FastRandomContext Class Reference

Fast randomness source. More...

#include <random.h>

Collaboration diagram for FastRandomContext:

Public Member Functions
	FastRandomContext (bool fDeterministic=false)
	FastRandomContext (const uint256 &seed)
	Initialize with explicit seed (only for testing) More...
uint64_t	rand64 ()
	Generate a random 64-bit integer. More...
uint64_t	randbits (int bits)
	Generate a random (bits)-bit integer. More...
uint64_t	randrange (uint64_t range)
	Generate a random integer in the range [0..range). More...
uint32_t	rand32 (uint32_t nMax)
uint32_t	operator() (uint32_t nMax)
std::vector< unsigned char >	randbytes (size_t len)
	Generate random bytes. More...
uint32_t	rand32 ()
	Generate a random 32-bit integer. More...
uint256	rand256 ()
	generate a random uint256. More...
bool	randbool ()
	Generate a random boolean. More...

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

Private Attributes
bool	requires_seed
ChaCha20	rng
unsigned char	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 insecure after that. This class is not thread-safe.

Definition at line 48 of file random.h.

Constructor & Destructor Documentation

FastRandomContext() [1/2]

FastRandomContext::FastRandomContext ( bool  fDeterministic = false )

explicit

Definition at line 478 of file random.cpp.

References base_blob< BITS >::begin(), rng, and ChaCha20::SetKey().

FastRandomContext() [2/2]

FastRandomContext::FastRandomContext ( const uint256 &  seed )

explicit

Initialize with explicit seed (only for testing)

Definition at line 429 of file random.cpp.

References base_blob< BITS >::begin(), rng, and ChaCha20::SetKey().

Member Function Documentation

FillBitBuffer()

void FastRandomContext::FillBitBuffer ( )

inlineprivate

Definition at line 70 of file random.h.

References bitbuf, bitbuf_size, and rand64().

Referenced by randbits().

FillByteBuffer()

void FastRandomContext::FillByteBuffer ( )

inlineprivate

Definition at line 61 of file random.h.

References bytebuf, bytebuf_size, ChaCha20::Keystream(), RandomSeed(), requires_seed, and rng.

Referenced by rand256(), and rand64().

operator()()

uint32_t FastRandomContext::operator() ( uint32_t  nMax )

inline

Definition at line 121 of file random.h.

References rand32().

rand256()

uint256 FastRandomContext::rand256

(

)

generate a random uint256.

Definition at line 409 of file random.cpp.

References base_blob< BITS >::begin(), bytebuf, bytebuf_size, FillByteBuffer(), and memcpy().

Referenced by MerkleRoot().

rand32() [1/2]

uint32_t FastRandomContext::rand32 ( uint32_t  nMax )

inline

Definition at line 117 of file random.h.

References rand32().

Referenced by FastRandom_32bit().

rand32() [2/2]

uint32_t FastRandomContext::rand32 ( )

inline

Generate a random 32-bit integer.

Definition at line 129 of file random.h.

References randbits().

Referenced by operator()(), and rand32().

rand64()

uint64_t FastRandomContext::rand64 ( )

inline

Generate a random 64-bit integer.

Definition at line 83 of file random.h.

References bytebuf, bytebuf_size, FillByteBuffer(), and ReadLE64().

Referenced by FillBitBuffer(), and randbits().

randbits()

uint64_t FastRandomContext::randbits ( int  bits )

inline

Generate a random (bits)-bit integer.

Definition at line 92 of file random.h.

References bitbuf, bitbuf_size, immer::detail::rbts::bits, FillBitBuffer(), and rand64().

Referenced by rand32(), randbool(), randrange(), and CAddrMan::Select_().

randbool()

bool FastRandomContext::randbool ( )

inline

Generate a random boolean.

Definition at line 135 of file random.h.

References randbits().

Referenced by ApproximateBestSubset(), and FastRandom_1bit().

randbytes()

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

(

size_t

len

)

Generate random bytes.

Definition at line 420 of file random.cpp.

References ChaCha20::Keystream(), and rng.

RandomSeed()

void FastRandomContext::RandomSeed ( )

private

Definition at line 402 of file random.cpp.

References base_blob< BITS >::begin(), GetRandHash(), requires_seed, rng, and ChaCha20::SetKey().

Referenced by FillByteBuffer().

randrange()

uint64_t FastRandomContext::randrange ( uint64_t  range )

inline

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

Definition at line 107 of file random.h.

References immer::detail::rbts::bits, CountBits(), and randbits().

Referenced by CCoinsViewDB::BatchWrite(), CCheckQueueSpeedPrevectorJob(), GetRand(), and CNode::PushAddress().

Member Data Documentation

bitbuf

uint64_t FastRandomContext::bitbuf

private

Definition at line 56 of file random.h.

Referenced by FillBitBuffer(), and randbits().

bitbuf_size

int FastRandomContext::bitbuf_size

private

Definition at line 57 of file random.h.

Referenced by FillBitBuffer(), and randbits().

bytebuf

unsigned char FastRandomContext::bytebuf[64]

private

Definition at line 53 of file random.h.

Referenced by FillByteBuffer(), rand256(), and rand64().

bytebuf_size

int FastRandomContext::bytebuf_size

private

Definition at line 54 of file random.h.

Referenced by FillByteBuffer(), rand256(), and rand64().

requires_seed

bool FastRandomContext::requires_seed

private

Definition at line 50 of file random.h.

Referenced by FillByteBuffer(), and RandomSeed().

rng

ChaCha20 FastRandomContext::rng

private

Definition at line 51 of file random.h.

Referenced by FastRandomContext(), FillByteBuffer(), randbytes(), and RandomSeed().

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

• src/random.h
• src/random.cpp