uk.ac.gla.terrier.structures.indexing
Class LexiconMap

java.lang.Object
  uk.ac.gla.terrier.structures.indexing.LexiconMap

Direct Known Subclasses:

BlockLexiconMap

public class LexiconMap
extends java.lang.Object

This class keeps track of the total counts of terms within a bundle of documents being indexed. Internally, uses hashmaps. This class replaces the LexiconTree etc.

Properties

• indexing.avg.unique.terms.per.bundle - the unique number of terms expected to be indexed in a bundle of documents. Not a limit, just a hint for the sizing of the hashmaps.Default to 120.

Constructor Summary

LexiconMap()

Method Summary

void	clear() Clear the lexicon map
int	getNumberOfNodes() Returns the numbe of nodes in the tree.
int	getNumberOfPointers() Returns the number of pointers in the tree.
void	insert(DocumentPostingList doc) Inserts all the terms from a document posting into the lexicon map
void	insert(java.lang.String term, int tf) Inserts a new term in the lexicon map.
void	storeToStream(LexiconOutputStream lexiconStream) Stores the lexicon tree to a lexicon stream as a sequence of entries.

Methods inherited from class java.lang.Object

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

Constructor Detail

LexiconMap

public LexiconMap()

Method Detail

clear

public void clear()

Clear the lexicon map

insert

public void insert(java.lang.String term,
                   int tf)

Inserts a new term in the lexicon map.

Parameters:

term - The term to be inserted.

tf - The id of the term.

insert

public void insert(DocumentPostingList doc)

Inserts all the terms from a document posting into the lexicon map

Parameters:

doc - The postinglist for that document

storeToStream

public void storeToStream(LexiconOutputStream lexiconStream)
                   throws java.io.IOException

Stores the lexicon tree to a lexicon stream as a sequence of entries. The binary tree is traversed in order, by called the method traverseAndStoreToStream.

Parameters:

lexiconStream - The lexicon output stream to store to.

Throws:

java.io.IOException

getNumberOfNodes

public int getNumberOfNodes()

Returns the numbe of nodes in the tree.

Returns:

int the number of nodes in the tree.

getNumberOfPointers

public int getNumberOfPointers()

Returns the number of pointers in the tree.

Returns:

int the number of pointers in the tree.