Cap’n Proto • Hacker News Board

Re: Cap’n Proto

#191

Post by easytiger » Tue, Sep 13, 2016, 10:11 AM UTC

easytiger wrote: post #190

kentonv wrote: post #186

Earlier quoted context omitted.

You can certainly serialize to a byte array. The example uses a file descriptor but in fact the code defines an abstract stream type which you can implement any way you want, and you can also obtain pointers to the message's underlying storage in order to extract the bytes directly (avoiding a copy).

Great thanks. I'll give it a go again for a current project I'm kicking off.

i've had a look in kj/io.h

I see the classes: ArrayOutputStream/VectorOutputStream, i assumed these are the ones you are discussing.

Re: Cap’n Proto

#192

Post by chaotic-good » Tue, Sep 13, 2016, 2:31 PM UTC

kentonv wrote: post #187

chaotic-good wrote: post #171

I think that compression is a must for the serialization library. Protobuf uses almost twice less memory than Cap'n Proto. Using an external compression is not an option in some cases. E.g. consider building tcp-server that communicates with thousands of clients simultaneously. Each client connection will have its own LZ4 context that should be heap allocated. I believe it's about 16KB per connection + buffers. This…

Cap'n Proto offers "packed" encoding which applies light compression (removing zero-valued padding bytes), brings it in-line with Protobuf, and ought to be much faster than the things Protobuf does for "compression" (varint is a very slow encoding!).

I'm glad that I was wrong about it.

Re: Cap’n Proto

#193

Post by Twonneilb22ll » Wed, Sep 14, 2016, 12:23 AM UTC

I'm happy to hear from you all in glad to see you're doing all you can for updates Programs codes appreciate the hard work

Re: Cap’n Proto

#194

Post by jcoffland » Wed, Sep 14, 2016, 5:26 PM UTC

kentonv wrote: post #166

jcoffland wrote: post #165

Earlier quoted context omitted.

Right, but you should be able to compile a library with either MinGW or clang from Linux that your users can use with MSVC.

Not if it uses C++. MinGW uses the G++ ABI which is totally incompatible with the MSVC ABI. (Also, a lot of the issues we face affect headers, which need to be compiled into the client projects.)

Since the code is so small and in C++ why not make it a header only library?