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:

• Header --> CodecHeader WriteHeader(DataOutput, String, Int32)
• FieldsCount --> VInt WriteVInt32(Int32)
• FieldName --> String WriteString(String)
• FieldBits, DocValuesBits --> Byte WriteByte(Byte)
• FieldNumber --> VInt WriteInt32(Int32)
• Attributes --> IDictionary<String,String>

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

Namespace: Lucene.Net.Codecs.Lucene42

Assembly: Lucene.Net.dll

Syntax

public class Lucene42FieldInfosFormat : FieldInfosFormat

Constructors

Lucene42FieldInfosFormat()

Sole constructor.

Declaration

public Lucene42FieldInfosFormat()

Properties

FieldInfosReader

Declaration

public override FieldInfosReader FieldInfosReader { get; }

Property Value

Type	Description
FieldInfosReader

Overrides

FieldInfosFormat.FieldInfosReader

FieldInfosWriter

Declaration

public override FieldInfosWriter FieldInfosWriter { get; }

Property Value

Type	Description
FieldInfosWriter

Overrides

FieldInfosFormat.FieldInfosWriter