Package org.apache.lucene.search

Class CachingWrapperFilter

  • public class CachingWrapperFilter
extends Filter
    Wraps another Filter's result and caches it. The purpose is to allow filters to simply filter, and then wrap with this class to add caching.

    • Constructor Detail

      • CachingWrapperFilter

        public CachingWrapperFilter​(Filter filter)
        Wraps another filter's result and caches it.
        Parameters:
        filter - Filter to cache results of

    • Method Detail

      • getFilter

        public Filter getFilter()
        Gets the contained filter.
        Returns:
        the contained filter.

      • getDocIdSet

        public DocIdSet getDocIdSet​(AtomicReaderContext context,
                            Bits acceptDocs)
                     throws java.io.IOException
        Description copied from class: Filter
        Creates a DocIdSet enumerating the documents that should be permitted in search results. NOTE: null can be returned if no documents are accepted by this Filter.

        Note: This method will be called once per segment in the index during searching. The returned DocIdSet must refer to document IDs for that segment, not for the top-level reader.

        Specified by:
        getDocIdSet in class Filter
        Parameters:
        context - a AtomicReaderContext instance opened on the index currently searched on. Note, it is likely that the provided reader info does not represent the whole underlying index i.e. if the index has more than one segment the given reader only represents a single segment. The provided context is always an atomic context, so you can call AtomicReader.fields() on the context's reader, for example.
        acceptDocs - Bits that represent the allowable docs to match (typically deleted docs but possibly filtering other documents)
        Returns:
        a DocIdSet that provides the documents which should be permitted or prohibited in search results. NOTE: null should be returned if the filter doesn't accept any documents otherwise internal optimization might not apply in the case an empty DocIdSet is returned.
        Throws:
        java.io.IOException

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • equals

        public boolean equals​(java.lang.Object o)
        Overrides:
        equals in class java.lang.Object

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • sizeInBytes

        public long sizeInBytes()
        Returns total byte size used by cached filters.