packing::utility::BufferReader< WordType > Class Template Reference

This class is a helper class for reading the buffer stored in the raw data format. More...

#include <BufferReader.h>

Public Member Functions
	BufferReader (const std::vector< uint8_t > &b)
	Initialize a reader by wrapping a buffer to read.
	operator bool ()
	Return state of buffer.
BufferReader &	operator>> (WordType &w)
	Streaming operator We get the next word if we are still in the buffer.

Private Member Functions
WordType	next ()
	Go to next word in buffer.

Private Attributes
const std::vector< uint8_t > &	buffer_
std::size_t	i_word_

Static Private Attributes
static const std::size_t	n_bytes_ {sizeof(WordType)}

Detailed Description

template<typename WordType>
class packing::utility::BufferReader< WordType >

This class is a helper class for reading the buffer stored in the raw data format.

The raw data format specifies that the buffer for all data is a specific type (vector of bytes), but the users in different subsystems/translators may want the buffer to be read in different size words than single bytes. This class helps in that translation.

A basic idea for using this reader is provided in the Ecal/Hcal raw decoders.

BufferReader<uint32_t> r{buffer_}; while (r >> head1 >> head2) { // do decoding, using r >> w; // to get next word in buffer }

Template Parameters

in] WordType type of word user wants to read out from buffer

Definition at line 34 of file BufferReader.h.

Constructor & Destructor Documentation

BufferReader()

template<typename WordType >

packing::utility::BufferReader< WordType >::BufferReader ( const std::vector< uint8_t > &  b )

inline

Initialize a reader by wrapping a buffer to read.

Definition at line 39 of file BufferReader.h.

: buffer_{b}, i_word_{0} {}

Member Function Documentation

next()

template<typename WordType >

WordType packing::utility::BufferReader< WordType >::next ( )

inlineprivate

Go to next word in buffer.

Note

We assume that we are always in the buffer.

Exceptions

std::out_of_range

if try to go past end of buffer

Returns

next word in buffer

Definition at line 74 of file BufferReader.h.

                  {
    WordType w{0};
    for (std::size_t i_byte{0}; i_byte < n_bytes_; i_byte++) {
      w |= (buffer_.at(i_word_ + i_byte) << 8 * i_byte);
    }
    i_word_ += n_bytes_;
    return w;
  }

Referenced by packing::utility::BufferReader< WordType >::operator>>().

operator bool()

template<typename WordType >

packing::utility::BufferReader< WordType >::operator bool ( )

inline

Return state of buffer.

false if buffer is done being read, true otherwise.

Definition at line 46 of file BufferReader.h.

{ return (i_word_ < buffer_.size()); }

operator>>()

template<typename WordType >

BufferReader & packing::utility::BufferReader< WordType >::operator>> ( WordType &  w )

inline

Streaming operator We get the next word if we are still in the buffer.

We always return ourselves so statements like

if (reader >> word1 >> word2)

can correctly fail on the first or second word.

See also

next for implementation of reading the next word

Parameters

[in]

w

reference to word to put data into

Returns

reference to us

Definition at line 61 of file BufferReader.h.

                                        {
    if (*this) w = next();
    return *this;
  }

References packing::utility::BufferReader< WordType >::next().

Member Data Documentation

buffer_

template<typename WordType >

const std::vector<uint8_t>& packing::utility::BufferReader< WordType >::buffer_

private

Definition at line 87 of file BufferReader.h.

i_word_

template<typename WordType >

std::size_t packing::utility::BufferReader< WordType >::i_word_

private

Definition at line 89 of file BufferReader.h.

n_bytes_

template<typename WordType >

const std::size_t packing::utility::BufferReader< WordType >::n_bytes_ {sizeof(WordType)}

staticprivate

Definition at line 85 of file BufferReader.h.

{sizeof(WordType)};

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

• Packing/include/Packing/Utility/BufferReader.h