The budget is freely available on their web site. It's worth noting that San Francisco is a consolidated city and county, so the budget covers things that most other cities don't (e.g. public transit, libraries, schools, jails). While there is indeed some consolidation San Francisco is on the hook for two separate law enforcement agencies (police – which are typically the domain of cities and sheriff – which are typically the domain of counties).
And an international airport and a water source and pipeline from the mountains. Crazy stuff
SFO is in San Mateo County.
San Francisco International Airport is owned and operated by the City and County of San Francisco and policed by San Francisco Police Department.
Surely the airport turns a profit?
It does. But it is still part of the “budget”, which is only money going out, and doesn’t count money coming in.