[LUCENE-2700] Expose DocValues via Fields

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: CSF branch
• Component/s: core/index
• Lucene Fields: New
• Assignee: Simon Willnauer
• Reporter: Simon Willnauer
• Created: 13/Oct/10 06:39
• Updated: 28/Aug/22 12:34
• Resolved: 25/Nov/10 10:41

Description

DocValues Reader are currently exposed / accessed directly via IndexReader. To integrate the new feature in a more "native" way we should expose the DocValues via Fields on a perSegment level and on MultiFields in the multi reader case. DocValues should be side by side with Fields.terms enabling access to Source, SortedSource and ValuesEnum something like that:

public abstract class Fields {
...

  public DocValues values();

}

public abstract class DocValues {
  /** on disk enum based API */
  public abstract ValuesEnum getEnum() throws IOException;
  /** in memory Random Access API - with enum support - first call loads values in ram*/
  public abstract Source getSource() throws IOException;
  /** sorted in memory Random Access API - optional operation */
  public SortedSource getSortedSource(Comparator<BytesRef> comparator) throws IOException, UnsupportedOperationException;
  /** unloads previously loaded source only but keeps the doc values open */
  public abstract unload();
  /** closes the doc values */
  public abstract close();
}

Issue Links

• is part of: LUCENE-2186 First cut at column-stride fields (index values storage)