同时从同一SslStream读取

Question

我当前正在从SslStream读取XML数据。流来自TcpClient对象。

using (XmlReader r = XmlReader.Create(sslStream, new XmlReaderSettings() { Async = true }))                
{
    while (await r.ReadAsync())
    {
        ResetStream = false;
        switch (r.NodeType)
        {
            case XmlNodeType.XmlDeclaration:
                ...
                break;
            case XmlNodeType.Element:
...

此外，我想直接从TcpClient读取每一个比特和字节，不管它是否是XML数据。我怎么能把同一条流读两遍？是否可以使用XmlReader读取并以某种方式转储流内容？

我想看看流中的内容，以及如何通过XmlReader对其进行解析以进行调试。

更新：

我想保持一个流运行，而不是有两个独立的流。由于我已经有了数据，所以在我的应用程序中，将数据再次存储在内存中是没有意义的。

Answer 1

如果刚刚读取的数据的回调对您来说是可以的，那么您可以创建一个包装器Stream来做到这一点：

public class TeeStream : Stream
{
    private readonly Stream m_underlyingStream;
    private readonly Action<byte[], int> m_readCallback;
    public TeeStream(Stream underlyingStream, Action<byte[], int> readCallback)
    {
        m_underlyingStream = underlyingStream;
        m_readCallback = readCallback;
    }
    public override int Read(byte[] buffer, int offset, int count)
    {
        var read = m_underlyingStream.Read(buffer, offset, count);
        m_readCallback(buffer, read);
        return read;
    }
    public override async Task<int> ReadAsync(
        byte[] buffer, int offset, int count,
        CancellationToken cancellationToken)
    {
        var read = await m_underlyingStream.ReadAsync(
            buffer, offset, count, cancellationToken);
        m_readCallback(buffer, read);
        return read;
    }
    // the remaining members that have to be overridden
    // just call the same member of underlyingStream
}

用法如下：

var teeStream = new TeeStream(sslStream, (bytes, read) => /* whatever */);
using (XmlReader reader = XmlReader.Create(
    teeStream, new XmlReaderSettings { Async = true }))
…

Answer 2

实现您自己的TeeStream类，该类派生自Stream，每次读取时都会写入一个MemoryStream。