org.apache.flink.util

Interface MutableObjectIterator<E>

Type Parameters:

E - The element type of the collection iterated over.

All Known Subinterfaces:

ResettableMutableObjectIterator<E>

All Known Implementing Classes:

BlockResettableMutableObjectIterator, ChannelReaderInputViewIterator, CompactingHashTable.EntryIterator, EmptyMutableObjectIterator, HashPartitionIterator, InputViewIterator, MergeIterator, MutableHashTable.HashBucketIterator, MutableHashTable.UnmatchedBuildIterator, ReaderIterator, RegularToMutableObjectIterator, SpillingResettableMutableObjectIterator

@Internal
public interface MutableObjectIterator<E>

A simple iterator interface. The key differences to the Iterator are

• It has two distinct next(), where one variant allows to pass an object that may be reused, if the type is mutable.
• It consolidates the logic in a single next() function, rather than splitting it over two different functions such as hasNext() and next()

Method Summary

Modifier and Type	Method and Description
E	next() Gets the next element from the collection.
E	next(E reuse) Gets the next element from the collection.

Method Detail

next

E next(E reuse)
throws IOException

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.

Parameters:

reuse - 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

E next()
throws IOException

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

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