Re: Generating .proto files from C++ classes
On Jan 7, 8:18 pm, Kenton Varda wrote: > IMO, there's not much reason to use the protobuf wire format unless you > explicitly intend for some users to read/write the format using actual > protocol buffers. Not entirely sure what you mean. This will probably get a lot clearer once we get Mike's requirements. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
On Wed, Jan 7, 2009 at 5:39 PM, Alek Storm wrote: > > Right, I guess I didn't explain why they don't work in this case. > Generating .proto files from C++ headers is obviously the reverse of > the normal sequence. In the PB method of versioning, the > original .proto is written and deployed. The next version then writes > an extension of the original. If the .proto file is generated from C+ > + headers, every time the headers are changed, the .proto is wiped out > and replaced with a new one. This is dangerous if a new C++ class > version redefines a field - it would break old code. > > To sum up, you'd lose the benefits of the PB versioning system. You > certainly could generate .proto files from C++, but I don't know what > you'd use them for - if you wanted to generate, for example, Java > bindings from them, then just write the .proto file manually in the > first place and generate C++ and Java bindings from that. Yep, good points. > That being said, you could still use the Protocol Buffers wire format, > but you'd probably need to add a version tag to each message. You can > use extend the Boost Serialization library for this, and Mike, I have > a note or two on this if you're interested. > IMO, there's not much reason to use the protobuf wire format unless you explicitly intend for some users to read/write the format using actual protocol buffers. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
Right, I guess I didn't explain why they don't work in this case. Generating .proto files from C++ headers is obviously the reverse of the normal sequence. In the PB method of versioning, the original .proto is written and deployed. The next version then writes an extension of the original. If the .proto file is generated from C+ + headers, every time the headers are changed, the .proto is wiped out and replaced with a new one. This is dangerous if a new C++ class version redefines a field - it would break old code. To sum up, you'd lose the benefits of the PB versioning system. You certainly could generate .proto files from C++, but I don't know what you'd use them for - if you wanted to generate, for example, Java bindings from them, then just write the .proto file manually in the first place and generate C++ and Java bindings from that. That being said, you could still use the Protocol Buffers wire format, but you'd probably need to add a version tag to each message. You can use extend the Boost Serialization library for this, and Mike, I have a note or two on this if you're interested. And there's still the possibility that I've completely missed something :) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
Protocol buffers are useful even if all users are using the same language. In fact, we used them in C++ for some time before anyone bothered writing Java and Python implementations. On Wed, Jan 7, 2009 at 3:43 PM, Alek Storm wrote: > > Mike, what exactly are you trying to accomplish? Do you just want to > persist a C++ class? If so, you don't need to generate a .proto file, > because other languages won't need to read it, and you know your own > encoding layout. So you could still use the Protocol Buffers wire > format. > > > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
Mike, what exactly are you trying to accomplish? Do you just want to persist a C++ class? If so, you don't need to generate a .proto file, because other languages won't need to read it, and you know your own encoding layout. So you could still use the Protocol Buffers wire format. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
On Jan 7, 4:21 pm, Kenton Varda wrote: > SWIG translates C/C++ APIs into other programming languages. Protocol > Buffers is not a programming language, so I don't see the analogy. What > would be the protocol buffer equivalent of a C function or a C++ class? Technically, SWIG generates wrappers around C/C++ APIs from header files so higher-level languages can call them. This is roughly what he wants to do for Protocol Buffers: generate .proto schemas from C++ header files. He might want to look into extending the Boost Serialization library somehow. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
SWIG translates C/C++ APIs into other programming languages. Protocol Buffers is not a programming language, so I don't see the analogy. What would be the protocol buffer equivalent of a C function or a C++ class? On Wed, Jan 7, 2009 at 2:00 PM, mikesparr...@gmail.com < mikesparr...@gmail.com> wrote: > > SWIG is an example of a project that does something in the same vein. > > On Jan 7, 1:50 pm, Kenton Varda wrote: > > How would that work, exactly? > > > > On Wed, Jan 7, 2009 at 11:50 AM, mikesparr...@gmail.com < > > > > mikesparr...@gmail.com> wrote: > > > > > Is there an existing convert that can take a header file and produce > > > a .proto file? > > > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
SWIG is an example of a project that does something in the same vein. On Jan 7, 1:50 pm, Kenton Varda wrote: > How would that work, exactly? > > On Wed, Jan 7, 2009 at 11:50 AM, mikesparr...@gmail.com < > > mikesparr...@gmail.com> wrote: > > > Is there an existing convert that can take a header file and produce > > a .proto file? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Re: Generating .proto files from C++ classes
How would that work, exactly? On Wed, Jan 7, 2009 at 11:50 AM, mikesparr...@gmail.com < mikesparr...@gmail.com> wrote: > > Is there an existing convert that can take a header file and produce > a .proto file? > > > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
Generating .proto files from C++ classes
Is there an existing convert that can take a header file and produce a .proto file? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~--~~~~--~~--~--~---
