MulAvailable

StgSharp.Device/PortStream.cs

@@ -0,0 +1,35 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace EM.LowLevel
+{
+    /// <summary>
+    ///   High-level transport abstraction for device communication. Derives from Stream and
+    ///   encapsulates initialization/handshake and frame (header/tail/checksum) handling as needed
+    ///   by the device. Implementations may wrap SerialPort, Sockets, USB, etc.
+    /// </summary>
+    public abstract class PortStream : Stream
+    {
+
+        /// <summary>
+        ///   Optional bytes available hint if the transport can provide it.
+        /// </summary>
+        public virtual long? BytesAvailable => null;
+
+        /// <summary>
+        ///   Close the underlying transport and release resources.
+        /// </summary>
+        public abstract override void Close();
+
+        /// <summary>
+        ///   Ensure the port is opened and ready. Idempotent. May perform device-specific
+        ///   handshakes.
+        /// </summary>
+        public abstract ValueTask OpenAsync(CancellationToken cancellationToken = default);
+
+        // Concrete transports must implement Stream's abstract members.
+        // Seek-related members are typically not supported and should throw NotSupportedException.
+    }
+}