C#: Add confirmed reads configuration (#3282)

Allows the SpacetimeDBClient to be configured with or without confirmed
reads. Like for [TypeScript], the parameter is optional -- the server
chooses the default if not set explicitly.

[TypeScript]: #3247

# Expected complexity level and risk

1

# Testing

I don't actually know what I'm doing 😅

Author: kim

sdks/csharp/src/SpacetimeDBClient.cs

@@ -21,6 +21,7 @@ public sealed class DbConnectionBuilder<DbConnection>
         string? token;
         Compression? compression;
         bool light;
+        bool? confirmedReads;
 
         public DbConnection Build()
         {
@@ -32,7 +33,7 @@ public DbConnection Build()
             {
                 throw new InvalidOperationException("Building DbConnection with a null nameOrAddress. Call WithModuleName() first.");
             }
-            conn.Connect(token, uri, nameOrAddress, compression ?? Compression.Brotli, light);
+            conn.Connect(token, uri, nameOrAddress, compression ?? Compression.Brotli, light, confirmedReads);
 #if UNITY_5_3_OR_NEWER
             if (SpacetimeDBNetworkManager._instance != null)
             {
@@ -72,6 +73,12 @@ public DbConnectionBuilder<DbConnection> WithLightMode(bool light)
             return this;
         }
 
+        public DbConnectionBuilder<DbConnection> WithConfirmedReads(bool confirmedReads)
+        {
+            this.confirmedReads = confirmedReads;
+            return this;
+        }
+
         public delegate void ConnectCallback(DbConnection conn, Identity identity, string token);
 
         public DbConnectionBuilder<DbConnection> OnConnect(ConnectCallback cb)
@@ -99,7 +106,7 @@ public DbConnectionBuilder<DbConnection> OnDisconnect(DisconnectCallback cb)
 
     public interface IDbConnection
     {
-        internal void Connect(string? token, string uri, string addressOrName, Compression compression, bool light);
+        internal void Connect(string? token, string uri, string addressOrName, Compression compression, bool light, bool? confirmedReads);
 
         internal void AddOnConnect(Action<Identity, string> cb);
         internal void AddOnConnectError(WebSocket.ConnectErrorEventHandler cb);
@@ -184,7 +191,7 @@ protected DbConnectionBase()
                     SpacetimeDBNetworkManager._instance.RemoveConnection(this);
                 }
             };
-            
+
 #if UNITY_WEBGL && !UNITY_EDITOR
             if (SpacetimeDBNetworkManager._instance != null)
                 SpacetimeDBNetworkManager._instance.StartCoroutine(ParseMessages());
@@ -484,7 +491,22 @@ public void Disconnect()
         /// </summary>
         /// <param name="uri"> URI of the SpacetimeDB server (ex: https://testnet.spacetimedb.com)
         /// <param name="addressOrName">The name or address of the database to connect to</param>
-        void IDbConnection.Connect(string? token, string uri, string addressOrName, Compression compression, bool light)
+        /// <param name="compression">The compression settings to use</param>
+        /// <param name="light">Whether or not to request light updates</param>
+        /// <param name="confirmedReads">
+        /// If set to true, instruct the server to send updates for transactions
+        /// only after they are confirmed to be durable.
+        ///
+        /// What durable means depends on the server configuration. In general,
+        /// a transaction is durable when it has been written to disk on one or
+        /// more servers.
+        ///
+        /// If set to false, instruct the server to send updates as soon as
+        /// transactions are committed in memory.
+        ///
+        /// If not set, the server chooses the default.
+        /// </param>
+        void IDbConnection.Connect(string? token, string uri, string addressOrName, Compression compression, bool light, bool? confirmedReads)
         {
             isClosing = false;
 
