Auxiliary class to read ROOT object from database. More...

#include <JDB.hh>

Public Member Functions
	JDBReader ()
	Default constructor. More...

void	reset ()
	Reset. More...

const T &	operator() (ResultSet &rs)
	Read ROOT object from result set. More...

Private Attributes
T	object

JROOT::JRootReader	reader

std::vector< JROOT::JRootReadableClass >	buffer

Detailed Description

template<class T>
struct JDATABASE::JDBReader< T >

Auxiliary class to read ROOT object from database.

Note that the list of columns associated to the template parameter is considered to be permanent.
If not, the method JDBReader::reset should be called before the next operation.

Definition at line 216 of file JDB.hh.

Constructor & Destructor Documentation

◆ JDBReader()

template<class T>

JDATABASE::JDBReader< T >::JDBReader ( )

inline

Default constructor.

Definition at line 220 of file JDB.hh.

                 :
       object(),
       reader(JLANG::null, JLANG::JEquationParameters(), JROOT::JRootDictionary::getInstance())
     {}

Member Function Documentation

◆ reset()

template<class T>

void JDATABASE::JDBReader< T >::reset ( )

inline

Reset.

Definition at line 229 of file JDB.hh.

     {
       buffer.clear();
     }

◆ operator()()

template<class T>

const T& JDATABASE::JDBReader< T >::operator() ( ResultSet & rs )

inline

Read ROOT object from result set.

Parameters

rs	result set

Returns: object

Definition at line 241 of file JDB.hh.

     {
       using namespace std;
       using namespace JPP;
  
       object = T();
  
       if (buffer.empty()) {
  
         JRootReadableClass cls(object);
  
         for (size_t i = 0; i != rs.FieldCount(); ++i) {
  
           string parameter = rs.FieldName(i);
  
           for (string::const_iterator i = SPECIAL_CHARACTERS.begin(); i != SPECIAL_CHARACTERS.end(); ++i) {
             for (string::size_type pos; (pos = parameter.find(*i)) != string::npos; ) {
               parameter.erase(pos);
             }
           }
         
           buffer.push_back(cls.find(parameter.c_str()));
         }
       }
  
       for (unsigned int i = 0; i != rs.FieldCount(); ++i) {
  
         if (buffer[i].is_valid()) {     
  
           JRedirectString redirect(reader, rs.GetString(i));
       
           reader.getObject(buffer[i]);
         }
       }
  
       return object;
     }