Interface IndexSorter
- All Known Implementing Classes:
IndexSorter.DoubleSorter,IndexSorter.FloatSorter,IndexSorter.IntSorter,IndexSorter.LongSorter,IndexSorter.StringSorter
Implementers must provide the following methods: getDocComparator(LeafReader,int) -
an object that determines how documents within a segment are to be sorted getComparableProviders(List) - an array of objects that return a sortable long value per
document and segment getProviderName() - the SPI-registered name of a SortFieldProvider to serialize the sort
The companion SortFieldProvider should be registered with SPI via
META-INF/services
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Nested Class Summary
Nested ClassesModifier and TypeInterfaceDescriptionstatic interfaceUsed for sorting documents across segmentsstatic interfaceA comparator of doc IDs, used for sorting documents within a segmentstatic final classSorts documents based on double values from a NumericDocValues instancestatic final classSorts documents based on float values from a NumericDocValues instancestatic final classSorts documents based on integer values from a NumericDocValues instancestatic final classSorts documents based on long values from a NumericDocValues instancestatic interfaceProvide a NumericDocValues instance for a LeafReaderstatic interfaceProvide a SortedDocValues instance for a LeafReaderstatic final classSorts documents based on terms from a SortedDocValues instance -
Method Summary
Modifier and TypeMethodDescriptiongetComparableProviders(List<? extends LeafReader> readers) Get an array ofIndexSorter.ComparableProvider, one per segment, for merge sorting documents in different segmentsgetDocComparator(LeafReader reader, int maxDoc) Get a comparator that determines the sort order of docs within a single Reader.The SPI-registered name of aSortFieldProviderthat will deserialize the parent SortField
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Method Details
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getComparableProviders
IndexSorter.ComparableProvider[] getComparableProviders(List<? extends LeafReader> readers) throws IOException Get an array ofIndexSorter.ComparableProvider, one per segment, for merge sorting documents in different segments- Parameters:
readers- the readers to be merged- Throws:
IOException
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getDocComparator
Get a comparator that determines the sort order of docs within a single Reader.NB We cannot simply use the
FieldComparatorAPI because it requires docIDs to be sent in-order. The default implementations allocate array[maxDoc] to hold native values for comparison, but 1) they are transient (only alive while sorting this one segment) and 2) in the typical index sorting case, they are only used to sort newly flushed segments, which will be smaller than merged segments- Parameters:
reader- the Reader to sortmaxDoc- the number of documents in the Reader- Throws:
IOException
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getProviderName
String getProviderName()The SPI-registered name of aSortFieldProviderthat will deserialize the parent SortField
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