::cartographer::common::Time FromRos(const ::ros::Time& time) {
// The epoch of the ICU Universal Time Scale is "0001-01-01 00:00:00.0 +0000",
// exactly 719162 days before the Unix epoch.
// ICU世界时标的纪元是“0001-01-01 00:00:00.0+0000”,正好比Unix纪元早719162天
return ::cartographer::common::FromUniversal(
(time.sec +
::cartographer::common::kUtsEpochOffsetFromUnixEpochInSeconds) *
10000000ll +
(time.nsec + 50) / 100); // + 50 to get the rounding correct.
}
constexpr int64 kUtsEpochOffsetFromUnixEpochInSeconds =
(719162ll * 24ll * 60ll * 60ll);
请问一下 两个纪元相差的天数转换为秒数再加上运行时间的秒数后边需要乘10000000是为什么阿