steam::engine::test::anonymous_namespace{testframe.cpp} Namespace Reference

Classes
class	DistinctNucleus
struct	TestFrameTable

Functions
HashVal	drawSeed (lib::Random &srcGen)
uint64_t	generateDiscriminator (uint seq, uint family)
HashVal	stampHeader ()
auto	buildDataGenFrom (uint64_t const &anchor)
TestFrame &	accessAsTestFrame (void *memoryLocation)

Variables
const size_t	SEQUENCE_SPREAD = 100
	Offset to set the seed values of »families« apart.
HashVal	dataSeed {drawSeed(lib::entropyGen)}
std::unique_ptr< TestFrameTable >	testFrames

Function Documentation

drawSeed()

HashVal drawSeed

(

lib::Random &

srcGen

)

Definition at line 74 of file testframe.cpp.

References RandomSequencer< GEN >::distribute(), drawSeed(), and SEQUENCE_SPREAD.

Referenced by drawSeed().

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generateDiscriminator()

uint64_t generateDiscriminator	(	uint	seq,
		uint	family
	)

helper for generating unique test frames. This »discriminator« is used as a random seed when filling the test frame data buffers. It is generated to be very likely different on adjacent frames of the same series, as well as to differ to all nearby neighbouring channels.

Note

the dataSeed hash is limited by SEQUENCE_SPREAD to prevent „risky“ families; the extreme case would be dataSeed+family ≡ 0 (all frames would be equal then)

Parameters

seq	the sequence number of the frame within the channel
family	the channel this frame belongs to

Definition at line 94 of file testframe.cpp.

References dataSeed, and generateDiscriminator().

Referenced by generateDiscriminator().

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stampHeader()

HashVal stampHeader

(

)

Returns

a stable characteristic memory marker for the metadata record

Definition at line 120 of file testframe.cpp.

References lib::entropyGen, RandomSequencer< GEN >::hash(), and stampHeader().

Referenced by stampHeader().

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buildDataGenFrom()

auto buildDataGenFrom

(

uint64_t const &

anchor

)

build a PRNG starting from the referred fixed seed

Definition at line 129 of file testframe.cpp.

References buildDataGenFrom().

Referenced by buildDataGenFrom().

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accessAsTestFrame()

TestFrame & accessAsTestFrame

(

void *

memoryLocation

)

Definition at line 137 of file testframe.cpp.

References accessAsTestFrame().

Referenced by accessAsTestFrame().

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Variable Documentation

SEQUENCE_SPREAD

const size_t SEQUENCE_SPREAD = 100

Offset to set the seed values of »families« apart.

The data in the test frames is generated from a distinctive ID-seed, which is controlled by the family and the seq-No within each family. The seeds for consecutive frames are spread apart by the dataSeed, and the SEQUENCE_SPREAD constant acts as minimum spread. While seed values can wrap within the 64bit number range, this generation scheme makes it very unlikely that neighbouring frames end up with the same seed.

Definition at line 71 of file testframe.cpp.

Referenced by drawSeed().

dataSeed

HashVal dataSeed {drawSeed(lib::entropyGen)}

a static seed hash used to anchor the data distinction ID-seeds

Definition at line 82 of file testframe.cpp.

Referenced by generateDiscriminator().

testFrames

std::unique_ptr<TestFrameTable> testFrames

Definition at line 178 of file testframe.cpp.