* properly do absolute scoring now, the previous scoring where
preference could get reduced could have caused incorrect early
pruning of search tree
* backtracking is now separated from package state, and first
branching point is the decision if a name is left unassigned
or if something _has_ to be assigned. this allows multiple future
search tree optimizations like handling of common dependencies
early.
* merge common dependency names early to provide deeper forward
checking.
Instead of "skipping" certain packages, we include them as-if required,
and at expansion time we decide if they actually need to be considered
for installation. This cleans up the expansion main loop a little bit
and makes the code work together better.
* cleaned up little bit on the internal state machine
* the decision applying mechanism now aborts early to avoid work
if we are approaching bad solution candidate
* package availability checking is now done on-demand; which
could still be improved
* solver internally calculates now using tags; not repository masks
* installeddb now contains the tag name where the package came from
-> we can now handle upgrades properly
* the pinning is still a preference, and not strictly enforced;
versioned dependencies may overrule preference
Forgot to reset per-name penalty when it got locked by apply_decision.
This also fine tunes compare_package_preference() to always prefer
packages specified on command line speeding up calculation certain
complicated solutions.
* upgrade needs explicit check so we don't try self-upgrade
(which would print additional messages on screen)
* add can fix problems, so check against the new world
* merge the code in few places
Previously we would cache the penalty when evaluating the final
solution, and adding that until we backtrack to first topology
position changing that penalty. However, we can just keep track
of minimum penalty based on name state, and add it. This allows
us to bail out early on bad branches because we know in advance
how things will turn out.
Previously we would not upgrade just by doing "apk add foo@tag" if
foo was already installed. It required explicit '-u'. This allows
'apk add' to explicitly prefer the newly specified pinning.
Improves /etc/apk/repositories format so you can say:
http://nl.alpinelinux.org/alpine/v2.3/main
@edge http://nl.alpinelinux.org/alpine/edge/main
@testing http://nl.alpinelinux.org/alpine/edge/testing
After which you can pin dependencies to these tags using:
apk add stableapp newapp@edge bleedingapp@testing
Apk will now by default only use the untagged repositories,
but adding a tag to specific dependency:
1. will prefer that tag for the name
2. allowing pulling in dependencies from that tag (though,
it prefers untagged packages to satisfy deps if possible)
fixes#575
allow per-name solver flags to be inheritable, and use them in
self-upgrade, add -u and the fix applet. this gives more familiar
behaviour for the upgrades.
the only bit of information needed in solver commit is the "hard"
topology sorting information for trigger ordering. fixes a bug in
"apk del" which uses the state pointers to do intermediate
calculations between solution solving and commit.
Allow to select packages that conflict in case we are looking for
errors. This allows 'add --force' to install (on boot) the set of
packages with minimum conflicts.
* each package name has two sorting positions, one which causes
install_if triggers to be run, and other for bulk dependencies
* fix also inverted ordering of package installations
* the solver no longer does look-ahead locking of names
(could be possibly optimized later); instead names are now
always ordered strictly to properly detect the package names
which are unsolveable
* basic error tests added, so we can see the most likely problem
in dependencies easily
* basic code for a backtracking, forward checking dependency satisfier
* works better when there are tricky dependencies to solve
(when can't just upgrade everything to most preferred versions)
* the new code always evaluates all of 'world' constraints
(old code just does incremental updates based on heuristics)
* is probably somewhat slower than old code (probably unnoticeable
difference in most cases)
* makes easier to write support for provides and repository pinning
* test applet and a bunch of test cases added which uses the new code
* from the old feature set install_if is not yet implemented
Timo Teräs