E
- The type of the record returned by the iterator.@PublicEvolving public final class SingletonResultIterator<E> extends RecyclableIterator<E> implements BulkFormat.RecordIterator<E>
BulkFormat.RecordIterator
that returns a single value. The iterator is mutable
to support object reuse and supports recycling.Constructor and Description |
---|
SingletonResultIterator() |
SingletonResultIterator(Runnable recycler) |
Modifier and Type | Method and Description |
---|---|
RecordAndPosition<E> |
next()
Gets the next record from the file, together with its position.
|
void |
set(E element,
long offset,
long skipCount)
Sets the single record to be returned by this iterator.
|
releaseBatch
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
releaseBatch
public void set(E element, long offset, long skipCount)
RecordAndPosition
, meaning they need
to point to AFTER this specific record (because a checkpoint taken after the record was
processed needs to resume from after this record).@Nullable public RecordAndPosition<E> next()
BulkFormat.RecordIterator
The position information returned with the record point to the record AFTER the returned record, because it defines the point where the reading should resume once the current record is emitted. The position information is put in the source's state when the record is emitted. If a checkpoint is taken directly after the record is emitted, the checkpoint must to describe where to resume the source reading from after that record.
Objects returned by this method may be reused by the iterator. By the time that this
method is called again, no object returned from the previous call will be referenced any
more. That makes it possible to have a single MutableRecordAndPosition
object and
return the same instance (with updated record and position) on every call.
next
in interface BulkFormat.RecordIterator<E>
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