org.terrier.matching.daat

Class CandidateResultSet

java.lang.Object

org.terrier.matching.daat.CandidateResultSet

All Implemented Interfaces:

Serializable, ResultSet

Direct Known Subclasses:

FatCandidateResultSet

public class CandidateResultSet
extends Object
implements ResultSet, Serializable

ResultSet which is created from a set of CandidateResults. Used by DAAT matching strategies.

Since:

3.5

Author:

Nicola Tonellotto

See Also:

CandidateResult, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	docids
protected int	exactResultSize
protected Lock	lock
protected short[]	occurrences
protected int	resultSize
protected double[]	scores
protected int	statusCode

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CandidateResultSet()
	CandidateResultSet(List<CandidateResult> q) Create a ResultSet from the specified list of results
	CandidateResultSet(Queue<CandidateResult> q) Create a ResultSet from the specified queue of results

Method Summary

Methods

Modifier and Type	Method and Description
void	addMetaItem(String name, int docid, String value) Adds a metadata value for a given document
void	addMetaItems(String name, String[] values) Adds the metadata values for all the documents in the result set.
int[]	getDocids() Returns the documents ids after retrieval
int	getExactResultSize() Returns the exact size of the result set.
Lock	getLock() Returns the lock associated with the result set.
String	getMetaItem(String name, int docid) Gets a metadata value for a given document.
String[]	getMetaItems(String name) Gets the metadata information for all documents.
String[]	getMetaKeys() Returns the names of the meta keys which this resultset has
short[]	getOccurrences() Returns the occurrences array.
ResultSet	getResultSet(int[] positions) Extracts a subset of the resultset given by the list parameter, which contains a list of positions in the resultset that should be saved.
ResultSet	getResultSet(int start, int length) Crops the existing result file and extracts a subset from the given starting point, with the given length.
int	getResultSize() Returns the effective size of the result set.
double[]	getScores() Returns the documents scores after retrieval
int	getStatusCode() Returns a status code for the result set
boolean	hasMetaItems(String name) Returns true if the resultset already has a set of metaitems with the specified name.
void	initialise() Initialises the arrays prior of retrieval.
void	initialise(double[] scs) Initialises the result set with the given scores.
void	setExactResultSize(int newExactResultSize) Sets the exact size of the result set, that is the number of documents that contain at least one query term.
void	setResultSize(int newResultSize) Sets the effective size of the result set, that is the number of documents to be sorted after retrieval.
void	setStatusCode(int _statusCode) Sets the status code.
void	sort() Sorts all documents in this resultset by descending score
void	sort(int topDocs) Sorts the top topDocs document in this resultset be first.

Methods inherited from class java.lang.Object

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

Field Detail

docids

protected int[] docids

scores

protected double[] scores

occurrences

protected short[] occurrences

resultSize

protected int resultSize

exactResultSize

protected int exactResultSize

lock

protected Lock lock

statusCode

protected int statusCode

Constructor Detail

CandidateResultSet

protected CandidateResultSet()

CandidateResultSet

public CandidateResultSet(Queue<CandidateResult> q)

Create a ResultSet from the specified queue of results

CandidateResultSet

public CandidateResultSet(List<CandidateResult> q)

Create a ResultSet from the specified list of results

Method Detail

getLock

public Lock getLock()

Returns the lock associated with the result set. The lock is used for modifying the result set concurrently by more than one threads.

Specified by:

getLock in interface ResultSet

Returns:

the lock.

getStatusCode

public int getStatusCode()

Returns a status code for the result set

Specified by:

getStatusCode in interface ResultSet

Returns:

a integer status code. 0 stands success. 1 stands for empty result set. 2 stands for wrong setting of start/end parameters. 3 stands for query timeout. The values assigned to the status codes are increasing accordingly to the severity of the status.

setStatusCode

public void setStatusCode(int _statusCode)

Sets the status code.

Specified by:

setStatusCode in interface ResultSet

Parameters:

_statusCode - - the code to return to the user

addMetaItem

public void addMetaItem(String name,
               int docid,
               String value)

Description copied from interface: ResultSet

Adds a metadata value for a given document

Specified by:

addMetaItem in interface ResultSet

Parameters:

name - the name of the metadata type. For example, it can be url for adding the URLs of documents.

docid - the document identifier of the document.

value - the metadata value.

addMetaItems

public void addMetaItems(String name,
                String[] values)

Description copied from interface: ResultSet

Adds the metadata values for all the documents in the result set. The length of the metadata array values should be equal to the length of the docids array.

