org.galagosearch.core.retrieval.structured
Class ExtentIterator

java.lang.Object
  org.galagosearch.core.retrieval.structured.CountIterator
      org.galagosearch.core.retrieval.structured.ExtentIterator

All Implemented Interfaces:

java.lang.Comparable<CountIterator>, StructuredIterator

Direct Known Subclasses:

ExtentConjunctionIterator, ExtentDisjunctionIterator, ExtentIndexReader.Iterator, NullExtentIterator, PositionIndexReader.Iterator

public abstract class ExtentIterator
extends CountIterator

This is base interface for all inverted lists that return count information. See the CountIterator class for documentation on most of these methods.

Author:

trevor

Constructor Summary

ExtentIterator()

Method Summary

abstract int	count() Returns the number of occurrences of this iterator's term in the current document.
abstract int	document() Returns the current document.
abstract ExtentArray	extents()
abstract boolean	isDone() Returns true if there is no data left in the list and false otherwise.
abstract void	nextDocument() Moves the iterator to the next document in the list.
abstract void	reset() Resets the position of this iterator to the start of the list.
boolean	skipToDocument(int document) Skips forward in the list until a document is found that is greater than or equal to the parameter.

Methods inherited from class org.galagosearch.core.retrieval.structured.CountIterator

compareTo

Methods inherited from class java.lang.Object

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

Constructor Detail

ExtentIterator

public ExtentIterator()

Method Detail

nextDocument

public abstract void nextDocument()
                           throws java.io.IOException

Description copied from class: CountIterator

Moves the iterator to the next document in the list. If no such document is available, isDone() will return true after this method is called.

Specified by:

nextDocument in class CountIterator

Throws:

java.io.IOException

document

public abstract int document()

Description copied from class: CountIterator

Returns the current document.

Specified by:

document in class CountIterator

count

public abstract int count()

Description copied from class: CountIterator

Returns the number of occurrences of this iterator's term in the current document.

Specified by:

count in class CountIterator

extents

public abstract ExtentArray extents()

isDone

public abstract boolean isDone()

Description copied from class: CountIterator

Returns true if there is no data left in the list and false otherwise. If the result of this method is true, the data returned from document() and count() is meaningless.

Specified by:

isDone in class CountIterator

reset

public abstract void reset()
                    throws java.io.IOException

Description copied from class: CountIterator

Resets the position of this iterator to the start of the list.

Specified by:

reset in interface StructuredIterator

Specified by:

reset in class CountIterator

Throws:

java.io.IOException

skipToDocument

public boolean skipToDocument(int document)
                       throws java.io.IOException

Description copied from class: CountIterator

Skips forward in the list until a document is found that is greater than or equal to the parameter. If the iterator is currently pointing to a document that is greater than or equal to the parameter, nothing happens.

Overrides:

skipToDocument in class CountIterator

Returns:

true, if the iterator is now pointing at the desired document, or false otherwise.

Throws:

java.io.IOException