[AMCP] #475 Added special command REQ that can be prepended before an…

…y command to identify the response with a client specified request id, allowing a client to know exactly what asynchronous response matched a specific request.

CHANGELOG

@@ -56,6 +56,9 @@ AMCP
     values.
   o MIXER CHROMA syntax deprecated (still supported) in favour of the more
     advanced syntax required by the rewritten chroma key code.
+  o Added special command REQ that can be prepended before any command to
+    identify the response with a client specified request id, allowing a client
+    to know exactly what asynchronous response matched a specific request.
 
 
 

protocol/amcp/AMCPCommand.h

@@ -95,6 +95,7 @@ namespace amcp {
 		int					min_num_params_;
 		std::wstring		name_;
 		std::wstring		replyString_;
+		std::wstring		request_id_;
 	public:
 		AMCPCommand(const command_context& ctx, const amcp_command_func& command, int min_num_params, const std::wstring& name)
 			: ctx_(ctx)
@@ -134,9 +135,17 @@ namespace amcp {
 			return name_;
 		}
 
+		void set_request_id(std::wstring request_id)
+		{
+			request_id_ = std::move(request_id);
+		}
+
 		void SetReplyString(const std::wstring& str)
 		{
-			replyString_ = str;
+			if (request_id_.empty())
+				replyString_ = str;
+			else
+				replyString_ = L"RES " + request_id_ + L" " + str;
 		}
 	};
 }}}

protocol/amcp/AMCPCommandsImpl.cpp

@@ -2948,6 +2948,21 @@ std::wstring lock_command(command_context& ctx)
 	CASPAR_THROW_EXCEPTION(file_not_found() << msg_info(L"Unknown LOCK command " + command));
 }
 
+void req_describer(core::help_sink& sink, const core::help_repository& repo)
+{
+	sink.short_description(L"Perform any command with an additional request id identifying the response.");
+	sink.syntax(L"REQ [request_id:string] COMMAND...");
+	sink.para()
+		->text(L"This special command modifies the AMCP protocol a little bit to prepend ")
+		->code(L"RES request_id")->text(L" to the response, in order to see what asynchronous response matches what request.");
+	sink.para()->text(L"Examples:");
+	sink.example(L"REQ unique PLAY 1-0 AMB\n");
+	sink.example(
+		L">> REQ unique PLAY 1-0 AMB\n"
+		L"<< RES unique 202 PLAY OK");
+}
+
+
 void register_commands(amcp_command_repository& repo)
 {
 	repo.register_channel_command(	L"Basic Commands",		L"LOADBG",						loadbg_describer,					loadbg_command,					1);
@@ -3034,6 +3049,8 @@ void register_commands(amcp_command_repository& repo)
 	repo.register_command(			L"Query Commands",		L"HELP",						help_describer,						help_command,					0);
 	repo.register_command(			L"Query Commands",		L"HELP PRODUCER",				help_producer_describer,			help_producer_command,			0);
 	repo.register_command(			L"Query Commands",		L"HELP CONSUMER",				help_consumer_describer,			help_consumer_command,			0);
+
+	repo.help_repo()->register_item({ L"AMCP", L"Protocol Commands" }, L"REQ", req_describer);
 }
 
 }	//namespace amcp

protocol/amcp/AMCPProtocolStrategy.cpp

@@ -19,7 +19,7 @@
 * Author: Nicklas P Andersson
 */
 
- 
+
 #include "../StdAfx.h"
 
 #include "AMCPProtocolStrategy.h"
@@ -106,7 +106,7 @@ struct AMCPProtocolStrategy::impl
 	void Parse(const std::wstring& message, ClientInfoPtr client)
 	{
 		CASPAR_LOG_COMMUNICATION(info) << L"Received message from " << client->address() << ": " << message << L"\\r\\n";
-	
+
 		command_interpreter_result result;
 		if(interpret_command_string(message, result, client))
 		{
@@ -115,7 +115,7 @@ struct AMCPProtocolStrategy::impl
 			else
 				result.queue->AddCommand(result.command);
 		}
-		
+
 		if (result.error != error_state::no_error)
 		{
 			std::wstringstream answer;
@@ -157,6 +157,22 @@ struct AMCPProtocolStrategy::impl
 			if (!tokens.empty() && tokens.front().at(0) == L'/')
 				tokens.pop_front();
 
+			std::wstring request_id;
+
+			if (boost::iequals(tokens.front(), L"REQ"))
+			{
+				tokens.pop_front();
+
+				if (tokens.empty())
+				{
+					result.error = error_state::parameters_error;
+					return false;
+				}
+
+				request_id = tokens.front();
+				tokens.pop_front();
+			}
+
 			// Fail if no more tokens.
 			if (tokens.empty())
 			{
@@ -234,6 +250,9 @@ struct AMCPProtocolStrategy::impl
 				if (result.command->parameters().size() < result.command->minimum_parameters())
 					result.error = error_state::parameters_error;
 			}
+
+			if (result.command)
+				result.command->set_request_id(std::move(request_id));
 		}
 		catch (std::out_of_range&)
 		{

protocol/amcp/amcp_command_repository.cpp

@@ -225,4 +225,9 @@ void amcp_command_repository::register_channel_command(
 	self.channel_commands.insert(std::make_pair(std::move(name), std::make_pair(std::move(command), min_num_params)));
 }
 
+spl::shared_ptr<core::help_repository> amcp_command_repository::help_repo() const
+{
+	return impl_->help_repo;
+}
+
 }}}

protocol/amcp/amcp_command_repository.h

@@ -60,6 +60,7 @@ class amcp_command_repository : boost::noncopyable
 
 	void register_command(std::wstring category, std::wstring name, core::help_item_describer describer, amcp_command_func command, int min_num_params);
 	void register_channel_command(std::wstring category, std::wstring name, core::help_item_describer describer, amcp_command_func command, int min_num_params);
+	spl::shared_ptr<core::help_repository> help_repo() const;
 private:
 	struct impl;
 	spl::shared_ptr<impl> impl_;