E
- The type of the record returned by the iterator.@PublicEvolving public final class IteratorResultIterator<E> extends RecyclableIterator<E> implements BulkFormat.RecordIterator<E>
BulkFormat.RecordIterator
that returns the elements of an iterator, augmented
with position information.Constructor and Description |
---|
IteratorResultIterator(Iterator<E> records,
long offset,
long startingSkipCount)
Creates a new
RecordIterator returning the records from the given iterator, augmented
with their position information. |
IteratorResultIterator(Iterator<E> records,
long offset,
long startingSkipCount,
Runnable recycler)
Creates a new
RecordIterator returning the records from the given iterator, augmented
with their position information. |
Modifier and Type | Method and Description |
---|---|
RecordAndPosition<E> |
next()
Gets the next record from the file, together with its position.
|
releaseBatch
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
releaseBatch
public IteratorResultIterator(Iterator<E> records, long offset, long startingSkipCount)
RecordIterator
returning the records from the given iterator, augmented
with their position information.
Each record's RecordAndPosition
will have the same offset value for RecordAndPosition.getOffset()
. The first returned record will have a records-to-skip count
of startingSkipCount + 1
, following the contract that each record needs to point to
the position AFTER itself (because a checkpoint taken after the record was emitted needs to
resume from after that record).
public IteratorResultIterator(Iterator<E> records, long offset, long startingSkipCount, @Nullable Runnable recycler)
RecordIterator
returning the records from the given iterator, augmented
with their position information. When the iterator is marked as done (via RecyclableIterator.releaseBatch()
, the given recycler
is called.
Each record's RecordAndPosition
will have the same offset value for RecordAndPosition.getOffset()
. The first returned record will have a records-to-skip count
of startingSkipCount + 1
, following the contract that each record needs to point to
the position AFTER itself (because a checkpoint taken after the record was emitted needs to
resume from after that 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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