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virtual | ~FieldComparator () |
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virtual String | getClassName () |
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boost::shared_ptr< FieldComparator > | shared_from_this () |
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virtual int32_t | compare (int32_t slot1, int32_t slot2)=0 |
| Compare hit at slot1 with hit at slot2.
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virtual void | setBottom (int32_t slot)=0 |
| Set the bottom slot, ie the "weakest" (sorted last) entry in the queue. When compareBottom is called, you should compare against this slot. This will always be called before compareBottom .
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virtual int32_t | compareBottom (int32_t doc)=0 |
| Compare the bottom of the queue with doc. This will only invoked after setBottom has been called. This should return the same result as compare(int,int) } as if bottom were slot1 and the new document were slot 2.
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virtual void | copy (int32_t slot, int32_t doc)=0 |
| This method is called when a new hit is competitive. You should copy any state associated with this document that will be required for future comparisons, into the specified slot.
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virtual void | setNextReader (const IndexReaderPtr &reader, int32_t docBase)=0 |
| Set a new Reader. All doc correspond to the current Reader.
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virtual void | setScorer (const ScorerPtr &scorer) |
| Sets the Scorer to use in case a document's score is needed.
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virtual ComparableValue | value (int32_t slot)=0 |
| Return the actual value in the slot.
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virtual | ~LuceneObject () |
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virtual void | initialize () |
| Called directly after instantiation to create objects that depend on this object being fully constructed.
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virtual LuceneObjectPtr | clone (const LuceneObjectPtr &other=LuceneObjectPtr()) |
| Return clone of this object.
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virtual int32_t | hashCode () |
| Return hash code for this object.
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virtual bool | equals (const LuceneObjectPtr &other) |
| Return whether two objects are equal.
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virtual int32_t | compareTo (const LuceneObjectPtr &other) |
| Compare two objects.
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virtual String | toString () |
| Returns a string representation of the object.
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virtual | ~LuceneSync () |
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virtual SynchronizePtr | getSync () |
| Return this object synchronize lock.
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virtual LuceneSignalPtr | getSignal () |
| Return this object signal.
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virtual void | lock (int32_t timeout=0) |
| Lock this object using an optional timeout.
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virtual void | unlock () |
| Unlock this object.
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virtual bool | holdsLock () |
| Returns true if this object is currently locked by current thread.
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virtual void | wait (int32_t timeout=0) |
| Wait for signal using an optional timeout.
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virtual void | notifyAll () |
| Notify all threads waiting for signal.
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A FieldComparator compares hits so as to determine their sort order when collecting the top results with TopFieldCollector
. The concrete public FieldComparator classes here correspond to the SortField types.
This API is designed to achieve high performance sorting, by exposing a tight interaction with FieldValueHitQueue
as it visits hits. Whenever a hit is competitive, it's enrolled into a virtual slot, which is an int ranging from 0 to numHits-1. The FieldComparator
is made aware of segment transitions during searching in case any internal state it's tracking needs to be recomputed during these transitions.
A comparator must define these functions:
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compare
Compare a hit at 'slot a' with hit 'slot b'.
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setBottom
This method is called by FieldValueHitQueue
to notify the FieldComparator of the current weakest ("bottom") slot. Note that this slot may not hold the weakest value according to your comparator, in cases where your comparator is not the primary one (ie, is only used to break ties from the comparators before it).
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compareBottom
Compare a new hit (docID) against the "weakest" (bottom) entry in the queue.
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copy
Installs a new hit into the priority queue. The FieldValueHitQueue
calls this method when a new hit is competitive.
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setNextReader
Invoked when the search is switching to the next segment. You may need to update internal state of the comparator, for example retrieving new values from the FieldCache
.
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value
Return the sort value stored in the specified slot. This is only called at the end of the search, in order to populate FieldDoc#fields
when returning the top results.
virtual int32_t Lucene::FieldComparator::compareBottom |
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int32_t |
doc | ) |
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pure virtual |
Compare the bottom of the queue with doc. This will only invoked after setBottom has been called. This should return the same result as compare(int,int)
} as if bottom were slot1 and the new document were slot 2.
For a search that hits many results, this method will be the hotspot (invoked by far the most frequently).
- Parameters
-
- Returns
- any N < 0 if the doc's value is sorted after the bottom entry (not competitive), any N > 0 if the doc's value is sorted before the bottom entry and 0 if they are equal.
Implemented in Lucene::NumericComparator< TYPE >, Lucene::NumericComparator< double >, Lucene::NumericComparator< int32_t >, Lucene::NumericComparator< int64_t >, Lucene::NumericComparator< uint8_t >, Lucene::DocComparator, Lucene::DoubleComparator, Lucene::IntComparator, Lucene::LongComparator, Lucene::RelevanceComparator, Lucene::StringComparatorLocale, Lucene::StringOrdValComparator, and Lucene::StringValComparator.