nf7/common/nfile_win.cc

81 lines
2.1 KiB
C++

#include "common/nfile.hh"
extern "C" {
#include <windows.h>
}
namespace nf7 {
void NFile::Init() {
DWORD acc = 0;
DWORD flags = 0;
if (flags_ & kRead) {
acc |= GENERIC_READ;
flags |= OPEN_EXISTING;
}
if (flags_ & kWrite) {
acc |= GENERIC_WRITE;
flags |= OPEN_ALWAYS;
}
HANDLE h = CreateFileA(
path_.string().c_str(),
acc, 0, nullptr, flags, FILE_ATTRIBUTE_NORMAL, nullptr);
if (h == INVALID_HANDLE_VALUE) {
throw NFile::Exception {"open failure"};
}
handle_ = reinterpret_cast<uintptr_t>(h);
}
NFile::~NFile() noexcept {
auto h = reinterpret_cast<HANDLE>(handle_);
if (!CloseHandle(h)) {
// ;(
}
}
size_t NFile::Read(size_t offset, uint8_t* buf, size_t size) {
const auto h = reinterpret_cast<HANDLE>(handle_);
LONG off_low = offset & 0xFFFFFFFF;
LONG off_high = offset >> 32;
if (INVALID_SET_FILE_POINTER == SetFilePointer(h, off_low, &off_high, FILE_BEGIN)) {
throw NFile::Exception {"failed to set file pointer"};
}
DWORD ret;
if (!ReadFile(h, buf, static_cast<DWORD>(size), &ret, nullptr)) {
throw NFile::Exception {"read failure"};
}
return static_cast<size_t>(ret);
}
size_t NFile::Write(size_t offset, const uint8_t* buf, size_t size) {
const auto h = reinterpret_cast<HANDLE>(handle_);
LONG off_low = offset & 0xFFFFFFFF;
LONG off_high = offset >> 32;
if (INVALID_SET_FILE_POINTER == SetFilePointer(h, off_low, &off_high, FILE_BEGIN)) {
throw NFile::Exception {"failed to set file pointer"};
}
DWORD ret;
if (!WriteFile(h, buf, static_cast<DWORD>(size), &ret, nullptr)) {
throw NFile::Exception {"read failure"};
}
return static_cast<size_t>(ret);
}
size_t NFile::Truncate(size_t size) {
const auto h = reinterpret_cast<HANDLE>(handle_);
LONG off_low = size & 0xFFFFFFFF;
LONG off_high = size >> 32;
if (INVALID_SET_FILE_POINTER == SetFilePointer(h, off_low, &off_high, FILE_BEGIN)) {
throw NFile::Exception {"failed to set file pointer"};
}
if (!SetEndOfFile(h)) {
throw NFile::Exception {"SetEndOfFile failure"};
}
return size;
}
} // namespace nf7