Renci.SshNet.Sftp.SftpSession.RequestOpen C# (CSharp) Method

        public byte[] RequestOpen(string path, Flags flags, bool nullOnError = false)
        {
            byte[] handle = null;
            SshException exception = null;

            using (var wait = new AutoResetEvent(false))
            {
                var request = new SftpOpenRequest(ProtocolVersion, NextRequestId, path, Encoding, flags,
                    response =>
                        {
                            handle = response.Handle;
                            wait.Set();
                        },
                    response =>
                        {
                            exception = GetSftpException(response);
                            wait.Set();
                        });

                SendRequest(request);

                WaitOnHandle(wait, OperationTimeout);
            }

            if (!nullOnError && exception != null)
            {
                throw exception;
            }

            return handle;
        }

        internal SftpContextStream(SftpSession session, string path, FileMode mode, FileAccess access,
                                   SftpFileAttributes attributes)
        {
            Flags flags = Flags.None;

            switch (access)
            {
                case FileAccess.Read:
                    flags = Flags.Read;
                    break;
                case FileAccess.Write:
                    flags = Flags.Write;
                    break;
                case FileAccess.ReadWrite:
                    flags = Flags.Read | Flags.Write;
                    break;
            }

            switch (mode)
            {
                case FileMode.Append:
                    flags |= Flags.Append;
                    break;
                case FileMode.Create:
                    if (attributes == null)
                    {
                        flags |= Flags.CreateNew;
                    }
                    else
                    {
                        flags |= Flags.Truncate;
                    }
                    break;
                case FileMode.CreateNew:
                    flags |= Flags.CreateNew;
                    break;
                case FileMode.Open:
                    break;
                case FileMode.OpenOrCreate:
                    flags |= Flags.CreateNewOrOpen;
                    break;
                case FileMode.Truncate:
                    flags |= Flags.Truncate;
                    break;
            }

            _session = session;

            _handle = _session.RequestOpen(path, flags);

            _attributes = attributes ?? _session.RequestFStat(_handle);


            if (access.HasFlag(FileAccess.Write))
            {
                _writeBuffer = new byte[WRITE_BUFFER_SIZE];
                _writeMode = true;
            }

            _position = mode != FileMode.Append ? 0 : _attributes.Size;
        }