com.pervasive.datarush.operators.io

Class AbstractRecordFormatter

java.lang.Object

com.pervasive.datarush.operators.io.AbstractRecordFormatter

All Implemented Interfaces:

DataFormat.DataFormatter

public abstract class AbstractRecordFormatter
extends Object
implements DataFormat.DataFormatter

Skeleton implementation of a formatter for writing records to a sink. Provides a basic loop over the input data, deferring to subclasses to do format-specific processing.

Constructor Summary

Constructors

Constructor and Description
AbstractRecordFormatter()

Method Summary

Modifier and Type	Method and Description
void	bindInput(SteppableRecordValued source) Simple implementation which passes an input port buffer to bindInputFields(RecordValued).
protected abstract void	bindInputFields(RecordValued source) Provides the buffer holding input data to be formatted.
abstract void	close() Called to signal that writing is complete.
protected abstract void	formatRecord() Called to write a formatted record.
protected abstract void	initialize(ByteSink sink, WriteMode mode) Prepares the formatter for writing to the provided sink.
void	writeData(ByteSink sink, WriteMode mode) Simple implementation of a control loop formatting records.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractRecordFormatter

public AbstractRecordFormatter()

Method Detail

bindInputFields

protected abstract void bindInputFields(RecordValued source)

Provides the buffer holding input data to be formatted. This will be called once, when the input is bound to the formatter.

Parameters:

source - a record valued container which will hold the current value to be formatted

bindInput

public final void bindInput(SteppableRecordValued source)

Simple implementation which passes an input port buffer to bindInputFields(RecordValued).

Specified by:

bindInput in interface DataFormat.DataFormatter

Parameters:

source - the input port providing records

initialize

protected abstract void initialize(ByteSink sink,
                                   WriteMode mode)
                            throws IOException

Prepares the formatter for writing to the provided sink. This will be called once, after #bindInput(RecordInput) has been called, but before formatRecord() is called.

This method is always called, even if the input has no data.

Parameters:

sink - the target to which data is written

mode - how an existing sink should be handled

Throws:

IOException - if an I/O error occurs

formatRecord

protected abstract void formatRecord()
                              throws IOException

Called to write a formatted record. The method is expected to format the record in the buffer passed in previously through bindInputFields(RecordValued) and write it to the sink passed to initialize(ByteSink, WriteMode).

This method is called repeatedly while the record source still has data.

Throws:

IOException - if an I/O error occurs while writing the record

writeData

public final void writeData(ByteSink sink,
                            WriteMode mode)

Simple implementation of a control loop formatting records. It first initializes the formatter with initialize(ByteSink, WriteMode). If successfully initialized, it then iterates over the previously bound input, calling formatRecord() for each record on the port.

Specified by:

writeData in interface DataFormat.DataFormatter

Parameters:

sink - the data sink to which formatted records are to be written

mode - the access mode for the write

close

public abstract void close()

Called to signal that writing is complete. If bindInputFields(RecordValued) has returned successfully, it is guaranteed that this method will be called, even if errors occur.

This method is called once, after the last call to formatRecord() Any allocated resources which need to be released should be handled within the implementation of this method.

Specified by:

close in interface DataFormat.DataFormatter