libcryfs/src/cpp-utils/data/DataFixture.cpp

25 lines
937 B
C++

#include "DataFixture.h"
#include "SerializationHelper.h"
namespace cpputils {
Data DataFixture::generate(size_t size, unsigned long long int seed) {
Data result(size);
unsigned long long int val = seed;
for(size_t i=0; i<size/sizeof(unsigned long long int); ++i) {
//MMIX linear congruential generator
val *= 6364136223846793005L;
val += 1442695040888963407;
serialize<unsigned long long int>(result.dataOffset(i*sizeof(unsigned long long int)), val);
}
uint64_t alreadyWritten = (size/sizeof(unsigned long long int))*sizeof(unsigned long long int);
val *= 6364136223846793005L;
val += 1442695040888963407;
unsigned char *remainingBytes = reinterpret_cast<unsigned char*>(&val);
//Fill remaining bytes
for(size_t i=0; i<size-alreadyWritten; ++i) {
serialize<unsigned char>(result.dataOffset(alreadyWritten + i), remainingBytes[i]);
}
return result;
}
}