FastRandomContext Class Reference

Fast randomness source. More...

#include <random.h>

Collaboration diagram for FastRandomContext:

Public Types
typedef uint64_t	result_type

Public Member Functions
	FastRandomContext (bool fDeterministic=false) noexcept
	FastRandomContext (const uint256 &seed) noexcept
	Initialize with explicit seed (only for testing) More...
	FastRandomContext (const FastRandomContext &)=delete
	FastRandomContext (FastRandomContext &&)=delete
FastRandomContext &	operator= (const FastRandomContext &)=delete
FastRandomContext &	operator= (FastRandomContext &&from) noexcept
	Move a FastRandomContext. More...
uint64_t	rand64 () noexcept
	Generate a random 64-bit integer. More...
uint64_t	randbits (int bits) noexcept
	Generate a random (bits)-bit integer. More...
uint64_t	randrange (uint64_t range) noexcept
	Generate a random integer in the range [0..range). More...
std::vector< unsigned char >	randbytes (size_t len)
	Generate random bytes. More...
uint32_t	rand32 () noexcept
	Generate a random 32-bit integer. More...
uint256	rand256 () noexcept
	generate a random uint256. More...
bool	randbool () noexcept
	Generate a random boolean. More...
template<typename Tp >
Tp	rand_uniform_delay (const Tp &time, typename Tp::duration range)
	Return the time point advanced by a uniform random duration. More...
template<typename Chrono >
Chrono::duration	rand_uniform_duration (typename Chrono::duration range) noexcept
	Generate a uniform random duration in the range from 0 (inclusive) to range (exclusive). More...
uint64_t	operator() () noexcept

Static Public Member Functions
static constexpr uint64_t	min ()
static constexpr uint64_t	max ()

Private Member Functions
void	RandomSeed ()
void	FillBitBuffer ()

Private Attributes
bool	requires_seed
ChaCha20	rng
uint64_t	bitbuf
int	bitbuf_size

Detailed Description

Fast randomness source.

This is seeded once with secure random data, but is completely deterministic and does not gather more entropy after that.

This class is not thread-safe.

Definition at line 143 of file random.h.

Member Typedef Documentation

result_type

typedef uint64_t FastRandomContext::result_type

Definition at line 243 of file random.h.

Constructor & Destructor Documentation

FastRandomContext() [1/4]

FastRandomContext::FastRandomContext ( bool  fDeterministic = false )

explicitnoexcept

Definition at line 653 of file random.cpp.

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FastRandomContext() [2/4]

FastRandomContext::FastRandomContext ( const uint256 &  seed )

explicitnoexcept

Initialize with explicit seed (only for testing)

Definition at line 602 of file random.cpp.

FastRandomContext() [3/4]

FastRandomContext::FastRandomContext ( const FastRandomContext &  )

delete

FastRandomContext() [4/4]

FastRandomContext::FastRandomContext ( FastRandomContext &&  )

delete

Member Function Documentation

FillBitBuffer()

void FastRandomContext::FillBitBuffer ( )

inlineprivate

Definition at line 154 of file random.h.

max()

static constexpr uint64_t FastRandomContext::max ( )

inlinestaticconstexpr

Definition at line 245 of file random.h.

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min()

static constexpr uint64_t FastRandomContext::min ( )

inlinestaticconstexpr

Definition at line 244 of file random.h.

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operator()()

uint64_t FastRandomContext::operator() ( )

inlinenoexcept

Definition at line 246 of file random.h.

operator=() [1/2]

FastRandomContext& FastRandomContext::operator= ( const FastRandomContext &  )

delete

operator=() [2/2]

FastRandomContext & FastRandomContext::operator= ( FastRandomContext &&  from )

noexcept

Move a FastRandomContext.

If the original one is used again, it will be reseeded.

Definition at line 662 of file random.cpp.

rand256()

uint256 FastRandomContext::rand256 ( )

noexcept

generate a random uint256.

Definition at line 584 of file random.cpp.

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rand32()

uint32_t FastRandomContext::rand32 ( )

inlinenoexcept

Generate a random 32-bit integer.

Definition at line 217 of file random.h.

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rand64()

uint64_t FastRandomContext::rand64 ( )

inlinenoexcept

Generate a random 64-bit integer.

Definition at line 175 of file random.h.

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rand_uniform_delay()

template<typename Tp >

Tp FastRandomContext::rand_uniform_delay ( const Tp &  time, typename Tp::duration  range  )

inline

Return the time point advanced by a uniform random duration.

Definition at line 227 of file random.h.

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rand_uniform_duration()

template<typename Chrono >

Chrono::duration FastRandomContext::rand_uniform_duration ( typename Chrono::duration  range )

inlinenoexcept

Generate a uniform random duration in the range from 0 (inclusive) to range (exclusive).

Definition at line 234 of file random.h.

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randbits()

uint64_t FastRandomContext::randbits ( int  bits )

inlinenoexcept

Generate a random (bits)-bit integer.

Definition at line 184 of file random.h.

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randbool()

bool FastRandomContext::randbool ( )

inlinenoexcept

Generate a random boolean.

Definition at line 223 of file random.h.

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randbytes()

std::vector< unsigned char > FastRandomContext::randbytes

(

size_t

len

)

Generate random bytes.

Definition at line 592 of file random.cpp.

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RandomSeed()

void FastRandomContext::RandomSeed ( )

private

Definition at line 577 of file random.cpp.

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randrange()

uint64_t FastRandomContext::randrange ( uint64_t  range )

inlinenoexcept

Generate a random integer in the range [0..range).

Precondition: range > 0.

Definition at line 202 of file random.h.

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Member Data Documentation

bitbuf

uint64_t FastRandomContext::bitbuf

private

Definition at line 149 of file random.h.

bitbuf_size

int FastRandomContext::bitbuf_size

private

Definition at line 150 of file random.h.

requires_seed

bool FastRandomContext::requires_seed

private

Definition at line 146 of file random.h.

rng

ChaCha20 FastRandomContext::rng

private

Definition at line 147 of file random.h.

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

• src/random.h
• src/random.cpp