Package com.atlassian.jira.issue.statistics.util

Class OneDimensionalObjectHitCollector

java.lang.Object
org.apache.lucene.search.SimpleCollector
com.atlassian.jira.issue.statistics.util.OneDimensionalObjectHitCollector
All Implemented Interfaces:
org.apache.lucene.search.Collector, org.apache.lucene.search.LeafCollector
public class OneDimensionalObjectHitCollector extends org.apache.lucene.search.SimpleCollector
A HitCollector that creates a doc -> object mapping. This is useful for collecting documents where there are a limited number of terms. The caching also ensures that if multiple searches sort on the same terms, the doc -> object mapping is maintained.

This HitCollector can be quite memory intensive, however the cache is stored with a weak reference, so it will be garbage collected.

This HitCollector differs from OneDimensionalTermHitCollector in that it performs the term -> object conversion here, rather than later. This is more expensive, but useful for StatisticsMappers that perform some sort of runtime conversion / translation (eg a StatisticsMapper that groups dates by Month, or groups users by email domain name).

  • Constructor Details

    • OneDimensionalObjectHitCollector

      public OneDimensionalObjectHitCollector(String fieldName, StatisticsMapper statisticsMapper, Map result)
      Creates a normal one-dimensional object hit collector. This is equivalent to OneDimensionalObjectHitCollector(String, StatisticsMapper, Map, boolean)} with false provided for isUnique, which should be safe for use with all fields. However, if it is known in advance that the field contains at most one value for the field, then specifying isUnique will be more efficient.
      Parameters:
      statisticsMapper - provides the information required to map the field
      result - the map to which the result will be published

    • OneDimensionalObjectHitCollector

      @ExperimentalApi public OneDimensionalObjectHitCollector(String fieldName, StatisticsMapper statisticsMapper, Map result, boolean isUnique)
      Allows the caller to specify whether or not the hit collector may assume that the field will never have more than one value for any issue. This allows the hit collector to be much more efficient in gathering the data for that field, but it will give incorrect results if the field can contain multiple values. Examples of suitable fields where isUnique should be set include the project id, issue type, created date, and resolved date.
      Parameters:
      statisticsMapper - provides the information required to map the field
      result - the map to which the result will be published
      isUnique - true if the field can safely be assumed to have at most one value for any issue; false if the field might be allowed to contain multiple values per issue

  • Method Details

    • collect

      public void collect(int i) throws IOException
      Specified by:
      collect in interface org.apache.lucene.search.LeafCollector
      Specified by:
      collect in class org.apache.lucene.search.SimpleCollector
      Throws:
      IOException

    • setScorer

      public void setScorer(org.apache.lucene.search.Scorer scorer) throws IOException
      Specified by:
      setScorer in interface org.apache.lucene.search.LeafCollector
      Overrides:
      setScorer in class org.apache.lucene.search.SimpleCollector
      Throws:
      IOException

    • doSetNextReader

      protected void doSetNextReader(org.apache.lucene.index.LeafReaderContext context) throws IOException
      Overrides:
      doSetNextReader in class org.apache.lucene.search.SimpleCollector
      Throws:
      IOException

    • needsScores

      public boolean needsScores()