// EventHeader.h

#ifndef EventHeader_EventHeader_H
#define EventHeader_EventHeader_H

// ATLAS event header. Collection of peresistent location
// strings indexed by content (type and key). The persistency
// mechanism is responsible for interpreting the location.
// For POOL, these could be token strings.
//
// If string is not appropriate, this class can be replaced
// by a template with the appropriate type as argument.

#include <string>
#include <map>
#include "EventHeader/ContentId.h"

class EventHeader {

public:  // typedefs

  typedef std::string Location;
  typedef std::map<ContentId,Location> Map;
  typedef Map::size_type size_type;
  typedef Map::const_iterator const_iterator;

public:  // functions

  // Constructor.
  EventHeader();

  // Add an entry.
  // Returns 0 if content is invalid or already appears.
  // Returns the size of the container for success.
  size_type insert(const ContentId& cid, Location loc);

  // Size.
  size_type size() const { return m_map.size(); }

  // Find an entry.
  // Returns the iterator for the specified content.
  const_iterator find(const ContentId& cid);

  // Return begin iterator over pair<ContentId,Location>.
  const_iterator begin() const { return m_map.begin(); }

  // Return end iterator.
  const_iterator end() const { return m_map.end(); }

private:  //data

  Map m_map;

};

// Output stream.
std::ostream& operator<<(ostream& lhs, const EventHeader& rhs);

#endif