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...

template<typename B = unsigned char>
std::vector< B >	randbytes (size_t len)
	Generate random bytes. More...

void	fillrand (Span< std::byte > output)
	Fill a byte Span with 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 244 of file random.h.

Constructor & Destructor Documentation

◆ FastRandomContext() [1/4]

FastRandomContext::FastRandomContext ( bool fDeterministic = false )

explicitnoexcept

Definition at line 661 of file random.cpp.

◆ FastRandomContext() [2/4]

FastRandomContext::FastRandomContext ( const uint256 & seed )

explicitnoexcept

Initialize with explicit seed (only for testing)

Definition at line 611 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.

◆ fillrand()

void FastRandomContext::fillrand ( Span< std::byte > output )

Fill a byte Span with random bytes.

Definition at line 605 of file random.cpp.

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◆ max()

static constexpr uint64_t FastRandomContext::max ( )

inlinestatic

Definition at line 249 of file random.h.

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◆ min()

static constexpr uint64_t FastRandomContext::min ( )

inlinestatic

Definition at line 248 of file random.h.

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◆ operator()()

uint64_t FastRandomContext::operator() ( )

inlinenoexcept

Definition at line 250 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 668 of file random.cpp.

◆ rand256()

uint256 FastRandomContext::rand256 ( )

noexcept

generate a random uint256.

Definition at line 587 of file random.cpp.

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◆ rand32()

uint32_t FastRandomContext::rand32 ( )

inlinenoexcept

Generate a random 32-bit integer.

Definition at line 221 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 231 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 238 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 227 of file random.h.

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◆ randbytes()

template<typename B >

template std::vector< std::byte > FastRandomContext::randbytes ( size_t len )

Generate random bytes.

Definition at line 596 of file random.cpp.

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◆ RandomSeed()

void FastRandomContext::RandomSeed ( )

private

Definition at line 580 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.

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

src/random.h
src/random.cpp

Public Types

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ result_type

Constructor & Destructor Documentation

◆ FastRandomContext() [1/4]

◆ FastRandomContext() [2/4]

◆ FastRandomContext() [3/4]

◆ FastRandomContext() [4/4]

Member Function Documentation

◆ FillBitBuffer()

◆ fillrand()

◆ max()

◆ min()

◆ operator()()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ rand256()

◆ rand32()

◆ rand64()

◆ rand_uniform_delay()

◆ rand_uniform_duration()

◆ randbits()

◆ randbool()

◆ randbytes()

◆ RandomSeed()

◆ randrange()

Member Data Documentation

◆ bitbuf

◆ bitbuf_size

◆ requires_seed

◆ rng