com.fasterxml.sort.util

Class BlockingQueueReader<E>

java.lang.Object

com.fasterxml.sort.DataReader<E>

com.fasterxml.sort.util.BlockingQueueReader<E>

public abstract class BlockingQueueReader<E>
extends DataReader<E>

Base implementation for DataReader that uses a BlockingQueue for getting input. The only missing part is implementation for estimateSizeInBytes(Object), since there is no way to provide a meaningful estimate without knowing object type.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	_closed
protected E	_endMarker
protected BlockingQueue<E>	_queue

Constructor Summary

Constructors

Constructor and Description
BlockingQueueReader(BlockingQueue<E> q) Deprecated.
BlockingQueueReader(BlockingQueue<E> q, E endMarker)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Method for closing the reader.
abstract int	estimateSizeInBytes(E item) Method that should estimate memory usage of given item, for purpose of limiting amount of data kept in memory during pre-sorting phase.
E	readNext() Method for reading the next data item; will return null to indicate end of input, otherwise return a non-null item.

Methods inherited from class java.lang.Object

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

Field Detail

_queue

protected final BlockingQueue<E> _queue

_endMarker

protected final E _endMarker

_closed

protected boolean _closed

Constructor Detail

BlockingQueueReader

@Deprecated
public BlockingQueueReader(BlockingQueue<E> q)

Deprecated.

BlockingQueueReader

public BlockingQueueReader(BlockingQueue<E> q,
                   E endMarker)

Parameters:

q - Queue to read entries from

endMarker - Value that is used to signal end-of-input; when this value is gotten from queue, reader assumes that no more input is coming and will return null from readNext().

Method Detail

close

public void close()
           throws IOException

Description copied from class: DataReader

Method for closing the reader. Note that reader needs to ensure that it is ok to call close multiple times. Reader may also close underlying resources as soon as it has reached end of input.

Specified by:

close in class DataReader<E>

Throws:

IOException

estimateSizeInBytes

public abstract int estimateSizeInBytes(E item)

Description copied from class: DataReader

Method that should estimate memory usage of given item, for purpose of limiting amount of data kept in memory during pre-sorting phase.

Specified by:

estimateSizeInBytes in class DataReader<E>

readNext

public E readNext()
           throws IOException

Description copied from class: DataReader

Method for reading the next data item; will return null to indicate end of input, otherwise return a non-null item.

Specified by:

readNext in class DataReader<E>

Throws:

IOException