Package org.apache.lucene.codecs
Class FieldsConsumer
java.lang.Object
org.apache.lucene.codecs.FieldsConsumer
- All Implemented Interfaces:
Closeable
,AutoCloseable
- Direct Known Subclasses:
Lucene90BlockTreeTermsWriter
Abstract API that consumes terms, doc, freq, prox, offset and payloads postings. Concrete
implementations of this actually do "something" with the postings (write it into the index in a
specific format).
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionabstract void
close()
void
merge
(MergeState mergeState, NormsProducer norms) Merges in the fields from the readers inmergeState
.abstract void
write
(Fields fields, NormsProducer norms) Write all fields, terms and postings.
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Constructor Details
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FieldsConsumer
protected FieldsConsumer()Sole constructor. (For invocation by subclass constructors, typically implicit.)
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Method Details
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write
Write all fields, terms and postings. This the "pull" API, allowing you to iterate more than once over the postings, somewhat analogous to using a DOM API to traverse an XML tree.Notes:
- You must compute index statistics, including each Term's docFreq and totalTermFreq, as well as the summary sumTotalTermFreq, sumTotalDocFreq and docCount.
- You must skip terms that have no docs and fields that have no terms, even though the provided Fields API will expose them; this typically requires lazily writing the field or term until you've actually seen the first term or document.
- The provided Fields instance is limited: you cannot call any methods that return statistics/counts; you cannot pass a non-null live docs when pulling docs/positions enums.
- Throws:
IOException
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merge
Merges in the fields from the readers inmergeState
. The default implementation skips and maps around deleted documents, and callswrite(Fields,NormsProducer)
. Implementations can override this method for more sophisticated merging (bulk-byte copying, etc).- Throws:
IOException
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close
- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Throws:
IOException
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