===================== RANDOM NUMBER GENERATION CLASSES ===================== More...

#include <random.h>

Public Types
typedef uint64_t	result_type

Public Member Functions
constexpr	RandomMixin () noexcept=default

	RandomMixin (const RandomMixin &)=delete

RandomMixin &	operator= (const RandomMixin &)=delete

	RandomMixin (RandomMixin &&)=delete

RandomMixin &	operator= (RandomMixin &&)=delete

uint64_t	randbits (int bits) noexcept
	Generate a random (bits)-bit integer. More...

template<int Bits>
uint64_t	randbits () noexcept
	Same as above, but with compile-time fixed bits count. More...

template<std::integral I>
I	randrange (I range) noexcept
	Generate a random integer in the range [0..range), with range > 0. More...

void	fillrand (Span< std::byte > span) noexcept
	Fill a Span with random bytes. More...

template<std::integral I>
I	rand () noexcept
	Generate a random integer in its entire (non-negative) range. More...

template<BasicByte B = uint8_t>
std::vector< B >	randbytes (size_t len) noexcept
	Generate 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...

template<typename Chrono > requires StdChronoDuration<typename Chrono::duration>
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...

template<StdChronoDuration Dur>
Dur	randrange (typename std::common_type_t< Dur > range) noexcept
	Generate a uniform random duration in the range [0..max). More...

std::chrono::microseconds	rand_exp_duration (std::chrono::microseconds mean) noexcept
	Return a duration sampled from an exponential distribution (https://en.wikipedia.org/wiki/Exponential_distribution). More...

uint64_t	operator() () noexcept

Static Public Member Functions
static constexpr uint64_t	min () noexcept

static constexpr uint64_t	max () noexcept

Protected Member Functions
constexpr void	FlushCache () noexcept

Private Member Functions
RandomNumberGenerator auto &	Impl () noexcept
	Access the underlying generator. More...

Private Attributes
uint64_t	bitbuf {0}

int	bitbuf_size {0}

Detailed Description

template<typename T>
class RandomMixin< T >

===================== RANDOM NUMBER GENERATION CLASSES =====================

Mixin class that provides helper randomness functions.

In this section, 3 classes are defined:

RandomMixin: a base class that adds functionality to all RNG classes.
FastRandomContext: a cryptographic RNG (seeded through GetRandBytes in its default constructor).
InsecureRandomContext: a non-cryptographic, very fast, RNG.

Intended to be used through CRTP: https://en.cppreference.com/w/cpp/language/crtp. An RNG class FunkyRNG would derive publicly from RandomMixin<FunkyRNG>. This permits RandomMixin from accessing the derived class's rand64() function, while also allowing the derived class to provide more.

The derived class must satisfy the RandomNumberGenerator concept.

Definition at line 184 of file random.h.

Member Typedef Documentation

◆ result_type

template<typename T >

typedef uint64_t RandomMixin< T >::result_type

Definition at line 397 of file random.h.

Constructor & Destructor Documentation

◆ RandomMixin() [1/3]

template<typename T >

constexpr RandomMixin< T >::RandomMixin ( )

constexprdefaultnoexcept

◆ RandomMixin() [2/3]

template<typename T >

RandomMixin< T >::RandomMixin ( const RandomMixin< T > & )

delete

◆ RandomMixin() [3/3]

template<typename T >

RandomMixin< T >::RandomMixin ( RandomMixin< T > && )

delete

Member Function Documentation

◆ fillrand()

template<typename T >

void RandomMixin< T >::fillrand ( Span< std::byte > span )

inlinenoexcept

Fill a Span with random bytes.

Definition at line 281 of file random.h.

Here is the call graph for this function:

◆ FlushCache()

template<typename T >

constexpr void RandomMixin< T >::FlushCache ( )

inlineconstexprprotectednoexcept

Definition at line 201 of file random.h.

◆ Impl()

template<typename T >

RandomNumberGenerator auto & RandomMixin< T >::Impl ( )

inlineprivatenoexcept

Access the underlying generator.

This also enforces the RandomNumberGenerator concept. We cannot declare that in the template (no template<RandomNumberGenerator T>) because the type isn't fully instantiated yet there.

Definition at line 196 of file random.h.

Here is the caller graph for this function:

◆ max()

template<typename T >

static constexpr uint64_t RandomMixin< T >::max ( )

inlinestaticconstexprnoexcept

Definition at line 399 of file random.h.

◆ min()

template<typename T >

static constexpr uint64_t RandomMixin< T >::min ( )

inlinestaticconstexprnoexcept

Definition at line 398 of file random.h.

