migrate off of main nostr repository.

listener.go

@@ -0,0 +1,94 @@
+package main
+
+import (
+	"encoding/json"
+	"sync"
+
+	"github.com/gorilla/websocket"
+)
+
+var watchers = make(map[string][]*websocket.Conn)
+var backwatchers = make(map[*websocket.Conn][]string)
+var wlock = sync.Mutex{}
+
+func watchPubKey(key string, ws *websocket.Conn) {
+	wlock.Lock()
+	defer wlock.Unlock()
+
+	currentKeys, _ := backwatchers[ws]
+	backwatchers[ws] = append(currentKeys, key)
+
+	if wss, ok := watchers[key]; ok {
+		watchers[key] = append(wss, ws)
+	} else {
+		watchers[key] = []*websocket.Conn{ws}
+	}
+}
+
+func unwatchPubKey(excludedKey string, ws *websocket.Conn) {
+	wlock.Lock()
+	defer wlock.Unlock()
+
+	if wss, ok := watchers[excludedKey]; ok {
+		newWss := make([]*websocket.Conn, len(wss)-1)
+
+		var i = 0
+		for _, existingWs := range wss {
+			if existingWs == ws {
+				continue
+			}
+			newWss[i] = existingWs
+			i++
+		}
+
+		watchers[excludedKey] = newWss
+	}
+
+	currentKeys, _ := backwatchers[ws]
+	newKeys := make([]string, 0, len(currentKeys))
+	for _, currentKey := range currentKeys {
+		if excludedKey == currentKey {
+			continue
+		}
+		newKeys = append(newKeys, currentKey)
+	}
+
+	backwatchers[ws] = newKeys
+}
+
+func removeFromWatchers(es *websocket.Conn) {
+	wlock.Lock()
+	defer wlock.Unlock()
+
+	for _, key := range backwatchers[es] {
+		if arr, ok := watchers[key]; ok {
+			newarr := make([]*websocket.Conn, len(arr)-1)
+			i := 0
+			for _, oldes := range arr {
+				if oldes == es {
+					continue
+				}
+				newarr[i] = oldes
+				i++
+			}
+			watchers[key] = newarr
+		}
+	}
+	delete(backwatchers, es)
+}
+
+func notifyPubKeyEvent(key string, evt *Event) {
+	wlock.Lock()
+	arr, ok := watchers[key]
+	wlock.Unlock()
+
+	if ok {
+		for _, conn := range arr {
+			jevent, _ := json.Marshal([]interface{}{
+				evt,
+				"n",
+			})
+			conn.WriteMessage(websocket.TextMessage, jevent)
+		}
+	}
+}