org.apache.flink.runtime.operators.resettable

Class BlockResettableMutableObjectIterator<T>

java.lang.Object

org.apache.flink.runtime.operators.resettable.BlockResettableMutableObjectIterator<T>

All Implemented Interfaces:

MemoryBlockIterator, ResettableMutableObjectIterator<T>, MutableObjectIterator<T>

public class BlockResettableMutableObjectIterator<T>
extends Object
implements ResettableMutableObjectIterator<T>

Implementation of an iterator that fetches a block of data into main memory and offers resettable access to the data in that block.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	closed
protected SimpleCollectingOutputView	collectingView
protected ArrayList<MemorySegment>	emptySegments
protected ArrayList<MemorySegment>	fullSegments
static org.slf4j.Logger	LOG
protected int	numRecordsInBuffer
protected int	numRecordsReturned
protected RandomAccessInputView	readView
protected TypeSerializer<T>	serializer

Constructor Summary

Constructors

Constructor and Description
BlockResettableMutableObjectIterator(MemoryManager memoryManager, MutableObjectIterator<T> input, TypeSerializer<T> serializer, int numMemoryPages, AbstractInvokable ownerTask)

Method Summary

Modifier and Type	Method and Description
void	close() This method closes the iterator and releases all resources.
protected T	getNextRecord()
protected T	getNextRecord(T reuse)
boolean	hasFurtherInput() Checks, whether the input that is blocked by this iterator, has further elements available.
T	next() Gets the next element from the collection.
T	next(T target) Gets the next element from the collection.
boolean	nextBlock() Move the iterator to the next memory block.
void	open()
void	reset() Resets the iterator.
protected boolean	writeNextRecord(T record)

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

readView

protected final RandomAccessInputView readView

collectingView

protected final SimpleCollectingOutputView collectingView

serializer

protected final TypeSerializer<T> serializer

numRecordsInBuffer

protected int numRecordsInBuffer

numRecordsReturned

protected int numRecordsReturned

emptySegments

protected final ArrayList<MemorySegment> emptySegments

fullSegments

protected final ArrayList<MemorySegment> fullSegments

closed

protected volatile boolean closed

Constructor Detail

BlockResettableMutableObjectIterator

public BlockResettableMutableObjectIterator(MemoryManager memoryManager,
                                            MutableObjectIterator<T> input,
                                            TypeSerializer<T> serializer,
                                            int numMemoryPages,
                                            AbstractInvokable ownerTask)
                                     throws MemoryAllocationException

Throws:

MemoryAllocationException

Method Detail

next

public T next(T target)
       throws IOException

Description copied from interface: MutableObjectIterator

Gets the next element from the collection. The contents of that next element is put into the given reuse object, if the type is mutable.

Specified by:

next in interface MutableObjectIterator<T>

Parameters:

target - The target object into which to place next element if E is mutable.

Returns:

The filled object or null if the iterator is exhausted.

Throws:

IOException - Thrown, if a problem occurred in the underlying I/O layer or in the serialization / deserialization logic

next

public T next()
       throws IOException

Description copied from interface: MutableObjectIterator

Gets the next element from the collection. The iterator implementation must obtain a new instance.

Specified by:

next in interface MutableObjectIterator<T>

Returns:

The object or null if the iterator is exhausted.

Throws:

IOException - Thrown, if a problem occurred in the underlying I/O layer or in the serialization / deserialization logic

reset

public void reset()

Description copied from interface: ResettableMutableObjectIterator

Resets the iterator.

Specified by:

reset in interface ResettableMutableObjectIterator<T>

nextBlock

public boolean nextBlock()
                  throws IOException

Description copied from interface: MemoryBlockIterator

Move the iterator to the next memory block. The next memory block starts at the first element that was not in the block before. A special case is when no record was in the block before, which happens when this function is invoked two times directly in a sequence, without calling hasNext() or next in between. Then the block moves one element.

Specified by:

nextBlock in interface MemoryBlockIterator

Returns:

True if a new memory block was loaded, false if there were no further records and hence no further memory block.

Throws:

IOException - Thrown, when advancing to the next block failed.

hasFurtherInput

public boolean hasFurtherInput()

Checks, whether the input that is blocked by this iterator, has further elements available. This method may be used to forecast (for example at the point where a block is full) whether there will be more data (possibly in another block).

Returns:

True, if there will be more data, false otherwise.

close

public void close()

This method closes the iterator and releases all resources. This method works both as a regular shutdown and as a canceling method. The method may be called multiple times and will not produce an error.

open

public void open()

writeNextRecord

protected boolean writeNextRecord(T record)
                           throws IOException

Throws:

IOException

getNextRecord

protected T getNextRecord(T reuse)
                   throws IOException

Throws:

IOException

getNextRecord

protected T getNextRecord()
                   throws IOException

Throws:

IOException