state/apiserver/machine: Pull out common help

state/apiserver/machine: Pull out common help

There were a few bits of testing infrastructure that I want to use for the
Upgrader code, so I pulled those out into state/apiserver/testing.

Further, we have a MachineWatchResults struct, which just holds a slice of
EntityWatchResult objects. I'm guessing we'll have several APIs that just
return ids for entity watching. So it made sense to me to have a generic struct
for those cases. (Ultimately Upgrader will need a custom watcher, but
in a first pass I'll probably start with an entity watcher because the code
is already available.)

https://code.launchpad.net/~jameinel/juju-core/machine-api-tweaks-for-upgrader/+merge/171536

(do not edit description out of merge proposal)

[jameinel, 2013-06-26 12:44:23]

Please take a look.

[rog, 2013-06-26 12:50:25]

On 2013/06/26 12:44:23, jameinel wrote:
> Please take a look.

LGTM

[fwereade, 2013-06-26 13:08:42]

LGTM modulo name bikeshedding.

https://codereview.appspot.com/10608043/diff/1/state/api/params/params.go
File state/api/params/params.go (right):

https://codereview.appspot.com/10608043/diff/1/state/api/params/params.go#new...
state/api/params/params.go:71: type EntityWatchResults struct {
I'm starting to like the NotifyWatcher name -- Entity is a bit overly
specific,it's used for things that aren't necessarily entities.

[fwereade, 2013-06-26 14:51:26]

Oh, and -- I'm pretty sure a NotifyWatcher will work ok here regardless. I'm
slightly suspicious of changes that include actual data vs those that send
change notifications and leave the client to get the data when it's ready for
it.

[jameinel, 2013-06-27 06:16:09]

m

https://codereview.appspot.com/10608043/diff/1/state/api/params/params.go
File state/api/params/params.go (right):

https://codereview.appspot.com/10608043/diff/1/state/api/params/params.go#new...
state/api/params/params.go:71: type EntityWatchResults struct {
On 2013/06/26 13:08:42, fwereade wrote:
> I'm starting to like the NotifyWatcher name -- Entity is a bit overly
> specific,it's used for things that aren't necessarily entities.

I like NotifyWatcher more than EntityWatcher as well (given the point is that it
just has an event with no content). EventWatcher?

But we can rename all that in bulk with another proposal.

[jameinel, 2013-06-27 06:57:51]

Please take a look.