Package org.apache.lucene.search

Record Class CollectionStatistics

java.lang.Object

java.lang.Record

org.apache.lucene.search.CollectionStatistics

Record Components:

field - Field's name.

This value is never null.

maxDoc - The total number of documents in the range [1 .. Long.MAX_VALUE], regardless of whether they all contain values for this field.

This value is always a positive number. @see IndexReader#maxDoc()

docCount - The total number of documents that have at least one term for this field , in the range [1 .. maxDoc()].

This value is always a positive number, and never exceeds maxDoc(). @see Terms#getDocCount()

sumTotalTermFreq - The total number of tokens for this field , in the range [sumDocFreq() .. Long.MAX_VALUE]. This is the "word count" for this field across all documents. It is the sum of TermStatistics.totalTermFreq() across all terms. It is also the sum of each document's field length across all documents.

This value is always a positive number, and always at least sumDocFreq(). @see Terms#getSumTotalTermFreq()

sumDocFreq - The total number of posting list entries for this field, in the range [docCount() .. sumTotalTermFreq()]. This is the sum of term-document pairs: the sum of TermStatistics.docFreq() across all terms. It is also the sum of each document's unique term count for this field across all documents.

This value is always a positive number, always at least docCount(), and never exceeds sumTotalTermFreq(). @see Terms#getSumDocFreq()

public record CollectionStatistics(String field, long maxDoc, long docCount, long sumTotalTermFreq, long sumDocFreq)
extends Record

Contains statistics for a collection (field).

This class holds statistics across all documents for scoring purposes:

• maxDoc(): number of documents.
• docCount(): number of documents that contain this field.
• sumDocFreq(): number of postings-list entries.
• sumTotalTermFreq(): number of tokens.

The following conditions are always true:

• All statistics are positive integers: never zero or negative.
• docCount <= maxDoc
• docCount <= sumDocFreq <= sumTotalTermFreq

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
CollectionStatistics(String field, long maxDoc, long docCount, long sumTotalTermFreq, long sumDocFreq)	Creates statistics instance for a collection (field).

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Details

CollectionStatistics

public CollectionStatistics(String field,
 long maxDoc,
 long docCount,
 long sumTotalTermFreq,
 long sumDocFreq)

Creates statistics instance for a collection (field).

Throws:

IllegalArgumentException - if maxDoc is negative or zero.

IllegalArgumentException - if docCount is negative or zero.

IllegalArgumentException - if docCount is more than maxDoc.

IllegalArgumentException - if sumDocFreq is less than docCount.

IllegalArgumentException - if sumTotalTermFreq is less than sumDocFreq.

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.

field

public String field()

Returns the value of the field record component.

Returns:

the value of the field record component

maxDoc

public long maxDoc()

Returns the value of the maxDoc record component.

Returns:

the value of the maxDoc record component

docCount

public long docCount()

Returns the value of the docCount record component.

Returns:

the value of the docCount record component

sumTotalTermFreq

public long sumTotalTermFreq()

Returns the value of the sumTotalTermFreq record component.

Returns:

the value of the sumTotalTermFreq record component

sumDocFreq

public long sumDocFreq()

Returns the value of the sumDocFreq record component.

Returns:

the value of the sumDocFreq record component