具有 binary/byte[] 流的 SocketAsyncEventArgs

Question

我是 C# 和套接字的新手，所以如果我的问题不合时宜，我深表歉意。我开始使用 link 中的示例构建套接字接口： https://code.msdn.microsoft.com/High-Performance-NET-69c2df2f

我希望能够通过套接字传输二进制文件，所以我做了一个假设（也许是错误的假设）我不应该使用 StringBuilder。我将原来的 OSUserToken 更改为使用 MemoryStream 和 BinaryWriter（注释掉原始代码）。

在代码的其他地方（来自上面的 link），SocketAsyncEventArgs 被初始化为 SetBuffer(new Byte[_bufferSize], 0, _bufferSize);。我担心这不会与我的 MemoryStream 和 BinaryWriter 很好地融合，但它似乎有效。

sealed class UserToken : IDisposable
{
    private Socket _ownerSocket;
    public Socket ownerSocket { get { return _ownerSocket; } }

    private MemoryStream _memoryStream;
    private BinaryWriter _binaryWriter;
    //private StringBuilder stringbuilder;

    private int totalByteCount;

    public String LastError;

    public UserToken(Socket readSocket, int bufferSize)
    {
        _ownerSocket = readSocket;
        _memoryStream = new MemoryStream();
        _binaryWriter = new BinaryWriter(_memoryStream);
        //stringbuilder = new StringBuilder(bufferSize);
    }

    // Do something with the received data, then reset the token for use by another connection.
    // This is called when all of the data have been received for a read socket.
    public void ProcessData(SocketAsyncEventArgs args)
    {
        String received = System.Text.Encoding.ASCII.GetString(_memoryStream.ToArray());
        //String received = stringbuilder.ToString();

        Debug.Write("Received: \"" + received + "\". The server has read " + received.Length + " bytes.");

        _memoryStream.SetLength(0);
        //stringbuilder.Length = 0;
        totalByteCount = 0;
    }

    public bool ReadSocketData(SocketAsyncEventArgs readSocket)
    {
        int byteCount = readSocket.BytesTransferred;

        /*
        if ((totalByteCount + byteCount) > stringbuilder.Capacity)
        {
            LastError = "Receive Buffer cannot hold the entire message for this connection.";
            return false;
        }
        else
        {
        */
            //stringbuilder.Append(Encoding.ASCII.GetString(readSocket.Buffer, readSocket.Offset, byteCount));
            _binaryWriter.Write(readSocket.Buffer,readSocket.Offset,byteCount);
            totalByteCount += byteCount;
            return true;
        /*}*/
    }

    public void Dispose()
    {
        _memoryStream.Dispose();
        _binaryWriter.Dispose();
        try
        {
            _ownerSocket.Shutdown(SocketShutdown.Both);
        }
        catch
        {
            //Nothing to do here, connection is closed already
        }
        finally
        {
            _ownerSocket.Close();
        }
    }
}

当我运行这个时，它似乎没有问题。即使我设置 protected const int DEFAULT_BUFFER_SIZE = 1 它也会接受 >1 字节的流：

17:11:20:433 - Debug - Initializing the listener on port 5000...
17:11:20:439 - Debug - Starting the listener...
17:11:20:444 - Debug - Server started.
17:11:31:856 - Debug - Received: "listener". The server has read 8 bytes.
17:11:33:264 - Debug - Received: "l". The server has read 1 bytes.
17:11:33:268 - Debug - Received: "istener". The server has read 7 bytes.
17:11:36:744 - Debug - Received: "l". The server has read 1 bytes.
17:11:36:744 - Debug - Received: "i". The server has read 1 bytes.
17:11:36:746 - Debug - Received: "stener". The server has read 6 bytes.

我的问题是：

StringBuilder 不适用于二进制文件，我应该使用 MemoryStream 和 BinaryWriter 吗？
如果在程序的其他地方 SocketAsyncEventArgs 是用 SetBuffer(new Byte[_bufferSize], 0, _bufferSize); 初始化的，我是否需要担心缓冲区溢出？
如果我必须遵守缓冲区大小限制，我是否需要对发送数据的客户端设置相同的缓冲区限制？

Answer 1

我找到了问题的答案

StringBuilder 工作正常。只需在发送前对 base64 中的字符串进行编码，并在接收后进行解码。无论发送文本还是二进制数据都应该这样做。看我下面写的class
仍然不知道这个问题的答案，但看到 StringBuilder & base64 适用于二进制，此问题不再相关。
我认为这个问题的答案是肯定的。客户端应具有最大消息长度。我根据我定义消息长度的套接字的 header 部分进行控制。 header 是固定长度，我的最大消息长度是 0xFFFFF.

Class 对于 encoding/decoding base64:

public static class Base64
{
    public static string EncodeBase64(string text)
    {
        return System.Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(text));
    }

    public static string EncodeBase64(byte[] array)
    {
        return System.Convert.ToBase64String(array);
    }

    public static string DecodeBase64ToString(string base64String)
    {
        return System.Text.Encoding.UTF8.GetString(System.Convert.FromBase64String(base64String));
    }

    public static Byte[] DecodeBase64ToBinary(string base64String)
    {
        Byte[] bytes = System.Convert.FromBase64String(base64String);
        return bytes;
    }
}

具有 binary/byte[] 流的 SocketAsyncEventArgs

SocketAsyncEventArgs with binary/byte[] streams

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socketasynceventargs