org.sindice.siren.index

Class ConstrainedNodesEnum

java.lang.Object

org.sindice.siren.index.DocsNodesAndPositionsEnum

org.sindice.siren.index.ConstrainedNodesEnum

All Implemented Interfaces:

DocsAndNodesIterator, PositionsIterator

Direct Known Subclasses:

IntervalConstrainedNodesEnum, LevelConstrainedNodesEnum, SingleIntervalConstrainedNodesEnum

public abstract class ConstrainedNodesEnum
extends DocsNodesAndPositionsEnum

Abstraction of a DocsNodesAndPositionsEnum that filters nodes that do not satisfy some constraints.

This DocsNodesAndPositionsEnum wraps another DocsNodesAndPositionsEnum and applies the node constraints. It filters all the nodes that do not satisfy the constraints.

See Also:

NodeUtils#isConstraintSatisfied(int[], int[], int[], boolean)

Field Summary

Fields

Modifier and Type	Field and Description
protected DocsNodesAndPositionsEnum	docsEnum

Fields inherited from interface org.sindice.siren.index.DocsAndNodesIterator

NO_MORE_DOC, NO_MORE_NOD

Fields inherited from interface org.sindice.siren.index.PositionsIterator

NO_MORE_POS

Constructor Summary

Constructors

Constructor and Description
ConstrainedNodesEnum(DocsNodesAndPositionsEnum docsEnum)

Method Summary

Methods

Modifier and Type	Method and Description
int	doc() Returns the following: -1 or DocsAndNodesIterator.NO_MORE_DOC if DocsAndNodesIterator.nextDocument() or DocsAndNodesIterator.skipTo(int) were not called yet.
boolean	nextDocument() Advances to the next document in the set.
abstract boolean	nextNode() Move to the next node path in the current document.
boolean	nextPosition() Move to the next position in the current node matching the query.
org.apache.lucene.util.IntsRef	node() Returns the following: -1 or DocsAndNodesIterator.NO_MORE_NOD if DocsAndNodesIterator.nextNode() or #skipTo(int, int[]) were not called yet.
int	nodeFreqInDoc() Returns node frequency in the current document.
int	pos() Returns the following: -1 or PositionsIterator.NO_MORE_POS if PositionsIterator.nextPosition() were not called yet.
boolean	skipTo(int target) Skip to the first document beyond (see NOTE below) the current whose number is greater than or equal to target.
int	termFreqInNode() Returns term frequency in the current node.

Methods inherited from class org.sindice.siren.index.DocsNodesAndPositionsEnum

attributes

Methods inherited from class java.lang.Object

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

Field Detail

docsEnum

protected final DocsNodesAndPositionsEnum docsEnum

Constructor Detail

ConstrainedNodesEnum

public ConstrainedNodesEnum(DocsNodesAndPositionsEnum docsEnum)

Method Detail

nextDocument

public boolean nextDocument()
                     throws IOException

Description copied from interface: DocsAndNodesIterator

Advances to the next document in the set.

Returns:

false if there is no more docs in the set.

Throws:

IOException

nextNode

public abstract boolean nextNode()
                          throws IOException

Description copied from interface: DocsAndNodesIterator

Move to the next node path in the current document.

Should not be called until DocsAndNodesIterator.nextDocument() or DocsAndNodesIterator.skipTo(int) are called for the first time.

Returns:

false if there is no more node for the current document or if DocsAndNodesIterator.nextDocument() or DocsAndNodesIterator.skipTo(int) were not called yet.

Throws:

IOException

skipTo

public boolean skipTo(int target)
               throws IOException

Description copied from interface: DocsAndNodesIterator

Skip to the first document beyond (see NOTE below) the current whose number is greater than or equal to target. Returns false if there are no more docs in the set.

Behaves as if written:

 boolean skipTo(int target) {
   while (nextDocument()) {
     if (target ≤ doc())
       return true;
   }
   return false;
 }
 

Some implementations are considerably more efficient than that.

NOTE: when target ≤ current implementations must not advance beyond their current DocsAndNodesIterator.doc().

Throws:

IOException

doc

public int doc()

Description copied from interface: DocsAndNodesIterator

Returns the following:

• -1 or DocsAndNodesIterator.NO_MORE_DOC if DocsAndNodesIterator.nextDocument() or DocsAndNodesIterator.skipTo(int) were not called yet.
• DocsAndNodesIterator.NO_MORE_DOC if the iterator has exhausted.
• Otherwise it should return the doc ID it is currently on.

node

public org.apache.lucene.util.IntsRef node()

Description copied from interface: DocsAndNodesIterator

Returns the following:

• -1 or DocsAndNodesIterator.NO_MORE_NOD if DocsAndNodesIterator.nextNode() or #skipTo(int, int[]) were not called yet.
• DocsAndNodesIterator.NO_MORE_NOD if the iterator has exhausted.
• Otherwise it should return the node it is currently on.

nextPosition

public boolean nextPosition()
                     throws IOException

Description copied from interface: PositionsIterator

Move to the next position in the current node matching the query.

Should not be called until DocsAndNodesIterator.nextNode() or DocsAndNodesIterator#skipTo(int, int) are called for the first time.

Returns:

false if there is no more position for the current node or if DocsAndNodesIterator.nextNode() or DocsAndNodesIterator#skipTo(int, int) were not called yet.

Throws:

IOException

pos

public int pos()

Description copied from interface: PositionsIterator

Returns the following:

• -1 or PositionsIterator.NO_MORE_POS if PositionsIterator.nextPosition() were not called yet.
• PositionsIterator.NO_MORE_POS if the iterator has exhausted.
• Otherwise it should return the position it is currently on.

termFreqInNode

public int termFreqInNode()
                   throws IOException

Description copied from class: DocsNodesAndPositionsEnum

Returns term frequency in the current node. Do not call this before DocsAndNodesIterator.nextNode() is first called, nor after DocsAndNodesIterator.nextNode() returns false or DocsAndNodesIterator.node() returns DocsAndNodesIterator.NO_MORE_NOD.

Specified by:

termFreqInNode in class DocsNodesAndPositionsEnum

Throws:

IOException

nodeFreqInDoc

public int nodeFreqInDoc()
                  throws IOException

Description copied from class: DocsNodesAndPositionsEnum

Returns node frequency in the current document. Do not call this before #nextDoc is first called, nor after #nextDoc returns false or DocsAndNodesIterator.doc() returns DocsAndNodesIterator.NO_MORE_DOC.

Specified by:

nodeFreqInDoc in class DocsNodesAndPositionsEnum

Throws:

IOException