Boost C++ Libraries: Ticket #8088: Limited Forward Compatibility

attachment set

Sun, 17 Feb 2013 15:33:29 GMT

attachment → skip_unknown_tail_tags.patch

anonymous — Sat, 20 Jun 2015 00:26:38 GMT

Does anyone know when or if this patch will be accepted? We use boost to serialize classes for transmitting over CORBA and have just now run into the problem where a newer client application is sending a version 1 buffer to an older version of the server which causes an exception to be raised upon de-serialization. This patch seems like it would solve our problem.

Robert Ramey — Sat, 20 Jun 2015 00:36:16 GMT

well, this patch wouldn't change the behavior of the "older server" You'd have to upgrade that to include the new functionality. But then if you upgrade the server, you won't have the problem any more.

Never the less, I'll take a look at this.

anonymous — Sat, 20 Jun 2015 00:50:32 GMT

Yes it is an interesting situation, but it would at least prevent the problem from arising again which is another concern.

Thanks for looking into it.

Replying to ramey:

well, this patch wouldn't change the behavior of the "older server" You'd have to upgrade that to include the new functionality. But then if you upgrade the server, you won't have the problem any more.

Never the less, I'll take a look at this.

anonymous — Wed, 17 Aug 2016 14:18:42 GMT

Does anyone know if this patch has get into the codebase?

anonymous — Wed, 17 Aug 2016 14:18:45 GMT

Does anyone know if this patch has get into the codebase?

anonymous — Wed, 17 Aug 2016 14:18:47 GMT

Does anyone know if this patch has get into the codebase?

Mon, 05 Sep 2016 21:53:49 GMT

No, it hasn't. The current archive_flags enum doesn't contain skip_unknown_tail_tags https://github.com/boostorg/serialization/blob/develop/include/boost/archive/basic_archive.hpp#L237 You can apply this patch locally and rebuild the library.

ramey, does patch have any issues? I'm happy to change it according to your concerns. Also, it doesn't change a library behavior if the flag is not set

Replying to anonymous:

Does anyone know if this patch has get into the codebase?

cc set

Tue, 04 Apr 2017 12:53:04 GMT

cc pareshvarshney@… added

Does boost supports (if this made it to actual boost code) this for binary archives?

sena@… — Mon, 27 Nov 2017 10:56:08 GMT

Replying to Paresh Varshney <pareshvarshney@…>:

Does boost supports (if this made it to actual boost code) this for binary archives?

This will not be possible without 2 significant modifications:

Store the name of the field in binary_oarchive, like it is done in xml_oarchive. This way binary_iarchive will be able to identify new fields.
Store the size of the field in binary_oarchive, this way binary_iarchive will know how many bytes it should skip.

I created experimental archive which supports forward compatibility. It stores output in boost::property_tree::ptree, which can be serialized to json. Here is the link https://github.com/sena73/ptree_archive