com.sun.labs.minion.indexer.dictionary
Class DiskDictionary.DiskDictionaryIterator

java.lang.Object
  com.sun.labs.minion.indexer.dictionary.DiskDictionary.DiskDictionaryIterator

All Implemented Interfaces:

DictionaryIterator, java.lang.Comparable, java.util.Iterator<QueryEntry>

Enclosing class:

DiskDictionary

public class DiskDictionary.DiskDictionaryIterator
extends java.lang.Object
implements DictionaryIterator, java.lang.Comparable

A class that can be used as an iterator for this block.

Field Summary

protected boolean	actualOnly A flag indicating whether we should try to ignore entries whose names have not actually occurred in the indexed material.
protected PostingsInput[]	buffChans Buffered channels for reading postings.
protected boolean	casedEntries Whether our entries are cased.
protected Entry	curr The current entry.
protected int	estSize The estimated size of the results set for this iterator.
protected DiskDictionary.LookupState	lus Our lookup state.
protected int	pos The position in the dictionary.
protected java.lang.Object	prevName The name of the previous entry.
protected boolean	returnCurr
protected int	startPos The position to start iterating from
protected int	stopPos The position to stop iterating at

Constructor Summary

DiskDictionary.DiskDictionaryIterator(int begin, int end)
Gets an iterator for the dictionary that starts and stops at the given indices in the dictionary.

DiskDictionary.DiskDictionaryIterator(java.lang.Object startEntry, boolean includeStart, java.lang.Object stopEntry, boolean includeStop)
Creates a DictionaryIterator that iterates over a range of entries.

Method Summary

int	compareTo(java.lang.Object o)
int	estimateSize() Estimates the size of the document set that would be returned for all the entries that this iterator would produce.
QueryEntry	get(int id) Gets an entry for a specific ID from the dictionary that this iterator is iterating through.
QueryEntry	get(java.lang.Object name) Gets an entry for a specific name from the dictionary that this iterator is iterating through.
int	getNEntries() Gets the number of entries that will be returned by this iterator.
boolean	hasNext()
QueryEntry	next()
void	remove()
void	setActualOnly(boolean actualOnly) Modifies the iterator so that it only returns entries whose names have actually occurred in the indexed material.

Methods inherited from class java.lang.Object

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

Field Detail

estSize

protected int estSize

The estimated size of the results set for this iterator.

pos

protected int pos

The position in the dictionary.

lus

protected DiskDictionary.LookupState lus

Our lookup state.

prevName

protected java.lang.Object prevName

The name of the previous entry.

curr

protected Entry curr

The current entry.

startPos

protected int startPos

The position to start iterating from

stopPos

protected int stopPos

The position to stop iterating at

buffChans

protected PostingsInput[] buffChans

Buffered channels for reading postings.

actualOnly

protected boolean actualOnly

A flag indicating whether we should try to ignore entries whose names have not actually occurred in the indexed material. This will allow us to iterate through the entries in a dictionary where the names are strings and the entries are cased and only show entry names that actually occurred in the indexed material.

casedEntries

protected boolean casedEntries

Whether our entries are cased.

returnCurr

protected boolean returnCurr

Constructor Detail

DiskDictionary.DiskDictionaryIterator

public DiskDictionary.DiskDictionaryIterator(java.lang.Object startEntry,
                                             boolean includeStart,
                                             java.lang.Object stopEntry,
                                             boolean includeStop)

Creates a DictionaryIterator that iterates over a range of entries.

Parameters:

startEntry - the name of the entry to start iterating at, or null to start at the first entry

includeStart - if true and startEntry is non-null, then the iterator will return startEntry, if it is in the dictionary.

stopEntry - the name of the entry to stop iterating at, or null to stop after the last entry.

includeStop - if true and stopEntry is non-null, then the iterator will return stopEntry, if it is in the dictionary.

DiskDictionary.DiskDictionaryIterator

public DiskDictionary.DiskDictionaryIterator(int begin,
                                             int end)

Gets an iterator for the dictionary that starts and stops at the given indices in the dictionary. This can be used when we want to process pieces of a dictionary in different threads.

Parameters:

begin - the beginning index in the dictionary, counting from 0. If this value is less than zero it will be clamped to zero.

end - the ending index in the dictionary, counting from 0. If this value is greater than the number of entries in the dictionary, it will be limited to that number.

Method Detail

setActualOnly

public void setActualOnly(boolean actualOnly)

Modifies the iterator so that it only returns entries whose names have actually occurred in the indexed material. So, for example, if the word Dog occurs in the indexed material, and is the only occurrence of that word, then the entry dog in a cased dictionary would not be returned if this method is called with a value of true.

Note that this option really only makes sense for dictionaries that use cased entries.

Specified by:

setActualOnly in interface DictionaryIterator

Parameters:

actualOnly - if true only entries with names that actually occurred in the indexed material will be returned. If false all entries will be returned.

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator<QueryEntry>

next

public QueryEntry next()
                throws java.util.NoSuchElementException

Specified by:

next in interface java.util.Iterator<QueryEntry>

Throws:

java.util.NoSuchElementException

remove

public void remove()

Specified by:

remove in interface java.util.Iterator<QueryEntry>

compareTo

public int compareTo(java.lang.Object o)

Specified by:

compareTo in interface java.lang.Comparable

estimateSize

public int estimateSize()

Estimates the size of the document set that would be returned for all the entries that this iterator would produce. This is a gross hack!

Specified by:

estimateSize in interface DictionaryIterator

getNEntries

public int getNEntries()

Description copied from interface: DictionaryIterator

Gets the number of entries that will be returned by this iterator.

Specified by:

getNEntries in interface DictionaryIterator

get

public QueryEntry get(int id)

Description copied from interface: DictionaryIterator

Gets an entry for a specific ID from the dictionary that this iterator is iterating through. This is an atypical iterator method, but it may be a lot faster, especially if the implementation keeps a local copy of dictionary data for faster uncontended access.

Specified by:

get in interface DictionaryIterator

get

public QueryEntry get(java.lang.Object name)

Description copied from interface: DictionaryIterator

Gets an entry for a specific name from the dictionary that this iterator is iterating through. This is an atypical iterator method, but it may be a lot faster, especially if the implementation keeps a local copy of dictionary data for faster uncontended access.

Specified by:

get in interface DictionaryIterator