// edm_event.h
#ifndef INCLUDED_EDM_EVENT
#define INCLUDED_EDM_EVENT

// PURPOSE
//   Provide a repository of all data related to a given particle collision. 
//
// CLASSES
//       edm_Event: Protocol describing event data repository.
//   edm_ChunkIter: Protocol describing a read-only iterator that provides
//                  sequential access to the data chunks of an event.
//
// DESCRIPTION
//   This component describes the protocol for the event data repository.  The
//   combination of keys and handles are used to retrieve chunks from the event
//   object.
//
// More comments need to go here!

class edm_Chunk;
class edm_Key;
class edm_ConstKey;

                        // ===============
                        // CLASS edm_Event
                        // ===============

class edm_Event {

  public:
    // CREATORS
    virtual ~edm_Event();
           
    // MANIPULATORS
    virtual int addChunk(edm_Chunk *chunk) = 0;
        // Add the specified data chunk to this event and return 0 on success;
        // else return 1 if chunk is not valid.
        // NOTE: The chunk will now be owned and managed by this event object.
 
    // ACCESSORS
    virtual bool getChunk(edm_Key *key) = 0;
    virutal bool const edm_Chunk* getChunk(edm_ConstKey *key) const = 0;
        // Return the data chunk specfied by key if found; else return 0.
};

                        // ===================
                        // CLASS edm_ChunkIter
                        // ===================

class edm_ChunkIter {

  public:
    // CREATORS
    virtual ~edm_ChunkIter();
 
    // MANIPULATORS
    virtual void operator++() = 0;
        // Advance to the next data chunk.
        // The behavior is undefined if the iteration state is not valid.
 
    // ACCESSORS
    virtual operator const void *() const = 0;
        // Return non-zero if iterator is valid; else 0;
 
    virtual const edm_Chunk& operator()() const = 0;
        // Return the current data chunk.
        // The behavior is undefined if the iteration state is not valid.
};

#endif