Bruno Mars -- It's Like That Whole Cocaine Thing Never Happened

Bruno Mars will have a spotless criminal record tomorrow ... because sources tell us the judge in his cocaine possession case will officially dismiss the charge.

You'll recall Mars was arrested in Las Vegas in September, 2010 at the Hard Rock Hotel and Casino after a bathroom attendant told security a man was doing coke in one of the stalls.

Mars pled guilty, but he was not convicted. The judge deferred the matter and gave Bruno a year to complete 200 hours of community service and attend drug education classes.

We've learned Mars has exceeded the number of required community service hours -- he's logged more than 230 hours, working for children's charities as well as some health-related charities. And he has completed his classes.