FileDocCategorySizeDatePackage
Hits.javaAPI DocApache Lucene 1.4.34841Tue Mar 30 00:48:04 BST 2004org.apache.lucene.search

Hits

public final class Hits extends Object
A ranked list of documents, used to hold search results.

Fields Summary
private Query
query
private Searcher
searcher
private Filter
filter
private Sort
sort
private int
length
private Vector
hitDocs
private HitDoc
first
private HitDoc
last
private int
numDocs
private int
maxDocs
Constructors Summary
Hits(Searcher s, Query q, Filter f)

    // max to cache

          
    query = q;
    searcher = s;
    filter = f;
    getMoreDocs(50); // retrieve 100 initially
Hits(Searcher s, Query q, Filter f, Sort o)

    query = q;
    searcher = s;
    filter = f;
    sort = o;
    getMoreDocs(50); // retrieve 100 initially
Methods Summary
private final voidaddToFront(org.apache.lucene.search.HitDoc hitDoc)

  // insert at front of cache
    if (first == null) {
      last = hitDoc;
    } else {
      first.prev = hitDoc;
    }

    hitDoc.next = first;
    first = hitDoc;
    hitDoc.prev = null;

    numDocs++;
public final org.apache.lucene.document.Documentdoc(int n)
Returns the stored fields of the nth document in this set.

Documents are cached, so that repeated requests for the same element may return the same Document object.

    HitDoc hitDoc = hitDoc(n);

    // Update LRU cache of documents
    remove(hitDoc);               // remove from list, if there
    addToFront(hitDoc);           // add to front of list
    if (numDocs > maxDocs) {      // if cache is full
      HitDoc oldLast = last;
      remove(last);             // flush last
      oldLast.doc = null;       // let doc get gc'd
    }

    if (hitDoc.doc == null) {
      hitDoc.doc = searcher.doc(hitDoc.id);  // cache miss: read document
    }

    return hitDoc.doc;
private final voidgetMoreDocs(int min)
Tries to add new documents to hitDocs. Ensures that the hit numbered min has been retrieved.

    if (hitDocs.size() > min) {
      min = hitDocs.size();
    }

    int n = min * 2;	// double # retrieved
    TopDocs topDocs = (sort == null) ? searcher.search(query, filter, n) : searcher.search(query, filter, n, sort);
    length = topDocs.totalHits;
    ScoreDoc[] scoreDocs = topDocs.scoreDocs;

    float scoreNorm = 1.0f;
    if (length > 0 && scoreDocs[0].score > 1.0f) {
      scoreNorm = 1.0f / scoreDocs[0].score;
    }

    int end = scoreDocs.length < length ? scoreDocs.length : length;
    for (int i = hitDocs.size(); i < end; i++) {
      hitDocs.addElement(new HitDoc(scoreDocs[i].score * scoreNorm,
                                    scoreDocs[i].doc));
    }
private final org.apache.lucene.search.HitDochitDoc(int n)

    if (n >= length) {
      throw new IndexOutOfBoundsException("Not a valid hit number: " + n);
    }

    if (n >= hitDocs.size()) {
      getMoreDocs(n);
    }

    return (HitDoc) hitDocs.elementAt(n);
public final intid(int n)
Returns the id for the nth document in this set.

    return hitDoc(n).id;
public final intlength()
Returns the total number of hits available in this set.

    return length;
private final voidremove(org.apache.lucene.search.HitDoc hitDoc)

	  // remove from cache
    if (hitDoc.doc == null) {     // it's not in the list
      return;					  // abort
    }

    if (hitDoc.next == null) {
      last = hitDoc.prev;
    } else {
      hitDoc.next.prev = hitDoc.prev;
    }

    if (hitDoc.prev == null) {
      first = hitDoc.next;
    } else {
      hitDoc.prev.next = hitDoc.next;
    }

    numDocs--;
public final floatscore(int n)
Returns the score for the nth document in this set.

    return hitDoc(n).score;