Package org.apache.lucene.index
Class SlowCompositeReaderWrapper
java.lang.Object
org.apache.lucene.index.IndexReader
org.apache.lucene.index.AtomicReader
org.apache.lucene.index.SlowCompositeReaderWrapper
- All Implemented Interfaces:
Closeable
,AutoCloseable
This class forces a composite reader (eg a
MultiReader
or DirectoryReader
) to emulate an
atomic reader. This requires implementing the postings
APIs on-the-fly, using the static methods in MultiFields
, MultiDocValues
, by stepping through
the sub-readers to merge fields/terms, appending docs, etc.
NOTE: this class almost always results in a
performance hit. If this is important to your use case,
you'll get better performance by gathering the sub readers using
IndexReader.getContext()
to get the
atomic leaves and then operate per-AtomicReader,
instead of using this class.
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.index.IndexReader
IndexReader.ReaderClosedListener
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Method Summary
Modifier and TypeMethodDescriptionprotected void
doClose()
Implements close.void
document
(int docID, StoredFieldVisitor visitor) Expert: visits the fields of a stored document, for custom processing/loading of each field.fields()
ReturnsFields
for this reader.getBinaryDocValues
(String field) ReturnsBinaryDocValues
for this field, or null if noBinaryDocValues
were indexed for this field.Expert: Returns a key for this IndexReader that also includes deletions, so FieldCache/CachingWrapperFilter can find it again.Expert: Returns a key for this IndexReader, so FieldCache/CachingWrapperFilter can find it again.getDocsWithField
(String field) Returns aBits
at the size ofreader.maxDoc()
, with turned on bits for each docid that does have a value for this field, or null if no DocValues were indexed for this field.Get theFieldInfos
describing all fields in this reader.Returns theBits
representing live (not deleted) docs.getNormValues
(String field) ReturnsNumericDocValues
representing norms for this field, or null if noNumericDocValues
were indexed.getNumericDocValues
(String field) ReturnsNumericDocValues
for this field, or null if noNumericDocValues
were indexed for this field.getSortedDocValues
(String field) ReturnsSortedDocValues
for this field, or null if noSortedDocValues
were indexed for this field.getSortedSetDocValues
(String field) ReturnsSortedSetDocValues
for this field, or null if noSortedSetDocValues
were indexed for this field.getTermVectors
(int docID) Retrieve term vectors for this document, or null if term vectors were not indexed.int
maxDoc()
Returns one greater than the largest possible document number.int
numDocs()
Returns the number of documents in this index.toString()
static AtomicReader
wrap
(IndexReader reader) This method is sugar for getting anAtomicReader
from anIndexReader
of any kind.Methods inherited from class org.apache.lucene.index.AtomicReader
docFreq, getContext, getDocCount, getSumDocFreq, getSumTotalTermFreq, hasNorms, termDocsEnum, termPositionsEnum, terms, totalTermFreq
Methods inherited from class org.apache.lucene.index.IndexReader
addReaderClosedListener, close, decRef, document, document, ensureOpen, equals, getRefCount, getTermVector, hasDeletions, hashCode, incRef, leaves, numDeletedDocs, open, open, open, open, open, registerParentReader, removeReaderClosedListener, tryIncRef
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Method Details
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wrap
This method is sugar for getting anAtomicReader
from anIndexReader
of any kind. If the reader is already atomic, it is returned unchanged, otherwise wrapped by this class.- Throws:
IOException
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toString
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fields
Description copied from class:AtomicReader
ReturnsFields
for this reader. This method may return null if the reader has no postings.- Specified by:
fields
in classAtomicReader
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getNumericDocValues
Description copied from class:AtomicReader
ReturnsNumericDocValues
for this field, or null if noNumericDocValues
were indexed for this field. The returned instance should only be used by a single thread.- Specified by:
getNumericDocValues
in classAtomicReader
- Throws:
IOException
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getDocsWithField
Description copied from class:AtomicReader
Returns aBits
at the size ofreader.maxDoc()
, with turned on bits for each docid that does have a value for this field, or null if no DocValues were indexed for this field. The returned instance should only be used by a single thread- Specified by:
getDocsWithField
in classAtomicReader
- Throws:
IOException
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getBinaryDocValues
Description copied from class:AtomicReader
ReturnsBinaryDocValues
for this field, or null if noBinaryDocValues
were indexed for this field. The returned instance should only be used by a single thread.- Specified by:
getBinaryDocValues
in classAtomicReader
- Throws:
IOException
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getSortedDocValues
Description copied from class:AtomicReader
ReturnsSortedDocValues
for this field, or null if noSortedDocValues
were indexed for this field. The returned instance should only be used by a single thread.- Specified by:
getSortedDocValues
in classAtomicReader
- Throws:
IOException
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getSortedSetDocValues
Description copied from class:AtomicReader
ReturnsSortedSetDocValues
for this field, or null if noSortedSetDocValues
were indexed for this field. The returned instance should only be used by a single thread.- Specified by:
getSortedSetDocValues
in classAtomicReader
- Throws:
IOException
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getNormValues
Description copied from class:AtomicReader
ReturnsNumericDocValues
representing norms for this field, or null if noNumericDocValues
were indexed. The returned instance should only be used by a single thread.- Specified by:
getNormValues
in classAtomicReader
- Throws:
IOException
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getTermVectors
Description copied from class:IndexReader
Retrieve term vectors for this document, or null if term vectors were not indexed. The returned Fields instance acts like a single-document inverted index (the docID will be 0).- Specified by:
getTermVectors
in classIndexReader
- Throws:
IOException
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numDocs
public int numDocs()Description copied from class:IndexReader
Returns the number of documents in this index.- Specified by:
numDocs
in classIndexReader
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maxDoc
public int maxDoc()Description copied from class:IndexReader
Returns one greater than the largest possible document number. This may be used to, e.g., determine how big to allocate an array which will have an element for every document number in an index.- Specified by:
maxDoc
in classIndexReader
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document
Description copied from class:IndexReader
Expert: visits the fields of a stored document, for custom processing/loading of each field. If you simply want to load all fields, useIndexReader.document(int)
. If you want to load a subset, useDocumentStoredFieldVisitor
.- Specified by:
document
in classIndexReader
- Throws:
IOException
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getLiveDocs
Description copied from class:AtomicReader
Returns theBits
representing live (not deleted) docs. A set bit indicates the doc ID has not been deleted. If this method returns null it means there are no deleted documents (all documents are live). The returned instance has been safely published for use by multiple threads without additional synchronization.- Specified by:
getLiveDocs
in classAtomicReader
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getFieldInfos
Description copied from class:AtomicReader
Get theFieldInfos
describing all fields in this reader.- Specified by:
getFieldInfos
in classAtomicReader
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getCoreCacheKey
Description copied from class:IndexReader
Expert: Returns a key for this IndexReader, so FieldCache/CachingWrapperFilter can find it again. This key must not have equals()/hashCode() methods, so "equals" means "identical".- Overrides:
getCoreCacheKey
in classIndexReader
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getCombinedCoreAndDeletesKey
Description copied from class:IndexReader
Expert: Returns a key for this IndexReader that also includes deletions, so FieldCache/CachingWrapperFilter can find it again. This key must not have equals()/hashCode() methods, so "equals" means "identical".- Overrides:
getCombinedCoreAndDeletesKey
in classIndexReader
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doClose
Description copied from class:IndexReader
Implements close.- Specified by:
doClose
in classIndexReader
- Throws:
IOException
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