Interface BulkWriter<T>

  • Type Parameters:
    T - The type of the elements encoded through this encoder.

    @PublicEvolving
    public interface BulkWriter<T>
    An encoder that encodes data in a bulk fashion, encoding many records together at a time.

    Examples for bulk encoding are most compressed formats, including formats like Parquet and ORC which encode batches of records into blocks of column vectors.

    The bulk encoder may be stateful and is bound to a single stream during its lifetime.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Interface Description
      static interface  BulkWriter.Factory<T>
      A factory that creates a BulkWriter.
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void addElement​(T element)
      Adds an element to the encoder.
      void finish()
      Finishes the writing.
      void flush()
      Flushes all intermediate buffered data to the output stream.
    • Method Detail

      • addElement

        void addElement​(T element)
                 throws IOException
        Adds an element to the encoder. The encoder may temporarily buffer the element, or immediately write it to the stream.

        It may be that adding this element fills up an internal buffer and causes the encoding and flushing of a batch of internally buffered elements.

        Parameters:
        element - The element to add.
        Throws:
        IOException - Thrown, if the element cannot be added to the encoder, or if the output stream throws an exception.
      • flush

        void flush()
            throws IOException
        Flushes all intermediate buffered data to the output stream. It is expected that flushing often may reduce the efficiency of the encoding.
        Throws:
        IOException - Thrown if the encoder cannot be flushed, or if the output stream throws an exception.
      • finish

        void finish()
             throws IOException
        Finishes the writing. This must flush all internal buffer, finish encoding, and write footers.

        The writer is not expected to handle any more records via addElement(Object) after this method is called.

        Important: This method MUST NOT close the stream that the writer writes to. Closing the stream is expected to happen through the invoker of this method afterwards.

        Throws:
        IOException - Thrown if the finalization fails.