_REMOVE:
			{
				char *basename = git_path_basename(update->path);
				error = git_treebuilder_remove(git_array_last(stack)->bld, basename);
				git__free(basename);
				break;
			}
			default:
				git_error_set(GIT_ERROR_TREE, "unknown action for update");
				error = -1;
				goto cleanup;
		}

		if (error < 0)
			goto cleanup;
	}

	/* We're done, go up the stack again and write out the tree */
	{
		tree_stack_entry *current = NULL, *popped = NULL;
		while ((popped = git_array_pop(stack)) != NULL) {
			current = git_array_last(stack);
			/* We've reached the top, current is the root tree */
			if (!current)
				break;

			if ((error = create_popped_tree(current, popped, &component)) < 0)
				goto cleanup;
		}

		/* Write out the root tree */
		git__free(popped->name);
		git_tree_free(popped->tree);

		error = git_treebuilder_write(out, popped->bld);
		git_treebuilder_free(popped->bld);
		if (error < 0)
			goto cleanup;
	}

cleanup:
	{
		tree_stack_entry *e;
		while ((e = git_array_pop(stack)) != NULL) {
			git_treebuilder_free(e->bld);
			git_tree_free(e->tree);
			git__free(e->name);
		}
	}

	git_buf_dispose(&component);
	git_array_clear(stack);
	git_vector_free(&entries);
	return error;
}