Documentation
¶
Index ¶
- Variables
- func Bookkeeper(incOutCh chan Event) (chan Event, chan Event)
- func BookkeeperReceiver(incInCh chan Event) chan Event
- func Broadcaster(inCh chan Event, outChs []chan Event)
- func Merger(inCh chan Event, outCh chan Event)
- type Book
- type Endpoint
- type EndpointFunc
- type Event
- type Forwarder
- type ManagedEndpoint
- type NodeInfo
- type NodeStatus
- type Reactor
- type Watcher
Constants ¶
This section is empty.
Variables ¶
var ERROR_HANDLER_WAIT_TIMEOUT = errors.New("Handler wait timed out")
Functions ¶
func Bookkeeper ¶
Bookkeeper accepts full and incremental updates on his returned channels and sends redundant-free incremental events out on the incOutCh channel. It enables watchers which only get a full list of backends to send them without further bookkeeping. Full updates on fullInCh have to be a single Event with multiple nodes, only accepting EventNodeUp types.
func BookkeeperReceiver ¶
BookkeeperReceiver reads an incremental event channel incInCh and returns a channel with full updates send on request. If incInCh gets closed, the output channel is closed.
func Broadcaster ¶
Types ¶
type Book ¶
type Book struct {
// contains filtered or unexported fields
}
Book is a datastructure needed for bookkeeping of node data. It receives incremental and full updates on the list of running nodes by events and tracks a list of all nodes currently up. Therefore it's capable of filtering redundant events and only returns necessary incremental updates. Is thread-safe.
func (*Book) Full ¶
Full returns a event containing all nodes currently up. If there are no nodes an event without nodes is returned.
func (*Book) UpdateFull ¶
UpdateFull updates the book with the list of nodes inside the event. The event represents a full update, so only EventNodeUp is allowed. Missing nodes are marked as EventNodeDown and removed from book.
func (*Book) UpdateInc ¶
UpdateInc updates the book with an incremental event ev and returns an event if the update changed the book. If the update contains a node with status EventNodeDown but was never seen by the book, the node is ignored. Incremental updates only work if book receives events from start up and never miss an event.
type Endpoint ¶
type Endpoint interface {
// Started in seperate go routine
Handle(eventCh chan Event, closeCh chan struct{})
}
type EndpointFunc ¶
type EndpointFunc func(eventCh chan Event, closeCh chan struct{})
func (EndpointFunc) Handle ¶
func (f EndpointFunc) Handle(eventCh chan Event, closeCh chan struct{})
type Event ¶
func NewEventWithNode ¶
func NewEventWithNode(name string, status NodeStatus, host string, port uint16) Event
func (Event) AddNewNode ¶
func (e Event) AddNewNode(name string, status NodeStatus, host string, port uint16)
type Forwarder ¶
type Forwarder struct {
// contains filtered or unexported fields
}
func NewForwarder ¶
NewForwarder creates a new forwarder for given output channel.
type ManagedEndpoint ¶
type ManagedEndpoint struct {
Endpoint Endpoint
DoneCh chan struct{}
CloseCh chan struct{}
// contains filtered or unexported fields
}
ManagedHandler wraps a Handler to control its shutdown behaviour.
func NewManagedEndpoint ¶
func NewManagedEndpoint(handle Endpoint) *ManagedEndpoint
NewManagedHandler creates a wrapper around an handler which manages the shutdown behaviour.
func (*ManagedEndpoint) Handle ¶
func (m *ManagedEndpoint) Handle(eventCh chan Event)
Handle starts the wrapped handler on the given eventChannel and closes the DoneCh if handler returns. Blocks until handler returns.
func (*ManagedEndpoint) Stop ¶
func (m *ManagedEndpoint) Stop()
Stop signals the handler to exit by using its close channel, stop will not close the event channel.
func (*ManagedEndpoint) WaitTimeout ¶
func (m *ManagedEndpoint) WaitTimeout(timeout time.Duration) error
WaitTimeout waits for the handler to stop or timeout to occur.
type NodeInfo ¶
type NodeInfo struct {
Name string
Status NodeStatus
Host string
Port uint16
}
func NewNodeInfo ¶
func NewNodeInfo(name string, status NodeStatus, host string, port uint16) NodeInfo
type NodeStatus ¶
type NodeStatus int
const ( NodeUp NodeStatus = iota + 1 // Node is up NodeDown )
func (NodeStatus) String ¶
func (s NodeStatus) String() string
type Reactor ¶
type Reactor interface {
// Setup configures the reactor with a global config
Setup(cfg json.RawMessage) error
// Accept configures an instance of the reactor dedicated to a service.
// Returns an Endpoint ready to communicate on the pipeline.
Accept(cfg json.RawMessage) (Endpoint, error)
}
Reactor is the sink of events, it "reacts" on incoming events.
type Watcher ¶
type Watcher interface {
// Setup configures the watcher with a global config
Setup(cfg json.RawMessage) error
// Accept configures an instance of the watcher dedicated to a service.
// Returns an Endpoint ready to communicate on the pipeline.
Accept(cfg json.RawMessage) (Endpoint, error)
}
Watcher is the source of events, it "watches" a system and generates events which are then send down the pipeline.
Source Files