Class TokenStreamFromTermVector
- All Implemented Interfaces:
Closeable
,AutoCloseable
reset()
, so there's no need to wrap with a
caching impl.
The implementation will create an array of tokens indexed by token position. As long as there aren't massive jumps in positions, this is fine. And it assumes there aren't large numbers of tokens at the same position, since it adds them to a linked-list per position in O(N^2) complexity. When there aren't positions in the term vector, it divides the startOffset by 8 to use as a temporary substitute. In that case, tokens with the same startOffset will occupy the same final position; otherwise tokens become adjacent.
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Nested Class Summary
Nested ClassesNested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate boolean
private final int
private OffsetAttribute
private PayloadAttribute
private BytesRefArray
private final PositionIncrementAttribute
private BytesRefBuilder
private final CharTermAttribute
private CharsRefBuilder
private final Terms
Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token.private void
init()
private TokenStreamFromTermVector.TokenLL[]
void
reset()
This method is called by a consumer before it begins consumption usingTokenStream.incrementToken()
.Methods inherited from class org.apache.lucene.analysis.TokenStream
close, end
Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
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Field Details
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vector
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termAttribute
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positionIncrementAttribute
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maxStartOffset
private final int maxStartOffset -
offsetAttribute
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payloadAttribute
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termCharsBuilder
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payloadsBytesRefArray
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spareBytesRefBuilder
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firstToken
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incrementToken
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initialized
private boolean initialized
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Constructor Details
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TokenStreamFromTermVector
Constructor. The uninversion doesn't happen here; it's delayed till the first call toincrementToken
.- Parameters:
vector
- Terms that contains the data for creating the TokenStream. Must have positions and/or offsets.maxStartOffset
- if a token's start offset exceeds this then the token is not added. -1 disables the limit.- Throws:
IOException
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Method Details
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getTermVectorTerms
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reset
Description copied from class:TokenStream
This method is called by a consumer before it begins consumption usingTokenStream.incrementToken()
.Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.
If you override this method, always call
super.reset()
, otherwise some internal state will not be correctly reset (e.g.,Tokenizer
will throwIllegalStateException
on further usage).- Overrides:
reset
in classTokenStream
- Throws:
IOException
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init
- Throws:
IOException
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initTokensArray
- Throws:
IOException
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incrementToken
Description copied from class:TokenStream
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriateAttributeImpl
s with the attributes of the next token.The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
andAttributeSource.getAttribute(Class)
, references to allAttributeImpl
s that this stream uses should be retrieved during instantiation.To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in
TokenStream.incrementToken()
.- Specified by:
incrementToken
in classTokenStream
- Returns:
- false for end of stream; true otherwise
- Throws:
IOException
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