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...
template<BasicByte B = uint8_t>
std::vector< B >	randbytes (size_t len) noexcept
	Generate random bytes. More...
void	fillrand (Span< std::byte > output) noexcept
	Fill a byte Span with random bytes. More...
uint32_t	rand32 () noexcept
	Generate a random 32-bit integer. More...
uint160	rand160 () noexcept
	generate a random uint160. 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) noexcept
	Return the time point advanced by a uniform random duration. More...
uint64_t	operator() () noexcept

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

Private Member Functions
void	RandomSeed () noexcept
void	FillBitBuffer () noexcept

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 156 of file random.h.

Member Typedef Documentation

result_type

typedef uint64_t FastRandomContext::result_type

Definition at line 278 of file random.h.

Constructor & Destructor Documentation

FastRandomContext() [1/4]

FastRandomContext::FastRandomContext ( bool  fDeterministic = false )

explicitnoexcept

Definition at line 742 of file random.cpp.

FastRandomContext() [2/4]

FastRandomContext::FastRandomContext ( const uint256 &  seed )

explicitnoexcept

Initialize with explicit seed (only for testing)

Definition at line 681 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 ( )

inlineprivatenoexcept

Definition at line 166 of file random.h.

fillrand()

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

noexcept

Fill a byte Span with random bytes.

Definition at line 674 of file random.cpp.

max()

static constexpr uint64_t FastRandomContext::max ( )

inlinestaticconstexprnoexcept

Definition at line 280 of file random.h.

min()

static constexpr uint64_t FastRandomContext::min ( )

inlinestaticconstexprnoexcept

Definition at line 279 of file random.h.

operator()()

uint64_t FastRandomContext::operator() ( )

inlinenoexcept

Definition at line 283 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 750 of file random.cpp.

rand160()

uint160 FastRandomContext::rand160 ( )

inlinenoexcept

generate a random uint160.

Definition at line 247 of file random.h.

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rand256()

uint256 FastRandomContext::rand256 ( )

inlinenoexcept

generate a random uint256.

Definition at line 254 of file random.h.

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rand32()

uint32_t FastRandomContext::rand32 ( )

inlinenoexcept

Generate a random 32-bit integer.

Definition at line 244 of file random.h.

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rand64()

uint64_t FastRandomContext::rand64 ( )

inlinenoexcept

Generate a random 64-bit integer.

Definition at line 190 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  )

inlinenoexcept

Return the time point advanced by a uniform random duration.

Definition at line 265 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 200 of file random.h.

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randbool()

bool FastRandomContext::randbool ( )

inlinenoexcept

Generate a random boolean.

Definition at line 261 of file random.h.

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randbytes()

template<BasicByte B = uint8_t>

std::vector< B > FastRandomContext::randbytes ( size_t  len )

inlinenoexcept

Generate random bytes.

Definition at line 234 of file random.h.

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RandomSeed()

void FastRandomContext::RandomSeed ( )

privatenoexcept

Definition at line 668 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 220 of file random.h.

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Member Data Documentation

bitbuf

uint64_t FastRandomContext::bitbuf

private

Definition at line 161 of file random.h.

bitbuf_size

int FastRandomContext::bitbuf_size

private

Definition at line 162 of file random.h.

requires_seed

bool FastRandomContext::requires_seed

private

Definition at line 158 of file random.h.

rng

ChaCha20 FastRandomContext::rng

private

Definition at line 159 of file random.h.

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

• /work/src/random.h
• /work/src/random.cpp