org.elasticsearch.action.termvectors

Class TermVectorsFields

java.lang.Object

org.apache.lucene.index.Fields

org.elasticsearch.action.termvectors.TermVectorsFields

All Implemented Interfaces:

Iterable<String>

public final class TermVectorsFields
extends org.apache.lucene.index.Fields

This class represents the result of a TermVectorsRequest. It works exactly like the Fields class except for one thing: It can return offsets and payloads even if positions are not present. You must call nextPosition() anyway to move the counter although this method only returns -1,, if no positions were returned by the TermVectorsRequest.

The data is stored in two byte arrays (headerRef and termVectors, both BytesRef) that have the following format:

headerRef: Stores offsets per field in the termVectors array and some header information as BytesRef. Format is

• String : "TV"
• vint: version (=-1)
• boolean: hasTermStatistics (are the term statistics stored?)
• boolean: hasFieldStatitsics (are the field statistics stored?)
• vint: number of fields
• • String: field name 1
  • vint: offset in termVectors for field 1
  • ...
  • String: field name last field
  • vint: offset in termVectors for last field

termVectors: Stores the actual term vectors as a BytesRef.

Term vectors for each fields are stored in blocks, one for each field. The offsets in headerRef are used to find where the block for a field starts. Each block begins with a

• vint: number of terms
• boolean: positions (has it positions stored?)
• boolean: offsets (has it offsets stored?)
• boolean: payloads (has it payloads stored?)

If the field statistics were requested (hasFieldStatistics is true, see headerRef), the following numbers are stored:

• vlong: sum of total term freqencies of the field (sumTotalTermFreq)
• vlong: sum of document frequencies for each term (sumDocFreq)
• vint: number of documents in the shard that has an entry for this field (docCount)

After that, for each term it stores

• vint: term lengths
• BytesRef: term name

If term statistics are requested (hasTermStatistics is true, see headerRef):

• vint: document frequency, how often does this term appear in documents?
• vlong: total term frequency. Sum of terms in this field.

After that

• vint: frequency (always returned)
• • vint: position_1 (if positions == true)
  • vint: startOffset_1 (if offset == true)
  • vint: endOffset_1 (if offset == true)
  • BytesRef: payload_1 (if payloads == true)
  • ...
  • vint: endOffset_freqency (if offset == true)
  • BytesRef: payload_freqency (if payloads == true)

Field Summary

Fields

Modifier and Type	Field and Description
boolean	hasScores

Fields inherited from class org.apache.lucene.index.Fields

EMPTY_ARRAY

Constructor Summary

Constructors

Constructor and Description
TermVectorsFields(BytesReference headerRef, BytesReference termVectors)

Method Summary

Methods

Modifier and Type	Method and Description
Iterator<String>	iterator()
int	size()
org.apache.lucene.index.Terms	terms(String field)

Methods inherited from class java.lang.Object

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

Field Detail

hasScores

public final boolean hasScores

Constructor Detail

TermVectorsFields

public TermVectorsFields(BytesReference headerRef,
                 BytesReference termVectors)
                  throws IOException

Parameters:

headerRef - Stores offsets per field in the termVectors and some header information as BytesRef.

termVectors - Stores the actual term vectors as a BytesRef.

Throws:

IOException

Method Detail

iterator

public Iterator<String> iterator()

Specified by:

iterator in interface Iterable<String>

Specified by:

iterator in class org.apache.lucene.index.Fields

terms

public org.apache.lucene.index.Terms terms(String field)
                                    throws IOException

Specified by:

terms in class org.apache.lucene.index.Fields

Throws:

IOException

size

public int size()

Specified by:

size in class org.apache.lucene.index.Fields