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#include <memory>
#include <vector>
#include "data.h"
#include "win.h"
template <typename T>
inline unsigned char* ValToBuf(const T& val, unsigned char* const buf)
{
memcpy(buf, &val, sizeof(val));
return buf+sizeof(val);
}
template <typename T>
inline unsigned char* BufToVal(unsigned char* const buf, T& val)
{
memcpy(&val, buf, sizeof(val));
return buf+sizeof(val);
}
FileView::FileView(const wchar_t* const filename, const size_t cb)
{
hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
0, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
if (hf == INVALID_HANDLE_VALUE) {
if (GetLastError() == ERROR_FILE_NOT_FOUND) {
hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
0, nullptr, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr);
if (hf == INVALID_HANDLE_VALUE)
throw Win32Error{};
} else
throw Win32Error{};
}
LARGE_INTEGER cbMap;
cbMap.QuadPart = cb;
hm = CreateFileMapping(hf, nullptr, PAGE_READWRITE,
cbMap.HighPart, cbMap.LowPart, nullptr);
if (!hm)
throw Win32Error{};
view = reinterpret_cast<unsigned char*>(MapViewOfFile(hm, FILE_MAP_ALL_ACCESS, 0, 0, 0));
if (!view)
throw Win32Error{};
}
FileView::~FileView()
{
FlushViewOfFile(view, 0);
UnmapViewOfFile(view);
CloseHandle(hm);
CloseHandle(hf);
}
void Write(unsigned char* buf, const ElvData& e)
{
memcpy(buf, reinterpret_cast<const unsigned char*>(&e), sizeof(e));
}
ElvData* Read(unsigned char* const buf)
{
if (buf[0] != 'a')
return nullptr;
return reinterpret_cast<ElvData*>(buf);
}
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