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CdbNTupleBase.hh

Go to the documentation of this file.

#ifndef CDB_NTUPLE_BASE_HH
#define CDB_NTUPLE_BASE_HH

// File and Version Information:
//      $Id: CdbNTupleBase.hh,v 1.5 2004/04/02 07:41:27 gapon Exp $

#include "CdbBase/CdbCommon.hh"

#include <string>
#include <vector>

/// A base class for abstract n-tuples.
/**
  * This class provides common metadata infrastructure for an abstract n-tuple
  * template class to prevent code bloat at the template level.
  *
  * Notes:
  *
  * - The number of columns is specified through the class's constructor.
  *
  * - The names of columns (either generated by default or explicitly passed to the corresponding
  *   constructor of n-tuple) can be used when doing queries on values of elements of the n-tuple.
  */
class CdbNTupleBase {

private:

  /// The default constructor (NOT IMPLEMENTED)
  /**
    * This constructor is disabled since we need to know the width of
    * the n-tuple.
    */
    CdbNTupleBase( );

protected:

  /// The constructor
  /**
    * The constructor will assign default names to the columns. These names will be derived
    * from relative locations of the corresponding columns in a row. For example, for an n-tuple
    * of the width of 4 we would have:
    *
    *   "#0" "#1" "#2" "#3"
    */
    CdbNTupleBase( unsigned int       theNumberOfColumns,
                   const std::string& theName,
                   const std::string& theDescription );

  /// The constructor
  /**
    * This constructor can be used to specify custom names of columns. The vector of names
    * passed as the first parameter can be of any length, where it would be shorter or longer
    * than the width of n-tuple.
    *
    * Columns naming rules:
    *
    * (1) Names passed in the vector must be unique.
    *
    * (2) Names begining with the '#' symbol are considered as "system" names.
    *     Using system names is generally prohibited, except just one case described
    *     by the rule (3) below.
    *
    * (3) The default system names assigned by the above defined constructor can only be used
    *     if their naming follows the same rules. A run-time assertion will happen in case
    *     of violation of this rule.
    *
    * (4) If the vector is shorter then elements of the vector will be used to name the first
    *     the rest of names will be filled with default names derived from relative position of
    *     the corresponding column in a row. See the above defined constructor's description
    *     for details.
    *
    * (5) If the vector is longer - then the rest of the vector will be simply ignored.
    *     No correctness checks for names in the rest of the vector would be performed.
    */
    CdbNTupleBase( unsigned int                    theNumberOfColumns,
                   const std::vector<std::string>& theCollumnNames,
                   const std::string&              theName,
                   const std::string&              theDescription );

  /// The copy constructor
  /**
    * Copy the local context.
    */
    CdbNTupleBase( const CdbNTupleBase& theOther );

  /// The assignment operator
  /**
    * Copy the local context.
    */
    CdbNTupleBase& operator=( const CdbNTupleBase& theOther );

public:

  /// The destructor
  /**
    * Just to enforce the virtual destructor.
    */
    virtual ~CdbNTupleBase( );

  /// Get the current width (the number of columns) of n-tuple

    unsigned int columns( ) const;

  /// The name of the n-tuple

    std::string name( ) const;

  /// The name can also be dynamically assigned

    void set_name( const std::string& theName );

  /// The description of the n-tuple

    std::string description( ) const;

  /// The description can also be dynamically assigned

    void set_description( const std::string& theDescription );

  /// Get a vector with all column names
  /**
    * The order of names in the vector will be exactly the same as it's
    * defined in an tuple.
    */
    void column_names( std::vector<std::string>& theVectorOfNames ) const;

  /// Get the name of specified column number
  /**
    * The column must fit into the n-tuple's width.
    * The method would return CdbStatus::NotFound if it couldn't fine the column.
    */
    CdbStatus column_name( unsigned int theNumber,
                           std::string& theName ) const;

  /// Get the number of specified column name
  /**
    * The column with specified name must be known.
    * The method would return CdbStatus::NotFound if it couldn't fine the column.
    */
    CdbStatus column_number( const std::string& theName,
                             unsigned int&      theNumber ) const;

  /// Set the name of specified column
  /**
    * The column must fit into the n-tuple's width.
    */
    CdbStatus set_column_name( unsigned int       theNumber,
                               const std::string& theName );

public:

  /// Check if specified name correspond to so called "system" names of columns
  /**
    * The rules for how these default system names will look alike are described
    * in the documentation for constructors of the class.
    *
    * @see CdbNTupleBase::CdbNTupleBase
    */
    static bool is_system_name( const std::string& theName );

  /// Get the default column name for specified column number
  /**
    * The rules for how these default names will look alike are described
    * in the documentation for constructors of the class.
    *
    * @see CdbNTupleBase::CdbNTupleBase
    */
    static std::string default_column_name( unsigned int theNumber );

private:

  // Parameters of the n-tuple

    unsigned int _ncol;

    std::string _name;
    std::string _description;

    std::vector<std::string> _columns;
};

#endif // CDB_NTUPLE_BASE_HH

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