@@ -509,7 +531,7 @@ async Task Function()
                 {
                     try
                     {
-                        await webSocket.Connect(token, uri, addressOrName, ConnectionId, compression, light);
+                        await webSocket.Connect(token, uri, addressOrName, ConnectionId, compression, light, confirmedReads);
                     }
                     catch (Exception e)
                     {
@@ -879,8 +901,8 @@ void IDbConnection.Unsubscribe(QueryId queryId)
     /// Represents the result of parsing a database update message from SpacetimeDB.
     /// Contains updates for all tables affected by the update, with each entry mapping a table handle
     /// to its respective set of row changes (by primary key or row instance).
-    /// 
-    /// Note: Due to C#'s struct constructor limitations, you must use <see cref="ParsedDatabaseUpdate.New"/> 
+    ///
+    /// Note: Due to C#'s struct constructor limitations, you must use <see cref="ParsedDatabaseUpdate.New"/>
     /// to create new instances.
     /// Do not use the default constructor, as it will not initialize the Updates dictionary.
     /// </summary>

sdks/csharp/src/WebSocket.cs

@@ -61,7 +61,7 @@ public WebSocket(ConnectOptions options)
         private bool _isConnected = false;
         private bool _isConnecting = false;
         public bool IsConnected => _isConnected;
-#else 
+#else
         public bool IsConnected { get { return Ws != null && Ws.State == WebSocketState.Open; } }
 #endif
 
@@ -136,22 +136,28 @@ private void InitializeWebGL()
         var messagePtr = Marshal.GetFunctionPointerForDelegate((Action<int, IntPtr, int>)WebGLOnMessage);
         var closePtr = Marshal.GetFunctionPointerForDelegate((Action<int, int, IntPtr>)WebGLOnClose);
         var errorPtr = Marshal.GetFunctionPointerForDelegate((Action<int>)WebGLOnError);
-        
+
         WebSocket_Init(openPtr, messagePtr, closePtr, errorPtr);
     }
 #endif
 
-        public async Task Connect(string? auth, string host, string nameOrAddress, ConnectionId connectionId, Compression compression, bool light)
+        public async Task Connect(string? auth, string host, string nameOrAddress, ConnectionId connectionId, Compression compression, bool light, bool? confirmedReads)
         {
 #if UNITY_WEBGL && !UNITY_EDITOR
             if (_isConnecting || _isConnected) return;
-    
+
             _isConnecting = true;
             try
             {
                 var uri = $"{host}/v1/database/{nameOrAddress}/subscribe?connection_id={connectionId}&compression={compression}";
                 if (light) uri += "&light=true";
-        
+                if (confirmedReads.HasValue)
+                {
+                    // Ensure to transmit the bool as lowercase.
+                    var enabled = confirmedReads.GetValueOrDefault() ? "true" : "false";
+                    uri += $"&confirmed={enabled}";
+                }
+
                 _socketId = new TaskCompletionSource<int>();
                 var callbackPtr = Marshal.GetFunctionPointerForDelegate((Action<int>)OnSocketIdReceived);
                 WebSocket_Connect(host, uri, _options.Protocol, auth, callbackPtr);
@@ -177,6 +183,12 @@ public async Task Connect(string? auth, string host, string nameOrAddress, Conne
             {
                 uri += "&light=true";
             }
+            if (confirmedReads.HasValue)
+            {
+                // Ensure to transmit the bool as lowercase.
+                var enabled = confirmedReads.GetValueOrDefault() ? "true" : "false";
+                uri += $"&confirmed={enabled}";
+            }
             var url = new Uri(uri);
             Ws.Options.AddSubProtocol(_options.Protocol);
 
@@ -457,15 +469,15 @@ public void HandleWebGLOpen(int socketId)
                     dispatchQueue.Enqueue(() => OnConnect());
             }
         }
-        
+
         public void HandleWebGLMessage(int socketId, byte[] message)
         {
             if (socketId == _webglSocketId && OnMessage != null)
             {
                 dispatchQueue.Enqueue(() => OnMessage(message, DateTime.UtcNow));
             }
         }
-        
+
         public void HandleWebGLClose(int socketId, int code, string reason)
         {
             UnityEngine.Debug.Log($"HandleWebGLClose: {code} {reason}");
@@ -476,7 +488,7 @@ public void HandleWebGLClose(int socketId, int code, string reason)
                 dispatchQueue.Enqueue(() => OnClose?.Invoke(ex));
             }
         }
-        
+
         public void HandleWebGLError(int socketId)
         {
             UnityEngine.Debug.Log($"HandleWebGLError: {socketId}");