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[u/mrichter/AliRoot.git] / HLT / BASE / util / AliHLTBlockFilterComponent.h

// -*- Mode: C++ -*-
// @(#) $Id$

#ifndef ALIHLTBLOCKFILTERCOMPONENT_H
#define ALIHLTBLOCKFILTERCOMPONENT_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   AliHLTBlockFilterComponent.h
    @author Matthias Richter
    @date   
    @brief  A simple data block filter and merger, merges block descriptors
*/

#include "AliHLTProcessor.h"

/**
 * @class AliHLTBlockFilterComponent
 * A data block merger and filter.
 * It merges data block descriptors fulfilling the filtering rules and
 * forwards the descriptors to the output. The actual data is not touched.
 *
 * <h2>General properties:</h2>
 *
 * Component ID: \b BlockFilter                                         <br>
 * Library: \b libAliHLTUtil.so						<br>
 * Input Data Types: kAliHLTAnyDataType					<br>
 * Output Data Types: according to parameter and input blocks		<br>
 *
 * <h2>Mandatory arguments:</h2>
 * <!-- NOTE: ignore the \li. <i> and </i>: it's just doxygen formatting -->
 *      
 * <h2>Optional arguments:</h2>
 * <!-- NOTE: ignore the \li. <i> and </i>: it's just doxygen formatting -->
 * \li -datatype     <i> id origin      </i>                            <br>
 *      e.g. <tt> -datatype 'ESD_TREE' 'TPC ' </tt>                     <br>
 *      \b Note: due to the 4-character data origin it might be necessary to
 *      append a blank to the detectorname, e.g. <tt>TPC -> 'TPC '</tt>
 *
 * \li -origin  <i> origin  </i>                                        <br>
 *      e.g. -origin 'TPC ', \b Note:  the filter rule has type id 'ANY'
 *
 * \li -typeid  <i> id      </i>                                        <br>
 *      e.g. -typeid ESD_TREE, \b Note: the filter rule has origin 'ANY'
 *
 * \li -dataspec     <i> specification </i>                             <br>
 *      data specification treated as decimal number or hex number if
 *      prepended by '0x'
 *
 * \li -verbose                                                         <br>
 *      print out some more info messages, mainly for the sake of tutorials
 *
 * <h2>Configuration:</h2>
 * <!-- NOTE: ignore the \li. <i> and </i>: it's just doxygen formatting -->
 * Configuration by component arguments.
 *
 * <h2>Default CDB entries:</h2>
 * The component loads no CDB entries.
 *
 * <h2>Performance:</h2>
 * The component does not process any event data.
 *
 * <h2>Memory consumption:</h2>
 * The component does not process any event data.
 *
 * <h2>Output size:</h2>
 * No additional data is produced. Data blocks are just forwarded.
 *
 * By default, all blocks will be published. By means of the \em -datatype,
 * \em -origin, and \em -typeid arguments, the blocks can be selected. A list
 * of filter rules can be built up by multiple usage of the arguments. Each
 * time a new filter rule is added.
 *
 * No filtering by the data specification is applied unless then \em
 * -specification argument is used. The specification applies to to the
 * current filter rule, regardless of the sequence of -datatype/-specification
 * arguments.
 *
 * @ingroup alihlt_util_components
 */
class AliHLTBlockFilterComponent : public AliHLTProcessor
{
 public:
  /** standard constructor */
  AliHLTBlockFilterComponent();
  /** destructor */
  virtual ~AliHLTBlockFilterComponent();

  /**
   * The id of the component.
   * @return component id (string)
   */
  virtual const char* GetComponentID() {return "BlockFilter";};

  /**
   * Get the input data types of the component.
   * @return list of data types in the vector reference
   */
  void GetInputDataTypes( AliHLTComponentDataTypeList& );

  /**
   * Get the output data type of the component.
   * If @ref kAliHLTMultipleDataType is returned, the framework invokes
   * @ref GetOutputDataTypes.
   * @return output data type
   */
  AliHLTComponentDataType GetOutputDataType();

  /**
   * Get the output data types of the component.
   * The function can be implemented to indicate multiple output data types
   * in the target array.
   * @ref GetOutputDataType must return @ref kAliHLTMultipleDataType in order
   * to invoke this method.
   * @param tgtList          list to receive the data types
   * @return no of output data types, data types in the target list
   */
  int GetOutputDataTypes(AliHLTComponentDataTypeList& tgtList);

  /**
   * Get a ratio by how much the data volume is shrinked or enhanced.
   * @param constBase        <i>return</i>: additive part, independent of the
   *                                   input data volume  
   * @param inputMultiplier  <i>return</i>: multiplication ratio
   * @return values in the reference variables
   */
  void GetOutputDataSize( unsigned long& constBase, double& inputMultiplier );

  /**
   * Spawn function.
   * @return new class instance
   */
  virtual AliHLTComponent* Spawn() {return new AliHLTBlockFilterComponent;}

 protected:

  /**
   * Data processing method for the component.
   * Filters the incoming data descriptors according to the rules and forwards
   * them into the output.
   * @return neg. error code if failed 
   */
  int DoEvent( const AliHLTComponentEventData& evtData,
	       const AliHLTComponentBlockData* blocks, 
	       AliHLTComponentTriggerData& trigData,
	       AliHLTUInt8_t* outputPtr, 
	       AliHLTUInt32_t& size,
	       AliHLTComponentBlockDataList& outputBlocks );
  
  using AliHLTProcessor::DoEvent;

  /**
   * Component initialisation and argument scan.
   */
  int DoInit( int argc, const char** argv );

  /**
   * Component cleanup.
   */
  int DoDeinit();

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

  /**
   * Check if the data block is selected by the filter rules.
   * @return 1 if selected
   */
  int IsSelected(const AliHLTComponentBlockData& block);

  /** filtering rules, only the data type and specification members are use */
  AliHLTComponentBlockDataList fFilterRules;                       //! transient

  ClassDef(AliHLTBlockFilterComponent, 0)
};
#endif