Class Lucene40StoredFieldsFormat

Lucene 4.0 Stored Fields Format.

Stored fields are represented by two files:

1. The field index, or .fdx file.

   This is used to find the location within the field data file of the fields of a particular document. Because it contains fixed-length data, this file may be easily randomly accessed. The position of document n 's field data is the Uint64 (WriteInt64(long)) at n*8 in this file.

   This contains, for each document, a pointer to its field data, as follows:

   • FieldIndex (.fdx) --> <Header>, <FieldValuesPosition> ^SegSize
   • Header --> CodecHeader (WriteHeader(DataOutput, string, int))
   • FieldValuesPosition --> Uint64 (WriteInt64(long))

2. The field data, or .fdt file.

   This contains the stored fields of each document, as follows:

   • FieldData (.fdt) --> <Header>, <DocFieldData> ^SegSize
   • Header --> CodecHeader (WriteHeader(DataOutput, string, int))
   • DocFieldData --> FieldCount, <FieldNum, Bits, Value> ^FieldCount
   • FieldCount --> VInt (WriteVInt32(int))
   • FieldNum --> VInt (WriteVInt32(int))
   • Bits --> Byte (WriteByte(byte))
     • low order bit reserved.
     • second bit is one for fields containing binary data
     • third bit reserved.
     • 4th to 6th bit (mask: 0x7<<3) define the type of a numeric field:
       • all bits in mask are cleared if no numeric field at all
       • 1<<3: Value is Int
       • 2<<3: Value is Long
       • 3<<3: Value is Int as Float (as of Int32BitsToSingle(int)
       • 4<<3: Value is Long as Double (as of Int64BitsToDouble(long)
   • Value --> String | BinaryValue | Int | Long (depending on Bits)
   • BinaryValue --> ValueSize, < Byte (WriteByte(byte)) >^ValueSize
   • ValueSize --> VInt (WriteVInt32(int))

Note

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

Inheritance

object

StoredFieldsFormat

Lucene40StoredFieldsFormat

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Lucene.Net.Codecs.Lucene40

Assembly: Lucene.Net.dll

Syntax

public class Lucene40StoredFieldsFormat : StoredFieldsFormat

Constructors

Lucene40StoredFieldsFormat()

Sole constructor.

Declaration

public Lucene40StoredFieldsFormat()

Methods

FieldsReader(Directory, SegmentInfo, FieldInfos, IOContext)

Returns a StoredFieldsReader to load stored fields.

Declaration

public override StoredFieldsReader FieldsReader(Directory directory, SegmentInfo si, FieldInfos fn, IOContext context)

Parameters

Type	Name	Description
Directory	directory
SegmentInfo	si
FieldInfos	fn
IOContext	context

Returns

Type	Description
StoredFieldsReader

Overrides

StoredFieldsFormat.FieldsReader(Directory, SegmentInfo, FieldInfos, IOContext)

FieldsWriter(Directory, SegmentInfo, IOContext)

Returns a StoredFieldsWriter to write stored fields.

Declaration

public override StoredFieldsWriter FieldsWriter(Directory directory, SegmentInfo si, IOContext context)

Parameters

Type	Name	Description
Directory	directory
SegmentInfo	si
IOContext	context

Returns

Type	Description
StoredFieldsWriter

Overrides

StoredFieldsFormat.FieldsWriter(Directory, SegmentInfo, IOContext)