// XEmacs -*-C++-*-
// @(#) $Id$
#ifndef ALIHLTTPCDIGITREADER_H
#define ALIHLTTPCDIGITREADER_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 AliHLTTPCDigitReader.h
@author Timm Steinbeck, Jochen Thaeder, Matthias Richter, Kenneth Aamodt
@date
@brief An abstract reader class for TPC data.
*/
#include "AliHLTLogging.h"
#include "TObject.h"
/**
* @class AliHLTTPCDigitReader
* An abstract reader class for the TPC data. The Data is treated as a stream
* of data points, each containing row number, pad number, time bin and ADC
* value. The class hides the actual encoding of the data stream for the sub-
* sequent components like the cluster finder.
*
* Some of the data decoders allow random access of the data within one channel.
* This functionality is available for all readers if caching is enabled (see
* @ref EnableCaching).
*
* The digit reader can be locked for the current channel. If locked, function
* @ref Next will return false if data of the current channel is finnished.
* @ingroup alihlt_tpc
*/
class AliHLTTPCDigitReader : public AliHLTLogging {
public:
/** standard constructor
*/
AliHLTTPCDigitReader();
/** destructor */
virtual ~AliHLTTPCDigitReader();
/**
* Init the reader with a data block.
* The function fetches the first and last row for the readout partition
* from @ref AliHLTTPCTransform. The method is pure virtual and must be implemented
* by the child class.
* @param ptr pointer to data buffer
* @param size size of the data buffer
* @param patch patch (readout partition) number within the slice
* @param slice sector no (0 to 35)
*/
virtual int InitBlock(void* ptr,unsigned long size, Int_t patch, Int_t slice)=0;
/**
* Old Init function.
* Note: This method is for backward compatibility only, not for further
* use. The firstrow and lastrow parameters are fetched from
* @ref AliHLTTPCTransform.
*
* @param ptr pointer to data buffer
* @param size size of the data buffer
* @param firstrow first row occuring in the data
* @param lastrow last row occuring in the data
* @param patch patch (readout partition) number within the slice
* @param slice sector no (0 to 35)
*/
virtual int InitBlock(void* ptr,unsigned long size,Int_t firstrow,Int_t lastrow, Int_t patch, Int_t slice);
/**
* Set the reader position to the next value.
* If the reader was not yet initialized, initialization is carried out and
* the position set to the beginning of the stream (which is in essence the
* end of the data block due to the back-linked list).
*
* If the reader is locked for a pad/channel, Next operates only on the data
* belonging to the current channel and returns false at the end of the
* channel.
*
* The function does some basic stuff and forwards to @ref NextSignal.
* @return true if data is available, false if not
*/
bool Next();
/**
* Get the row number of the current value.
*/
virtual int GetRow()=0;
/**
* Get the pad number of the current value.
*/
virtual int GetPad()=0;
/**
* Get the current ADC value.
*/
virtual int GetSignal()=0;
/**
* Get the time bin of the current value.
*/
virtual int GetTime()=0;
/**
* Method to use old rcu fomat.
*/
virtual void SetOldRCUFormat(Bool_t oldrcuformat);
/**
* Method to set read unsorted flag.
*/
virtual void SetUnsorted(Bool_t unsorted);
/**
* Enable chaching of the current channel.
* Some of the readers allow random data access within one channel.
* The others have the possibility to cache the data in order to support
* this functionality. Caching is off by default.
* @param bCache the current channel is cached
*/
void EnableCaching(bool bCache=false);
/**
* Rewind the current channel to the beginning.
* The function uses the reader methods @ref RewindCurrentChannel or
* @ref RewindToPrevChannel to set the stream position to the beginning of the
* current channel. If the reader is locked for a channel, the function
* rewinds to the begnning of that channel.
*/
int RewindChannel();
/**
* Access operator to the data of a specific time bin.
* Not clear if we can manage this.
*/
//int operator[](int timebin);
class LockGuard {
public:
/** constructor, locks reader for the current pad */
LockGuard(AliHLTTPCDigitReader& reader)
: fReader(reader)
{reader.fLckRow=reader.GetRow(); reader.fLckPad=reader.GetPad(); reader.SetFlag(kLocked);}
/** destructor, unlocks reader */
~LockGuard()
{fReader.ClearFlag(kLocked|kChannelOverwrap); fReader.fLckRow=-1; fReader.fLckPad=-1;}
private:
/** instance of the controlled reader */
AliHLTTPCDigitReader& fReader; //!transient
};
enum {
/** reader locked for the current channel */
kLocked = 0x1,
/** stream position already at the next channel */
kChannelOverwrap = 0x2,
/** reader doe not allow channel rewind */
kNoRewind = 0x4,
/** channel caching enabled */
kChannelCaching = 0x100
};
protected:
/**
* Set the reader position to the next value.
* This is the reader specific method called by @ref Next.
*/
virtual bool NextSignal()=0;
/**
* Set a status flag of the reader.
* @return current value of the status flags
*/
unsigned int SetFlag(unsigned int flag);
/**
* Clear a status flag of the reader.
* @return current value of the status flags
*/
unsigned int ClearFlag(unsigned int flag);
/**
* Check a status flag of the reader.
*/
inline int CheckFlag(unsigned int flag) {return (fFlags&flag)!=0;}
/**
* Rewind to the beginning.of the current channel.
*/
virtual int RewindCurrentChannel();
/**
* Rewind to the beginning of the previous channel.
*/
virtual int RewindToPrevChannel();
private:
/** pad/channel is locked */
unsigned int fFlags; //!transient
/** row the reader is locked to */
int fLckRow; //!transient
/** pad the reader is locked to */
int fLckPad; //!transient
ClassDef(AliHLTTPCDigitReader, 0)
};
#endif