org.apache.lucene.search
Class TopTermsRewrite<Q extends Query>

java.lang.Object
  org.apache.lucene.search.MultiTermQuery.RewriteMethod
      org.apache.lucene.search.TopTermsRewrite<Q>

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

MultiTermQuery.TopTermsBoostOnlyBooleanQueryRewrite, MultiTermQuery.TopTermsScoringBooleanQueryRewrite

public abstract class TopTermsRewrite<Q extends Query>
extends MultiTermQuery.RewriteMethod

Base rewrite method for collecting only the top terms via a priority queue.

See Also:

Serialized Form

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Only public to be accessible by spans package.

Nested Class Summary

protected static interface

TermCollectingRewrite.TermCollector

Constructor Summary

TopTermsRewrite(int size)
Create a TopTermsBooleanQueryRewrite for at most size terms.

Method Summary

protected abstract void	addClause(Q topLevel, Term term, float boost) Add a MultiTermQuery term to the top-level query
protected void	collectTerms(IndexReader reader, MultiTermQuery query, TermCollectingRewrite.TermCollector collector)
boolean	equals(Object obj)
protected abstract int	getMaxSize() return the maximum size of the priority queue (for boolean rewrites this is BooleanQuery#getMaxClauseCount).
int	getSize() return the maximum priority queue size
protected abstract Q	getTopLevelQuery() Return a suitable top-level Query for holding all expanded terms.
int	hashCode()
Q	rewrite(IndexReader reader, MultiTermQuery query)

Methods inherited from class org.apache.lucene.search.MultiTermQuery.RewriteMethod

getTermsEnum

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TopTermsRewrite

public TopTermsRewrite(int size)

Create a TopTermsBooleanQueryRewrite for at most size terms.

NOTE: if BooleanQuery.getMaxClauseCount() is smaller than size, then it will be used instead.

Method Detail

getSize

public int getSize()

return the maximum priority queue size

getMaxSize

protected abstract int getMaxSize()

return the maximum size of the priority queue (for boolean rewrites this is BooleanQuery#getMaxClauseCount).

rewrite

public Q rewrite(IndexReader reader,
                 MultiTermQuery query)
                        throws IOException

Specified by:

rewrite in class MultiTermQuery.RewriteMethod

Throws:

IOException

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

getTopLevelQuery

protected abstract Q getTopLevelQuery()
                                             throws IOException

Return a suitable top-level Query for holding all expanded terms.

Throws:

IOException

addClause

protected abstract void addClause(Q topLevel,
                                  Term term,
                                  float boost)
                           throws IOException

Add a MultiTermQuery term to the top-level query

Throws:

IOException

collectTerms

protected final void collectTerms(IndexReader reader,
                                  MultiTermQuery query,
                                  TermCollectingRewrite.TermCollector collector)
                           throws IOException

Throws:

IOException