make cache a special kind of repository, and automatically cache
special packages (virtual packages, or ones installed from command
line). add test cases for handling virtual packages. fixes#1617.
It is incorrect optimization causing valid solutions to be skipped.
Any performance it might've gained, should be fixed by reintroduction
of the minimum penalty logic added in previous commit.
Enabled when all attempts to satisfy a name failed, we know that we
can ignore all decisions until we find a decision affecting the name
we wanted to satisfy.
We can't just use the primary name, as that would mess up
backtracking. We need to record the name which caused the name
to get considered - that way the right last_touched_decision is
used on backtracking.
* push_decision expects to always get the package primary 'name'
as apk_name. ASSERT that and fix problem cases.
(though - this might need to be reverted, and store the non
primary name in apk_decision instead to accomodate for better
backtracking optimizations)
* fix error reporting of virtual package names
* make 'assign_name' errors soft. the incorrect packages just are
no longer consider instead of aborting whole calculation.
* fix backtracking of virtual packages that are not depended
directly
apk_name_state is now quite small; and we avoid overhead of two
pointers (+ malloc overhead) when we just make it part of apk_name.
It also fixes some problems (that got introduced) where apk_name_state
was not allocated.
Solver will now never report partial solution where a conflict
constraint is not satisfied. The is because with --force we might
install the partial solution; and if conflicted packages were to
be installed we might have extra trouble.
Required for provides support as package might be pulled in via
non-primary package name. This allows relatively easily to pass
through inherited flags via the provided names. ref #574.
Reasoning:
- it is less useful now that we do not do common dependency merging
- provides support would make the required logic overly complicated
- callgrind reports that depending on the case it can improve or
decrease performance (the overhead pays off only in some cases);
the difference is not large either way
Otherwise we might start to change packages unexpectedly when not
upgrading. This also fixes some other things the solver might've
decided to do.
Add also few test cases to detect bad behaviour.