[distcc] distcc/ccache?? cache management in a distcc environment.

[David Weeks]

Hello again.

Continuing with my earlier question, I now ask how distcc and ccache 
interact.  I'm assuming at this point that the client/server 
relationship of distcc solves potential recurssion problems within 
distcc operations.  In other words, I assume it is the distcc client 
that distrubutes service requests to distcc daemons, yet the daemons 
themselves NEVER distrubute service request, delivering to the compiler 
instead, and routing the compilied binary back to the requesting host.

So I now wonder about the utilization of ccache.  It seems to me that 
the originating host ought to first que its compile list to its own 
ccache, and where there is a miss, perhaps then que the job to a remote 
host.  When the remote host receives the service request, it too should 
examine its ccache, and build only when necessary.  Regardless of which 
host eventually compiles an object, the originating host ALWAYS get's 
the completed list of objects.  Is there any state management of ccache 
at this point?  I don't know how ccache determines freshness, but I'm 
sure it is some comparision of source code, say a check sum?  Or is it a 
make function?  I don't know, but would like to.

Thanks.

David Weeks,
Tampa, Florida, USA.