Method Read

src/leveldb/util/env_windows.cc:194–212

  ~WindowsRandomAccessFile() override = default;

  Status Read(uint64_t offset, size_t n, Slice* result,
              char* scratch) const override {
    DWORD bytes_read = 0;
    OVERLAPPED overlapped = {0};

    overlapped.OffsetHigh = static_cast<DWORD>(offset >> 32);
    overlapped.Offset = static_cast<DWORD>(offset);
    if (!::ReadFile(handle_.get(), scratch, static_cast<DWORD>(n), &bytes_read,
                    &overlapped)) {
      DWORD error_code = ::GetLastError();
      if (error_code != ERROR_HANDLE_EOF) {
        *result = Slice(scratch, 0);
        return Status::IOError(filename_, GetWindowsErrorMessage(error_code));
      }
    }

    *result = Slice(scratch, bytes_read);
    return Status::OK();
  }

  std::string GetName() const override { return filename_; }