Flatten ReceivedMessage structure

src/ArtemisNetCoreClient/Framing/Incoming/SessionReceiveMessage.cs

@@ -1,3 +1,4 @@
+using System.Collections.Frozen;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
@@ -14,17 +15,31 @@ public SessionReceiveMessage(ReadOnlySpan<byte> buffer)
     {
         var readBytes = 0;
         readBytes += DecodeMessageBody(buffer, out var body);
-        readBytes += DecodeHeaders(buffer[readBytes..], out var headers);
+        readBytes += ArtemisBinaryConverter.ReadInt64(buffer[readBytes..], out var messageId);
+        readBytes += ArtemisBinaryConverter.ReadNullableSimpleString(buffer[readBytes..], out var address);
+        readBytes += ArtemisBinaryConverter.ReadNullableGuid(buffer[readBytes..], out var userId);
+        readBytes += ArtemisBinaryConverter.ReadByte(buffer[readBytes..], out var type);
+        readBytes += ArtemisBinaryConverter.ReadBool(buffer[readBytes..], out var durable);
+        readBytes += ArtemisBinaryConverter.ReadInt64(buffer[readBytes..], out var expiration);
+        readBytes += ArtemisBinaryConverter.ReadInt64(buffer[readBytes..], out var timestamp);
+        readBytes += ArtemisBinaryConverter.ReadByte(buffer[readBytes..], out var priority);
         readBytes += DecodeProperties(buffer[readBytes..], out var properties);
         readBytes += ArtemisBinaryConverter.ReadInt64(buffer[readBytes..], out ConsumerId);
         readBytes += ArtemisBinaryConverter.ReadInt32(buffer[readBytes..], out DeliveryCount);
 
         Message = new ReceivedMessage
         {
             Body = body,
-            Headers = headers,
+            MessageId = messageId,
+            Address = address ?? "",
+            UserId = userId,
+            Type = type,
+            Durable = durable,
+            Expiration = expiration == 0 ? DateTimeOffset.MinValue : DateTimeOffset.FromUnixTimeMilliseconds(expiration),
+            Timestamp =  timestamp == 0 ? DateTimeOffset.MinValue : DateTimeOffset.FromUnixTimeMilliseconds(timestamp),
+            Priority = priority,
             Properties = properties,
-            MessageDelivery = new MessageDelivery(ConsumerId, headers.MessageId)
+            MessageDelivery = new MessageDelivery(ConsumerId, messageId),
         };
 
         Debug.Assert(readBytes == buffer.Length, $"Expected to read {buffer.Length} bytes but got {readBytes}");
@@ -43,34 +58,6 @@ private static int DecodeMessageBody(ReadOnlySpan<byte> buffer, out ReadOnlyMemo
 
         return offset + bodyLength;
     }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static int DecodeHeaders(ReadOnlySpan<byte> buffer, out ReadOnlyHeaders value)
-    {
-        var offset = 0;
-        offset += ArtemisBinaryConverter.ReadInt64(buffer, out var messageId);
-        offset += ArtemisBinaryConverter.ReadNullableSimpleString(buffer[offset..], out var address);
-        offset += ArtemisBinaryConverter.ReadNullableGuid(buffer[offset..], out var userId);
-        offset += ArtemisBinaryConverter.ReadByte(buffer[offset..], out var type);
-        offset += ArtemisBinaryConverter.ReadBool(buffer[offset..], out var durable);
-        offset += ArtemisBinaryConverter.ReadInt64(buffer[offset..], out var expiration);
-        offset += ArtemisBinaryConverter.ReadInt64(buffer[offset..], out var timestamp);
-        offset += ArtemisBinaryConverter.ReadByte(buffer[offset..], out var priority);
-
-        value = new ReadOnlyHeaders
-        {
-            MessageId = messageId,
-            Address = address ?? "",
-            UserId = userId,
-            Type = type,
-            Durable = durable,
-            Expiration = expiration == 0 ? DateTimeOffset.MinValue : DateTimeOffset.FromUnixTimeMilliseconds(expiration),
-            Timestamp = timestamp == 0 ? DateTimeOffset.MinValue : DateTimeOffset.FromUnixTimeMilliseconds(timestamp),
-            Priority = priority
-        };
-
-        return offset;
-    }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static int DecodeProperties(ReadOnlySpan<byte> buffer, out IReadOnlyDictionary<string, object?> value)
@@ -87,7 +74,7 @@ private static int DecodeProperties(ReadOnlySpan<byte> buffer, out IReadOnlyDict
                 properties.Add(key, obj);
             }
 
-            value = properties;
+            value = properties.ToFrozenDictionary();
 
             return readBytes;
         }

src/ArtemisNetCoreClient/ReceivedMessage.cs

@@ -6,10 +6,29 @@ namespace ActiveMQ.Artemis.Core.Client;
 /// </summary>
 public class ReceivedMessage
 {
+    public required long MessageId { get; init; }
+
+    public required string Address { get; init; }
+
+    public required Guid? UserId { get; init; }
+
+    public required byte Type { get; init; }
+
+    public required bool Durable { get; init; }
+
     /// <summary>
-    /// The message headers
+    /// Gets the date and time when this message expires. If set to <see cref="DateTimeOffset.MinValue"/>,
+    /// the message is considered to never expire.
     /// </summary>
-    public required ReadOnlyHeaders Headers { get; init; }
+    public DateTimeOffset Expiration { get; init; }
+
+    /// <summary>
+    /// Gets the date and time when this message was created.
+    /// </summary>
+    public required DateTimeOffset Timestamp { get; init; }
+
+    // TODO: Enum?
+    public required byte Priority { get; init; }
 
     /// <summary>
     /// The message properties

test/ArtemisNetCoreClient.Tests/MessageExpirationSpec.cs

@@ -42,7 +42,7 @@ await producer.SendMessageAsync(new Message
         // Assert
         Assert.NotNull(receivedMessage);
         Assert.Equal("expiry_message"u8.ToArray(), receivedMessage.Body.ToArray());
-        Assert.Equal(expiration.DropTicsPrecision(), receivedMessage.Headers.Expiration);
+        Assert.Equal(expiration.DropTicsPrecision(), receivedMessage.Expiration);
     }
 
     [Fact]

test/ArtemisNetCoreClient.Tests/MessageTimestampSpec.cs

@@ -40,6 +40,6 @@ await producer.SendMessageAsync(new Message
 
         // Assert
         Assert.NotNull(receivedMessage);
-        Assert.Equal(timestamp.DropTicsPrecision(), receivedMessage.Headers.Timestamp);
+        Assert.Equal(timestamp.DropTicsPrecision(), receivedMessage.Timestamp);
     }
 }