Capturing response filter ASP.NET

gistfile1.cs

class CapturingResponseFilter : Stream
{
    private Stream _sink;
    private MemoryStream mem;

    public APIAccessLogItem AccessLogItem { get; set; }

    public CapturingResponseFilter(Stream sink, APIAccessLogItem item)
    {
        _sink = sink;
        AccessLogItem = item;
        mem = new MemoryStream();
    }

    public override bool CanRead
    {
        get { return _sink.CanRead; }
    }

    public override bool CanSeek
    {
        get { return _sink.CanSeek; }
    }

    public override bool CanWrite
    {
        get { return _sink.CanWrite; }
    }

    public override long Length
    {
        get { return _sink.Length; }
    }

    public override long Position
    {
        get
        {
            return _sink.Position;
        }
        set
        {
            _sink.Position = value;
        }
    }

    public override long Seek(long offset, SeekOrigin direction)
    {
        return _sink.Seek(offset,direction);
    }

    public override void SetLength(long length)
    {
        _sink.SetLength(length);
    }

    public override void Close()
    {
        _sink.Close();
        mem.Close();
    }

    public override void Flush()
    {
        _sink.Flush();

        AccessLogItem.ResponseBody = GetContents(new UTF8Encoding(false));
        //YOU CAN STORE YOUR DATA TO YOUR DATABASE HERE
    }

    public override int Read(byte[] buffer, int offset, int count)
    {
        return _sink.Read(buffer, offset, count);
    }

    public override void Write(byte[] buffer, int offset, int count)
    {
        mem.Write(buffer, 0, count);
        _sink.Write(buffer, offset, count);
    }

    public string GetContents(Encoding enc)
    {
        var buffer = new byte[mem.Length];
        mem.Position = 0;
        mem.Read(buffer, 0, buffer.Length);
        return enc.GetString(buffer, 0, buffer.Length);
    }
}