DataArray Class Reference

Helper class for getting data words from a finesse buffer Keeps checksum counter for each extracted data word and calculates tcp checksum on request. More...

#include <TOPUnpackerModule.h>

Public Member Functions
	DataArray (const int *data, int size, bool swap=false)
	Constructor.
int	getWord ()
	Returns consecutive data word Updates internal checksum counter for each extracted word.
int	peekWord ()
	Returns next data word without incrementing the memory pointer and without modifying the checksum counter.
int	getLastWord ()
	Returns last data word.
unsigned int	getIndex () const
	Returns index of last returned data word.
int	getRemainingWords () const
	Returns number of remaining words in the buffer.
void	resetChecksum ()
	Resets internal checksum counter.
unsigned int	foldChecksum ()
	Performs folding of carry bits into checksum until only 16 LSBs are populated.
bool	validateChecksum ()
	Validates current checksum counter status.

Private Member Functions
int	swap32 (int x)
	Swap bytes of a 32-bit integer.

Private Attributes
int	m_size = 0
	buffer size
const int *	m_data = 0
	buffer data
int	m_i = 0
	index
bool	m_swap = false
	if true, swap bytes
unsigned int	m_checksumCounter
	check sum counter

Detailed Description

Helper class for getting data words from a finesse buffer Keeps checksum counter for each extracted data word and calculates tcp checksum on request.

Definition at line 38 of file TOPUnpackerModule.h.

Constructor & Destructor Documentation

DataArray()

DataArray ( const int *  data, int  size, bool  swap = false  )

inline

Constructor.

Parameters

data	pointer to finesse buffer (pointer must be valid)
size	buffer size
swap	if set to true, swap bytes

Definition at line 48 of file TOPUnpackerModule.h.

      {
        m_data = data;
        m_size = size;
        m_i = -1;
        m_swap = swap;
        m_checksumCounter = 0;
      }

Member Function Documentation

foldChecksum()

unsigned int foldChecksum ( )

inline

Performs folding of carry bits into checksum until only 16 LSBs are populated.

Returns

reduced checksum counter

Definition at line 122 of file TOPUnpackerModule.h.

      {
        unsigned int chk = m_checksumCounter;
        while ((chk >> 16) > 0) {
          chk = (chk & 0xFFFF) + (chk >> 16);
        }
        return chk;
      };

getIndex()

unsigned int getIndex ( ) const

inline

Returns index of last returned data word.

Returns

index

Definition at line 104 of file TOPUnpackerModule.h.

{return m_i;}

getLastWord()

int getLastWord ( )

inline

Returns last data word.

Returns

last data word

Definition at line 93 of file TOPUnpackerModule.h.

      {
        if (m_size <= 0) return 0;
        if (m_swap) return swap32(m_data[m_size - 1]);
        return m_data[m_size - 1];
      }

getRemainingWords()

int getRemainingWords ( ) const

inline

Returns number of remaining words in the buffer.

Returns

number of remaining words

Definition at line 110 of file TOPUnpackerModule.h.

{return m_size - m_i - 1;}

getWord()

int getWord ( )

inline

Returns consecutive data word Updates internal checksum counter for each extracted word.

Verify checksum using DataArray::validateChecksum()

Returns

data word

Definition at line 63 of file TOPUnpackerModule.h.

      {
        m_i++;
        if (m_i < m_size) {
          m_checksumCounter += (m_data[m_i] & 0xFFFF) + ((m_data[m_i] >> 16) & 0xFFFF);
          if (m_swap) return swap32(m_data[m_i]);
          return m_data[m_i];
        }
        B2ERROR("Bug in data format: DataArray - index out of range");
        return 0;
      }

peekWord()

int peekWord ( )

inline

Returns next data word without incrementing the memory pointer and without modifying the checksum counter.

Returns

data word

Definition at line 79 of file TOPUnpackerModule.h.

      {
        if (m_i + 1 < m_size) {
          if (m_swap) return swap32(m_data[m_i + 1]);
          return m_data[m_i + 1];
        }
 
        return 0;
      }

resetChecksum()

void resetChecksum ( )

inline

Resets internal checksum counter.

Call at the beginning of each new block that is checksummed.

Definition at line 116 of file TOPUnpackerModule.h.

{m_checksumCounter = 0;}

swap32()

int swap32 ( int  x )

inlineprivate

Swap bytes of a 32-bit integer.

Definition at line 146 of file TOPUnpackerModule.h.

      {
        return (((x << 24) & 0xFF000000) |
                ((x <<  8) & 0x00FF0000) |
                ((x >>  8) & 0x0000FF00) |
                ((x >> 24) & 0x000000FF));
      }

validateChecksum()

bool validateChecksum ( )

inline

Validates current checksum counter status.

Call at the end of each block that is checksummed.

Returns

checksum status, true if checksum is correct.

Definition at line 136 of file TOPUnpackerModule.h.

      {
        return (foldChecksum() == 0xFFFF);
      }

Member Data Documentation

m_checksumCounter

unsigned int m_checksumCounter

private

check sum counter

Definition at line 158 of file TOPUnpackerModule.h.

m_data

const int* m_data = 0

private

buffer data

Definition at line 155 of file TOPUnpackerModule.h.

m_i

int m_i = 0

private

index

Definition at line 156 of file TOPUnpackerModule.h.

m_size

int m_size = 0

private

buffer size

Definition at line 154 of file TOPUnpackerModule.h.

m_swap

bool m_swap = false

private

if true, swap bytes

Definition at line 157 of file TOPUnpackerModule.h.

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The documentation for this class was generated from the following file:

• top/modules/TOPUnpacker/include/TOPUnpackerModule.h