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Adding Event Manager

Barebones Event Manager implementation

This change also fixes a linting issue with logging in server/
eventmanager
Sarah Jamie Lewis 11 months ago
parent
commit
39d174ca26
6 changed files with 221 additions and 2 deletions
  1. 31
    0
      event/EventQueue.go
  2. 83
    0
      event/eventmanager.go
  3. 104
    0
      event/eventmanager_test.go
  4. 1
    1
      server/metrics/monitors.go
  5. 1
    1
      server/serverConfig.go
  6. 1
    0
      testing/tests.sh

+ 31
- 0
event/EventQueue.go View File

@@ -0,0 +1,31 @@
package event

// Queue is a wrapper around a channel for handling Events in a consistent way across subsystems.
// The expectation is that each subsystem in Cwtch will manage a given an event.Queue fed from
// the event.Manager.
type Queue struct {
EventChannel chan Event
}

// NewEventQueue initializes an event.Queue of the given buffer size.
func NewEventQueue(buffer int) *Queue {
queue := new(Queue)
queue.EventChannel = make(chan Event, buffer)
return queue
}

// Backlog returns the length of the queue backlog
func (eq *Queue) Backlog() int {
return len(eq.EventChannel)
}

// Next returns the next available event from the front of the queue
func (eq *Queue) Next() (event Event) {
event = <-eq.EventChannel
return
}

// Shutdown closes our EventChannel
func (eq *Queue) Shutdown() {
close(eq.EventChannel)
}

+ 83
- 0
event/eventmanager.go View File

@@ -0,0 +1,83 @@
package event

import (
"git.openprivacy.ca/openprivacy/libricochet-go/log"
"sync"
)

// Event is a structure which binds a given set of data to an EventType
type Event struct {
EventType string
Data []byte
}

// Manager is an Event Bus which allows subsystems to subscribe to certain EventTypes and publish others.
type Manager struct {
subscribers map[string][]chan Event
events chan Event
mapMutex sync.Mutex
internal chan bool
}

// Initialize sets up the Manager.
func (em *Manager) Initialize() {
em.subscribers = make(map[string][]chan Event)
em.events = make(chan Event)
em.internal = make(chan bool)
go em.eventBus()
}

// Subscribe takes an eventType and an Channel and associates them in the eventBus. All future events of that type
// will be sent to the eventChannel.
func (em *Manager) Subscribe(eventType string, eventChannel chan Event) {
em.mapMutex.Lock()
defer em.mapMutex.Unlock()
em.subscribers[eventType] = append(em.subscribers[eventType], eventChannel)
}

// Publish takes an Event and sends it to the internal eventBus where it is distributed to all Subscribers
func (em *Manager) Publish(event Event) {
if event.EventType != "" {
em.events <- event
}
}

// eventBus is an internal function that is used to distribute events to all subscribers
func (em *Manager) eventBus() {
for {
event := <-em.events

// In the case on an empty event. Teardown the Queue
if event.EventType == "" {
break
}

// maps aren't thread safe
em.mapMutex.Lock()
subscribers := em.subscribers[event.EventType]
em.mapMutex.Unlock()

// Send the event to any subscribers to that event type
for _, subscriber := range subscribers {
select {
case subscriber <- event:
log.Debugf("Sending %v to %v", event.EventType, subscriber)
default:
log.Errorf("Failed to send %v to %v. The subsystem might be running too slow!", event.EventType, subscriber)
}

}
}

// We are about to exit the eventbus thread, fire off an event internally
em.internal <- true
}

// Shutdown triggers, and waits for, the internal eventBus goroutine to finish
func (em *Manager) Shutdown() {
em.events <- Event{"", []byte{}}
// wait for eventBus to finish
<-em.internal
close(em.events)
close(em.internal)
}

+ 104
- 0
event/eventmanager_test.go View File

@@ -0,0 +1,104 @@
package event

import (
"git.openprivacy.ca/openprivacy/libricochet-go/log"
"testing"
"time"
)

// Most basic Manager Test, Initialize, Subscribe, Publish, Receive
func TestEventManager(t *testing.T) {
eventManager := new(Manager)
eventManager.Initialize()

// We need to make this buffer at least 1, otherwise we will log an error!
testChan := make(chan Event, 1)
eventManager.Subscribe("TEST", testChan)
eventManager.Publish(Event{EventType: "TEST", Data: []byte("Hello World")})

event := <-testChan
if event.EventType == "TEST" && string(event.Data) == "Hello World" {

