fix tcp buffering with optimization, package updates, and C mem lib readmes

2 files changed, 51 insertions, 6 deletions

diff --git a/lib/Net.Transport.SimpleTCP/src/SocketPipeLineWorker.cs b/lib/Net.Transport.SimpleTCP/src/SocketPipeLineWorker.cs
index db87357..209ab91 100644
--- a/lib/Net.Transport.SimpleTCP/src/SocketPipeLineWorker.cs
+++ b/lib/Net.Transport.SimpleTCP/src/SocketPipeLineWorker.cs
@@ -29,6 +29,7 @@ using System.Threading;
 using System.Net.Sockets;
 using System.IO.Pipelines;
 using System.Threading.Tasks;
+using System.Runtime.InteropServices;
 
 using VNLib.Utils.Memory;
 using VNLib.Utils.Memory.Caching;
@@ -234,7 +235,7 @@ namespace VNLib.Net.Transport.Tcp
                             //Write segment to socket, and upate written data
                             int written = await sock.SendAsync(reader.Window, SocketFlags.None);
 
-                            if(written >= reader.WindowSize)
+                            if(written == reader.WindowSize)
                             {
                                 //All data was written
                                 break;
@@ -274,6 +275,7 @@ namespace VNLib.Net.Transport.Tcp
 
 
         private FlushResult _recvFlushRes;
+        private int _sysSocketBufferSize;
 
         private async Task RecvDoWorkAsync(Socket sock, bool initialData)
         {
@@ -284,7 +286,7 @@ namespace VNLib.Net.Transport.Tcp
             try
             {
                 //Avoid syscall?
-                int bufferSize = sock.ReceiveBufferSize;
+                _sysSocketBufferSize = sock.ReceiveBufferSize;
 
                 //If initial data was buffered, it needs to be published to the reader
                 if (initialData)
@@ -303,7 +305,7 @@ namespace VNLib.Net.Transport.Tcp
                 while (true)
                 {
                     //Get buffer from pipe writer
-                    Memory<byte> buffer = RecvPipe.Writer.GetMemory(bufferSize);
+                    Memory<byte> buffer = RecvPipe.Writer.GetMemory(_sysSocketBufferSize);
                     
                     //Wait for data or error from socket
                     int count = await sock.ReceiveAsync(buffer, SocketFlags.None, _cts.Token);
@@ -397,8 +399,10 @@ namespace VNLib.Net.Transport.Tcp
             SendTimer.Restart(SendTimeoutMs);
             try
             {
+                CopyAndPublishDataOnSendPipe(data);
+
                 //Send the segment
-                ValueTask<FlushResult> result = SendPipe.Writer.WriteAsync(data, cancellation);
+                ValueTask<FlushResult> result = SendPipe.Writer.FlushAsync(cancellation);
 
                 //Task completed successfully, so 
                 if (result.IsCompleted)
@@ -430,8 +434,10 @@ namespace VNLib.Net.Transport.Tcp
 
         private ValueTask SendWithoutTimerInternalAsync(ReadOnlyMemory<byte> data, CancellationToken cancellation)
         {
+            CopyAndPublishDataOnSendPipe(data);
+
             //Send the segment
-            ValueTask<FlushResult> result = SendPipe.Writer.WriteAsync(data, cancellation);
+            ValueTask<FlushResult> result = SendPipe.Writer.FlushAsync(cancellation);
 
             //Task completed successfully, so 
             if (result.IsCompleted)
@@ -454,6 +460,45 @@ namespace VNLib.Net.Transport.Tcp
             }
         }
 
+        private void CopyAndPublishDataOnSendPipe(ReadOnlyMemory<byte> src)
+        {
+            /*
+             * Clamp the buffer size to the system socket buffer size. If the 
+             * buffer is larger then, we will need to publish multiple segments
+             */
+            if(src.Length > _sysSocketBufferSize)
+            {
+                //Store local src buffer reference to copy to
+                ref byte srcRef = ref MemoryMarshal.GetReference(src.Span);
+
+                uint written = 0;
+                while (written < src.Length)
+                {
+                    int dataToCopy = (int)Math.Min(_sysSocketBufferSize, src.Length - written);
+
+                    //Get a new buffer span, and ref
+                    Span<byte> dest = SendPipe.Writer.GetSpan(dataToCopy);
+                    ref byte destRef = ref MemoryMarshal.GetReference(dest);
+
+                    //Copy data to the buffer at the new position
+                    MemoryUtil.Memmove(ref srcRef, written, ref destRef, 0, (uint)dataToCopy);
+
+                    //Advance the writer by the number of bytes written
+                    SendPipe.Writer.Advance(dataToCopy);
+
+                    //Increment the written count
+                    written += (uint)dataToCopy;
+                }
+            }
+            else
+            {
+                //Single segment, just copy to the writer
+                Span<byte> dest = SendPipe.Writer.GetSpan(src.Length);
+                src.Span.CopyTo(dest);
+                SendPipe.Writer.Advance(src.Length);
+            }
+        }
+
         ValueTask ITransportInterface.SendAsync(ReadOnlyMemory<byte> data, CancellationToken cancellation)
         {
             //Use timer if timeout is set, dont otherwise
diff --git a/lib/Net.Transport.SimpleTCP/src/VNLib.Net.Transport.SimpleTCP.csproj b/lib/Net.Transport.SimpleTCP/src/VNLib.Net.Transport.SimpleTCP.csproj
index bfd9fda..ac3e0a1 100644
--- a/lib/Net.Transport.SimpleTCP/src/VNLib.Net.Transport.SimpleTCP.csproj
+++ b/lib/Net.Transport.SimpleTCP/src/VNLib.Net.Transport.SimpleTCP.csproj
@@ -32,7 +32,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="System.IO.Pipelines" Version="7.0.0" />
+    <PackageReference Include="System.IO.Pipelines" Version="8.0.0" />
   </ItemGroup>
 
   <ItemGroup>