Package org.terrier.realtime.memory

Class MemoryLexiconEntry

java.lang.Object

org.terrier.structures.LexiconEntry

org.terrier.realtime.memory.MemoryLexiconEntry

All Implemented Interfaces:

java.io.Serializable, org.apache.hadoop.io.Writable, MemoryPointer, EntryStatistics, Pointer

Direct Known Subclasses:

MemoryFieldsLexiconEntry

public class MemoryLexiconEntry
extends LexiconEntry
implements MemoryPointer, java.io.Serializable

A lexicon entry stored in a MemoryLexicon. Implements MemoryPointer such that it can be used to look up posting lists in a MemoryInvertedIndex.

Since:

4.0

Author:

Richard McCreadie, Stuart Mackie

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
MemoryLexiconEntry()	Constructor.
MemoryLexiconEntry(int termid)	Constructor (termid).
MemoryLexiconEntry(int df, int tf)	Constructor (df, tf).
MemoryLexiconEntry(int termid, int df, int tf)	Constructor (termid, df, tf).
MemoryLexiconEntry(int termid, int df, int tf, int maxtf)

Method Summary

Modifier and Type	Method	Description
void	add(EntryStatistics es)	Increment the statistics of this object by that of another.
MemoryLexiconEntry	clone()
int	getDocumentFrequency()	Return the number of documents that the term occurs in.
int	getFrequency()	Return the frequency (total number of occurrences) of the term.
int	getMaxFrequencyInDocuments()	Return the maximum in-document term frequency of the term among all documents the terms appears in.
int	getNumberOfEntries()	Pointer implementation: how many entries in the inverted index.
int	getPointer()	Get pointer value (termid).
int	getTermId()	Return the id of the term.
java.lang.String	pointerToString()	Returns a textual representation of the pointer alone
void	readFields(java.io.DataInput arg0)	Not implemented.
void	setDocumentFrequency(int nt)	Set the number of documents that the term occurs in.
void	setFrequency(int F)	Set the frequency (total number of occurrences) of the term.
void	setMaxFrequencyInDocuments(int max)	Set the maximum in-document term frequency of the term among all documents the terms appears in.
void	setNumberOfEntries(int df)	Update the number of entries in the pointer
void	setPointer(Pointer p)	Update the pointer
void	setStatistics(int df, int tf)	Update the document frequency and term frequency
void	setTermId(int termid)	Set the term ID, the integer representation of the term in the index, e.g.
void	subtract(EntryStatistics es)	Decrement the statistics of this object by that of another.
void	write(java.io.DataOutput out)	Not implemented.

Methods inherited from class org.terrier.structures.LexiconEntry

equals, getWritableEntryStatistics, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MemoryLexiconEntry

public MemoryLexiconEntry()

Constructor.

MemoryLexiconEntry

public MemoryLexiconEntry(int termid)

Constructor (termid).

MemoryLexiconEntry

public MemoryLexiconEntry(int df,
                          int tf)

Constructor (df, tf).

MemoryLexiconEntry

public MemoryLexiconEntry(int termid,
                          int df,
                          int tf)

Constructor (termid, df, tf).

MemoryLexiconEntry

public MemoryLexiconEntry(int termid,
                          int df,
                          int tf,
                          int maxtf)

Method Detail

getTermId

public int getTermId()

Return the id of the term.

Specified by:

getTermId in interface EntryStatistics

Returns:

the id of the term.

setTermId

public void setTermId(int termid)

Set the term ID, the integer representation of the term in the index, e.g. as used in direct index posting structures.

Specified by:

setTermId in class LexiconEntry

getDocumentFrequency

public int getDocumentFrequency()

Return the number of documents that the term occurs in.

Specified by:

getDocumentFrequency in interface EntryStatistics

Returns:

the number of documents that the term occurs in.

getFrequency

public int getFrequency()

Return the frequency (total number of occurrences) of the term.

Specified by:

getFrequency in interface EntryStatistics

Returns:

the frequency (total number of occurrences) of the entry (term).

setStatistics

public void setStatistics(int df,
                          int tf)

Update the document frequency and term frequency

Specified by:

setStatistics in class LexiconEntry

add

public void add(EntryStatistics es)

Increment the statistics of this object by that of another.

Specified by:

add in interface EntryStatistics

Parameters:

es - the other object whose statistics are used to increment the statistics of this object.

subtract

public void subtract(EntryStatistics es)

Decrement the statistics of this object by that of another.

Specified by:

subtract in interface EntryStatistics

Parameters:

es - the other object whose statistics are used to decrement the statistics of this object.

getNumberOfEntries

public int getNumberOfEntries()

Pointer implementation: how many entries in the inverted index. Usually the same as getDocumentFrequency().

Specified by:

getNumberOfEntries in interface Pointer

Overrides:

getNumberOfEntries in class LexiconEntry

Returns:

the number of "things" that this pointer refers to.

setNumberOfEntries

public void setNumberOfEntries(int df)

Update the number of entries in the pointer

Specified by:

setNumberOfEntries in interface Pointer

Overrides:

setNumberOfEntries in class LexiconEntry

Parameters:

df - the number of "things" that the pointer refers to.

getPointer

public int getPointer()

Get pointer value (termid).

Specified by:

getPointer in interface MemoryPointer

setPointer

public void setPointer(Pointer p)

Update the pointer

Specified by:

setPointer in interface Pointer

Overrides:

setPointer in class LexiconEntry

Parameters:

p - other pointer to update the pointer in this object.

pointerToString

public java.lang.String pointerToString()

Returns a textual representation of the pointer alone

Specified by:

pointerToString in interface Pointer

Overrides:

pointerToString in class LexiconEntry

getMaxFrequencyInDocuments

public int getMaxFrequencyInDocuments()

Description copied from interface: EntryStatistics

Return the maximum in-document term frequency of the term among all documents the terms appears in.

Specified by:

getMaxFrequencyInDocuments in interface EntryStatistics

Returns:

the maximum in-document term frequency of the term among all documents the terms appears in.

setMaxFrequencyInDocuments

public void setMaxFrequencyInDocuments(int max)

Description copied from interface: EntryStatistics

Set the maximum in-document term frequency of the term among all documents the terms appears in.

Specified by:

setMaxFrequencyInDocuments in interface EntryStatistics

Parameters:

max - the maximum in-document term frequency of the term among all documents the terms appears in.

readFields

public void readFields(java.io.DataInput arg0)
                throws java.io.IOException

Not implemented.

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

write

public void write(java.io.DataOutput out)
           throws java.io.IOException

Not implemented.

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

clone

public MemoryLexiconEntry clone()

Overrides:

clone in class java.lang.Object

setFrequency

public void setFrequency(int F)

Description copied from interface: EntryStatistics

Set the frequency (total number of occurrences) of the term.

Specified by:

setFrequency in interface EntryStatistics

Parameters:

F - the frequency (total number of occurrences) of the entry (term).

setDocumentFrequency

public void setDocumentFrequency(int nt)

Description copied from interface: EntryStatistics

Set the number of documents that the term occurs in.

Specified by:

setDocumentFrequency in interface EntryStatistics

Parameters:

nt - the number of documents that the term occurs in.