org.apache.lucene.search.function
public abstract class FieldCacheSource extends ValueSource
FieldCache
.
Fields used herein nust be indexed (doesn't matter if these fields are stored or not).
It is assumed that each such indexed field is untokenized, or at least has a single token in a document. For documents with multiple tokens of the same field, behavior is undefined (It is likely that current code would use the value of one of these tokens, but this is not guaranteed).
Document with no tokens in this field are assigned the Zero
value.
WARNING: The status of the search.function package is experimental. The APIs introduced here might change in the future and will not be supported anymore in such a case.
Constructor Summary | |
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FieldCacheSource(String field)
Create a cached field source for the input field. |
Method Summary | |
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abstract boolean | cachedFieldSourceEquals(FieldCacheSource other)
Check if equals to another FieldCacheSource, already knowing that cache and field are equal. |
abstract int | cachedFieldSourceHashCode()
Return a hash code of a FieldCacheSource, without the hash-codes of the field
and the cache (those are taken care of elsewhere). |
String | description() |
boolean | equals(Object o) |
abstract DocValues | getCachedFieldValues(FieldCache cache, String field, IndexReader reader)
Return cached DocValues for input field and reader. |
DocValues | getValues(IndexReader reader) |
int | hashCode() |
See Also: Object#equals(java.lang.Object)
See Also: Object#hashCode()
Parameters: cache FieldCache so that values of a field are loaded once per reader (RAM allowing) field Field for which values are required.
See Also: ValueSource