Robert Ramey schrieb:

Christian R�ssel wrote:

...

Dear all,

I want to receive a boost::archive::text_iarchive using the boost::asio::read_until () function.

boost::asio::streambuf response; boost::asio::read_until(socket, response, boost::regex("\r\n")); std::istream responseStream(&response); boost::archive::text_iarchive responseArchive (responseStream); responseArchive >> retVal;

The data is sent using code linke this:

boost::asio::streambuf response; std::ostream commandStream (&response); boost::archive::text_oarchive responseArchive (commandStream); const ReturnValue retVal (42); responseArchive << retVal; boost::asio::write(socket, response);

If I use boost::regex("\r\n") or a character that does not occur in the sent archive, read_until throws an eof exception. If I use a delimiter that is contained in the archive, read_until succeeds and the streambuf does contain the entire archive, not only up to the delimiter.

What is the correct way to read the entire archive without throwing an exception?

I think the "correct way is to be sure the archive is destroyed before sending. This should append a /n at the end - (at least in 1.34 - this might be a problem with previous versions - or maybe not.) So the above would look like:

Appending a '\n' by destroying the archive does not work with boost 1.33.1, at least in my case.

boost::asio::streambuf response; std::ostream commandStream (&response); { boost::archive::text_oarchive responseArchive (commandStream); const ReturnValue retVal (42); responseArchive << retVal; } // archive closed appends /n at this point. boost::asio::write(socket, response);

or you could just append a \n to commandStream

This did the job for me. Thanks. But there is still Christophers question:

Is there a guarantee that a "\n" delimiter will not occur in the middle of the serialised output?

Cheers, Christian

Hi Robert, Robert Ramey wrote:

No- in fact it does. I appears on text archives and xml archives in order to enhance readability by humans.

its treated as white space by input streams so it should be no problem.

That may be true for iostreams and the serialization library, but it's not true with respect to delimiters for use with Boost.Asio's read_until function. Is there any character that is guaranteed not to appear in the output of a text archive? I'm guessing there isn't one, so I would recommend that Christian use the approach of the serialization example included with Boost.Asio, which is to have a fixed size message header containing the length of the message body. Cheers, Chris