Package org.apache.lucene.index

Class SortedDocValues

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.index.SortedDocValues

Direct Known Subclasses:

FilterSortedDocValues, MultiDocValues.MultiSortedDocValues

public abstract class SortedDocValues
extends DocIdSetIterator

A per-document byte[] with presorted values. This is fundamentally an iterator over the int ord values per document, with random access APIs to resolve an int ord to BytesRef.

Per-Document values in a SortedDocValues are deduplicated, dereferenced, and sorted into a dictionary of unique values. A pointer to the dictionary value (ordinal) can be retrieved for each document. Ordinals are dense and in increasing sorted order.

Field Summary

Fields inherited from class org.apache.lucene.search.DocIdSetIterator

NO_MORE_DOCS

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SortedDocValues()	Sole constructor.

Method Summary

Modifier and Type	Method	Description
abstract boolean	advanceExact(int target)	Advance the iterator to exactly target and return whether target has a value.
abstract int	getValueCount()	Returns the number of unique values.
TermsEnum	intersect(CompiledAutomaton automaton)	Returns a TermsEnum over the values, filtered by a CompiledAutomaton The enum supports TermsEnum.ord().
abstract BytesRef	lookupOrd(int ord)	Retrieves the value for the specified ordinal.
int	lookupTerm(BytesRef key)	If key exists, returns its ordinal, else returns -insertionPoint-1, like Arrays.binarySearch.
abstract int	ordValue()	Returns the ordinal for the current docID.
TermsEnum	termsEnum()	Returns a TermsEnum over the values.

Methods inherited from class org.apache.lucene.search.DocIdSetIterator

advance, all, cost, docID, empty, nextDoc, range, slowAdvance

Methods inherited from class java.lang.Object

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

Constructor Detail

SortedDocValues

protected SortedDocValues()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Detail

ordValue

public abstract int ordValue()
                      throws IOException

Returns the ordinal for the current docID. It is illegal to call this method after advanceExact(int) returned false.

Returns:

ordinal for the document: this is dense, starts at 0, then increments by 1 for the next value in sorted order.

Throws:

IOException

lookupOrd

public abstract BytesRef lookupOrd(int ord)
                            throws IOException

Retrieves the value for the specified ordinal. The returned BytesRef may be re-used across calls to lookupOrd(int) so make sure to copy it if you want to keep it around.

Parameters:

ord - ordinal to lookup (must be >= 0 and < getValueCount())

Throws:

IOException

See Also:

ordValue()

getValueCount

public abstract int getValueCount()

Returns the number of unique values.

Returns:

number of unique values in this SortedDocValues. This is also equivalent to one plus the maximum ordinal.

lookupTerm

public int lookupTerm(BytesRef key)
               throws IOException

If key exists, returns its ordinal, else returns -insertionPoint-1, like Arrays.binarySearch.

Parameters:

key - Key to look up

Throws:

IOException

termsEnum

public TermsEnum termsEnum()
                    throws IOException

Returns a TermsEnum over the values. The enum supports TermsEnum.ord() and TermsEnum.seekExact(long).

Throws:

IOException

intersect

public TermsEnum intersect(CompiledAutomaton automaton)
                    throws IOException

Returns a TermsEnum over the values, filtered by a CompiledAutomaton The enum supports TermsEnum.ord().

Throws:

IOException

advanceExact

public abstract boolean advanceExact(int target)
                              throws IOException

Advance the iterator to exactly target and return whether target has a value. target must be greater than or equal to the current doc ID and must be a valid doc ID, ie. ≥ 0 and < maxDoc. After this method returns, DocIdSetIterator.docID() returns target.

Throws:

IOException