testframe.cpp File Reference

Implementation of fake data frames to support unit testing. More...

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Description

Implementation of fake data frames to support unit testing.

The data generation is based on a discriminator seed value, which is computed as a linear combination of a statically fixed anchor-seed combined with the family-number and sequence number. Based on this seed, the contents are then filled by a pseudo-random sequence.

Note

while initially drawn from real entropy, the anchor-seed can be reset from the default PRNG, which allows to establish a totally deterministically setup from test code, because the test itself can seed the default PRNG and thus establish a reproducible state.

Additionally, beyond this basic test-data feature, the contents can be manipulated freely, and a new checksum can be stored in the metadata, which allows to build pseudo media computation functions with a reproducible effect — so that the proper invocation of several computation steps invoked deep down in the render engine can be verified after completing a test invocation.

Definition in file testframe.cpp.

#include "lib/error.hpp"
#include "lib/random.hpp"
#include "lib/hash-standard.hpp"
#include "lib/hash-combine.hpp"
#include "steam/engine/testframe.hpp"
#include "lib/nocopy.hpp"
#include "lib/util.hpp"
#include <climits>
#include <memory>
#include <deque>

Namespaces
namespace	steam
	Steam-Layer implementation namespace root.
namespace	steam::engine
	Lumiera's render engine core and operational control.
namespace	steam::engine::test
namespace	steam::engine::test::anonymous_namespace{testframe.cpp}

Typedefs
using	PseudoRandom = lib::RandomSequencer< std::minstd_rand >

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)
TestFrame &	testData (uint seqNr=0, uint chanNr=0)
	Helper to access a specific frame of test data at a fixed memory location.

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