org.apache.lucene.codecs

Class MappingMultiDocsEnum

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.index.DocsEnum

org.apache.lucene.codecs.MappingMultiDocsEnum

public final class MappingMultiDocsEnum
extends DocsEnum

Exposes flex API, merged from flex API of sub-segments, remapping docIDs (this is used for segment merging).

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

Field Summary

Fields inherited from class org.apache.lucene.index.DocsEnum

FLAG_FREQS, FLAG_NONE

Fields inherited from class org.apache.lucene.search.DocIdSetIterator

NO_MORE_DOCS

Constructor Summary

Constructors

Constructor and Description
MappingMultiDocsEnum() Sole constructor.

Method Summary

Methods

Modifier and Type	Method and Description
int	advance(int target) Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself.
long	cost() Returns the estimated cost of this DocIdSetIterator.
int	docID() Returns the following: -1 or DocIdSetIterator.NO_MORE_DOCS if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
int	freq() Returns term frequency in the current document, or 1 if the field was indexed with FieldInfo.IndexOptions.DOCS_ONLY.
int	getNumSubs() How many sub-readers we are merging.
MultiDocsEnum.EnumWithSlice[]	getSubs() Returns sub-readers we are merging.
int	nextDoc() Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set. NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.
void	setMergeState(MergeState mergeState) Sets the MergeState, which is used to re-map document IDs.

Methods inherited from class org.apache.lucene.index.DocsEnum

attributes

Methods inherited from class org.apache.lucene.search.DocIdSetIterator

empty, slowAdvance

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MappingMultiDocsEnum

public MappingMultiDocsEnum()

Sole constructor.

Method Detail

setMergeState

public void setMergeState(MergeState mergeState)

Sets the MergeState, which is used to re-map document IDs.

getNumSubs

public int getNumSubs()

How many sub-readers we are merging.

See Also:

getSubs()

getSubs

public MultiDocsEnum.EnumWithSlice[] getSubs()

Returns sub-readers we are merging.

freq

public int freq()
         throws IOException

Description copied from class: DocsEnum

Returns term frequency in the current document, or 1 if the field was indexed with FieldInfo.IndexOptions.DOCS_ONLY. Do not call this before DocIdSetIterator.nextDoc() is first called, nor after DocIdSetIterator.nextDoc() returns DocIdSetIterator.NO_MORE_DOCS.

NOTE: if the DocsEnum was obtain with DocsEnum.FLAG_NONE, the result of this method is undefined.

Specified by:

freq in class DocsEnum

Throws:

IOException

docID

public int docID()

Description copied from class: DocIdSetIterator

Returns the following:

• -1 or DocIdSetIterator.NO_MORE_DOCS if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
• DocIdSetIterator.NO_MORE_DOCS if the iterator has exhausted.
• Otherwise it should return the doc ID it is currently on.

Specified by:

docID in class DocIdSetIterator

advance

public int advance(int target)

Description copied from class: DocIdSetIterator

Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself. Exhausts the iterator and returns DocIdSetIterator.NO_MORE_DOCS if target is greater than the highest document number in the set.

The behavior of this method is undefined when called with target ≤ current, or after the iterator has exhausted. Both cases may result in unpredicted behavior.

When target > current it behaves as if written:

 int advance(int target) {
   int doc;
   while ((doc = nextDoc()) < target) {
   }
   return doc;
 }
 

Some implementations are considerably more efficient than that.

NOTE: this method may be called with DocIdSetIterator.NO_MORE_DOCS for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

Specified by:

advance in class DocIdSetIterator

nextDoc

public int nextDoc()
            throws IOException

Description copied from class: DocIdSetIterator

Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.
NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.

Specified by:

nextDoc in class DocIdSetIterator

Throws:

IOException

cost

public long cost()

Description copied from class: DocIdSetIterator

Returns the estimated cost of this DocIdSetIterator.

This is generally an upper bound of the number of documents this iterator might match, but may be a rough heuristic, hardcoded value, or otherwise completely inaccurate.

Specified by:

cost in class DocIdSetIterator