libcryfs/utils/Data.cpp

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#include <messmer/blockstore/utils/Data.h>
#include <messmer/blockstore/utils/FileDoesntExistException.h>
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#include <stdexcept>
#include <fstream>
using std::istream;
using std::ofstream;
using std::ifstream;
using std::ios;
using std::unique_ptr;
using std::make_unique;
namespace bf = boost::filesystem;
namespace blockstore {
Data::Data(size_t size)
: _size(size), _data(std::malloc(size)) {
if (nullptr == _data) {
throw std::bad_alloc();
}
}
Data::Data(Data &&rhs)
: _size(rhs._size), _data(rhs._data) {
// Make rhs invalid, so the memory doesn't get freed in its destructor.
rhs._data = nullptr;
}
Data::~Data() {
std::free(_data);
_data = nullptr;
}
Data Data::copy() const {
Data copy(_size);
std::memcpy(copy._data, _data, _size);
return copy;
}
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void *Data::data() {
return const_cast<void*>(const_cast<const Data*>(this)->data());
}
const void *Data::data() const {
return _data;
}
size_t Data::size() const {
return _size;
}
void Data::FillWithZeroes() {
std::memset(_data, 0, _size);
}
void Data::StoreToFile(const bf::path &filepath) const {
ofstream file(filepath.c_str(), ios::binary | ios::trunc);
file.write((const char*)_data, _size);
}
Data Data::LoadFromFile(const bf::path &filepath) {
ifstream file(filepath.c_str(), ios::binary);
_assertFileExists(file, filepath);
size_t size = _getStreamSize(file);
Data result(size);
result._readFromStream(file);
return result;
}
void Data::_assertFileExists(const ifstream &file, const bf::path &filepath) {
if (!file.good()) {
throw FileDoesntExistException(filepath);
}
}
size_t Data::_getStreamSize(istream &stream) {
auto current_pos = stream.tellg();
//Retrieve length
stream.seekg(0, stream.end);
auto endpos = stream.tellg();
//Restore old position
stream.seekg(current_pos, stream.beg);
return endpos - current_pos;
}
void Data::_readFromStream(istream &stream) {
stream.read((char*)_data, _size);
}
}