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FastRandomContext Class Reference

Fast randomness source. More...

#include <random.h>

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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
 
FastRandomContextoperator= (const FastRandomContext &)=delete
 
FastRandomContextoperator= (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< uint8_t > randbytes (size_t len)
 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...
 
uint64_t operator() () noexcept
 

Static Public Member Functions

static constexpr uint64_t min ()
 
static constexpr uint64_t max ()
 

Private Member Functions

void RandomSeed ()
 
void FillByteBuffer ()
 
void FillBitBuffer ()
 

Private Attributes

bool requires_seed
 
ChaCha20 rng
 
uint8_t bytebuf [64]
 
int bytebuf_size
 
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 129 of file random.h.

Member Typedef Documentation

◆ result_type

Definition at line 232 of file random.h.

Constructor & Destructor Documentation

◆ FastRandomContext() [1/4]

FastRandomContext::FastRandomContext ( bool  fDeterministic = false)
explicitnoexcept

Definition at line 761 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 700 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 150 of file random.h.

◆ FillByteBuffer()

void FastRandomContext::FillByteBuffer ( )
inlineprivate

Definition at line 142 of file random.h.

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◆ max()

static constexpr uint64_t FastRandomContext::max ( )
inlinestaticconstexpr

Definition at line 234 of file random.h.

◆ min()

static constexpr uint64_t FastRandomContext::min ( )
inlinestaticconstexpr

Definition at line 233 of file random.h.

◆ operator()()

uint64_t FastRandomContext::operator() ( )
inlinenoexcept

Definition at line 237 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 771 of file random.cpp.

◆ rand160()

uint160 FastRandomContext::rand160 ( )
noexcept

generate a random uint160.

Definition at line 670 of file random.cpp.

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◆ rand256()

uint256 FastRandomContext::rand256 ( )
noexcept

generate a random uint256.

Definition at line 680 of file random.cpp.

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◆ rand32()

uint32_t FastRandomContext::rand32 ( )
inlinenoexcept

Generate a random 32-bit integer.

Definition at line 220 of file random.h.

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◆ rand64()

uint64_t FastRandomContext::rand64 ( )
inlinenoexcept

Generate a random 64-bit integer.

Definition at line 174 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 229 of file random.h.

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◆ randbytes()

std::vector< uint8_t > FastRandomContext::randbytes ( size_t  len)

Generate random bytes.

Definition at line 689 of file random.cpp.

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◆ RandomSeed()

void FastRandomContext::RandomSeed ( )
private

Definition at line 664 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 204 of file random.h.

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Member Data Documentation

◆ bitbuf

uint64_t FastRandomContext::bitbuf
private

Definition at line 137 of file random.h.

◆ bitbuf_size

int FastRandomContext::bitbuf_size
private

Definition at line 138 of file random.h.

◆ bytebuf

uint8_t FastRandomContext::bytebuf[64]
private

Definition at line 134 of file random.h.

◆ bytebuf_size

int FastRandomContext::bytebuf_size
private

Definition at line 135 of file random.h.

◆ requires_seed

bool FastRandomContext::requires_seed
private

Definition at line 131 of file random.h.

◆ rng

ChaCha20 FastRandomContext::rng
private

Definition at line 132 of file random.h.


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