Package org.terrier.structures.postings

Class BasicPostingImpl

java.lang.Object

org.terrier.structures.postings.BasicPostingImpl

All Implemented Interfaces:

java.io.Serializable, org.apache.hadoop.io.Writable, Posting, WritablePosting

Direct Known Subclasses:

BasicIterablePosting, BlockPostingImpl, FieldPostingImpl

public class BasicPostingImpl
extends java.lang.Object
implements WritablePosting

Implementation of a Posting that is non-iterable.

Since:

3.0

Author:

Craig Macdonald

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected int	dl
protected int	id	id of the posting
protected int	tf	frequency of this posting

Constructor Summary

Constructors

Constructor	Description
BasicPostingImpl()	Empty constructor - needed for Writable
BasicPostingImpl(int docid, int frequency)	Constructor that sets both id and frequency

Method Summary

Modifier and Type	Method	Description
WritablePosting	asWritablePosting()	Copy this posting to one free of an iterator.
int	getDocumentLength()	Returns 0
int	getFrequency()	Return the frequency of the term in the current document, in tokens.
int	getId()	Return the id of the current posting.
void	readFields(java.io.DataInput in)	Reads the a single posting (not an iterable posting - use BitPostingIndex for that)
void	setDocumentLength(int l)	Set the length of the document of the current posting in tokens.
void	setId(int _id)	Set the id of this posting
void	setTf(int tf)	Set the term frequency in the document
java.lang.String	toString()	Makes a human readable form of this posting
void	write(java.io.DataOutput out)	Writes the current posting (not an iterable posting - use DirectInvertedOutputStream for that).

Methods inherited from class java.lang.Object

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

Field Detail

dl

protected int dl

id

protected int id

id of the posting

tf

protected int tf

frequency of this posting

Constructor Detail

BasicPostingImpl

public BasicPostingImpl()

Empty constructor - needed for Writable

BasicPostingImpl

public BasicPostingImpl(int docid,
                        int frequency)

Constructor that sets both id and frequency

Method Detail

getId

public final int getId()

Return the id of the current posting. For the inverted index, this is the current docid; for the direct index it corresponds to the current term id.

Specified by:

getId in interface Posting

Returns:

id of the posting.

getFrequency

public final int getFrequency()

Return the frequency of the term in the current document, in tokens.

Specified by:

getFrequency in interface Posting

Returns:

frequency of the term in the current document, in tokens.

readFields

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

Reads the a single posting (not an iterable posting - use BitPostingIndex for that)

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

Writes the current posting (not an iterable posting - use DirectInvertedOutputStream for that). Compression using this method is not expected to be comparable to bit-level compression.

Specified by:

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

Throws:

java.io.IOException

setId

public void setId(int _id)

Set the id of this posting

Specified by:

setId in interface Posting

Specified by:

setId in interface WritablePosting

getDocumentLength

public int getDocumentLength()

Returns 0

Specified by:

getDocumentLength in interface Posting

Returns:

length of the document of the current posting in tokens.

asWritablePosting

public WritablePosting asWritablePosting()

Copy this posting to one free of an iterator. Kind of like a clone.

Specified by:

asWritablePosting in interface Posting

Returns:

an identical posting, but which can be manipulated free of this iterator

toString

public java.lang.String toString()

Makes a human readable form of this posting

Overrides:

toString in class java.lang.Object

setDocumentLength

public void setDocumentLength(int l)

Description copied from interface: WritablePosting

Set the length of the document of the current posting in tokens.

Specified by:

setDocumentLength in interface WritablePosting

Parameters:

l - length of the document of the current posting in tokens.

setTf

public void setTf(int tf)

Set the term frequency in the document

Parameters:

tf -