org.terrier.matching

Class TRECResultsMatching

java.lang.Object

org.terrier.matching.TRECResultsMatching

All Implemented Interfaces:

Matching

public class TRECResultsMatching
extends Object
implements Matching

A matching implementation that retrieves results from a TREC result file rather than the current index. Such a result file must be compatible with trec_eval, i.e., it should have the following format:

queryID Q0 docno score rank label

Properties:

• matching.trecresults.file - the path to the TREC results file.
• matching.trecresults.format - the input format to parse document identifiers. Defaults to DOCNO. DOCNO assumes that docno is a reverse lookup key in the MetaIndex. If DOCID is specified, then the docnos are assumed to represent Terrier's docids, as generated by TRECDocidOutputFormat.
• matching.trecresults.scores - whether scores should be parsed. Defaults to true.
• matching.trecresults.length - the maximum number of documents per query. Defaults to 1000. Note that setting this property to 0 may slow down the retrieval process for large collections, as a result set of the size of the collection will be allocated in memory.

Author:

Craig Macdonald, Rodrygo Santos

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TRECResultsMatching.InputFormat The result set input format.

Field Summary

Fields

Modifier and Type	Field and Description
protected CollectionStatistics	collStats The underlying collections statistics.
protected int	docid The current read document identifier.
protected static String	DSMNS The default namespace for document score modifiers.
protected List<DocumentScoreModifier>	dsms The list of document score modifiers to be applied.
protected String	filename The TREC results filename.
protected TRECResultsMatching.InputFormat	format The input format to use when parsing document identifiers.
protected boolean	found Whether the current query was found in the results file.
protected Index	index The underlying index.
protected org.apache.log4j.Logger	logger This object's logger.
protected int	maxResults The maximum number of results to read per query.
protected boolean	parseScores Whether document scores should be parsed from the results file.
protected String	qid The current query id.
protected BufferedReader	reader The TREC results file reader.
protected boolean	reset Whether the current file has already been reset.
protected ResultSet	rs The result set for a query.
protected double	score The current read score.
protected static Pattern	SPLIT_SPACE_PLUS

Constructor Summary

Constructors

Constructor and Description
TRECResultsMatching(Index _index) Contructs an instance of the TRECResultsMatching given an index.
TRECResultsMatching(Index _index, String _filename) Contructs an instance of the TRECResultsMatching.
TRECResultsMatching(Index _index, String _filename, String defDSMs) Contructs an instance of the TRECResultsMatching.

Method Summary

Methods

Modifier and Type	Method and Description
protected boolean	checkValid()
protected void	finalize()
CollectionStatistics	getCollectionStatistics() Returns collection statistics.
protected int	getDocid(String docno)
String	getInfo() Return a human readable description of this Matching class
protected void	initDSMs(String defDSMs)
protected void	initialise(int max) Initialises the current result set by allocating memory for max results.
ResultSet	match(String _qid, MatchingQueryTerms mqt) Get a ResultSet for the given query terms.
protected boolean	read(String _qid)
protected void	reopen()
void	setCollectionStatistics(CollectionStatistics _collStats) Update the collection statistics being used by this matching instance

Methods inherited from class java.lang.Object

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

Field Detail

SPLIT_SPACE_PLUS

protected static final Pattern SPLIT_SPACE_PLUS

index

protected Index index

The underlying index.

collStats

protected CollectionStatistics collStats

The underlying collections statistics.

DSMNS

protected static final String DSMNS

The default namespace for document score modifiers.

See Also:

Constant Field Values

dsms

protected List<DocumentScoreModifier> dsms

The list of document score modifiers to be applied.

filename

protected String filename

The TREC results filename.

reader

protected BufferedReader reader

The TREC results file reader.

format

protected final TRECResultsMatching.InputFormat format

The input format to use when parsing document identifiers.

parseScores

protected final boolean parseScores

Whether document scores should be parsed from the results file.

maxResults

protected final int maxResults

The maximum number of results to read per query.

qid

protected String qid

The current query id.

rs

protected ResultSet rs

The result set for a query.

docid

protected int docid

The current read document identifier.

score

protected double score

The current read score.

found

protected boolean found

Whether the current query was found in the results file.

reset

protected boolean reset

Whether the current file has already been reset.

logger

protected org.apache.log4j.Logger logger

This object's logger.

Constructor Detail

TRECResultsMatching

public TRECResultsMatching(Index _index)
                    throws IOException

Contructs an instance of the TRECResultsMatching given an index.

Parameters:

_index -

Throws:

IOException

TRECResultsMatching

public TRECResultsMatching(Index _index,
                   String _filename)
                    throws IOException

Contructs an instance of the TRECResultsMatching.

Parameters:

_index -

_filename -

Throws:

IOException

TRECResultsMatching

public TRECResultsMatching(Index _index,
                   String _filename,
                   String defDSMs)
                    throws IOException

Contructs an instance of the TRECResultsMatching.

Parameters:

_index -

_filename -

defDSMs -

Throws:

IOException

Method Detail

reopen

protected void reopen()
               throws IOException

Throws:

IOException

initDSMs

protected void initDSMs(String defDSMs)

getInfo

public String getInfo()

Description copied from interface: Matching

Return a human readable description of this Matching class

Specified by:

getInfo in interface Matching

getDocid

protected int getDocid(String docno)
                throws IOException

Throws:

IOException

read

protected boolean read(String _qid)
                throws IOException

Throws:

IOException

checkValid

protected boolean checkValid()

match

public ResultSet match(String _qid,
              MatchingQueryTerms mqt)
                throws IOException

Description copied from interface: Matching

Get a ResultSet for the given query terms.

Specified by:

match in interface Matching

Parameters:

_qid - - some ID of the query

mqt - - query terms to match

Returns:

ResultSet - the matched results

Throws:

IOException - if a problem occurs during matching

setCollectionStatistics

public void setCollectionStatistics(CollectionStatistics _collStats)

Description copied from interface: Matching

Update the collection statistics being used by this matching instance

Specified by:

setCollectionStatistics in interface Matching

Parameters:

_collStats - CollectionStatistics to use during matching

getCollectionStatistics

public CollectionStatistics getCollectionStatistics()

Returns collection statistics.

Returns:

collection statistics

initialise

protected void initialise(int max)

Initialises the current result set by allocating memory for max results.

Parameters:

max - The maximum number of results to be stored.

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class Object

Throws:

Throwable