From 79dbe8f387187caf552c84e5922b0d4a1669e272 Mon Sep 17 00:00:00 2001
From: Francisco Gindre <francisco@z.cash>
Date: Fri, 8 Jul 2022 16:49:24 -0300
Subject: [PATCH] [#404] Configure GRPC KeepAlive according to docs (#409)

Closes #404

This commit updates LightWalletGRPCService conform to latest
Swift-GRPC recommendations on how to set Connections KeepAlive
parameters.

See https://github.com/grpc/grpc-swift/blob/main/docs/keepalive.md
---
 .../Service/LightWalletGRPCService.swift      | 21 ++++++++++++-------
 Tests/TestUtils/Tests+Utils.swift             | 21 ++++++++++++-------
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/Sources/ZcashLightClientKit/Service/LightWalletGRPCService.swift b/Sources/ZcashLightClientKit/Service/LightWalletGRPCService.swift
index dacd8e71..7b8e72f4 100644
--- a/Sources/ZcashLightClientKit/Service/LightWalletGRPCService.swift
+++ b/Sources/ZcashLightClientKit/Service/LightWalletGRPCService.swift
@@ -112,14 +112,19 @@ public class LightWalletGRPCService {
         self.streamingCallTimeout = TimeLimit.timeout(.milliseconds(streamingCallTimeout))
         self.singleCallTimeout = TimeLimit.timeout(.milliseconds(singleCallTimeout))
 
-        let configuration = ClientConnection.Configuration(
-            target: .hostAndPort(host, port),
-            eventLoopGroup: MultiThreadedEventLoopGroup(numberOfThreads: 1),
-            connectivityStateDelegate: connectionManager,
-            connectivityStateDelegateQueue: queue,
-            tls: secure ? .init() : nil
-        )
-        let channel = ClientConnection(configuration: configuration)
+        let connectionBuilder = secure ?
+        ClientConnection.usingPlatformAppropriateTLS(for: MultiThreadedEventLoopGroup(numberOfThreads: 1)) :
+        ClientConnection.insecure(group: MultiThreadedEventLoopGroup(numberOfThreads: 1))
+
+        let channel = connectionBuilder
+            .withConnectivityStateDelegate(connectionManager, executingOn: queue)
+            .withKeepalive(
+                ClientConnectionKeepalive(
+                  interval: .seconds(15),
+                  timeout: .seconds(10)
+                )
+            )
+            .connect(host: host, port: port)
 
         self.channel = channel
 
diff --git a/Tests/TestUtils/Tests+Utils.swift b/Tests/TestUtils/Tests+Utils.swift
index e42d9ba6..4d110bc1 100644
--- a/Tests/TestUtils/Tests+Utils.swift
+++ b/Tests/TestUtils/Tests+Utils.swift
@@ -38,14 +38,21 @@ enum LightWalletEndpointBuilder {
 class ChannelProvider {
     func channel(secure: Bool = false) -> GRPCChannel {
         let endpoint = LightWalletEndpointBuilder.default
-        
-        let configuration = ClientConnection.Configuration(
-            target: .hostAndPort(endpoint.host, endpoint.port),
-            eventLoopGroup: MultiThreadedEventLoopGroup(numberOfThreads: 1),
-            tls: secure ? .init() : nil
-        )
 
-        return ClientConnection(configuration: configuration)
+        let connectionBuilder = secure ?
+        ClientConnection.usingPlatformAppropriateTLS(for: MultiThreadedEventLoopGroup(numberOfThreads: 1)) :
+        ClientConnection.insecure(group: MultiThreadedEventLoopGroup(numberOfThreads: 1))
+
+        let channel = connectionBuilder
+            .withKeepalive(
+                ClientConnectionKeepalive(
+                  interval: .seconds(15),
+                  timeout: .seconds(10)
+                )
+            )
+            .connect(host: endpoint.host, port: endpoint.port)
+
+        return channel
     }
 }