public class EarlyTerminatingSortingCollector extends Collector
Collector
that early terminates collection of documents on a
per-segment basis, if the segment was sorted according to the given
Sorter
.
NOTE: the Collector
detects sorted segments according to
SortingMergePolicy
, so it's best used in conjunction with it. Also,
it collects up to a specified num docs from each segment, and therefore is
mostly suitable for use in conjunction with collectors such as
TopDocsCollector
, and not e.g. TotalHitCountCollector
.
NOTE: If you wrap a TopDocsCollector
that sorts in the same
order as the index order, the returned TopDocsCollector.topDocs()
will be correct. However the total of hit count
will be underestimated since not all matching documents will have
been collected.
NOTE: This Collector
uses Sorter.getID()
to detect
whether a segment was sorted with the same Sorter
as the one given in
EarlyTerminatingSortingCollector(Collector, Sorter, int)
. This has
two implications:
Sorter.getID()
is not implemented correctly and returns
different identifiers for equivalent Sorter
s, this collector will not
detect sorted segments,IndexWriter
's
SortingMergePolicy
to sort according to another criterion and if both
the old and the new Sorter
s have the same identifier, this
Collector
will incorrectly detect sorted segments.Modifier and Type | Field and Description |
---|---|
protected Collector |
in |
protected int |
numDocsToCollect |
protected boolean |
segmentSorted |
protected int |
segmentTotalCollect |
protected Sorter |
sorter |
Constructor and Description |
---|
EarlyTerminatingSortingCollector(Collector in,
Sorter sorter,
int numDocsToCollect)
Create a new
EarlyTerminatingSortingCollector instance. |
Modifier and Type | Method and Description |
---|---|
boolean |
acceptsDocsOutOfOrder() |
void |
collect(int doc) |
void |
setNextReader(AtomicReaderContext context) |
void |
setScorer(Scorer scorer) |
protected final Collector in
protected final Sorter sorter
protected final int numDocsToCollect
protected int segmentTotalCollect
protected boolean segmentSorted
public EarlyTerminatingSortingCollector(Collector in, Sorter sorter, int numDocsToCollect)
EarlyTerminatingSortingCollector
instance.in
- the collector to wrapsorter
- the same sorter as the one which is used by IndexWriter
's
SortingMergePolicy
numDocsToCollect
- the number of documents to collect on each segment. When wrapping
a TopDocsCollector
, this number should be the number of
hits.public void setScorer(Scorer scorer) throws IOException
setScorer
in class Collector
IOException
public void collect(int doc) throws IOException
collect
in class Collector
IOException
public void setNextReader(AtomicReaderContext context) throws IOException
setNextReader
in class Collector
IOException
public boolean acceptsDocsOutOfOrder()
acceptsDocsOutOfOrder
in class Collector
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