Added Span overloads for Socket.SendFile

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -406,6 +406,7 @@ public static void Select(System.Collections.IList? checkRead, System.Collection
         public bool SendAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
         public void SendFile(string? fileName) { }
         public void SendFile(string? fileName, byte[]? preBuffer, byte[]? postBuffer, System.Net.Sockets.TransmitFileOptions flags) { }
+        public void SendFile(string? fileName, System.ReadOnlySpan<byte> preBuffer, System.ReadOnlySpan<byte> postBuffer, System.Net.Sockets.TransmitFileOptions flags) { }
         public bool SendPacketsAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
         public int SendTo(byte[] buffer, int offset, int size, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEP) { throw null; }
         public int SendTo(byte[] buffer, int size, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEP) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Unix.cs

@@ -195,7 +195,7 @@ private static void CheckTransmitFileOptions(TransmitFileOptions flags)
             }
         }
 
-        private void SendFileInternal(string? fileName, byte[]? preBuffer, byte[]? postBuffer, TransmitFileOptions flags)
+        private void SendFileInternal(string? fileName, ReadOnlySpan<byte> preBuffer, ReadOnlySpan<byte> postBuffer, TransmitFileOptions flags)
         {
             CheckTransmitFileOptions(flags);
 
@@ -208,7 +208,7 @@ private void SendFileInternal(string? fileName, byte[]? preBuffer, byte[]? postB
             {
                 // Send the preBuffer, if any
                 // This will throw on error
-                if (preBuffer != null && preBuffer.Length > 0)
+                if (!preBuffer.IsEmpty)
                 {
                     Send(preBuffer);
                 }
@@ -230,7 +230,7 @@ private void SendFileInternal(string? fileName, byte[]? preBuffer, byte[]? postB
 
             // Send the postBuffer, if any
             // This will throw on error
-            if (postBuffer != null && postBuffer.Length > 0)
+            if (!postBuffer.IsEmpty)
             {
                 Send(postBuffer);
             }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Windows.cs

@@ -392,7 +392,7 @@ private Socket GetOrCreateAcceptSocket(Socket? acceptSocket, bool checkDisconnec
             return acceptSocket;
         }
 
-        private void SendFileInternal(string? fileName, byte[]? preBuffer, byte[]? postBuffer, TransmitFileOptions flags)
+        private void SendFileInternal(string? fileName, ReadOnlySpan<byte> preBuffer, ReadOnlySpan<byte> postBuffer, TransmitFileOptions flags)
         {
             // Open the file, if any
             FileStream? fileStream = OpenFile(fileName);

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1269,10 +1269,36 @@ public int Send(ReadOnlySpan<byte> buffer, SocketFlags socketFlags, out SocketEr
 
         public void SendFile(string? fileName)
         {
-            SendFile(fileName, null, null, TransmitFileOptions.UseDefaultWorkerThread);
+            SendFile(fileName, ReadOnlySpan<byte>.Empty, ReadOnlySpan<byte>.Empty, TransmitFileOptions.UseDefaultWorkerThread);
         }
 
         public void SendFile(string? fileName, byte[]? preBuffer, byte[]? postBuffer, TransmitFileOptions flags)
+        {
+            SendFile(fileName, preBuffer.AsSpan(), postBuffer.AsSpan(), flags);
+        }
+
+        /// <summary>
+        /// Sends the file <paramref name="fileName"/> and buffers of data to a connected <see cref="Socket"/> object
+        /// using the specified <see cref="TransmitFileOptions"/> value.
+        /// </summary>
+        /// <param name="fileName">
+        /// A <see cref="string"/> that contains the path and name of the file to be sent. This parameter can be <see langword="null"/>.
+        /// </param>
+        /// <param name="preBuffer">
+        /// A <see cref="byte"/> array that contains data to be sent before the file is sent. This parameter can be <see langword="null"/>.
+        /// </param>
+        /// <param name="postBuffer">
+        /// A <see cref="byte"/> array that contains data to be sent after the file is sent. This parameter can be <see langword="null"/>.
+        /// </param>
+        /// <param name="flags">
+        /// One or more of <see cref="TransmitFileOptions"/> values.
+        /// </param>
+        /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+        /// <exception cref="NotSupportedException">The <see cref="Socket"/> object is not connected to a remote host.</exception>
+        /// <exception cref="InvalidOperationException">The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</exception>
+        /// <exception cref="FileNotFoundException">The file <paramref name="fileName"/> was not found.</exception>
+        /// <exception cref="SocketException">An error occurred when attempting to access the socket.</exception>
+        public void SendFile(string? fileName, ReadOnlySpan<byte> preBuffer, ReadOnlySpan<byte> postBuffer, TransmitFileOptions flags)
         {
             ThrowIfDisposed();
 
