I previously broke the pkg auto edges because the package list wasn't
available by the time it was called. This fixes the pkg resource so that
it gets the necessary list of packages when needed. Since this means
that a possible failure could happen, we also update the AutoEdges API
to support errors. Errors can only be generated at AutoEdge struct
creation, once the struct has been returned (right before modification
of the graph structure) there is no possibility to return any errors.
It's important to remember that the AutoEdges stuff gets called because
the Init of each resource, so make sure it doesn't depend on anything
that happens there or that gets cached as a result of Init.
This is all much nicer now and has a test too :)
This is required if we're going to have out of package resources. In
particular for third party packages, and also for if we decide to split
out each resource into a separate sub package.
Avoid use of the reflect package, and use an extensible list of registred
resource kinds. This also has the benefit of removing the empty VirtRes and
AugeasRes struct types when compiling without libvirt and libaugeas.
I'm still working on reducing the size of the monster patches that I
land, but I'm exercising the priviledge as the initial author. In any
case, this refactors worker into two, and cleans up the passing around
of the processChan. This puts common code into Init and Close.
When creating new resources, we didn't specify the defaults, which for
the limit metaparam caused invalid resources by default. It would be
nice to change the limit param to have the 1/X (reciprocal) as the
default, although the problem with that is that (1) it is illogical, and
(2) it's not clear if the precision for the common cases is enough.
If someone wants to investigate this further, please do! Zero value
structs are definitely more useful! In any case, we can now specify the
default. It's not entirely obvious to me if this is the best way to do
it, or if there is a superior method.
Remove the New constructors since calling Init should be done by the
engine, and not by the user even when using mgmt as a lib. This is also
the case in tests! It used to be the case that a user might want to call
Init manually, but that is no longer the case!
