[zeromq-dev] cppzmq revival and RFC on design goals and supported platforms

Thu May 24 13:55:33 CEST 2018

Hi Simon,
I'm talking about the issue discussed here
https://lists.zeromq.org/pipermail/zeromq-dev/2012-February/015526.html ,
yep, a long time ago..

BTW, about owning pointers. The interface of functions which take a pointer
to a buffer, but does not own it, like:
`inline message_t(void *data_, size_t size_, free_fn *ffn_, void *hint_ =
NULL)`
What if the pointer to the data is managed anywhere else? like a pointer
from std::unique_ptr<uint8_t>? in this case, definitely I dont want to
provide a deleter, because it is wrong to delete this pointer by any mean
except upon destruction of `unique_ptr` instance. So, I would end with a
piece of code like this:
`zmq::message_t msg(const_cast<void*>(data), size, [](void*, void*) {},
nullptr);`
Which is ugly as hell. Cant we just get a set of function which receive
non-owning pointers? Or an overload of existing functions with some king of
`tag` telling the message how to treat the pointer?

Sincerely,
Ernest

On Thu, May 24, 2018 at 10:14 AM, <Simon.Giesecke at btc-ag.com> wrote:

> Hi Ernest,
>
>
>
> thanks for your mail!
>
>
>
> I am not sure if I get exactly what you want to achieve by detaching.
> Maybe open an issue on github with some code sketch of how you would use
> that, and/or a PR that implements it? I am not sure what kind of “hack” you
> refer to. If it is something that could be easily misused, it might be
> better not to include it.
>
>
>
> Regarding your second question, well, the community is in charge ;) I
> personally am not working on the zguide. If you would like to improve that,
> it would be very welcome.
>
>
>
> Best wishes
>
> Simon
>
>
>
> *Von:* zeromq-dev [mailto:zeromq-dev-bounces at lists.zeromq.org] *Im
> Auftrag von *Ernest Zed
> *Gesendet:* Donnerstag, 24. Mai 2018 06:36
> *An:* ZeroMQ development list <zeromq-dev at lists.zeromq.org>
> *Betreff:* Re: [zeromq-dev] cppzmq revival and RFC on design goals and
> supported platforms
>
>
>
> Hi,
>
> It is a blessed move... so far, I'm missing few things, one of it, ability
> to detach pointer from received message and pass ownership to another
> object. I know it is not achievable by zmq, but there is a hack to
> implement it.
>
> Second, who is in charge of C++ examples? As I've reported before, the
> Paranoid Pirate example doesnt work.
>
>
>
> Sincerely,
>
> Ernest
>
>
>
> On Wed, May 23, 2018 at 10:09 PM, Gyorgy Szekely <hoditohod at gmail.com>
> wrote:
>
> Hi Simon,
>
> This is great news! We're using cppzmq in a message broker and an
> accompanying communication library for 2 years now.
>
>
>
> I fully agree with the declared goals. libzmq has a simple and concise API
> with object oriented mindset. It works well on its own, but cppzmq makes it
> a whole lot easier. What's particularly good about it:
>
> - type safety and RAII: it's very straigtforward to think in classes that
> properly clean-up resources at destruction
>
> - higher level functions: multipart messages are really nice, though the
> API is/was a bit inconsistent (socket.send(msg) vs, msg.send(socket))
>
> - header only, it's very easy to use. Header only libraries usually mean
> template heavy monsters, but fortunately not in this case
>
>
>
> What I personally really like is it's a thin wrapper and doesn't want to
> be more than libzmq. Methods usually map 1-to-1 to libzmq calls, there's no
> hidden trickery and the documentation at api.zeromq.org
> <https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fapi.zeromq.org&data=02%7C01%7Csimon.giesecke%40btc-ag.com%7C90d876b632924bc4519b08d5c12feb4f%7Cc064efb078954eebb406a40bc377bc7d%7C0%7C0%7C636627333917558531&sdata=JrTOCmytDVgVHiCOffOAv3pQ6I%2BWOJ7hVeiefD0CjQw%3D&reserved=0>
> is fully relevant.
>
>
>
> I haven't checked the recent updates (yet), but I found a few strange bits
> while working with cppzmq. Like the above mentioned sending inconsistency,
> or having to cast the socket to void* to use it in a pollset. Apart from
> that I completely agree with the direction. This is how a thin C++ wrapper
> should look like for a good base C API.
>
>
>
> BTW, we're using the lib on Ubuntu16.04 64bit / G++ 5.3, no issues so far.
>
>
>
> Regards,
>
>   Gyorgy
>
>
>
> On Wed, May 23, 2018 at 6:07 PM, <Simon.Giesecke at btc-ag.com> wrote:
>
> Hi,
>
> Pawel Kurdybacha (kurdybacha) and me (sigiesec) have recently started to
