Fabcoin Core  0.16.2
P2P Digital Currency
Public Member Functions | Protected Member Functions | Private Attributes | List of all members
MersenneTwister< K, M, N, F, S > Class Template Reference

Mersenne Twister class for Monte-Carlo simulations. More...

#include <mersenne.h>

Inheritance diagram for MersenneTwister< K, M, N, F, S >:
[legend]
Collaboration diagram for MersenneTwister< K, M, N, F, S >:
[legend]

Public Member Functions

 MersenneTwister (unsigned long seed=S)
 Construct a Mersenne Twister. More...
 
void GenerateBlock (byte *output, size_t size)
 Generate random array of bytes. More...
 
word32 GenerateWord32 (word32 min=0, word32 max=0xffffffffL)
 Generate a random 32-bit word in the range min to max, inclusive. More...
 
void DiscardBytes (size_t n)
 Generate and discard n bytes. More...
 
- Public Member Functions inherited from RandomNumberGenerator
virtual ~RandomNumberGenerator ()
 
virtual void IncorporateEntropy (const byte *input, size_t length)
 Update RNG state with additional unpredictable values. More...
 
virtual bool CanIncorporateEntropy () const
 Determines if a generator can accept additional entropy. More...
 
virtual byte GenerateByte ()
 Generate new random byte and return it. More...
 
virtual unsigned int GenerateBit ()
 Generate new random bit and return it. More...
 
virtual void GenerateIntoBufferedTransformation (BufferedTransformation &target, const std::string &channel, lword length)
 Generate random bytes into a BufferedTransformation. More...
 
template<class IT >
void Shuffle (IT begin, IT end)
 Randomly shuffle the specified array. More...
 
- Public Member Functions inherited from Algorithm
virtual ~Algorithm ()
 
 Algorithm (bool checkSelfTestStatus=true)
 Interface for all crypto algorithms. More...
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm. More...
 
- Public Member Functions inherited from Clonable
virtual ~Clonable ()
 
virtual ClonableClone () const
 Copies this object. More...
 

Protected Member Functions

word32 NextMersenneWord ()
 Returns the next 32-bit word from the state array. More...
 
void Twist ()
 Performs the twist operaton on the state array. More...
 

Private Attributes

FixedSizeSecBlock< word32, N+1 > m_state
 32-bit word state array of size N More...
 
unsigned int m_seed
 the value used to seed the generator More...
 
unsigned int m_idx
 the current index into the state array More...
 

Detailed Description

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
class MersenneTwister< K, M, N, F, S >

Mersenne Twister class for Monte-Carlo simulations.

Template Parameters
KMagic constant
MPeriod parameter
NSize of the state vector
FMultiplier constant
SInitial seed

Provides the MersenneTwister implementation. The class is a header-only implementation.

Warning
MersenneTwister is suitable for simulations, where uniformaly distrubuted numbers are required quickly. It should not be used for cryptographic purposes.
See also
MT19937, MT19937ar
Since
Crypto++ 5.6.3

Definition at line 31 of file mersenne.h.

Constructor & Destructor Documentation

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
MersenneTwister< K, M, N, F, S >::MersenneTwister ( unsigned long  seed = S)
inline

Construct a Mersenne Twister.

Parameters
seed32-bit seed

Defaults to template parameter S due to changing algorithm parameters over time

Definition at line 38 of file mersenne.h.

Member Function Documentation

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
void MersenneTwister< K, M, N, F, S >::DiscardBytes ( size_t  n)
inlinevirtual

Generate and discard n bytes.

Parameters
nthe number of bytes to discard, rounded up to a word32 size

If n is not a multiple of word32, then unused bytes are not accumulated for subsequent calls to GenerateBlock. Rather, the unused tail bytes are discarded, and the stream is continued at the next word32 boundary from the state array.

Reimplemented from RandomNumberGenerator.

Definition at line 120 of file mersenne.h.

Here is the call graph for this function:

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
void MersenneTwister< K, M, N, F, S >::GenerateBlock ( byte output,
size_t  size 
)
inlinevirtual

Generate random array of bytes.

Parameters
outputbyte buffer
sizelength of the buffer, in bytes

Bytes are written to output in big endian order. If output length is not a multiple of word32, then unused bytes are not accumulated for subsequent calls to GenerateBlock. Rather, the unused tail bytes are discarded, and the stream is continued at the next word32 boundary from the state array.

Reimplemented from RandomNumberGenerator.

Definition at line 52 of file mersenne.h.

Here is the call graph for this function:

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
word32 MersenneTwister< K, M, N, F, S >::GenerateWord32 ( word32  min = 0,
word32  max = 0xffffffffL 
)
inlinevirtual

Generate a random 32-bit word in the range min to max, inclusive.

Returns
random 32-bit word in the range min to max, inclusive

If the 32-bit candidate is not within the range, then it is discarded and a new candidate is used.

Reimplemented from RandomNumberGenerator.

Definition at line 98 of file mersenne.h.

Here is the call graph for this function:

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
word32 MersenneTwister< K, M, N, F, S >::NextMersenneWord ( )
inlineprotected

Returns the next 32-bit word from the state array.

Returns
the next 32-bit word from the state array

fetches the next word frm the state array, performs bit operations on it, and then returns the value to the caller.

Definition at line 132 of file mersenne.h.

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
void MersenneTwister< K, M, N, F, S >::Twist ( )
inlineprotected

Performs the twist operaton on the state array.

Definition at line 146 of file mersenne.h.

Member Data Documentation

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
unsigned int MersenneTwister< K, M, N, F, S >::m_idx
private

the current index into the state array

Definition at line 181 of file mersenne.h.

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
unsigned int MersenneTwister< K, M, N, F, S >::m_seed
private

the value used to seed the generator

Definition at line 179 of file mersenne.h.

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
FixedSizeSecBlock<word32, N+1> MersenneTwister< K, M, N, F, S >::m_state
private

32-bit word state array of size N

Definition at line 177 of file mersenne.h.


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