Method Seek

src/filesystem/fatfs/fatfs.cpp:436–463

}

auto FatFsFileSystem::FatFsFileOps::Seek(vfs::File* file, int64_t offset,
                                         vfs::SeekWhence whence)
    -> Expected<uint64_t> {
  auto* fi = static_cast<FatInode*>(file->inode->fs_private);
  if (fi->fil == nullptr) {
    return std::unexpected(Error{ErrorCode::kFsInvalidFd});
  }
  FSIZE_t new_pos = 0;
  switch (whence) {
    case vfs::SeekWhence::kSet:
      new_pos = static_cast<FSIZE_t>(offset);
      break;
    case vfs::SeekWhence::kCur:
      new_pos =
          static_cast<FSIZE_t>(static_cast<int64_t>(f_tell(fi->fil)) + offset);
      break;
    case vfs::SeekWhence::kEnd:
      new_pos =
          static_cast<FSIZE_t>(static_cast<int64_t>(f_size(fi->fil)) + offset);
      break;
  }
  FRESULT fr = f_lseek(fi->fil, new_pos);
  if (fr != FR_OK) {
    return std::unexpected(Error{FresultToErrorCode(fr)});
  }
  file->offset = static_cast<uint64_t>(new_pos);
  return static_cast<uint64_t>(new_pos);
}

auto FatFsFileSystem::FatFsFileOps::Close(vfs::File* file) -> Expected<void> {
  auto* fi = static_cast<FatInode*>(file->inode->fs_private);