Module org.apache.lucene.sandbox
Package org.apache.lucene.sandbox.search

Class CoveringQuery

java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.sandbox.search.CoveringQuery
All Implemented Interfaces:
Accountable
public final class CoveringQuery extends Query implements Accountable
A Query that allows to have a configurable number or required matches per document. This is typically useful in order to build queries whose query terms must all appear in documents.

  • Field Details

    • BASE_RAM_BYTES

      private static final long BASE_RAM_BYTES

    • queries

      private final Collection<Query> queries

    • minimumNumberMatch

      private final LongValuesSource minimumNumberMatch

    • hashCode

      private final int hashCode

    • ramBytesUsed

      private final long ramBytesUsed

  • Constructor Details

    • CoveringQuery

      public CoveringQuery(Collection<Query> queries, LongValuesSource minimumNumberMatch)
      Sole constructor.
      Parameters:
      queries - Sub queries to match.
      minimumNumberMatch - Per-document long value that records how many queries should match. Values that are less than 1 are treated like 1: only documents that have at least one matching clause will be considered matches. Documents that do not have a value for minimumNumberMatch do not match.

  • Method Details

    • toString

      public String toString(String field)
      Description copied from class: Query
      Prints a query to a string, with field assumed to be the default field and omitted.
      Specified by:
      toString in class Query

    • equals

      public boolean equals(Object obj)
      Description copied from class: Query
      Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly.

      Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical to those of the other instance. Utility methods are provided for certain repetitive code.

      Specified by:
      equals in class Query
      See Also:

    • computeHashCode

      private int computeHashCode()

    • hashCode

      public int hashCode()
      Description copied from class: Query
      Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.
      Specified by:
      hashCode in class Query
      See Also:

    • ramBytesUsed

      public long ramBytesUsed()
      Description copied from interface: Accountable
      Return the memory usage of this object in bytes. Negative values are illegal.
      Specified by:
      ramBytesUsed in interface Accountable

    • rewrite

      public Query rewrite(IndexSearcher indexSearcher) throws IOException
      Description copied from class: Query
      Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

      Callers are expected to call rewrite multiple times if necessary, until the rewritten query is the same as the original query.

      The rewrite process may be able to make use of IndexSearcher's executor and be executed in parallel if the executor is provided.

      However, if any of the intermediary queries do not satisfy the new API, parallel rewrite is not possible for any subsequent sub-queries. To take advantage of this API, the entire query tree must override this method.

      Overrides:
      rewrite in class Query
      Throws:
      IOException
      See Also:

    • visit

      public void visit(QueryVisitor visitor)
      Description copied from class: Query
      Recurse through the query tree, visiting any child queries.
      Specified by:
      visit in class Query
      Parameters:
      visitor - a QueryVisitor to be called by each query in the tree

    • createWeight

      public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException
      Description copied from class: Query
      Expert: Constructs an appropriate Weight implementation for this query.

      Only implemented by primitive queries, which re-write to themselves.

      Overrides:
      createWeight in class Query
      Parameters:
      scoreMode - How the produced scorers will be consumed.
      boost - The boost that is propagated by the parent queries.
      Throws:
      IOException