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7 Code Example

7.1 An Example of Creating a New Component

This simple example shows how to add a component to the gamess-component package. We choose to add an IntegralEvaluatorFactory component.

  1. configure and compile gamess-component-$VERSION package.

  2. create a sidl file ”test.sidl” under components/sidl and copy it to ports/sidl 
              package Tutorial version 1.0 {
            class IntegralComponent implements-all Chemistry.QC.GaussianBasis.IntegralEvaluatorFactoryInterface,
                                                   gov.cca.Component,
                                                   gov.cca.Port,
                                                   gov.cca.ComponentRelease {
                void print_in_wrapper(in string str);
            }
          }

  3. add ”sidl/test.sidl” to ”SIDL_FILES” list and ”Tutorial.IntegralComponent-cxx” to ”COMPONENTS” list in components/MakeIncl.components

  4. Generating Babel Server Code by run ”make .Tutorial.IntegralComponent-cxx” under components directory.

  5. Edit ”components/Tutorial/cxx/Tutorial_IntegralComponent_Impl.hxx” Insert headers 
              #include <iostream>
          using namespace std;

    Under ”protected” section, add variable declarations 

              gov::cca::Services                  services_;

  6. Edit ”Tutorial_IntegralComponent_Impl.cxx” Implement ”print_in_wrapper” method 
              gamess_print_(str.c_str(),strlen(str.c_str()));

    Implement ”setServices” method 

              services_ = services;
          if (services_._is_nil()) return;
          
          gov::cca::TypeMap tm = services.createTypeMap();
          if(tm._is_nil()) {
             fprintf(stderr, "Error:: %s:%d: gov::cca::TypeMap is nil\n",
                     __FILE__, __LINE__);
             exit(1);
          }
          gov::cca::Port p = (*this);      //  Babel required casting
          if(p._is_nil()) {
             fprintf(stderr, "Error:: %s:%d: Error casting (*this) to gov::cca::Port \n",
                     __FILE__, __LINE__);
             exit(1);
          }
          
          /*
           * setup provides port
           */
          try {
             services_.addProvidesPort(p,
                                       "IntegralEvaluatorFactoryInterface",
                                       "Chemistry.QC.GaussianBasis.IntegralEvaluatorFactoryInterface",
                                       tm);
          
            //  Babel required casting
            gov::cca::ComponentRelease cr = ::babel_cast< gov::cca::ComponentRelease >(*this);
          
            services_.registerForRelease(cr);
          
          } catch (gov::cca::CCAException e) {
            cout << "Error in setting up provides port - IntegralEvaluatorFactory!" << endl;
            cout << e.getNote() << endl;
          }
          
          return;

    Edit ”releaseServices” method 

              services.removeProvidesPort("IntegralEvaluatorFactoryInterface");

  7. Create ”legacy/gamess/wrapper/test.src”, and edit 
                    subroutine gamess_print(str)
                character str*(*)
                print *,"printing in GAMESS wrapper function ----"    
                print *,str
                end

    Edit ”legacy/gamess/Makefile” by adding ”test” into ”OBJS” list.

  8. Add function header Create legacy/gamess/include/test.fh 
              #ifdef __cplusplus
          extern "C" {
          #endif
          
          void gamess_print_(const char* str,int len);
          
          #ifdef __cplusplus
          }
          #endif

    Insert the include header to ”components/Tutorial/cxx/Tutorial_IntegralComponent_Impl.cxx” 

              #include "test.fh"

  9. Do ”make” under components directory and do ”make clean;make” under legacy/gamess directories

  10. Create a driver component Do ”make” under components/drivers/cxx and do ”make clean;make” under shared directory.
  11. Test the newly added components. Under components/examples directory, create a RC file ”my_rc”. Substitue ”the-path-to-gamess-component-$VERSION” with real path to shared directory; substitute ”the-path-to-cca-chem-generic2” with the prefix of cca-chem-generic2; substitute ”the-path-scratch-directory” with the path to GAMESS scratch directory. 
              #!ccaffeine bootstrap file.
          # ------- don't change anything ABOVE this line.-------------
          path set /the-path-to-gamess-component-$VERSION-source/shared
          path append /the-path-to-prefix-of-cca-chem-generic2/lib
          
          repository get-global drivers.MyDriver
          repository get-global Chemistry.MoleculeFactory
          repository get-global GAMESS.ModelFactory
          repository get-global Tutorial.IntegralComponent
          
          instantiate drivers.MyDriver driver
          instantiate Chemistry.MoleculeFactory molecule
          instantiate GAMESS.ModelFactory model
          instantiate Tutorial.IntegralComponent integral
          
          connect driver ModelFactoryInterface model ModelFactoryInterface
          connect model MoleculeFactoryInterface molecule MoleculeFactoryInterface
          connect driver IntegralEvaluatorFactoryInterface integral IntegralEvaluatorFactoryInterface
          
          parameter model CONFIG scratchParam /the-path-to-scratch-directory
          parameter model CONFIG theoryParam RHF
          parameter model CONFIG coordParam /the-path-to-gamess-component-$VERSION-source/components/examples/h2o.xyz
          parameter model CONFIG basisSetParam STO-3
          
          go driver go
          
          disconnect driver ModelFactoryInterface model ModelFactoryInterface
          disconnect model MoleculeFactoryInterface molecule MoleculeFactoryInterface
          
          remove model
          remove driver
          remove integral
          remove molecule
          
          quit

    Do ”./rungms exam01 my_rc” for testing.

  12. Sample output 
              ...
          begin to test IntegralComponent.print_in_wrapper()
          printing in GAMESS wrapper function ----
          calling print_in_wrapper from CCA
          ##specific go command successful
          ...

7.2 An Simple Example of Adding a New Option

If you want to add an option for user to specify, such as ”–with-mypath”, the follow steps may be helpful.

  1. add 
              AC_ARG_WITH(mypath,
          [  --with-mypath     set mypath],
          [MY_PATH=$withval]
          )
          AC_SUBST(MY_PATH)

    in the file ”configure.in”.

  2. type ”autoconf” in the command line.
  3. add ”–with-mypath=the-path-you-want-to-add” to your configuration
  4. edit ”MakeIncl.user.in” to add ”mypath=@MY_PATH@”.
  5. use ”$mypath” in the makefiles with ”MakeIncl.user” included.