Class Dataset.ColumnsDataReader

Method Details

• open

  public void open()

  Description copied from class: DataEndpoint

  Makes this endpoint ready for reading or writing.

  Overrides:

  open in class DataEndpoint

• readImpl

  protected Record readImpl() throws Throwable

  Description copied from class: DataReader

  Overridden by subclasses to read the next record from this DataReader. The default implementation of DataReader.read() now insures that this method will not be called again after it returns a null.

  If no record is available, null will be returned.

  Contract for subclasses (see also docs/authoring/DataReader.md):

  • Return null exactly once to signal end-of-stream.
  • Do not call this method directly — DataReader.read() is the template method that wraps exceptions, increments the record count, and tracks lineage.
  • Do not call DataEndpoint.incrementRecordCount() here; DataReader.read() already does.
  • Throw raw exceptions; DataReader.read() wraps them via exception(throwable).

  Specified by:

  readImpl in class DataReader

  Throws:

  Throwable

• available

  public int available()

  Description copied from class: DataReader

  Returns the number of records that can probably be read without blocking.

  Overrides:

  available in class DataReader