Class Lucene42FieldInfosFormat

Lucene 4.2 Field Infos format.

Field names are stored in the field info file, with suffix .fnm.

FieldInfos (.fnm) --> Header,FieldsCount, <FieldName,FieldNumber, FieldBits,DocValuesBits,Attributes> FieldsCount

Data types:

Field Descriptions:
  • FieldsCount: the number of fields in this file.
  • FieldName: name of the field as a UTF-8 String.
  • FieldNumber: the field's number. Note that unlike previous versions of Lucene, the fields are not numbered implicitly by their order in the file, instead explicitly.
  • FieldBits: a byte containing field options.
    • The low-order bit is one for indexed fields, and zero for non-indexed fields.
    • The second lowest-order bit is one for fields that have term vectors stored, and zero for fields without term vectors.
    • If the third lowest order-bit is set (0x4), offsets are stored into the postings list in addition to positions.
    • Fourth bit is unused.
    • If the fifth lowest-order bit is set (0x10), norms are omitted for the indexed field.
    • If the sixth lowest-order bit is set (0x20), payloads are stored for the indexed field.
    • If the seventh lowest-order bit is set (0x40), term frequencies and positions omitted for the indexed field.
    • If the eighth lowest-order bit is set (0x80), positions are omitted for the indexed field.
  • DocValuesBits: a byte containing per-document value types. The type recorded as two four-bit integers, with the high-order bits representing norms options, and the low-order bits representing DocValues options. Each four-bit integer can be decoded as such:
    • 0: no DocValues for this field.
    • 1: NumericDocValues. (NUMERIC)
    • 2: BinaryDocValues. (BINARY)
    • 3: SortedDocValues. (SORTED)
  • Attributes: a key-value map of codec-private attributes.

This is a Lucene.NET EXPERIMENTAL API, use at your own risk
Inheritance
System.Object
FieldInfosFormat
Lucene42FieldInfosFormat
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: Lucene.Net.Codecs.Lucene42
Assembly: Lucene.Net.dll
Syntax
[Obsolete("Only for reading old 4.2-4.5 segments")]
public class Lucene42FieldInfosFormat : FieldInfosFormat

Constructors

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Lucene42FieldInfosFormat()

Sole constructor.

Declaration
public Lucene42FieldInfosFormat()

Properties

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FieldInfosReader

Declaration
public override FieldInfosReader FieldInfosReader { get; }
Property Value
Type Description
FieldInfosReader
Overrides
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FieldInfosWriter

Declaration
public override FieldInfosWriter FieldInfosWriter { get; }
Property Value
Type Description
FieldInfosWriter
Overrides

Extension Methods