Added support for messages longer than 512 bytes. (#25)

Only expand buffer if we run out of space.

Author: corradocavalli

src/Tests/WebSocketChannelTests.cs

@@ -37,6 +37,24 @@ public async Task EchoChannelWorks()
         server.Dispose();
     }
 
+    [Fact]
+    public async Task EchoChannelWorksWithLongerText()
+    {
+        using var server = WebSocketServer.Create(EchoChannel);
+        using var client = new ClientWebSocket();
+        await client.ConnectAsync(server.Uri, CancellationToken.None);
+
+        var channel = WebSocketChannel.Create(client);
+
+        var longtext = new string('a', 1000000);
+        await channel.Writer.WriteAsync(Encoding.UTF8.GetBytes(longtext).AsMemory());
+
+        var value = await channel.Reader.ReadAsync();
+
+        Assert.Equal(longtext, Encoding.UTF8.GetString(value.Span));
+        server.Dispose();
+    }
+
     [Fact]
     public async Task EchoWorksWithTryWrite()
     {

src/WebSocketChannel/WebSocketChannel.cs

@@ -249,7 +249,14 @@ async ValueTask<ReadOnlyMemory<byte>> ReadCoreAsync(CancellationToken cancellati
                         if (received.Count == 0)
                             break;
 
-                        received = await channel.webSocket.ReceiveAsync(memoryOwner.Memory.Slice(count), cancellation).ConfigureAwait(false);
+                        if (!received.EndOfMessage && count >= memoryOwner.Memory.Length)
+                        {
+                            var tempMem = memoryOwner.Memory.Slice(0, count);
+                            memoryOwner = MemoryPool<byte>.Shared.Rent(count + 512);
+                            tempMem.CopyTo(memoryOwner.Memory);
+                        }
+
+                        received = await channel.webSocket.ReceiveAsync(memoryOwner.Memory.Slice(count, memoryOwner.Memory.Length - count), cancellation).ConfigureAwait(false);
                         count += received.Count;
                     }