Specified by:

addMetaItems in interface ResultSet

Parameters:

name - the name of the metadata type. For example, it can be url for adding the URLs of documents.

values - the metadata values.

getMetaItem

public String getMetaItem(String name,
                 int docid)

Description copied from interface: ResultSet

Gets a metadata value for a given document. If the requested metadata information is not specified, then we return null.

Specified by:

getMetaItem in interface ResultSet

Parameters:

name - the name of the metadata type.

docid - the document identifier of the document.

Returns:

a string with the metadata information, or null of the metadata is not available.

getMetaItems

public String[] getMetaItems(String name)

Description copied from interface: ResultSet

Gets the metadata information for all documents. If the requested metadata information is not specified, then we return null.

Specified by:

getMetaItems in interface ResultSet

Parameters:

name - the name of the metadata type.

Returns:

an array of strings with the metadata information, or null of the metadata is not available.

hasMetaItems

public boolean hasMetaItems(String name)

Description copied from interface: ResultSet

Returns true if the resultset already has a set of metaitems with the specified name.

Specified by:

hasMetaItems in interface ResultSet

Parameters:

name - of the desired metaitem set

Returns:

true if the set exists.

getMetaKeys

public String[] getMetaKeys()

Description copied from interface: ResultSet

Returns the names of the meta keys which this resultset has

Specified by:

getMetaKeys in interface ResultSet

Returns:

the list of key names

getDocids

public int[] getDocids()

Description copied from interface: ResultSet

Returns the documents ids after retrieval

Specified by:

getDocids in interface ResultSet

Returns:

the docids

getScores

public double[] getScores()

Description copied from interface: ResultSet

Returns the documents scores after retrieval

Specified by:

getScores in interface ResultSet

Returns:

score list in same order as docids array

getOccurrences

public short[] getOccurrences()

Description copied from interface: ResultSet

Returns the occurrences array.

Specified by:

getOccurrences in interface ResultSet

Returns:

short[] the array the occurrences array.

getResultSize

public int getResultSize()

Description copied from interface: ResultSet

Returns the effective size of the result set.

Specified by:

getResultSize in interface ResultSet

Returns:

int the effective size of the result set

getExactResultSize

public int getExactResultSize()

Description copied from interface: ResultSet

Returns the exact size of the result set.

Specified by:

getExactResultSize in interface ResultSet

Returns:

int the exact size of the result set

getResultSet

public ResultSet getResultSet(int start,
                     int length)

Crops the existing result file and extracts a subset from the given starting point, with the given length.

Specified by:

getResultSet in interface ResultSet

Parameters:

start - the beginning of the subset.

length - the length of the subset.

Returns:

a subset of the current result set.

getResultSet

public ResultSet getResultSet(int[] positions)

Description copied from interface: ResultSet

Extracts a subset of the resultset given by the list parameter, which contains a list of positions in the resultset that should be saved.

Specified by:

getResultSet in interface ResultSet

Parameters:

positions - the list of elements in the current list that should be kept.

Returns:

a subset of the current result set specified by the list.

initialise

public void initialise()

Description copied from interface: ResultSet

Initialises the arrays prior of retrieval.

Specified by:

initialise in interface ResultSet

initialise

public void initialise(double[] scs)

Description copied from interface: ResultSet

Initialises the result set with the given scores. If the length of the given array is different than the length of the internal arrays, then we re-allocate memory and create the arrays.

Specified by:

initialise in interface ResultSet

Parameters:

scs - double[] the scores to initiliase the result set with.

setExactResultSize

public void setExactResultSize(int newExactResultSize)

Description copied from interface: ResultSet

Sets the exact size of the result set, that is the number of documents that contain at least one query term.

Specified by:

setExactResultSize in interface ResultSet

Parameters:

newExactResultSize - int the effective size of the result set.

setResultSize

public void setResultSize(int newResultSize)

Description copied from interface: ResultSet

Sets the effective size of the result set, that is the number of documents to be sorted after retrieval.

Specified by:

setResultSize in interface ResultSet

Parameters:

newResultSize - int the effective size of the result set.

sort

public void sort()

Description copied from interface: ResultSet

Sorts all documents in this resultset by descending score

Specified by:

sort in interface ResultSet

sort

public void sort(int topDocs)

Description copied from interface: ResultSet

Sorts the top topDocs document in this resultset be first. The order of the remaining documents is undefined.

Specified by:

sort in interface ResultSet

Parameters:

topDocs - number of documents to top-rank