public final class TokenStreamFromTermVector extends TokenStream
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.
AttributeSource.State| Modifier and Type | Field and Description |
|---|---|
static AttributeFactory |
ATTRIBUTE_FACTORY |
DEFAULT_TOKEN_ATTRIBUTE_FACTORY| Constructor and Description |
|---|
TokenStreamFromTermVector(Terms vector,
int maxStartOffset)
Constructor.
|
| Modifier and Type | Method and Description |
|---|---|
Terms |
getTermVectorTerms() |
boolean |
incrementToken()
Consumers (i.e.,
IndexWriter) use this method to advance the stream to
the next token. |
void |
reset()
This method is called by a consumer before it begins consumption using
TokenStream.incrementToken(). |
close, endaddAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toStringpublic static final AttributeFactory ATTRIBUTE_FACTORY
public TokenStreamFromTermVector(Terms vector, int maxStartOffset) throws IOException
incrementToken.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.IOExceptionpublic Terms getTermVectorTerms()
public void reset() throws IOException
TokenStreamTokenStream.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
throw IllegalStateException on further usage).
reset in class TokenStreamIOExceptionpublic boolean incrementToken() throws IOException
TokenStreamIndexWriter) use this method to advance the stream to
the next token. Implementing classes must implement this method and update
the appropriate AttributeImpls 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) and AttributeSource.getAttribute(Class),
references to all AttributeImpls 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().
incrementToken in class TokenStreamIOException