DM_attribute_handling.cpp

//  =================================================================
//   managing attributes using addinfo layouts and views
//  =================================================================
 
#include <iostream>
#include <list>
#include <string>
 
#include "DM/IDatamanager.hpp"
#include "DM/IAddInfoLayout.hpp"
#include "DM/IAddInfoLayoutFactory.hpp"
 
using namespace std;
 
const char *typeNames [] = {
  "int32",  
  "uint32", 
  "int8", 
  "uint8",
  "int16",
  "uint16",
  "float",
  "double",
  "string",
  "int64",
  "cstr",
  "bool"
  };
 
void output_layout(DM::AddInfoLayoutHandle layout)
{
  for(unsigned i=0; i<layout->columns(); i++)
  {
    cout << "\t" << layout->name(i) << " (type = " << typeNames[ static_cast<int>(layout->type(i)) ] << ")" << endl;
 
    //pre-defined attribute do have a semantic. user-defined attributes have a unknown semantic and start with a '_' in the name
    DM::ColumnSemantic sem = layout->semantic(i);
    assert( (sem == DM::ColumnSemantic::null && layout->name(i)[0] == '_') ||
            (sem != DM::ColumnSemantic::null && layout->name(i)[0] != '_')    );
  }
}
 
 
void DM_attribute_handling(const char *filename)
{
  //create a point without attributs
  DM::PointHandle pt1 = DM::IPoint::New();
  assert( pt1->hasInfo() == false );  //point has no attributes (addinfo object) 
 
  //=================================================================================================================
  //now create layouts for the addinfo object
  DM::AddInfoLayoutFactoryHandle f = DM::IAddInfoLayoutFactory::New();
  f->addColumn(DM::ColumnSemantic::Amplitude);        //pre-defined attribute "Amplitude"
  f->addColumn(DM::ColumnSemantic::EchoWidth);        //pre-defined attribute "EchoWidth"
  f->addColumn(DM::ColumnType::uint32,"_testAttr");   //user-defined attribute "_testAttr" (type unsigned int)
  DM::AddInfoLayoutHandle layout1 = f->getLayout();   
 
  f->addColumn(DM::ColumnType::uint32,"_testAttr");   //user-defined attribute "_testAttr" (type unsigned int)
  DM::AddInfoLayoutHandle layout2 = f->getLayout();
 
  cout << "Layout 1:" << endl;
  output_layout(layout1);
 
  cout << "Layout 2:" << endl;
  output_layout(layout2);
 
  //create a point with 3 attribute columns
  DM::PointHandle pt2 = DM::IPoint::New(layout1); 
  assert( pt2->hasInfo() == true );     //point has an attributes
  assert( pt2->info().columns() == 3 ); //point has 3 attribute columns
 
  //cloning a point DOES NOT clone the attribute (AddInfo) object!
  DM::PointHandle pt3 = (DM::IPoint *)pt2->clone(); 
  assert( pt2->info().isNull(0) == true && pt3->info().isNull(0) == true ); ///attribute 0 (Amplitude) is not set yet
  assert( pt2->getAddInfo() == pt3->getAddInfo() );                         ///attribute object is the same for pt2 and pt3
  
  pt2->info().setFloat(0,10.23f);             ///setting attribute value
  float amp = pt3->info().getFloat(0);        
  assert( pt2->info().getFloat(0) == pt3->info().getFloat(0)) ; ///since both point use the same AddInfo object the attribute has to be same
 
 
  //to create a separate attribute object for each point, it is necessary clone it explicitly 
  DM::PointHandle pt4 = (DM::IPoint *)pt2->clone(); 
  pt4->setAddInfo( pt2->info().clone() );   //clone the attribute object
  assert( pt2->getAddInfo() != pt4->getAddInfo() ); /// p2 and p4 have different attribute objects
 
  pt2->info().setFloat(0,5.92f);  //change attribute 0 of p2
  assert( pt2->info().getFloat(0) == 5.92f && 
          pt4->info().getFloat(0) == 10.23f );
 
  
  //=================================================================================================================
  // using views only the attributes of interest are visible
  // since we want to access "_testAttr" only, we can apply a view (layout2)
  assert( pt2->info().isView() == false );
  pt2->setAddInfoView(layout2,true/*readOnly*/);
 
  assert( pt2->info().isView() == true );
  assert( layout2->columns() == 1 && pt2->info().columns() == 1 );
 
  pt2->info().setUInt32(0, 15); //set _testAttr to 15
 
  //since pt2 and pt3 point to the same attribute object the view is also applied to pt3
  assert( pt3->info().columns() == 1 && pt3->info().getUInt32(0) == 15 );
 
  //the view can be removed as well
  pt2->restoreAddInfoFullLayout();
  assert( pt2->info().isView() == false && pt2->info().columns() == 3 );
 
  unsigned value = pt3->info().getUInt32(2);  //in the real layout "_testAttr" is at index 2
  assert( value == 15 );
 
  //it is also possible to create a cloned view object, which still points to the same data object, but a new
  //attribute object is cerated. this allows to create multiple views on the same attribute data object
  pt3->cloneAddInfoView(layout2,true/*readOnly*/);
 
  assert( pt2->getAddInfo() != pt3->getAddInfo() );
  pt3->info().setUInt32(0,35);
  value = pt2->info().getUInt32(2);
  assert( pt2->info().getUInt32(2) == 35 && 
          pt3->info().getUInt32(0) == 35 ) ;
 
 
  //=================================================================================================================
  // simplified way to access attributes within an ODM by
  // list of given attribute names
  list<string> attributs;
  attributs.push_back("Amplitude");
  attributs.push_back("EchoWidth");
  attributs.push_back("_testAttr");
 
  //open the odm
  DM::DatamanagerHandle dm = DM::IDatamanager::load(filename,true/*readOnly*/,false/*threadSafety*/);
  //if the dm wasn't opened sucessful exit function
  if (!dm)
  {
    cout << "Unable to open ODM '" << filename << "'" << endl;
    return;
  }
 
  cout << "Create layout based on ODM '" << filename << "'" << endl;
  for(auto it = attributs.begin(); it != attributs.end(); ++it)
  {
    std::pair<DM::ColumnType,bool> ret = f->addColumn( *dm, it->c_str(), true/*foreAdding*/, DM::ColumnType::uint32/*defaultType*/ );
    if (ret.second == true)
      cout << "\t" << it->c_str() << " exists in ODM (type = " << typeNames[ static_cast<int>(ret.first) ] << ")" << endl;
    else      
      cout << "\t" << it->c_str() << " does NOT exist in ODM (type = " << typeNames[ static_cast<int>(ret.first) ] << ")" << endl;
  }
  DM::AddInfoLayoutHandle layout3 = f->getLayout(); 
 
  cout << "Layout 3:" << endl;
  output_layout(layout3);
}