libcryfs/data/DataFixture.cpp

24 lines
802 B
C++
Raw Normal View History

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