} else {
t.Errorf("Received Invalid Event")
}

eventManager.Shutdown()
}

// Most basic Manager Test, Initialize, Subscribe, Publish, Receive
func TestEventManagerOverflow(t *testing.T) {
eventManager := new(Manager)
eventManager.Initialize()

// Explicitly setting this to 0 log an error!
testChan := make(chan Event)
eventManager.Subscribe("TEST", testChan)
eventManager.Publish(Event{EventType: "TEST", Data: []byte("Hello World")})
}

func TestEventManagerMultiple(t *testing.T) {
log.SetLevel(log.LevelDebug)
eventManager := new(Manager)
eventManager.Initialize()

groupEventQueue := NewEventQueue(10)
peerEventQueue := NewEventQueue(10)
allEventQueue := NewEventQueue(10)


eventManager.Subscribe("PeerEvent", peerEventQueue.EventChannel)
eventManager.Subscribe("GroupEvent", groupEventQueue.EventChannel)
eventManager.Subscribe("PeerEvent", allEventQueue.EventChannel)
eventManager.Subscribe("GroupEvent", allEventQueue.EventChannel)
eventManager.Subscribe("ErrorEvent", allEventQueue.EventChannel)

eventManager.Publish(Event{EventType: "PeerEvent", Data: []byte("Hello World Peer")})
eventManager.Publish(Event{EventType: "GroupEvent", Data: []byte("Hello World Group")})
eventManager.Publish(Event{EventType: "PeerEvent", Data: []byte("Hello World Peer 2")})
eventManager.Publish(Event{EventType: "ErrorEvent", Data: []byte("Hello World Error")})

assertLength := func(len int, expected int, label string) {
if len != expected {
t.Errorf("Expected %s to be %v was %v", label, expected, len)
}
}

time.Sleep(time.Second)

assertLength(groupEventQueue.Backlog(), 1, "Group Event Queue Length")
assertLength(peerEventQueue.Backlog(), 2, "Peer Event Queue Length")
assertLength(allEventQueue.Backlog(), 4, "All Event Queue Length")

checkEvent := func(eventType string, expected string, label string) {
if eventType != expected {
t.Errorf("Expected %s to be %v was %v", label, expected, eventType)
}
}

event := groupEventQueue.Next()
checkEvent(event.EventType, "GroupEvent", "First Group Event")

event = peerEventQueue.Next()
checkEvent(event.EventType, "PeerEvent", "First Peer Event")
event = peerEventQueue.Next()
checkEvent(event.EventType, "PeerEvent", "Second Peer Event")

event = allEventQueue.Next()
checkEvent(event.EventType, "PeerEvent", "ALL: First Peer Event")
event = allEventQueue.Next()
checkEvent(event.EventType, "GroupEvent", "ALL: First Group Event")
event = allEventQueue.Next()
checkEvent(event.EventType, "PeerEvent", "ALL: Second Peer Event")
event = allEventQueue.Next()
checkEvent(event.EventType, "ErrorEvent", "ALL: First Error Event")

eventManager.Shutdown()
groupEventQueue.Shutdown()
peerEventQueue.Shutdown()
allEventQueue.Shutdown()

// Reading from a closed queue should result in an instant return and an empty event
event = groupEventQueue.Next()
checkEvent(event.EventType, "", "Test Next() on Empty Queue")
}

+ 1
- 1
server/metrics/monitors.go View File

@@ -59,7 +59,7 @@ func (mp *Monitors) run() {
func (mp *Monitors) report() {
f, err := os.Create(path.Join(mp.configDir, reportFile))
if err != nil {
log.Errorf("Could not open monitor reporting file: ", err)
log.Errorf("Could not open monitor reporting file: %v", err)
return
}
defer f.Close()

+ 1
- 1
server/serverConfig.go View File

@@ -50,7 +50,7 @@ func LoadConfig(configDir, filename string) Config {
err = json.Unmarshal(raw, &config)

if err != nil {
log.Errorf("reading config: ", err)
log.Errorf("reading config: %v", err)
}
}


+ 1
- 0
testing/tests.sh View File

@@ -3,6 +3,7 @@
set -e
pwd
go test ${1} -coverprofile=model.cover.out -v ./model
go test ${1} -coverprofile=event.cover.out -v ./event
go test ${1} -coverprofile=protocol.spam.cover.out -v ./protocol/spam
go test ${1} -coverprofile=storage.cover.out -v ./storage
go test ${1} -coverprofile=peer.connections.cover.out -v ./peer/connections

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