◆ operator()()

template<typename T >

uint64_t RandomMixin< T >::operator() ( )

inlinenoexcept

Definition at line 402 of file random.h.

Here is the call graph for this function:

◆ operator=() [1/2]

template<typename T >

RandomMixin & RandomMixin< T >::operator= ( const RandomMixin< T > & )

delete

◆ operator=() [2/2]

template<typename T >

RandomMixin & RandomMixin< T >::operator= ( RandomMixin< T > && )

delete

◆ rand()

template<typename T >

template<std::integral I>

I RandomMixin< T >::rand ( )

inlinenoexcept

Generate a random integer in its entire (non-negative) range.

Definition at line 299 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rand160()

template<typename T >

uint160 RandomMixin< T >::rand160 ( )

inlinenoexcept

generate a random uint160.

Definition at line 321 of file random.h.

Here is the call graph for this function:

◆ rand256()

template<typename T >

uint256 RandomMixin< T >::rand256 ( )

inlinenoexcept

generate a random uint256.

Definition at line 328 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rand32()

template<typename T >

uint32_t RandomMixin< T >::rand32 ( )

inlinenoexcept

Generate a random 32-bit integer.

Definition at line 318 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rand_exp_duration()

template<typename T >

std::chrono::microseconds RandomMixin< T >::rand_exp_duration ( std::chrono::microseconds mean )

inlinenoexcept

Return a duration sampled from an exponential distribution (https://en.wikipedia.org/wiki/Exponential_distribution).

Successive events whose intervals are distributed according to this form a memoryless Poisson process. This should be used for repeated network events (e.g. sending a certain type of message) to minimize leaking information to observers.

The probability of an event occurring before time x is 1 - e^-(x/a) where a is the average interval between events.

Definition at line 389 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rand_uniform_delay()

template<typename T >

template<typename Tp >

Tp RandomMixin< T >::rand_uniform_delay	(	const Tp &	time,
		typename Tp::duration	range
	)

inlinenoexcept

Return the time point advanced by a uniform random duration.

Definition at line 339 of file random.h.

Here is the caller graph for this function:

◆ rand_uniform_duration()

template<typename T >

template<typename Chrono >
requires StdChronoDuration<typename Chrono::duration>

Chrono::duration RandomMixin< T >::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 351 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ randbits() [1/2]

template<typename T >

template<int Bits>

uint64_t RandomMixin< T >::randbits ( )

inlinenoexcept

Same as above, but with compile-time fixed bits count.

Definition at line 244 of file random.h.

Here is the call graph for this function:

◆ randbits() [2/2]

template<typename T >

uint64_t RandomMixin< T >::randbits ( int bits )

inlinenoexcept

Generate a random (bits)-bit integer.

Definition at line 216 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ randbool()

template<typename T >

bool RandomMixin< T >::randbool ( )

inlinenoexcept

Generate a random boolean.

Definition at line 335 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ randbytes()

template<typename T >

template<BasicByte B = uint8_t>

std::vector< B > RandomMixin< T >::randbytes ( size_t len )

inlinenoexcept

Generate random bytes.

Definition at line 311 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ randrange() [1/2]

template<typename T >

template<std::integral I>

I RandomMixin< T >::randrange ( I range )

inlinenoexcept

Generate a random integer in the range [0..range), with range > 0.

Definition at line 266 of file random.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ randrange() [2/2]

template<typename T >

template<StdChronoDuration Dur>

Dur RandomMixin< T >::randrange ( typename std::common_type_t< Dur > range )

inlinenoexcept

Generate a uniform random duration in the range [0..max).

Precondition: max.count() > 0

Definition at line 368 of file random.h.

Here is the call graph for this function:

Member Data Documentation

◆ bitbuf

template<typename T >

uint64_t RandomMixin< T >::bitbuf {0}

private

Definition at line 186 of file random.h.

◆ bitbuf_size

template<typename T >

int RandomMixin< T >::bitbuf_size {0}

private

Definition at line 187 of file random.h.

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

/work/src/random.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ result_type

Constructor & Destructor Documentation

◆ RandomMixin() [1/3]

◆ RandomMixin() [2/3]

◆ RandomMixin() [3/3]

Member Function Documentation

◆ fillrand()

◆ FlushCache()

◆ Impl()

◆ max()

◆ min()

◆ operator()()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ rand()

◆ rand160()

◆ rand256()

◆ rand32()

◆ rand_exp_duration()

◆ rand_uniform_delay()

◆ rand_uniform_duration()

◆ randbits() [1/2]

◆ randbits() [2/2]

◆ randbool()

◆ randbytes()

◆ randrange() [1/2]

◆ randrange() [2/2]

Member Data Documentation

◆ bitbuf

◆ bitbuf_size