org.apache.flink.api.common.serialization

Interface BulkWriter<T>

Type Parameters:

T - The type of the elements encoded through this encoder.

All Known Subinterfaces:

HadoopPathBasedBulkWriter<T>

All Known Implementing Classes:

AvroBulkWriter, HadoopCompressionBulkWriter, NoCompressionBulkWriter, OrcBulkWriter, ParquetBulkWriter, SequenceFileWriter

@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 and Description
static interface	BulkWriter.Factory<T> A factory that creates a BulkWriter.

Method Summary

Modifier and Type	Method and 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.