state

Documentation

Index

• func Matcher(specifiers ...api.Event) events.MatcherFunc
• func NodeCheckState(n1, n2 *api.Node) bool
• func TaskCheckStateGreaterThan(t1, t2 *api.Task) bool
• func Watch(queue *watch.Queue, specifiers ...api.Event) (eventq chan events.Event, cancel func())
• type Change
• type EventCommit
  • func (e EventCommit) Matches(watchEvent events.Event) bool
• type Proposer

Functions

func Matcher

func Matcher(specifiers ...api.Event) events.MatcherFunc

Matcher returns an events.Matcher that Matches the specifiers with OR logic.

func NodeCheckState

func NodeCheckState(n1, n2 *api.Node) bool

NodeCheckState is a NodeCheckFunc for matching node state.

func TaskCheckStateGreaterThan

func TaskCheckStateGreaterThan(t1, t2 *api.Task) bool

TaskCheckStateGreaterThan is a TaskCheckFunc for checking task state.

func Watch

func Watch(queue *watch.Queue, specifiers ...api.Event) (eventq chan events.Event, cancel func())

Watch takes a variable number of events to match against. The subscriber will receive events that match any of the arguments passed to Watch.

Examples:

// subscribe to all events Watch(q)

// subscribe to all UpdateTask events Watch(q, EventUpdateTask{})

// subscribe to all task-related events Watch(q, EventUpdateTask{}, EventCreateTask{}, EventDeleteTask{})

// subscribe to UpdateTask for node 123 Watch(q, EventUpdateTask{Task: &api.Task{NodeID: 123},

Checks: []TaskCheckFunc{TaskCheckNodeID}})

// subscribe to UpdateTask for node 123, as well as CreateTask // for node 123 that also has ServiceID set to "abc" Watch(q, EventUpdateTask{Task: &api.Task{NodeID: 123},

                Checks: []TaskCheckFunc{TaskCheckNodeID}},
EventCreateTask{Task: &api.Task{NodeID: 123, ServiceID: "abc"},
                Checks: []TaskCheckFunc{TaskCheckNodeID,
                                        func(t1, t2 *api.Task) bool {
                                                return t1.ServiceID == t2.ServiceID
                                        }}})

Types

type Change

type Change struct {
	StoreActions []api.StoreAction
	Version      api.Version
}

A Change includes a version number and a set of store actions from a particular log entry.

type EventCommit

type EventCommit struct {
	Version *api.Version
}

EventCommit delineates a transaction boundary.

func (EventCommit) Matches

func (e EventCommit) Matches(watchEvent events.Event) bool

Matches returns true if this event is a commit event.

type Proposer

type Proposer interface {
	// ProposeValue adds storeAction to the distributed log. If this
	// completes successfully, ProposeValue calls cb to commit the
	// proposed changes. The callback is necessary for the Proposer to make
	// sure that the changes are committed before it interacts further
	// with the store.
	ProposeValue(ctx context.Context, storeAction []api.StoreAction, cb func()) error
	// GetVersion returns the monotonic index of the most recent item in
	// the distributed log.
	GetVersion() *api.Version
	// ChangesBetween returns the changes starting after "from", up to and
	// including "to". If these changes are not available because the log
	// has been compacted, an error will be returned.
	ChangesBetween(from, to api.Version) ([]Change, error)
}

A Proposer can propose actions to a cluster.