sdk: optimize caching lists (so we don't fetch twice in a row).

sdk/helpers.go

@@ -1,21 +1,35 @@
 package sdk
 
-import (
-	"strings"
-)
+import "time"
 
-// IsVirtualRelay returns true if the given normalized relay URL shouldn't be considered for outbox-model calculations.
-func IsVirtualRelay(url string) bool {
-	if len(url) < 6 {
-		// this is just invalid
-		return true
-	}
+var serial = 0
 
-	if strings.HasPrefix(url, "wss://feeds.nostr.band") ||
-		strings.HasPrefix(url, "wss://filter.nostr.wine") ||
-		strings.HasPrefix(url, "wss://cache") {
-		return true
-	}
-
-	return false
+func pickNext(list []string) string {
+	serial++
+	return list[serial%len(list)]
+}
+
+func doThisNotMoreThanOnceAnHour(key string) (doItNow bool) {
+	if _dtnmtoah == nil {
+		go func() {
+			_dtnmtoah = make(map[string]time.Time)
+			for {
+				time.Sleep(time.Minute * 10)
+				_dtnmtoahLock.Lock()
+				now := time.Now()
+				for k, v := range _dtnmtoah {
+					if v.Before(now) {
+						delete(_dtnmtoah, k)
+					}
+				}
+				_dtnmtoahLock.Unlock()
+			}
+		}()
+	}
+
+	_dtnmtoahLock.Lock()
+	defer _dtnmtoahLock.Unlock()
+
+	_, exists := _dtnmtoah[key]
+	return !exists
 }