Package org.apache.lucene.search

Record Class TermStatistics

java.lang.Object

java.lang.Record

org.apache.lucene.search.TermStatistics

Record Components:

term - Term bytes.

This value is never null.

docFreq - number of documents containing the term in the collection, in the range [1 .. totalTermFreq()].

This is the document-frequency for the term: the count of documents where the term appears at least one time.

This value is always a positive number, and never exceeds totalTermFreq. It also cannot exceed CollectionStatistics.sumDocFreq(). @see TermsEnum#docFreq()

totalTermFreq - number of occurrences of the term in the collection, in the range [docFreq() .. CollectionStatistics.sumTotalTermFreq()].

This is the token count for the term: the number of times it appears in the field across all documents.

This value is always a positive number, always at least docFreq(), and never exceeds CollectionStatistics.sumTotalTermFreq(). @see TermsEnum#totalTermFreq()

public record TermStatistics(BytesRef term, long docFreq, long totalTermFreq)
extends Record

Contains statistics for a specific term

This class holds statistics for this term across all documents for scoring purposes:

• docFreq: number of documents this term occurs in.
• totalTermFreq: number of tokens for this term.

The following conditions are always true:

• All statistics are positive integers: never zero or negative.
• docFreq <= totalTermFreq
• docFreq <= sumDocFreq of the collection
• totalTermFreq <= sumTotalTermFreq of the collection

Values may include statistics on deleted documents that have not yet been merged away.

Be careful when performing calculations on these values because they are represented as 64-bit integer values, you may need to cast to double for your use.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary

Constructors

Constructor	Description
TermStatistics(BytesRef term, long docFreq, long totalTermFreq)	Creates statistics instance for a term.

Method Summary

Modifier and Type	Method	Description
long	docFreq()	Returns the value of the docFreq record component.
final boolean	equals(Object o)	Indicates whether some other object is "equal to" this one.
final int	hashCode()	Returns a hash code value for this object.
BytesRef	term()	Returns the value of the term record component.
final String	toString()	Returns a string representation of this record class.
long	totalTermFreq()	Returns the value of the totalTermFreq record component.

Methods inherited from class java.lang.Object

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

Constructor Details

TermStatistics

public TermStatistics(BytesRef term,
 long docFreq,
 long totalTermFreq)

Creates statistics instance for a term.

Throws:

NullPointerException - if term is null.

IllegalArgumentException - if docFreq is negative or zero.

IllegalArgumentException - if totalTermFreq is less than docFreq.

Method Details

toString

public final String toString()

Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.

Specified by:

toString in class Record

Returns:

a string representation of this object

hashCode

public final int hashCode()

Returns a hash code value for this object. The value is derived from the hash code of each of the record components.

Specified by:

hashCode in class Record

Returns:

a hash code value for this object

equals

public final boolean equals(Object o)

Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. Reference components are compared with Objects::equals(Object,Object); primitive components are compared with '=='.

Specified by:

equals in class Record

Parameters:

o - the object with which to compare

Returns:

true if this object is the same as the o argument; false otherwise.

term

public BytesRef term()

Returns the value of the term record component.

Returns:

the value of the term record component

docFreq

public long docFreq()

Returns the value of the docFreq record component.

Returns:

the value of the docFreq record component

totalTermFreq

public long totalTermFreq()

Returns the value of the totalTermFreq record component.

Returns:

the value of the totalTermFreq record component