Added a Delay property.

Benchmarks/Millistream.Streaming.Benchmarks/MessageBenchmarks.cs

@@ -469,6 +469,9 @@ public void AddListBytes()
         [Benchmark]
         public void SetUtf8Validation() => _message.Utf8Validation = false;
 
+        [Benchmark]
+        public void SetDelay() => _message.Delay = 1;
+
         [Benchmark]
         public void Destroy() => _message.Dispose();
 

Source/Millistream.Streaming/IMessage.cs

@@ -32,6 +32,11 @@ public interface IMessage
         /// </summary>
         bool Utf8Validation { get; set; }
 
+        /// <summary>
+        /// Gets or sets the intended delay of the message.
+        /// </summary>
+        public byte Delay { get; set; }
+
         /// <summary>
         /// Adds a new message to the message handle. If the current active message is empty it will be reused to carry this new message.
         /// </summary>

Source/Millistream.Streaming/MarketDataFeed.cs

@@ -337,7 +337,7 @@ public string Ciphers
         public int Timeout => GetInt32Property(MDF_OPTION.MDF_OPT_TIMEOUT);
 
         /// <summary>
-        /// Enables or disables delay-mode in where the server adds the intended delay to each message sent. This also enables the client to set the intended delay of the messages the client sends to the server. It's disabled by default.
+        /// Gets or sets a value indicating whether delay-mode is enabled on the connection. It's disabled by default.
         /// </summary>
         /// <exception cref="InvalidOperationException">The native value of the <see cref="MDF_OPTION.MDF_OPT_HANDLE_DELAY"/> option cannot be fetched or modified.</exception>
         /// <exception cref="ObjectDisposedException">The <see cref="MarketDataFeed{TCallbackData,TStatusCallbackData}"/> instance has been disposed.</exception>

Source/Millistream.Streaming/Message.cs

@@ -14,6 +14,7 @@ public unsafe sealed partial class Message : IMessage, IDisposable
         private readonly NativeImplementation _nativeImplementation;
         private CompressionLevel _compressionLevel = CompressionLevel.Z_BEST_SPEED;
         private bool _utf8Validation = true;
+        private byte _delay;
         private bool _isDisposed;
 
         /// <summary>
@@ -53,7 +54,6 @@ private Message(string nativeLibraryPath, bool validateArgument)
         /// <summary>
         /// Gets or sets the zlib compression level used for the <see cref="AddString(uint, string)"/> and <see cref="AddString(uint, string, int)"/> methods.
         /// </summary>
-        /// <exception cref="InvalidOperationException">The installed version of the native library doesn't support setting the zlib compression level.</exception>
         /// <exception cref="InvalidOperationException">The installed version of the native library doesn't include the mdf_message_set_property function.</exception>
         /// <exception cref="ObjectDisposedException">The <see cref="Message"/> instance has been disposed.</exception>
         public CompressionLevel CompressionLevel
@@ -134,6 +134,27 @@ public bool Utf8Validation
             }
         }
 
+        /// <summary>
+        /// Gets or sets the intended delay of the message.
+        /// </summary>
+        /// <exception cref="InvalidOperationException">The installed version of the native library doesn't include the mdf_message_set_property function.</exception>
+        /// <exception cref="ObjectDisposedException">The <see cref="Message"/> instance has been disposed.</exception>
+        public byte Delay
+        {
+            get
+            {
+                ThrowIfDisposed();
+                return _delay;
+            }
+            set
+            {
+                ThrowIfDisposed();
+                ThrowIfNativeFunctionIsMissing(_nativeImplementation.mdf_message_set_property, nameof(_nativeImplementation.mdf_message_set_property));
+                if (_nativeImplementation.mdf_message_set_property(Handle, MDF_MSG_OPTION.MDF_MSG_OPT_DELAY, value) == 1)
+                    _delay = value;
+            }
+        }
+
         internal IntPtr Handle { get; }
 
         /// <summary>

Tests/Millistream.Streaming.IntegrationTests/MessageTests.cs

@@ -49,6 +49,16 @@ public void SetUtf8ValidationTest()
             Assert.IsFalse(message.Utf8Validation);
         }
 
+        [TestMethod]
+        public void SetDelayTest()
+        {
+            using Message message = new Message();
+            Assert.AreEqual(default, message.Delay);
+            const byte Delay = byte.MaxValue;
+            message.Delay = Delay;
+            Assert.AreEqual(Delay, message.Delay);
+        }
+
         [TestMethod]
         public void AddNumericTest()
         {

Tests/Millistream.Streaming.UnitTests/MessageTests.cs

@@ -94,6 +94,19 @@ public void GetAndSetUtf8ValidationTest()
             _nativeImplementation.Verify();
         }
 
+        [TestMethod]
+        public void GetAndSetDelayTest()
+        {
+            _nativeImplementation.Setup(x => x.mdf_message_set_property(It.IsAny<IntPtr>(), (int)MDF_MSG_OPTION.MDF_MSG_OPT_DELAY, It.IsAny<int>())).Returns(1)
+                .Verifiable();
+            using Message message = new();
+            Assert.AreEqual(default, message.Delay);
+            const byte Delay = byte.MaxValue - 10;
+            message.Delay = Delay;
+            Assert.AreEqual(Delay, message.Delay);
+            _nativeImplementation.Verify();
+        }
+
         [TestMethod]
         public void AddTest()
         {
@@ -438,6 +451,14 @@ public void DeserializeEmptyStringTest() =>
         [ExpectedException(typeof(ObjectDisposedException))]
         public void CannotSetUtf8ValidationAfterDisposeTest() => GetDisposedMessage().Utf8Validation = false;
 
+        [TestMethod]
+        [ExpectedException(typeof(ObjectDisposedException))]
+        public void CannotGetDelayAfterDisposeTest() => _ = GetDisposedMessage().Delay;
+
+        [TestMethod]
+        [ExpectedException(typeof(ObjectDisposedException))]
+        public void CannotSetDelayAfterDiposeTest() => GetDisposedMessage().Delay = 1;
+
         [TestMethod]
         public void CannotCallMethodsAfterDisposeTest()
         {
@@ -535,6 +556,7 @@ public unsafe void MemberThrowsWhenNativeFunctionIsMissingTest()
             using Message message = new(nativeImplementation);
             CatchInvalidOperationException(() => message.CompressionLevel = CompressionLevel.Z_BEST_COMPRESSION, nameof(nativeImplementation.mdf_message_set_property));
             CatchInvalidOperationException(() => message.Utf8Validation = false, nameof(nativeImplementation.mdf_message_set_property));
+            CatchInvalidOperationException(() => message.Delay = 1, nameof(nativeImplementation.mdf_message_set_property));
             CatchInvalidOperationException(() => message.AddInt64(default(uint), default, default), nameof(nativeImplementation.mdf_message_add_int));
             CatchInvalidOperationException(() => message.AddInt64(default(Field), default, default), nameof(nativeImplementation.mdf_message_add_int));
             CatchInvalidOperationException(() => message.AddUInt64(default(uint), default, default), nameof(nativeImplementation.mdf_message_add_uint));