@@ -1286,7 +1312,6 @@ public void SendFile(string? fileName, byte[]? preBuffer, byte[]? postBuffer, Tr
             if (NetEventSource.Log.IsEnabled()) NetEventSource.Info(this, $"::SendFile() SRC:{LocalEndPoint} DST:{RemoteEndPoint} fileName:{fileName}");
 
             SendFileInternal(fileName, preBuffer, postBuffer, flags);
-
         }
 
         // Sends data to a specific end point, starting at the indicated location in the buffer.

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -291,13 +291,13 @@ public static unsafe SocketError Send(SafeSocketHandle handle, ReadOnlySpan<byte
             return SocketError.Success;
         }
 
-        public static unsafe SocketError SendFile(SafeSocketHandle handle, SafeFileHandle? fileHandle, byte[]? preBuffer, byte[]? postBuffer, TransmitFileOptions flags)
+        public static unsafe SocketError SendFile(SafeSocketHandle handle, SafeFileHandle? fileHandle, ReadOnlySpan<byte> preBuffer, ReadOnlySpan<byte> postBuffer, TransmitFileOptions flags)
         {
             fixed (byte* prePinnedBuffer = preBuffer)
             fixed (byte* postPinnedBuffer = postBuffer)
             {
-                bool success = TransmitFileHelper(handle, fileHandle, null, preBuffer, postBuffer, flags);
-                return (success ? SocketError.Success : GetLastSocketError());
+                bool success = TransmitFileHelper(handle, fileHandle, null, (IntPtr)prePinnedBuffer, preBuffer.Length, (IntPtr)postPinnedBuffer, postBuffer.Length, flags);
+                return success ? SocketError.Success : GetLastSocketError();
             }
         }
 
@@ -1024,25 +1024,27 @@ private static unsafe bool TransmitFileHelper(
             SafeHandle socket,
             SafeHandle? fileHandle,
             NativeOverlapped* overlapped,
-            byte[]? preBuffer,
-            byte[]? postBuffer,
+            IntPtr pinnedPreBuffer,
+            int preBufferLength,
+            IntPtr pinnedPostBuffer,
+            int postBufferLength,
             TransmitFileOptions flags)
         {
             bool needTransmitFileBuffers = false;
-            Interop.Mswsock.TransmitFileBuffers transmitFileBuffers = default(Interop.Mswsock.TransmitFileBuffers);
+            Interop.Mswsock.TransmitFileBuffers transmitFileBuffers = default;
 
-            if (preBuffer != null && preBuffer.Length > 0)
+            if (preBufferLength > 0)
             {
                 needTransmitFileBuffers = true;
-                transmitFileBuffers.Head = Marshal.UnsafeAddrOfPinnedArrayElement(preBuffer, 0);
-                transmitFileBuffers.HeadLength = preBuffer.Length;
+                transmitFileBuffers.Head = pinnedPreBuffer;
+                transmitFileBuffers.HeadLength = preBufferLength;
             }
 
-            if (postBuffer != null && postBuffer.Length > 0)
+            if (postBufferLength > 0)
             {
                 needTransmitFileBuffers = true;
-                transmitFileBuffers.Tail = Marshal.UnsafeAddrOfPinnedArrayElement(postBuffer, 0);
-                transmitFileBuffers.TailLength = postBuffer.Length;
+                transmitFileBuffers.Tail = pinnedPostBuffer;
+                transmitFileBuffers.TailLength = postBufferLength;
             }
 
             bool releaseRef = false;
@@ -1077,8 +1079,10 @@ public static unsafe SocketError SendFileAsync(SafeSocketHandle handle, FileStre
                     handle,
                     fileStream?.SafeFileHandle,
                     asyncResult.DangerousOverlappedPointer, // SafeHandle was just created in SetUnmanagedStructures
-                    preBuffer,
-                    postBuffer,
+                    preBuffer is not null ? Marshal.UnsafeAddrOfPinnedArrayElement(preBuffer, 0) : IntPtr.Zero,
+                    preBuffer?.Length ?? 0,
+                    postBuffer is not null ? Marshal.UnsafeAddrOfPinnedArrayElement(postBuffer, 0) : IntPtr.Zero,
+                    postBuffer?.Length ?? 0,
                     flags);
 
                 return asyncResult.ProcessOverlappedResult(success, 0);