Class PerFieldPostingsFormat
java.lang.Object
org.apache.lucene.codecs.PostingsFormat
org.apache.lucene.codecs.perfield.PerFieldPostingsFormat
- All Implemented Interfaces:
NamedSPILoader.NamedSPI
Enables per field postings support.
Note, when extending this class, the name (PostingsFormat.getName()
) is written into the index. In
order for the field to be read, the name must resolve to your implementation via PostingsFormat.forName(String)
. This method uses Java's Service Provider Interface
to
resolve format names.
Files written by each posting format have an additional suffix containing the format name. For
example, in a per-field configuration instead of _1.prx
filenames would look like
_1_Lucene40_0.prx
.
- See Also:
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final String
FieldInfo
attribute name used to store the format name for each field.static final String
Name of thisPostingsFormat
.static final String
FieldInfo
attribute name used to store the segment suffix name for each field.Fields inherited from class org.apache.lucene.codecs.PostingsFormat
EMPTY
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionfinal FieldsConsumer
fieldsConsumer
(SegmentWriteState state) Writes a new segmentfinal FieldsProducer
fieldsProducer
(SegmentReadState state) Reads a segment.abstract PostingsFormat
getPostingsFormatForField
(String field) Returns the postings format that should be used for writing new segments offield
.Methods inherited from class org.apache.lucene.codecs.PostingsFormat
availablePostingsFormats, forName, getName, reloadPostingsFormats, toString
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Field Details
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PER_FIELD_NAME
Name of thisPostingsFormat
.- See Also:
-
PER_FIELD_FORMAT_KEY
FieldInfo
attribute name used to store the format name for each field. -
PER_FIELD_SUFFIX_KEY
FieldInfo
attribute name used to store the segment suffix name for each field.
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Constructor Details
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PerFieldPostingsFormat
protected PerFieldPostingsFormat()Sole constructor.
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Method Details
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fieldsConsumer
Description copied from class:PostingsFormat
Writes a new segment- Specified by:
fieldsConsumer
in classPostingsFormat
- Throws:
IOException
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fieldsProducer
Description copied from class:PostingsFormat
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.- Specified by:
fieldsProducer
in classPostingsFormat
- Throws:
IOException
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getPostingsFormatForField
Returns the postings format that should be used for writing new segments offield
.The field to format mapping is written to the index, so this method is only invoked when writing, not when reading.
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