Class SequentialRecordReader

tensorflow/core/lib/io/record_reader.h:120–153

High-level interface to read TFRecord files. Note: this class is not thread safe; external synchronization required.

//
// Note: this class is not thread safe; external synchronization required.
class SequentialRecordReader {
 public:
  // Create a reader that will return log records from "*file".
  // "*file" must remain live while this Reader is in use.
  explicit SequentialRecordReader(
      RandomAccessFile* file,
      const RecordReaderOptions& options = RecordReaderOptions());

  virtual ~SequentialRecordReader() = default;

  // Reads the next record in the file into *record. Returns OK on success,
  // OUT_OF_RANGE for end of file, or something else for an error.
  Status ReadRecord(string* record) {
    return underlying_.ReadRecord(&offset_, record);
  }

  // Returns the current offset in the file.
  uint64 TellOffset() { return offset_; }

  // Seek to this offset within the file and set this offset as the current
  // offset. Trying to seek backward will throw error.
  Status SeekOffset(uint64 offset) {
    if (offset < offset_)
      return errors::InvalidArgument(
          "Trying to seek offset: ", offset,
          " which is less than the current offset: ", offset_);
    offset_ = offset;
    return Status::OK();
  }

 private:
  RecordReader underlying_;
  uint64 offset_ = 0;
};

}  // namespace io
}  // namespace tensorflow