- All Implemented Interfaces:
Iterable<E>
,DataBag<E>
,org.apache.jena.atlas.lib.Closeable
,org.apache.jena.atlas.lib.Sink<E>
- Direct Known Subclasses:
DistinctDataBag
This data bag will gather items in memory until a size threshold is passed, at which point it will write out all of the items to disk using the supplied serializer.
After adding is finished, call iterator()
to set up the data bag for
reading back items and iterating over them. The iterator will retrieve the
items in sorted order using the supplied comparator.
IMPORTANT: You may not add any more items after this call. You may
subsequently call iterator()
multiple times which will give you a
new iterator for each invocation. If you do not consume the entire iterator,
you should call Iter.close(Iterator)
to close any FileInputStreams
associated with the iterator.
Additionally, make sure to call close()
when you are finished to
free any system resources (preferably in a finally block).
Implementation Notes: Data is stored in an ArrayList as it comes in. When it is time to spill, that data is sorted and written to disk. An iterator will read in each file and perform a merge-sort as the results are returned.
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Constructor Summary
ConstructorsConstructorDescriptionSortedDataBag
(ThresholdPolicy<E> policy, SerializationFactory<E> serializerFactory, Comparator<? super E> comparator) -
Method Summary
Modifier and TypeMethodDescriptionvoid
Add a tuple to the bag.void
cancel()
cancel arranges that further comparisons using the supplied comparator will abandon the sort in progress.void
close()
void
flush()
boolean
isCancelled is true iff cancel has been called on this bags comparator.boolean
isClosed()
isClosed returns true iff this bag has been closed.boolean
Find out if the bag is distinct.boolean
isSorted()
Find out if the bag is sorted.iterator()
Returns an iterator over a set of elements of type E.Methods inherited from class org.apache.jena.atlas.data.AbstractDataBag
isEmpty, send, size
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface java.lang.Iterable
forEach, spliterator
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Constructor Details
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SortedDataBag
public SortedDataBag(ThresholdPolicy<E> policy, SerializationFactory<E> serializerFactory, Comparator<? super E> comparator)
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Method Details
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cancel
public void cancel()cancel arranges that further comparisons using the supplied comparator will abandon the sort in progress. -
isCancelled
public boolean isCancelled()isCancelled is true iff cancel has been called on this bags comparator. (Used in testing.) -
isClosed
public boolean isClosed()isClosed returns true iff this bag has been closed. (Used in testing.) -
isSorted
public boolean isSorted()Description copied from interface:DataBag
Find out if the bag is sorted.- Returns:
- true if this is a sorted data bag, false otherwise.
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isDistinct
public boolean isDistinct()Description copied from interface:DataBag
Find out if the bag is distinct.- Returns:
- true if the bag is a distinct bag, false otherwise.
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add
Description copied from interface:DataBag
Add a tuple to the bag.- Parameters:
item
- tuple to add.
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flush
public void flush() -
iterator
Returns an iterator over a set of elements of type E. If you do not exhaust the iterator, you should callIter.close(Iterator)
to be sure any open file handles are closed.- Returns:
- an Iterator
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close
public void close()
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