Class MemoryPostingsFormat

Stores terms & postings (docs, positions, payloads) in RAM, using an FST.

Note that this codec implements advance as a linear scan! This means if you store large fields in here, queries that rely on advance will (AND BooleanQuery, PhraseQuery) will be relatively slow!

Note

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

Inheritance
object
PostingsFormat
MemoryPostingsFormat
Inherited Members
PostingsFormat.EMPTY
PostingsFormat.SetPostingsFormatFactory(IPostingsFormatFactory)
PostingsFormat.GetPostingsFormatFactory()
PostingsFormat.Name
PostingsFormat.AvailablePostingsFormats
Namespace: Lucene.Net.Codecs.Memory
Assembly: Lucene.Net.Codecs.dll
Syntax
[PostingsFormatName("Memory")]
public sealed class MemoryPostingsFormat : PostingsFormat

Constructors

MemoryPostingsFormat()

Stores terms & postings (docs, positions, payloads) in RAM, using an FST.

Note that this codec implements advance as a linear scan! This means if you store large fields in here, queries that rely on advance will (AND BooleanQuery, PhraseQuery) will be relatively slow!

Note

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

Declaration
public MemoryPostingsFormat()

MemoryPostingsFormat(bool, float)

Create MemoryPostingsFormat, specifying advanced FST options.

Declaration
public MemoryPostingsFormat(bool doPackFST, float acceptableOverheadRatio)
Parameters
Type Name Description
bool doPackFST

true if a packed FST should be built. NOTE: packed FSTs are limited to ~2.1 GB of postings.
float acceptableOverheadRatio

Allowable overhead for packed ints during FST construction.

Methods

FieldsConsumer(SegmentWriteState)

Writes a new segment.

Declaration
public override FieldsConsumer FieldsConsumer(SegmentWriteState state)
Parameters
Type Name Description
SegmentWriteState state
Returns
Type Description
FieldsConsumer
Overrides
Lucene.Net.Codecs.PostingsFormat.FieldsConsumer(Lucene.Net.Index.SegmentWriteState)

FieldsProducer(SegmentReadState)

Reads a segment. NOTE: by the time this call returns, it must hold open any files it will need to use; else, those files may be deleted. Additionally, required files may be deleted during the execution of this call before there is a chance to open them. Under these circumstances an IOException should be thrown by the implementation. IOExceptions are expected and will automatically cause a retry of the segment opening logic with the newly revised segments.

Declaration
public override FieldsProducer FieldsProducer(SegmentReadState state)
Parameters
Type Name Description
SegmentReadState state
Returns
Type Description
FieldsProducer
Overrides
Lucene.Net.Codecs.PostingsFormat.FieldsProducer(Lucene.Net.Index.SegmentReadState)

ToString()

Returns a string that represents the current object.

Declaration
public override string ToString()
Returns
Type Description
string

A string that represents the current object.
Overrides
Lucene.Net.Codecs.PostingsFormat.ToString()