digdiv Class Reference

Cut a string up as blocks of strings. More...

#include <streamconversion.h>

Collaboration diagram for digdiv:

List of all members.

Public Member Functions
void	forward (string const &in)
	Read the string into vi as blocks.
void	reverse (string &os)
	Write the blocks in vi out as a continuous string.
void	save (ostream &os) const
	Save this objects state.
void	restore (istream &in)
	Restore this object to the former state.
template<typename T >
void	eval (T &fn)
	Apply a function to vi[i].
Public Attributes
uint	blksz
	Block size.
vector< string >	vi
	A string of blocks.

---

Detailed Description

Cut a string up as blocks of strings.

This last string is padded with 0's. This operation is reversible and support for stream writing is included so the string can be written and read from a stream.

The class is designed to process the data as a block of strings. Strings are superior to streams for many reasons, mainly simplicity and reliability and use. Streams are a lower form of data.

Definition at line 36 of file streamconversion.h.

---

Member Function Documentation

template<typename T >

void digdiv::eval

(

T &

fn

)

[inline]

Apply a function to vi[i].

Definition at line 69 of file streamconversion.h.

References vi.

{
  if (vi.empty())
    return;

  uintc sz = vi.size();
  for (uint i=0; i<sz; ++i)
  {
    fn(vi[i],vi[i]);
  }

}

void digdiv::forward

(

string const &

in

)

Read the string into vi as blocks.

Definition at line 74 of file streamconversion.cpp.

References blksz, and vi.

Referenced by rsatest::test01().

{
  assert(blksz>0);

  uintc sz = in.size();
  uint i=0;
  vi.clear();
  i += blksz;
  for ( ; i<=sz; )
  {
    vi.push_back(in.substr(i-blksz,blksz));
    i += blksz;
  }  

  if ((sz%blksz)!=0)
  {
    pad = blksz - (sz%blksz);
    string s;
    for (uint k=0; k<pad; ++k)
      s += '0';
    s += in.substr(i-blksz);
    vi.push_back(s);
  }
  else
    pad=0;
}

void digdiv::restore

(

istream &

in

)

Restore this object to the former state.

Definition at line 154 of file streamconversion.cpp.

References blksz, and vi.

{
  if (in.eof()==false)
    in >> pad;
  else
    return;

  if (in.eof()==false)
    in >> blksz;
  else
    return;

  string s;
  in >> s;
  while (in.eof()==false)
  {
    vi.push_back(s);
    s.clear();
    in >> s;
  }
}

void digdiv::reverse

(

string &

os

)

Write the blocks in vi out as a continuous string.

Definition at line 101 of file streamconversion.cpp.

References blksz, and vi.

Referenced by rsatest::test01().

{
  if (vi.empty())
    return;

  os.clear();
  
  uintc sz = vi.size();

  // Correct the block sizes
  for (uint i=0; i<sz; ++i)
  {
    uintc si = vi[i].size();
    if (si != blksz)
    {
      if (si<blksz)
      {
        string tmp;
        for (uint k=si; k<blksz; ++k)
          tmp += '0';
        tmp += vi[i];
        vi[i] = tmp;
      }
      else
      {
        // A function should reduce the block size.
        assert(false);
      }
    }
  }
      
  if (pad==0)
  {
    for (uint i=0; i<sz; ++i)
      os += vi[i];
    return;
  }

  string last = vi[sz-1];
  last = last.substr(pad);
  for (uint i=0; i<sz-1; ++i)
    os += vi[i];
  os += last;
}

void digdiv::save

(

ostream &

os

)

const

Save this objects state.

eg to a file.

Definition at line 146 of file streamconversion.cpp.

References blksz, and vi.

{
  os << pad << endl;
  os << blksz << endl;
  for (uint i=0; i<vi.size(); ++i)
    os << vi[i] << endl;
}

---

Member Data Documentation

uint digdiv::blksz

Block size.

Definition at line 43 of file streamconversion.h.

Referenced by forward(), restore(), reverse(), save(), and rsatest::test01().

vector<string> digdiv::vi

A string of blocks.

Definition at line 45 of file streamconversion.h.

Referenced by eval(), forward(), restore(), reverse(), and save().

---

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

• rsa/streamconversion.h
• rsa/streamconversion.cpp