Package org.apache.lucene.monitor

Class PartitionMatcher<T extends QueryMatch>

java.lang.Object
org.apache.lucene.monitor.CandidateMatcher<T>
org.apache.lucene.monitor.PartitionMatcher<T>
Type Parameters:
T - the type of QueryMatch to return
public class PartitionMatcher<T extends QueryMatch> extends CandidateMatcher<T>
A multi-threaded matcher that collects all possible matches in one pass, and then partitions them amongst a number of worker threads to perform the actual matching.

This class delegates the matching to separate CandidateMatcher classes, built from a passed in MatcherFactory.

Use this if your query sets contain large numbers of very fast queries, where the synchronization overhead of ParallelMatcher can outweigh the benefit of multithreading.

See Also:

  • Method Details

    • matchQuery

      protected void matchQuery(String queryId, Query matchQuery, Map<String,String> metadata)
      Description copied from class: CandidateMatcher
      Runs the supplied query against this CandidateMatcher's set of documents, storing any resulting match, and recording the query in the presearcher hits
      Specified by:
      matchQuery in class CandidateMatcher<T extends QueryMatch>
      Parameters:
      queryId - the query id
      matchQuery - the query to run
      metadata - the query metadata

    • resolve

      public T resolve(T match1, T match2)
      Description copied from class: CandidateMatcher
      If two matches from the same query are found (for example, two branches of a disjunction), combine them.
      Specified by:
      resolve in class CandidateMatcher<T extends QueryMatch>
      Parameters:
      match1 - the first match found
      match2 - the second match found
      Returns:
      a Match object that combines the two

    • doFinish

      protected void doFinish()
      Description copied from class: CandidateMatcher
      Called when all monitoring of a batch of documents is complete
      Overrides:
      doFinish in class CandidateMatcher<T extends QueryMatch>

    • factory

      public static <T extends QueryMatch> MatcherFactory<T> factory(ExecutorService executor, MatcherFactory<T> matcherFactory, int threads)
      Create a new MatcherFactory for a PartitionMatcher
      Type Parameters:
      T - the type of QueryMatch generated
      Parameters:
      executor - the ExecutorService to use
      matcherFactory - the MatcherFactory to use to create submatchers
      threads - the number of threads to use

    • factory

      public static <T extends QueryMatch> MatcherFactory<T> factory(ExecutorService executor, MatcherFactory<T> matcherFactory)
      Create a new MatcherFactory for a PartitionMatcher

      This factory will create a PartitionMatcher that uses as many threads as there are cores available to the JVM (as determined by Runtime.getRuntime().availableProcessors()).

      Type Parameters:
      T - the type of QueryMatch generated
      Parameters:
      executor - the ExecutorService to use
      matcherFactory - the MatcherFactory to use to create submatchers