Class Lucene46FieldInfosFormat
java.lang.Object
org.apache.lucene.codecs.FieldInfosFormat
org.apache.lucene.codecs.lucene46.Lucene46FieldInfosFormat
Lucene 4.6 Field Infos format.
Field names are stored in the field info file, with suffix .fnm.
FieldInfos (.fnm) --> Header,FieldsCount, <FieldName,FieldNumber, FieldBits,DocValuesBits,DocValuesGen,Attributes> FieldsCount
Data types:
- Header -->
CodecHeader
- FieldsCount -->
VInt
- FieldName -->
String
- FieldBits, DocValuesBits -->
Byte
- FieldNumber -->
VInt
- Attributes -->
Map<String,String>
- DocValuesGen -->
Int64
- 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 representingDocValues
options. Each four-bit integer can be decoded as such:- 0: no DocValues for this field.
- 1: NumericDocValues. (
FieldInfo.DocValuesType.NUMERIC
) - 2: BinaryDocValues. (
DocValuesType#BINARY
) - 3: SortedDocValues. (
DocValuesType#SORTED
)
- DocValuesGen is the generation count of the field's DocValues. If this is -1,
there are no DocValues updates to that field. Anything above zero means there
are updates stored by
DocValuesFormat
. - Attributes: a key-value map of codec-private attributes.
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionReturns aFieldInfosReader
to read field infos from the indexReturns aFieldInfosWriter
to write field infos to the index
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Constructor Details
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Lucene46FieldInfosFormat
public Lucene46FieldInfosFormat()Sole constructor.
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Method Details
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getFieldInfosReader
Description copied from class:FieldInfosFormat
Returns aFieldInfosReader
to read field infos from the index- Specified by:
getFieldInfosReader
in classFieldInfosFormat
- Throws:
IOException
-
getFieldInfosWriter
Description copied from class:FieldInfosFormat
Returns aFieldInfosWriter
to write field infos to the index- Specified by:
getFieldInfosWriter
in classFieldInfosFormat
- Throws:
IOException
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