it.unimi.di.mg4j.index
Class QuasiSuccinctIndexReader.AbstractQuasiSuccinctIndexIterator

java.lang.Object
  it.unimi.di.mg4j.index.AbstractIndexIterator
      it.unimi.di.mg4j.index.QuasiSuccinctIndexReader.AbstractQuasiSuccinctIndexIterator

All Implemented Interfaces:

IndexIterator, DocumentIterator

Direct Known Subclasses:

QuasiSuccinctIndexReader.EliasFanoIndexIterator, QuasiSuccinctIndexReader.RankedIndexIterator

Enclosing class:

QuasiSuccinctIndexReader

protected abstract static class QuasiSuccinctIndexReader.AbstractQuasiSuccinctIndexIterator
extends AbstractIndexIterator

Field Summary

protected int	count The count of the current posting, or -1 if it is not known.
protected QuasiSuccinctIndexReader.CountReader	counts The count reader for the current term.
protected LongBigList	countsList A reference to the data for counts, or null of hasCounts is false.
protected int	currentDocument The current document.
protected int	currentTerm The index of the current term.
protected int	frequency The frequency of the current term.
protected boolean	hasCounts Cached from index.
protected boolean	hasPositions Cached from index.
protected QuasiSuccinctIndex	index The index of indexReader, cached.
protected QuasiSuccinctIndexReader	indexReader The index reader associated to this index iterator.
protected int	nextPosition The number of returned positions for the current document.
protected int	numberOfDocuments The number of documents (cached from index).
protected long	occurrency The occurrency of the current term.
protected LongBigList	pointersList A reference to the data for pointers.
protected QuasiSuccinctIndexReader.LongWordBitReader	pointersUpperBits A longword bit reader used for the upper bits of pointers and to check whether a posting list is ranked or not.
protected QuasiSuccinctIndexReader.PositionReader	positions The position reader for the current term.
protected LongBigList	positionsList A reference to the data for positions, or null of hasPositions is false.

Fields inherited from class it.unimi.di.mg4j.index.AbstractIndexIterator

id, term, weight

Fields inherited from interface it.unimi.di.mg4j.index.IndexIterator

END_OF_POSITIONS

Fields inherited from interface it.unimi.di.mg4j.search.DocumentIterator

END_OF_LIST

Constructor Summary

protected

QuasiSuccinctIndexReader.AbstractQuasiSuccinctIndexIterator(QuasiSuccinctIndexReader indexReader)

Method Summary

void	dispose() Disposes this document iterator, releasing all resources.
int	document() Returns the last document returned by DocumentIterator.nextDocument().
int	frequency() Returns the frequency, that is, the number of documents that will be returned by this iterator.
Index	index() Returns the index over which this iterator is built.
ReferenceSet<Index>	indices() Returns the set of indices over which this iterator is built.
IntervalIterator	intervalIterator() Returns the interval iterator of this document iterator for single-index queries.
IntervalIterator	intervalIterator(Index index) Returns the interval iterator of this document iterator for the given index.
Reference2ReferenceMap<Index,IntervalIterator>	intervalIterators() Returns an unmodifiable map from indices to interval iterators.
int	nextPosition() Returns the next position at which the term appears in the current document.
Payload	payload() Returns the payload, if any, associated with the current document.
protected boolean	ranked(int term)
int	termNumber() Returns the number of the term whose inverted list is returned by this index iterator.
String	toString()

Methods inherited from class it.unimi.di.mg4j.index.AbstractIndexIterator

accept, acceptOnTruePaths, id, id, term, term, weight, weight

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.di.mg4j.index.IndexIterator

count

Methods inherited from interface it.unimi.di.mg4j.search.DocumentIterator

mayHaveNext, nextDocument, skipTo

Field Detail

indexReader

protected final QuasiSuccinctIndexReader indexReader

The index reader associated to this index iterator.

index

protected final QuasiSuccinctIndex index

The index of indexReader, cached.

pointersList

protected final LongBigList pointersList

A reference to the data for pointers.

countsList

protected final LongBigList countsList

A reference to the data for counts, or null of hasCounts is false.

positionsList

protected final LongBigList positionsList

A reference to the data for positions, or null of hasPositions is false.

pointersUpperBits

protected final QuasiSuccinctIndexReader.LongWordBitReader pointersUpperBits

A longword bit reader used for the upper bits of pointers and to check whether a posting list is ranked or not.

counts

protected QuasiSuccinctIndexReader.CountReader counts

The count reader for the current term.

positions

protected QuasiSuccinctIndexReader.PositionReader positions

The position reader for the current term.

numberOfDocuments

protected final int numberOfDocuments

The number of documents (cached from index).

hasCounts

protected final boolean hasCounts

Cached from index.

hasPositions

protected final boolean hasPositions

Cached from index.

currentDocument

protected int currentDocument

The current document.

frequency

protected int frequency

The frequency of the current term.

occurrency

protected long occurrency

The occurrency of the current term.

currentTerm

protected int currentTerm

The index of the current term.

count

protected int count

The count of the current posting, or -1 if it is not known.

nextPosition

protected int nextPosition

The number of returned positions for the current document.

