com.sun.labs.minion.indexer.postings
Class PostingsIteratorFeatures

java.lang.Object
  com.sun.labs.minion.indexer.postings.PostingsIteratorFeatures

All Implemented Interfaces:

java.lang.Cloneable

public class PostingsIteratorFeatures
extends java.lang.Object
implements java.lang.Cloneable

A set of features that can be used to configure various aspects of a postings iterator.

Field Summary

protected boolean	caseSensitive Whether the iterator will return postings for case-sensitive or case insensitive variations.
protected int[]	fields The fields that we want to return postings for.
protected float[]	mult The multipliers that we wish to apply to scores from certain fields.
protected boolean	positions Whether the iterator must be able to return positions.
protected QueryStats	qs
protected WeightingComponents	wc A set of weighting components that can be used when calculating term weights.
protected WeightingFunction	wf The weighting function that the iterator will use to calculate weights.

Constructor Summary

PostingsIteratorFeatures()
Creates a default set of features.

PostingsIteratorFeatures(WeightingFunction wf, WeightingComponents wc)
Creates a set of features.

PostingsIteratorFeatures(WeightingFunction wf, WeightingComponents wc, int[] fields, float[] mult, boolean positions, boolean caseSensitive)
Creates a set of features.

Method Summary

java.lang.Object	clone() Clones this set of features.
boolean	getCaseSensitive() Gets the required case sensitivity for the postings.
int[]	getFields() Gets the fields that we're currently using.
float[]	getMult() Gets the field multipliers that we're currently using.
boolean	getPositions() Gets whether this set of features requires that iterators be able to return positions.
QueryStats	getQueryStats()
WeightingComponents	getWeightingComponents() Gets the weighting components to be used by iterators.
WeightingFunction	getWeightingFunction() Gets the weighting function to be used by iterators.
void	setCaseSensitive(boolean caseSensitive) Sets the case sensitiveness of the postings.
void	setFields(int[] fields) Sets the fields that we should use.
void	setFields(java.lang.String[] fields, InvFileDiskPartition dp) Sets the fields that we should use.
void	setMult(float[] mult) Sets the fied multipliers that we should be using.
void	setMult(java.util.Map mult, InvFileDiskPartition dp) Sets the field multipliers that we should be using.
void	setPositions(boolean positions) Sets the value of the positions.
void	setQueryStats(QueryStats qs)
void	setWeightingComponents(WeightingComponents wc) Sets the weighting components to be used by iterators.
void	setWeightingFunction(WeightingFunction wf) Sets the weighting function to be used by iterators.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

qs

protected QueryStats qs

wf

protected WeightingFunction wf

The weighting function that the iterator will use to calculate weights.

wc

protected WeightingComponents wc

A set of weighting components that can be used when calculating term weights.

fields

protected int[] fields

The fields that we want to return postings for. If the i^th element of this array is greater than zero, then the iterator will return postings for the field whose ID is i. If element 0 of the array is greater than zero, then postings that are not in any field will be returned.

mult

protected float[] mult

The multipliers that we wish to apply to scores from certain fields. The value in the i^th position indicates the weight that will be used to multiply the score of a term that has occurrences in the field whose ID is i. If this array is null, then no multipliers will be applied.

positions

protected boolean positions

Whether the iterator must be able to return positions. If true, then the iterator must be capable of returning positions.

caseSensitive

protected boolean caseSensitive

Whether the iterator will return postings for case-sensitive or case insensitive variations.

Constructor Detail

PostingsIteratorFeatures

public PostingsIteratorFeatures()

Creates a default set of features.

PostingsIteratorFeatures

public PostingsIteratorFeatures(WeightingFunction wf,
                                WeightingComponents wc)

Creates a set of features.

Parameters:

wf - A weighting function to use for these postings. If null, no weighting function will be used.

wc - a collection of components that can be used when calculating weighting functions.

PostingsIteratorFeatures

public PostingsIteratorFeatures(WeightingFunction wf,
                                WeightingComponents wc,
                                int[] fields,
                                float[] mult,
                                boolean positions,
                                boolean caseSensitive)

Creates a set of features.

Parameters:

wf - A weighting function to use for these postings. If null, no weighting function will be used.

wc - a collection of components that can be used when calculating weighting functions.

fields - If the i^th element of this field is greater than zero, then the iterator will return postings for the field whose ID is i. If element 0 of the array is greater than zero, then postings that are not in any field will be returned.

mult - An array of floats indicating the field IDs for which we want to apply multipliers. The value in the i^th position indicates the weight that will be used to multiply the score of a term that has occurrences in the field whose ID is i. If this array is null, then no multipliers will be applied.

positions - if true, then iterators created using this set of features must be able to return positions.

caseSensitive - if true then the iterator that is returned will be for case sensitive postings. If false then the iterator that is returned will be for case insensitive postings.

Method Detail

setWeightingFunction

public void setWeightingFunction(WeightingFunction wf)

Sets the weighting function to be used by iterators.

getWeightingFunction

public WeightingFunction getWeightingFunction()

Gets the weighting function to be used by iterators.

setWeightingComponents

public void setWeightingComponents(WeightingComponents wc)

Sets the weighting components to be used by iterators.

getWeightingComponents

public WeightingComponents getWeightingComponents()

Gets the weighting components to be used by iterators.

setQueryStats

public void setQueryStats(QueryStats qs)

getQueryStats

public QueryStats getQueryStats()

setPositions

public void setPositions(boolean positions)

Sets the value of the positions.

Parameters:

positions - if true, then iterators created using this set of features must be able to return positions.

getPositions

public boolean getPositions()

Gets whether this set of features requires that iterators be able to return positions.

setCaseSensitive

public void setCaseSensitive(boolean caseSensitive)

Sets the case sensitiveness of the postings.

Parameters:

caseSensitive - if true, postings will be returned for case sensitive instances of an entry in a dictionary.

getCaseSensitive

public boolean getCaseSensitive()

Gets the required case sensitivity for the postings.

setFields

public void setFields(int[] fields)

Sets the fields that we should use.

setFields

public void setFields(java.lang.String[] fields,
                      InvFileDiskPartition dp)

Sets the fields that we should use.

Parameters:

fields - The names of the fields of interest.

dp - A partition that we can use to map field names to field IDs.

getFields

public int[] getFields()

Gets the fields that we're currently using.

setMult

public void setMult(float[] mult)

Sets the fied multipliers that we should be using.

setMult

public void setMult(java.util.Map mult,
                    InvFileDiskPartition dp)

Sets the field multipliers that we should be using.

Parameters:

mult - A map from field names to multiplier values.

dp - A partition that we can use to map field names to field IDs.

getMult

public float[] getMult()

Gets the field multipliers that we're currently using.

clone

public java.lang.Object clone()

Clones this set of features.

Overrides:

clone in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object