Remove dependency between curator and web

[bernerdschaefer]

Since curation is a core prometheus feature, and reporting the current status on the HUD is not, this communication shouldn't happen through potentially blocking channel communication.

Proposal 1 (preferred)

Introduce a new struct which atomically reads/updates the curation state. It's simpler, and has the advantage that the curator and web are only synchronized when the status page is requested. Something like:

type CurationStatus struct {
  sync.Mutex
  state CurationState
}

func (s *CurationStatus) Replace(state CurationState) {
  s.Lock()
  defer s.Unlock()

  s.state = state
}

func (s *CurationStatus) State() CurationState {
  s.Lock()
  defer s.Unlock()

  return s.state
}

Proposal 2

Change the current status updates to nonblocking sends, e.g.:

// before: status <- CurationState{Active: false}
select {
case status <- CurationState{Active: false}:
}

[matttproud]

Option no. 1 was what I was leaning toward in the beginning but was time-constrained against. Go ahead and implement that.

[matttproud]

Also, I had not been aware of the non-blocking send idiom:

    var ch = someChannel
    select {
    case ch <-foo:
    // ch is able to receive.
    default:
    // ch is unavailable.
    }

Fascinating.

[bernerdschaefer]

Yep. Works for reads as well: http://play.golang.org/p/ql0qSUVXeX

[matttproud]

Great. Please keep this insights up. They are really appreciated. If you want to verbally work with me in compiling a list of smells, I will be happy to pay special attention to these in the design and code review process.

[juliusv]

The old storage is gone. Closing this.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.