rajive/DDSChatApp

Building a peer-to-peer distributed chat application using the Data Distribution Service (DDS)

ChatApp

Building a peer-to-peer Chat application using DDS, the data connectivity framework for Internet of Things (IoT).

The examples show evolution of datatypes versions as well as multiple component implementations for a given interface.

The common aspects are described below.

Organization

Each version is organized according to the following directory structure.

• doc/<ver>/

  • a README.md for the version <ver>

• if/<ver>/

  • the component interfaces: data-oriented interfaces (DDS-XML files)

• res/types/<ver>/

  • the datatype definitions (IDL files)

• res/qos/<ver>/

  • the qos profiles (DDS-XML files)

• src/<lang>/<ver>/<variant>/

  • a component implementation in the programming language of choice (e.g. C++, C#, Lua, ...)
  • in the instructions below, impl_xyz is a placeholder for one of these

Prerequisites

• RTI Connext DDS 6.0.0+

Generated Examples as Baseline

The starting point for the examples is the generated example code from the IDL file(s) in the res/ directory.

Modifications to the generated code are marked with for code blocks as follows.

/* >>> begin */
    :
/* <<< end */

Changes to an item within a single line are marked as follows.

/*>>><<<*/

The generated example code serves as the baseline to which the above modifications are applied.

Building the components

The top-level makefile can be used to recursively build the components in the repository as follows.

• Determine your platform

  For, example on Mac OSX:

    export PLATFORM=x64Darwin17clang9.0 
  

• Generate the makefile or solutions for the platform, e.g.

    make makefile/$PLATFORM
  

  For windows platform, a visual studio solution is generated.

• Clean old artifacts

   make clean
  

• Ensure that the NDDSHOME is set to the RTI Connext DDS install directory, e.g.

   export NDDSHOME=/opt/rti/NDDSHOME
  

• [Re]Build the artifacts

   make
  

Alternatively, the steps can be implemented one at a time as follows.

Generating the XML representation of the datatypes from IDL

• Run RTI Connext Launcher > Utilities > Type Convert

        Input file: res/types/<ver>/Chat.idl
        Output directory: src/<lang>/<ver>/<variant>/
  

• OR (non-Windows), simply use the makefile in the res/types/<ver>/ directory:

        cd res/types/<ver>/Chat.idl
        make
  

Generating the datatype handling code for a target language

• Run RTI Connext Launcher > Utilities > Code Generator

       Input file: res/types/<ver>/Chat.idl
       Output directory: src/<lang>/<ver>/<variant>/
       
       Language: Traditional C++ (namespaces)   
         -language C++ -unboundedSupport  -namespace -useStdString    
                       
       Example files: <disable>
       Type files: update
       Makefiles: update
       
      Confirm command: Y
      Run
  

  • On the command line

    • copy and paste the generated command line into a terminal window

    • append any additional arguments, e.g. ** -useStdString **

    • execute

       rtiddsgen -ppDisable -language C++ -unboundedSupport -namespace -useStdString -platform $PLATFORM -updatetypefiles -update makefiles -update examplefiles -d src/cpp res/types/Chat.idl 
      

• OR, simply use the makefile:

     cd src/<lang>/<ver>/<variant>/
     make Chat.h
  

Building the components

• Open Terminal

    RTI Connext Launcher > Utilities > Code Generator > Open Terminal
  

• Do the following steps in that terminal window.

• Switch to the component directory:

    cd src/<lang>/<ver>/<variant>/
  

• Build the C++ code

  • Linux | MacOS

        make
    

  • Windows

        Open Visual Studio Solution
    

Running the components (any language)

• Switch to the top-level working directory

  cd

• Define the list of DDS-XML files to be loaded via the NDDS_QOS_PROFILES environment variable

  • QoS profiles

    export NDDS_QOS_PROFILES="res/qos/MyService_qos.xml"
    

  • XML App Creation

    export NDDS_QOS_PROFILES="res/qos/MyService_qos.xml;if/MyService.xml"
    

Running the C++ components

• Run Subscriber Example:

    ./src/<lang>/<ver>/<variant>/objs/$PLATFORM/Chat_subscriber
  

• Run Publisher Example:

    ./src/<lang>/<ver>/<variant>/objs/$PLATFORM/Chat_publisher
  

Running the C# components

Replace Debug-VS2010 with your target

• Run Subscriber Example:

    ./src/<lang>/<ver>/<variant>/bin/Debug-VS2010/Chat_subscriber.exe
  

• Run Publisher Example:

    ./src/<lang>/<ver>/<variant>/bin/Debug-VS2010/Chat_publisher.exe
  

Running the Lua components

• Run Subscriber Example:

    rtiddsprototyper -cfgName MyServiceIfLib::Sub -luaFile src/lua/Chat_subscriber.lua
  

• Run Publisher Example:

    rtiddsprototyper -cfgName MyServiceIfLib::Pub -luaFile src/lua/Chat_publisher.lua
  

Running the Python components

• Run Subscriber Example:

    python src/python/Chat_reader.py
  

• Run Publisher Example:

    python src/python/Chat_writer.py 
  

Running the Web Integration Service components

• svc/web/README.md