> "revive" cppzmq (https://github.com/zeromq/cppzmq
> <https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fzeromq%2Fcppzmq&data=02%7C01%7Csimon.giesecke%40btc-ag.com%7C90d876b632924bc4519b08d5c12feb4f%7Cc064efb078954eebb406a40bc377bc7d%7C0%7C0%7C636627333917558531&sdata=31MtvPSLH6oBgRyHbkUQOeRCF1hAWBbqjK%2F31hFzutk%3D&reserved=0>),
> the light-weight C++ wrapper around libzmq. We added CI for Windows/MSVC,
> Linux and MacOS, implemented tests, cleaned up the CMake infrastructure,
> formatted the source code consistently and added some overview
> documentation.
>
> If you are using cppzmq or are interested in using it, we encourage you to
> have a look at the recent changes.
>
> One particular point we would like to seek feedback on are the design
> goals, which have recently been documented for the first time. I tried to
> extrapolate them from the actual design, and from the reasons we chose to
> use cppzmq in comparison to other alternatives. These are part of the
> https://github.com/zeromq/cppzmq/blob/master/README.md
> <https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fzeromq%2Fcppzmq%2Fblob%2Fmaster%2FREADME.md&data=02%7C01%7Csimon.giesecke%40btc-ag.com%7C90d876b632924bc4519b08d5c12feb4f%7Cc064efb078954eebb406a40bc377bc7d%7C0%7C0%7C636627333917558531&sdata=JuSiHQECJNykVjawgnuhXl6%2FYl6BYiuUDp6lksqEqyc%3D&reserved=0>
> file:
>
> * cppzmq maps the libzmq C API to C++ concepts. In particular:
>    * it is type-safe (the libzmq C API exposes various class-like concepts
> as void*)
>    * it provides exception-based error handling (the libzmq C API provides
> errno-based error handling)
>    * it provides RAII-style classes that automate resource management (the
> libzmq C API requires the user to take care to free resources explicitly)
> * cppzmq is a light-weight, header-only binding. You only need to include
> the header file zmq.hpp (and maybe zmq_addon.hpp) to use it.
> * zmq.hpp is meant to contain direct mappings of the abstractions provided
> by the libzmq C API, while zmq_addon.hpp provides additional higher-level
> abstractions.
>
> We would like to here from you if you agree with these design goals. If
> you have any opposing views, proposals for improvement or extension of the
> design goals, please share them on the mailing list or by sending a PR.
>
> Another part of the README is a section on the supported platforms. Please
> review this section, in particular if you do not use MacOS, Linux or
> Windows/MSVC with a recent compiler. If you successfully use a different
> platform, please send a PR to include this in the list of "Additional
> platforms that are known to work". Support for non-C++11 compilers is
> already partial only, and might be removed completely, unless there are
> users that still require such support.
>
> Of course, you are also invited to contribute extensions, new features,
> cleanup, further tests, etc. to cppzmq.
>
> Best regards
> Simon
>
> --
> i.A. Simon Giesecke
> BTC Business Technology Consulting AG
> Kurfürstendamm 33
> 10719 Berlin
> E-Mail: Simon.Giesecke at btc-ag.com
>
> Rechtliche Hinweise:
> www.btc-ag.com/impressum.htm
> Handelsregister: Amtsgericht Oldenburg HRB 4717
> Aufsichtsratsvorsitzender: Michael Heidkamp
> Vorstand: Dr. Jörg Ritter, Dirk Thole
>
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> https://lists.zeromq.org/mailman/listinfo/zeromq-dev
> <https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.zeromq.org%2Fmailman%2Flistinfo%2Fzeromq-dev&data=02%7C01%7Csimon.giesecke%40btc-ag.com%7C90d876b632924bc4519b08d5c12feb4f%7Cc064efb078954eebb406a40bc377bc7d%7C0%7C0%7C636627333917558531&sdata=krDx3Oxa5X3cOdIjY7SapwP2jkDRjtOjmbybsYnhkCA%3D&reserved=0>
>
>
>
>
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> https://lists.zeromq.org/mailman/listinfo/zeromq-dev
> <https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.zeromq.org%2Fmailman%2Flistinfo%2Fzeromq-dev&data=02%7C01%7Csimon.giesecke%40btc-ag.com%7C90d876b632924bc4519b08d5c12feb4f%7Cc064efb078954eebb406a40bc377bc7d%7C0%7C0%7C636627333917714776&sdata=5aDm6Y6OCvXfIywP8jozDgBReWdTwxG%2BPJWIYU84ri4%3D&reserved=0>
>
>
>
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> https://lists.zeromq.org/mailman/listinfo/zeromq-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.zeromq.org/pipermail/zeromq-dev/attachments/20180524/c3c9effb/attachment.htm>