Using std::chrono for passing durations

[ferchor2003]

I wanna share something that I have found really useful in my usage of the library.

I have found that in my code I have configuration parameters that are sometimes expressed in milliseconds and sometimes in seconds; I want to make sure that when reading the code I know what time units I'm dealing with. Also, I'm using Visual Studio 2015 which supports C++ 11, so I had to get rid of the nice TerminationDtmf type 👎

I have modified the Channel::Record for this purpose like this:

#if __cplusplus <= 201103L
	// Simpler, more expressive version working on C++ 11
	ProxyPar<Recording>& Record(const std::string& name, const std::string& format,
		const std::chrono::seconds& maxDurationSeconds = std::chrono::seconds::zero(),
		const std::chrono::seconds& maxSilenceSeconds = std::chrono::seconds::zero(),
		const std::string& ifExists = {}, bool beep = false, const std::string& terminateOn = "none") const
	{
		Recording recording(name, client);
		return ProxyPar<Recording>::Command(
			Method::post,
			"/ari/channels/" + id + "/record?"
			"name=" + UrlEncode(name) +
			"&format=" + format +
			"&terminateOn=" + terminateOn +
			(beep ? "&beep=true" : "&beep=false") +
			(ifExists.empty() ? "" : "&ifExists=" + ifExists) +
			(maxDurationSeconds == std::chrono::seconds::zero() ? "" : "&maxDurationSeconds=" + std::to_string(maxDurationSeconds.count())) +
			(maxSilenceSeconds == std::chrono::seconds::zero() ? "" : "&maxSilenceSeconds=" + std::to_string(maxSilenceSeconds.count())),
			client,
			recording
		);
	}
#else
  // C++ 17 version
#endif

[daniele77]

Thank you very much @ferchor2003 for commenting here.

I'm a big fan of using the right types (instead of basic types!) whenever possible. Especially for time durations.
In this case, however, I chose ints to have a default that is out of band (-1) because ARI APIs have three cases:

• no parameter
• parameter = 0
• parameter > 0

With int I mapped it in:

• default argument -1: no ARI parameter
• explicit argument 0: pass 0 to ARI
• explicit argument > 0: pass the argument to ARI

However, checking again the ARIs documentation, I guess the first two options are the same (i.e., no ARI parameter or 0 both mean: "no limit", in this case, I could consider using std::chrono::seconds as you suggested. I'm gonna add a new item to the issue tracker.

For what concerned TerminationDtmf , instead, I'm surprised that you had to remove it because it's C++11 compliant code. I tested again right now using compiler explorer and C++11 and it compiles without problems. Can you report to me the compiler error it gives you?

Thanks,
Daniele

[ferchor2003]

I just got the same error when trying to use the Channel::Snoop() method in my CallHandler class. When trying to compile something like

AstChannel->Snoop(getPlugin().getAstAppName(),
		aricpp::Channel::Direction::in,
		aricpp::Channel::Direction::none,
		"",
		"snoop."s + myId);

The compiler spits this amongst many other errors:
1> CallHandler.cpp 1>CallHandler.cpp(3044): error C2143: syntax error: missing ';' before '<end Parse>' 1> d:\aricpp\channel.h(505): note: while compiling class template static data member 'const aricpp::Channel::Direction aricpp::Channel::DirectionBase<void>::none' 1> d:\\aricpp\channel.h(86): note: see reference to class template instantiation 'aricpp::Channel::DirectionBase<void>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(66): note: see reference to class template instantiation 'boost::arg<9>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(65): note: see reference to class template instantiation 'boost::arg<8>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(64): note: see reference to class template instantiation 'boost::arg<7>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(63): note: see reference to class template instantiation 'boost::arg<6>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(62): note: see reference to class template instantiation 'boost::arg<5>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(61): note: see reference to class template instantiation 'boost::arg<4>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(60): note: see reference to class template instantiation 'boost::arg<3>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(59): note: see reference to class template instantiation 'boost::arg<2>' being compiled 1> D:\boost\boost_1_75_0\boost/bind/placeholders.hpp(58): note: see reference to class template instantiation 'boost::arg<1>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/use_future.hpp(139): note: see reference to class template instantiation 'boost::asio::use_future_t<std::allocator<void>>::std_allocator_void' being compiled 1> D:\boost\boost_1_75_0\boost/asio/use_future.hpp(147): note: see reference to class template instantiation 'boost::asio::use_future_t<std::allocator<void>>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/relationship.hpp(474): note: see reference to class template instantiation 'boost::asio::execution::detail::relationship_t<0>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/outstanding_work.hpp(475): note: see reference to class template instantiation 'boost::asio::execution::detail::outstanding_work_t<0>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/occupancy.hpp(123): note: see reference to class template instantiation 'boost::asio::execution::detail::occupancy_t<0>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/mapping.hpp(604): note: see reference to class template instantiation 'boost::asio::execution::detail::mapping_t<0>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/context.hpp(130): note: see reference to class template instantiation 'boost::asio::execution::detail::context_t<0>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/bulk_guarantee.hpp(687): note: see reference to class template instantiation 'boost::asio::execution::detail::bulk_guarantee_t<0>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/blocking_adaptation.hpp(663): note: see reference to class template instantiation 'boost::asio::execution::detail::blocking_adaptation_t<0>' being compiled 1> D:\boost\boost_1_75_0\boost/asio/execution/blocking.hpp(836): note: see reference to class template instantiation 'boost::asio::execution::detail::blocking_t<0>' being compiled

[daniele77]

From the error message I can't understand where the problem is :-(
Unfortunately, I haven't access to VS 2015 (I've only 2019 available), and I cannot reproduce the compilation error.
I hope someone else can try to compile with VS 2015 and gives us some hints about the issue.

[ferchor2003]

So I had to write a similar Channel::Snoop() function for Visual Studio 2015:

#if __cplusplus <= 201103L
	// Simpler version working on C++ 11
	Proxy& Snoop(const std::string& app, 
		const std::string& spy = "none",
		const std::string& whisper = "none",
		const std::string& appArgs = {}, const std::string& snoopId = {}) const
	{
		return Proxy::Command(
			Method::post,
			"/ari/channels/" + id + "/snoop?"
			"app=" + app +
			"&spy=" + spy +
			"&whisper=" + whisper +
			(appArgs.empty() ? "" : "&appArgs=" + appArgs) +
			(snoopId.empty() ? "" : "&snoopId=" + snoopId),
			client
		);
	}
#else
  // C++ 17 version
#endif