Notify every device only once #23

vknabel · May 14, 2020 · 16ebcaa · 16ebcaa
1 parent 247f2a5
commit 16ebcaa
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/PufferyServer/Sources/App/Services/PushService.swift b/PufferyServer/Sources/App/Services/PushService.swift
@@ -14,7 +14,7 @@ struct PushService {
     func notifyDevices(message: Message) -> EventLoopFuture<Void> {
         notifiableDeviceTokens(message: message)
             .flatMap { devices in
-                let apnsSends = devices.filter { !$0.token.isEmpty }.map { device in
+                let apnsSends = devices.unique(\.token).filter { !$0.token.isEmpty }.map { device in
                     self.send(message: message, to: device)
                 }
                 return self.req.eventLoop.flatten(apnsSends)
@@ -71,3 +71,10 @@ struct PushService {
             .all()
     }
 }
+
+private extension Sequence {
+    func unique<V: Hashable>(_ prop: (Iterator.Element) -> V) -> [Iterator.Element] {
+        var seen: Set<V> = []
+        return filter { seen.insert(prop($0)).inserted }
+    }
+}