Server Event Optimizations (#116)

environment/docker/container.go

@@ -342,10 +342,10 @@ func (e *Environment) followOutput() error {
 func (e *Environment) scanOutput(reader io.ReadCloser) {
 	defer reader.Close()
 
-	events := e.Events()
-
-	if err := system.ScanReader(reader, func(line string) {
-		events.Publish(environment.ConsoleOutputEvent, line)
+	if err := system.ScanReader(reader, func(v []byte) {
+		e.logCallbackMx.Lock()
+		defer e.logCallbackMx.Unlock()
+		e.logCallback(v)
 	}); err != nil && err != io.EOF {
 		log.WithField("error", err).WithField("container_id", e.Id).Warn("error processing scanner line in console output")
 		return

environment/docker/environment.go

@@ -49,7 +49,10 @@ type Environment struct {
 	// Holds the stats stream used by the polling commands so that we can easily close it out.
 	stats io.ReadCloser
 
-	emitter *events.EventBus
+	emitter *events.Bus
+
+	logCallbackMx sync.Mutex
+	logCallback   func([]byte)
 
 	// Tracks the environment state.
 	st *system.AtomicString
@@ -100,9 +103,9 @@ func (e *Environment) IsAttached() bool {
 	return e.stream != nil
 }
 
-func (e *Environment) Events() *events.EventBus {
+func (e *Environment) Events() *events.Bus {
 	e.eventMu.Do(func() {
-		e.emitter = events.New()
+		e.emitter = events.NewBus()
 	})
 
 	return e.emitter
@@ -214,3 +217,10 @@ func (e *Environment) SetState(state string) {
 		e.Events().Publish(environment.StateChangeEvent, state)
 	}
 }
+
+func (e *Environment) SetLogCallback(f func([]byte)) {
+	e.logCallbackMx.Lock()
+	defer e.logCallbackMx.Unlock()
+
+	e.logCallback = f
+}

environment/docker/stats.go

@@ -90,11 +90,7 @@ func (e *Environment) pollResources(ctx context.Context) error {
 				st.Network.TxBytes += nw.TxBytes
 			}
 
-			if b, err := json.Marshal(st); err != nil {
-				e.log().WithField("error", err).Warn("error while marshaling stats object for environment")
-			} else {
-				e.Events().Publish(environment.ResourceEvent, string(b))
-			}
+			e.Events().Publish(environment.ResourceEvent, st)
 		}
 	}
 }

environment/environment.go

@@ -8,7 +8,6 @@ import (
 )
 
 const (
-	ConsoleOutputEvent       = "console output"
 	StateChangeEvent         = "state change"
 	ResourceEvent            = "resources"
 	DockerImagePullStarted   = "docker image pull started"
@@ -35,7 +34,7 @@ type ProcessEnvironment interface {
 	// Returns an event emitter instance that can be hooked into to listen for different
 	// events that are fired by the environment. This should not allow someone to publish
 	// events, only subscribe to them.
-	Events() *events.EventBus
+	Events() *events.Bus
 
 	// Determines if the server instance exists. For example, in a docker environment
 	// this should confirm that the container is created and in a bootable state. In
@@ -108,4 +107,7 @@ type ProcessEnvironment interface {
 	// Uptime returns the current environment uptime in milliseconds. This is
 	// the time that has passed since it was last started.
 	Uptime(ctx context.Context) (int64, error)
+
+	// SetLogCallback sets the callback that the container's log output will be passed to.
+	SetLogCallback(func([]byte))
 }