Questions about how to get operator performance data?

[warming423]

Recently I am reading your source code, and I think the code is well-writen. But I still very confused about how did you achieve the function of getting operator performance data？The only possible file I found is convert directory, but i just find the code of how to convert proto types to GViz types. So, could you please tell me how did you get the performance data (eg. cpu launch time, how to get concrete time)?