Botan::FTW_EntropySource Class Reference

#include <es_ftw.h>

Inheritance diagram for Botan::FTW_EntropySource:

Public Member Functions
	FTW_EntropySource (const std::string &root_dir)
std::string	name () const
void	poll (Entropy_Accumulator &accum)
	~FTW_EntropySource ()

Detailed Description

File Tree Walking Entropy Source

Definition at line 18 of file es_ftw.h.

Constructor & Destructor Documentation

FTW_EntropySource()

Botan::FTW_EntropySource::FTW_EntropySource

(

const std::string &

p

)

FTW_EntropySource Constructor

Definition at line 136 of file es_ftw.cpp.

                                                       : path(p)
   {
   dir = 0;
   }

~FTW_EntropySource()

Botan::FTW_EntropySource::~FTW_EntropySource

(

)

FTW_EntropySource Destructor

Definition at line 144 of file es_ftw.cpp.

   {
   delete dir;
   }

Member Function Documentation

name()

std::string Botan::FTW_EntropySource::name ( ) const

inlinevirtual

Returns

name identifying this entropy source

Implements Botan::EntropySource.

Definition at line 21 of file es_ftw.h.

{ return "Proc Walker"; }

poll()

void Botan::FTW_EntropySource::poll ( Entropy_Accumulator & accum )

virtual

Perform an entropy gathering poll

Parameters

accum

is an accumulator object that will be given entropy

Implements Botan::EntropySource.

Definition at line 149 of file es_ftw.cpp.

   {
   const size_t MAX_FILES_READ_PER_POLL = 2048;
 
   if(!dir)
      dir = new Directory_Walker(path);
 
   MemoryRegion<byte>& io_buffer = accum.get_io_buffer(4096);
 
   for(size_t i = 0; i != MAX_FILES_READ_PER_POLL; ++i)
      {
      int fd = dir->next_fd();
 
      // If we've exhaused this walk of the directory, halt the poll
      if(fd == -1)
         {
         delete dir;
         dir = 0;
         break;
         }
 
      ssize_t got = ::read(fd, &io_buffer[0], io_buffer.size());
      ::close(fd);
 
      if(got > 0)
         accum.add(&io_buffer[0], got, .001);
 
      if(accum.polling_goal_achieved())
         break;
      }
   }

References Botan::Entropy_Accumulator::add(), Botan::Entropy_Accumulator::get_io_buffer(), Botan::Entropy_Accumulator::polling_goal_achieved(), and Botan::MemoryRegion< T >::size().

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

• src/entropy/proc_walk/es_ftw.h
• src/entropy/proc_walk/es_ftw.cpp