Constructor Detail

QuasiSuccinctIndexReader.AbstractQuasiSuccinctIndexIterator

protected QuasiSuccinctIndexReader.AbstractQuasiSuccinctIndexIterator(QuasiSuccinctIndexReader indexReader)

Method Detail

ranked

protected boolean ranked(int term)

index

public Index index()

Description copied from interface: IndexIterator

Returns the index over which this iterator is built.

Returns:

the index over which this iterator is built.

termNumber

public int termNumber()

Description copied from interface: IndexIterator

Returns the number of the term whose inverted list is returned by this index iterator.

Usually, the term number is automatically set by IndexReader.documents(CharSequence) or IndexReader.documents(int).

Returns:

the number of the term over which this iterator is built.

See Also:

IndexIterator.term()

frequency

public int frequency()
              throws IOException

Description copied from interface: IndexIterator

Returns the frequency, that is, the number of documents that will be returned by this iterator.

Returns:

the number of documents that will be returned by this iterator.

Throws:

IOException

payload

public Payload payload()
                throws IOException

Description copied from interface: IndexIterator

Returns the payload, if any, associated with the current document.

Returns:

the payload associated with the current document.

Throws:

IOException

nextPosition

public int nextPosition()
                 throws IOException

Description copied from interface: IndexIterator

Returns the next position at which the term appears in the current document.

Returns:

the next position of the current document in which the current term appears, or IndexIterator.END_OF_POSITIONS if there are no more positions.

Throws:

IOException

document

public int document()

Description copied from interface: DocumentIterator

Returns the last document returned by DocumentIterator.nextDocument().

Returns:

the last document returned by DocumentIterator.nextDocument(), -1 if no document has been returned yet, and DocumentIterator.END_OF_LIST if the list of results has been exhausted.

intervalIterators

public Reference2ReferenceMap<Index,IntervalIterator> intervalIterators()
                                                                 throws IOException

Description copied from interface: DocumentIterator

Returns an unmodifiable map from indices to interval iterators.

After a call to DocumentIterator.nextDocument(), this map can be used to retrieve the intervals in the current document. An invocation of Map.get(java.lang.Object) on this map with argument index yields the same result as intervalIterator(index).

Returns:

a map from indices to interval iterators over the current document.

Throws:

IOException

See Also:

DocumentIterator.intervalIterator(Index)

intervalIterator

public IntervalIterator intervalIterator()
                                  throws IOException

Description copied from interface: DocumentIterator

Returns the interval iterator of this document iterator for single-index queries.

This is a commodity method that can be used only for queries built over a single index.

Returns:

an interval iterator.

Throws:

IOException

See Also:

DocumentIterator.intervalIterator(Index)

intervalIterator

public IntervalIterator intervalIterator(Index index)
                                  throws IOException

Description copied from interface: DocumentIterator

Returns the interval iterator of this document iterator for the given index.

After a call to DocumentIterator.nextDocument(), this iterator can be used to retrieve the intervals in the current document (the one returned by DocumentIterator.nextDocument()) for the index index.

Note that if all indices have positions, it is guaranteed that at least one index will return an interval. However, for disjunctive queries it cannot be guaranteed that all indices will return an interval.

Indices without positions always return IntervalIterators.TRUE. Thus, in presence of indices without positions it is possible that no intervals at all are available.

Parameters:

index - an index (must be one over which the query was built).

Returns:

an interval iterator over the current document in index.

Throws:

IOException

indices

public ReferenceSet<Index> indices()

Description copied from interface: DocumentIterator

Returns the set of indices over which this iterator is built.

Returns:

the set of indices over which this iterator is built.

toString

public String toString()

Overrides:

toString in class Object

dispose

public void dispose()
             throws IOException

Description copied from interface: DocumentIterator

Disposes this document iterator, releasing all resources.

This method should propagate down to the underlying index iterators, where it should release resources such as open files and network connections. If you're doing your own resource tracking and pooling, then you do not need to call this method.

Throws:

IOException