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Show HN: Hexi – Modern header-only network binary serialisation for C++

(github.com)
118 points Chaosvex | 2 comments | 28 Mar 25 17:37 UTC | HN request time: 0.409s | source

Over the last few years, I've needed an easy way to quickly serialise and deserialise various network protocols safely and efficiently. Most of the libraries that existed at the time were either quite heavy, had less than stellar performance, or were an abstraction level above what I was looking for.

I decided to put together my own class to do the job, starting with an easy, low-overhead way to move bytes in and out of arbitrary buffers. Along the way, it picked up useful bits and pieces, such as buffer structures and allocators that made the byte shuffling faster, often being able to do it with zero allocations and zero copies. Safety features came along to make sure that malicious packet data or mistakes in the code wouldn't result in segfaults or vulnerabilities.

It's become useful enough to me that I've packaged it up in its own standalone library on the chance that it might be useful to others. It has zero dependencies other than the standard library and has been designed for quick integration into any project within minutes, or seconds with a copy paste of the amalgamated header. It can be used in production code but it's also ideal for for those that want to quickly hack away at binary data with minimal fuss.

1. codedokode ◴[28 Mar 25 19:13 UTC] No.43508979[source]▶
It doesn't look like zero-copy though in this example:

    UserPacket packet;
    stream >> packet;
That is at least one copy.
replies(1): >>43509015 #
2. Chaosvex ◴[28 Mar 25 19:16 UTC] No.43509015[source]▶
Correct but it doesn't claim to be zero-copy overall. Apologies if it was misleading. In the README, zero-copy is mentioned in context of using view() and span() to obtain views into the buffer, which does allow for it. Very much a "there be dragons but if you're sure..." feature but it's there as an option.

I've also built some tooling on top that makes use of those functions to do zero-copy deserialisation where viable, so it is possible in the right scenarios with a bit of work but it definitely isn't going to always fit.