org.apache.solr.request

Class UnInvertedField

java.lang.Object

org.apache.lucene.index.DocTermOrds

org.apache.solr.request.UnInvertedField

public class UnInvertedField
extends DocTermOrds

Final form of the un-inverted field: Each document points to a list of term numbers that are contained in that document. Term numbers are in sorted order, and are encoded as variable-length deltas from the previous term number. Real term numbers start at 2 since 0 and 1 are reserved. A term number of 0 signals the end of the termNumber list. There is a single int[maxDoc()] which either contains a pointer into a byte[] for the termNumber lists, or directly contains the termNumber list if it fits in the 4 bytes of an integer. If the first byte in the integer is 1, the next 3 bytes are a pointer into a byte[] where the termNumber list starts. There are actually 256 byte arrays, to compensate for the fact that the pointers into the byte arrays are only 3 bytes long. The correct byte array for a document is a function of it's id. To save space and speed up faceting, any term that matches enough documents will not be un-inverted... it will be skipped while building the un-inverted field structure, and will use a set intersection method during faceting. To further save memory, the terms (the actual string values) are not all stored in memory, but a TermIndex is used to convert term numbers to term values only for the terms needed after faceting has completed. Only every 128th term value is stored, along with it's corresponding term number, and this is used as an index to find the closest term and iterate until the desired number is hit (very much like Lucene's own internal term index).

Field Summary

Fields inherited from class org.apache.lucene.index.DocTermOrds

DEFAULT_INDEX_INTERVAL_BITS, docsEnum, field, index, indexedTermsArray, maxTermDocFreq, numTermsInField, ordBase, phase1_time, prefix, sizeOfIndexedStrings, termInstances, tnums, total_time

Constructor Summary

Constructors

Constructor and Description
UnInvertedField(String field, SolrIndexSearcher searcher)

Method Summary

Methods

Modifier and Type	Method and Description
NamedList<Integer>	getCounts(SolrIndexSearcher searcher, DocSet baseDocs, int offset, int limit, Integer mincount, boolean missing, String sort, String prefix)
int	getNumTerms()
StatsValues	getStats(SolrIndexSearcher searcher, DocSet baseDocs, String[] facet) Collect statistics about the UninvertedField.
static UnInvertedField	getUnInvertedField(String field, SolrIndexSearcher searcher)
long	memSize()
protected void	setActualDocFreq(int termNum, int docFreq)
String	toString()
protected void	visitTerm(TermsEnum te, int termNum)

Methods inherited from class org.apache.lucene.index.DocTermOrds

getOrdTermsEnum, isEmpty, iterator, lookupTerm, numTerms, ramUsedInBytes, uninvert

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

UnInvertedField

public UnInvertedField(String field,
               SolrIndexSearcher searcher)
                throws IOException

Throws:

IOException

Method Detail

visitTerm

protected void visitTerm(TermsEnum te,
             int termNum)
                  throws IOException

Overrides:

visitTerm in class DocTermOrds

Throws:

IOException

setActualDocFreq

protected void setActualDocFreq(int termNum,
                    int docFreq)

Overrides:

setActualDocFreq in class DocTermOrds

memSize

public long memSize()

getNumTerms

public int getNumTerms()

getCounts

public NamedList<Integer> getCounts(SolrIndexSearcher searcher,
                           DocSet baseDocs,
                           int offset,
                           int limit,
                           Integer mincount,
                           boolean missing,
                           String sort,
                           String prefix)
                             throws IOException

Throws:

IOException

getStats

public StatsValues getStats(SolrIndexSearcher searcher,
                   DocSet baseDocs,
                   String[] facet)
                     throws IOException

Collect statistics about the UninvertedField. Code is very similar to getCounts(org.apache.solr.search.SolrIndexSearcher, org.apache.solr.search.DocSet, int, int, Integer, boolean, String, String) It can be used to calculate stats on multivalued fields.

This method is mainly used by the StatsComponent.

Parameters:

searcher - The Searcher to use to gather the statistics

baseDocs - The DocSet to gather the stats on

facet - One or more fields to facet on.

Returns:

The StatsValues collected

Throws:

IOException - If there is a low-level I/O error.

toString

public String toString()

Overrides:

toString in class Object

getUnInvertedField

public static UnInvertedField getUnInvertedField(String field,
                                 SolrIndexSearcher searcher)
                                          throws IOException

Throws:

IOException