- singleton functionality added for component and configuration handler

[u/mrichter/AliRoot.git] / HLT / BASE / AliHLTEsdManager.h

//-*- Mode: C++ -*-
// $Id$

#ifndef ALIHLTESDMANAGER_H
#define ALIHLTESDMANAGER_H
//* This file is property of and copyright by the ALICE HLT Project        * 
//* ALICE Experiment at CERN, All rights reserved.                         *
//* See cxx source for full Copyright notice                               *

/** @file   AliHLTEsdManager.h
    @author Matthias Richter
    @date   
    @brief  Manager for merging and writing of HLT ESDs
*/

#include "AliHLTDataTypes.h"
#include "AliHLTLogging.h"
#include "TString.h"

class AliESDEvent;

/**
 * @class AliHLTEsdManager
 * Tool to write and merge HLT ESD objects.
 *
 * HLT components can produce ESD output. The ESD objects are sent via
 * a TMessage like mechanism as part of the HLTOUT data. This class retrieves
 * streamed AliESDEvent objects from an HLT output block. An ESD object can be
 * copied to a global ESD provided by the caller or to files. The name of the
 * ROOT files follows the scheme AliHLTDETESDs.root where DET denotes a detector.
 * E.g. the ESD from a data block of type {ESD_TREE,TPC} will be added to the
 * file AliHLTTPCESDs.root.
 *
 * For the sake of library (in)dependencies, the concrete implementation of
 * the AliHLTEsdManager is separated from the libHLTbase class as this would
 * introduce dependencies to AliRoot libraries. The user does not notice the
 * handling apart from the fact that an instance can not be created and
 * deleted directly. Instead 
 * <pre>
 *   AliHLTEsdManager* pManager=AliHLTEsdManager::New();
 *   // ....
 *   AliHLTEsdManager::Delete(pManager);
 * </pre>
 * must be used.
 *
 * @ingroup alihlt_aliroot_reconstruction
 */
class AliHLTEsdManager : public AliHLTLogging {
 public:
  /** create an instance of the manager */
  static AliHLTEsdManager* New();
  /** delete an instance of the manager */
  static void Delete(AliHLTEsdManager* instance);

  /**
   * Convert data buffer to ESD.
   * The buffer is supposed to describe a streamed AliESDEvent object.
   * If no target object is specified, the ESD is written to a file AliHLTdetESDs.root,
   * where 'det' is derived from the data type origin. Each time the function is invoked
   * a new event is created. Dummy events are added if the previous events did not contain
   *
   * @param pBuffer  [in] the data buffer
   * @param size     [in] data buffer size
   * @param dt       [in] data type of the block
   * @param tgtesd   [out] optional target
   * @param eventno  [in] optional event no
   */
  virtual int WriteESD(const AliHLTUInt8_t* pBuffer, AliHLTUInt32_t size, AliHLTComponentDataType dt,
	       AliESDEvent* tgtesd=NULL, int eventno=-1)=0;

  /**
   * Align all ESD to the same number of events.
   * The function adds empty events to all ESD files if their event number
   * does not match the specified one.
   * @param eventno     the desired event no
   * @return neg. error code if failed
   */
  virtual int PadESDs(int eventno)=0;

  /**
   * Set the target directory for the ESD files.
   */
  virtual void SetDirectory(const char* directory)=0;

  /**
   * Get the list of the internally created files.
   * Returns a blank separated list of the file names.
   */
  virtual TString GetFileNames(AliHLTComponentDataType dt=kAliHLTAnyDataType) const = 0;

 protected:
  /** constructor */
  AliHLTEsdManager();
  /** destructor */
  virtual ~AliHLTEsdManager();

 private:
  /** copy constructor prohibited */
  AliHLTEsdManager(const AliHLTEsdManager&);
  /** assignment operator prohibited */
  AliHLTEsdManager& operator=(const AliHLTEsdManager&);

  /** the name of the actual implementation */
  static const char* fgkImplName; //!

  /** the library of the implementation */
  static const char* fgkImplLibrary; //!

  ClassDef(AliHLTEsdManager, 0)
};

#endif