feat: distribute new local posts to followers via websocket

internal/streaming/event.go

@@ -5,10 +5,20 @@ import "encoding/json"
 type EventType int8
 
 const (
+	// Sent when an error occurs
+	// Payload: {code:int, message:string}
 	EventTypeError EventType = 1
-	EventTypePost  EventType = 2
+	// Sent when echoing back received messages
+	// Payload: <received message>
+	EventTypeEcho EventType = 2
+	// Sent on a new post being created
+	// Payload: <post object>
+	EventTypePost EventType = 3
 
-	EventTypeSubscribe   EventType = 126
+	// Receive events
+	// Subscribe to a new event
+	EventTypeSubscribe EventType = 126
+	// Unsubscribe from an event
 	EventTypeUnsubscribe EventType = 127
 )
 
@@ -16,6 +26,8 @@ func (et EventType) Valid() bool {
 	switch et {
 	case EventTypeError:
 		return true
+	case EventTypeEcho:
+		return true
 	case EventTypePost:
 		return true
 	case EventTypeSubscribe:

internal/streaming/sockets.go

@@ -13,6 +13,12 @@ type SocketHolder struct {
 	mu      sync.Mutex
 }
 
+func NewSocketHolder() *SocketHolder {
+	return &SocketHolder{
+		sockets: make(map[ulid.ULID]*userSockets),
+	}
+}
+
 func (sh *SocketHolder) Send(acctID ulid.ULID, et EventType, data any) {
 	userSockets := sh.SocketsFor(acctID)
 
@@ -22,7 +28,7 @@ func (sh *SocketHolder) Send(acctID ulid.ULID, et EventType, data any) {
 	userSockets.mu.Unlock()
 
 	for _, s := range sockets {
-		if s.willAcceptEvent(et) {
+		if s.WillAcceptEvent(et) {
 			// the socket might block for a bit, so spin this off into a separate goroutine
 			go func(s *Socket) {
 				s.ch <- Event{Type: et, Data: data}
@@ -71,7 +77,7 @@ type Socket struct {
 	mu sync.RWMutex
 }
 
-func (s *Socket) willAcceptEvent(mt EventType) bool {
+func (s *Socket) WillAcceptEvent(mt EventType) bool {
 	if mt == EventTypeError {
 		return true
 	}
@@ -109,6 +115,8 @@ func NewSocket(ctx context.Context, cancel context.CancelFunc) *Socket {
 		ctx:    ctx,
 		cancel: cancel,
 		ch:     make(chan Event),
-		types:  make(map[EventType]struct{}),
+		types: map[EventType]struct{}{
+			EventTypeEcho: {},
+		},
 	}
 }