Naming the resources "type" was a stupid mistake, and is a huge source
of confusion when also talking about real types. Fix this before it gets
out of hand.
* Fixup graph state readability
* Rename original SetState() to SetConvergedState() and friends...
* Add type state management for proper BackPoke() commands...
* Add better DEBUG logging
This is an important optimization that prevents running a BackPoke on a
parent which is in the process of running and will most certainly poke
the caller back in a moment. This avoids unnecessary roundtrips.
Unfortunately, there are still other algorithms required so that races
can't cause the graph to run for longer than necessary.
* Add exec type
* Switch erroneous use of fmt to log instead
* Check for edge existence for safety before using
* Avoid recalling etcd channel maker
* Clean up logging output
This is the third main feature of this system. The code needs a bunch of
polish, but it actually all works :)
I've tested this briefly with N <= 3.
Currently you have to build your own etcd cluster. It's quite easy, just
run `etcd` and it will be ready. I usually run it in a throw away /tmp/
dir so that I can blow away the stored data easily.
This is still a dirty prototype, so please excuse the mess. Please
excuse the fact that this is a mega patch. Once things settle down this
won't happen any more.
Some of the changes squashed into here include:
* Merge vertex loop with type loop
(The file watcher seems to cache events anyways)
* Improve pgraph library
* Add indegree, outdegree, and topological sort with tests
* Add reverse function for vertex list
* Tons of additional cleanup!
Amazingly, on my first successful compile, this seemed to run!
A special thanks to Ira Cooper who helped me talk through some of the
algorithmic decisions and for his help in finding better ones!
