utils.c

	if (__builtin_expect(needed > mgr->space, 0)) {
		size_t new_size = mgr->size * 2;

		while (new_size < needed)
			new_size *= 2;

		if (add_string_pool(mgr, new_size))
			return NULL;
	}

	result = mgr->pool->base + mgr->used;
	mgr->used += needed;
	mgr->space -= needed;
	return result;
}

void __ast_string_field_index_build(struct ast_string_field_mgr *mgr,
				    ast_string_field *fields, int num_fields,
				    int index, const char *format, ...)
{
	size_t needed;
	va_list ap1, ap2;

	va_start(ap1, format);
	va_copy(ap2, ap1);

	needed = vsnprintf(mgr->pool->base + mgr->used, mgr->space, format, ap1) + 1;

	va_end(ap1);

	if (needed > mgr->space) {
		size_t new_size = mgr->size * 2;

		while (new_size < needed)
			new_size *= 2;

		if (add_string_pool(mgr, new_size))
			return;

		vsprintf(mgr->pool->base + mgr->used, format, ap2);
	}

	fields[index] = mgr->pool->base + mgr->used;
	mgr->used += needed;
	mgr->space -= needed;

	va_end(ap2);
}