Method BundleReader

tensorflow/core/util/tensor_bundle/tensor_bundle.cc:891–933

// Interface for reading a tensor bundle.

BundleReader::BundleReader(Env* env, StringPiece prefix)
    : env_(env),
      prefix_(prefix),
      metadata_(nullptr),
      table_(nullptr),
      iter_(nullptr),
      need_to_swap_bytes_(false) {
  const string filename = MetaFilename(prefix_);
  uint64 file_size;
  status_ = env_->GetFileSize(filename, &file_size);
  if (!status_.ok()) return;

  // Opens the metadata table.
  std::unique_ptr<RandomAccessFile> wrapper;
  status_ = env_->NewRandomAccessFile(filename, &wrapper);
  if (!status_.ok()) return;
  metadata_ = wrapper.release();
  status_ = table::Table::Open(table::Options(), metadata_, file_size, &table_);
  if (!status_.ok()) return;
  iter_ = table_->NewIterator();

  // Reads "num_shards_" from the first entry.
  iter_->Seek(kHeaderEntryKey);
  if (!iter_->Valid()) {
    status_ = CorruptFileError(iter_->status(), filename,
                               "failed to seek to header entry");
    return;
  }
  BundleHeaderProto header;
  status_ = ParseEntryProto(iter_->key(), iter_->value(), &header);
  if (!status_.ok()) {
    status_ = CorruptFileError(status_, filename, "unable to parse header");
    return;
  }
  num_shards_ = header.num_shards();
  if ((header.endianness() == BundleHeaderProto::BIG && port::kLittleEndian) ||
      (header.endianness() == BundleHeaderProto::LITTLE &&
       !port::kLittleEndian)) {
    need_to_swap_bytes_ = true;
  }
  status_ = CheckVersions(header.version(), kTensorBundleVersion,
                          kTensorBundleMinProducer, "Checkpoint", "checkpoint");
}

BundleReader::~BundleReader() {
  delete metadata_;