I was working on adding the tar streaming functionality we talked about at the developer meeting to pg_basebackup, and rapidly ran across the issue that Andres has been complaining about for a while. The code in receivelog.c just passes an insane number of parameters around. Adding or changing even a small thing ends up touching a huge number of places.
Other than the lack of comments on the fields in StreamCtl to indicate their functions I think this looks good.
I copied that lack of comments from the previous implementation :P
But yeah, I agree, it's probably a good idea to add them.
I didn't find any mistakes, but I do admit my eyes started glazing over after a bit.
I'd rather not have StreamCtl as a typedef of an anonymous struct if it's exposed in a header though. It should have a name that can be used in forward declarations etc.
It's not exactly uncommon with anonymous ones either in our code, but I see no problem adding that.
