+++ /dev/null
-package org.apache.lucene.facet.search;
-
-import java.io.IOException;
-import java.util.List;
-
-import org.apache.lucene.index.IndexReader;
-
-import org.apache.lucene.facet.search.params.FacetSearchParams;
-import org.apache.lucene.facet.search.params.FacetRequest;
-import org.apache.lucene.facet.search.results.FacetResult;
-import org.apache.lucene.facet.taxonomy.TaxonomyReader;
-
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/**
- * Driver for Accumulating facets of faceted search requests over given
- * documents.
- *
- * @lucene.experimental
- */
-public abstract class FacetsAccumulator {
-
- /**
- * Default threshold for using the complements optimization.
- * If accumulating facets for a document set larger than this ratio of the index size than
- * perform the complement optimization.
- * @see #setComplementThreshold(double) for more info on the complements optimization.
- */
- public static final double DEFAULT_COMPLEMENT_THRESHOLD = 0.6;
-
- /**
- * Passing this to {@link #setComplementThreshold(double)} will disable using complement optimization.
- */
- public static final double DISABLE_COMPLEMENT = Double.POSITIVE_INFINITY; // > 1 actually
-
- /**
- * Passing this to {@link #setComplementThreshold(double)} will force using complement optimization.
- */
- public static final double FORCE_COMPLEMENT = 0; // <=0
-
- private double complementThreshold = DEFAULT_COMPLEMENT_THRESHOLD;
-
- protected final TaxonomyReader taxonomyReader;
- protected final IndexReader indexReader;
- protected FacetSearchParams searchParams;
-
- private boolean allowLabeling = true;
-
- public FacetsAccumulator(FacetSearchParams searchParams,
- IndexReader indexReader,
- TaxonomyReader taxonomyReader) {
- this.indexReader = indexReader;
- this.taxonomyReader = taxonomyReader;
- this.searchParams = searchParams;
- }
-
- /**
- * Accumulate facets over given documents, according to facet requests in effect.
- * @param docids documents (and their scores) for which facets are Accumulated.
- * @return Accumulated facets.
- * @throws IOException on error.
- */
- // internal API note: it was considered to move the docids into the constructor as well,
- // but this prevents nice extension capabilities, especially in the way that
- // Sampling Accumulator works with the (any) delegated accumulator.
- public abstract List<FacetResult> accumulate(ScoredDocIDs docids) throws IOException;
-
- /**
- * @return the complement threshold
- * @see #setComplementThreshold(double)
- */
- public double getComplementThreshold() {
- return complementThreshold;
- }
-
- /**
- * Set the complement threshold.
- * This threshold will dictate whether the complements optimization is applied.
- * The optimization is to count for less documents. It is useful when the same
- * FacetSearchParams are used for varying sets of documents. The first time
- * complements is used the "total counts" are computed - counting for all the
- * documents in the collection. Then, only the complementing set of documents
- * is considered, and used to decrement from the overall counts, thereby
- * walking through less documents, which is faster.
- * <p>
- * Note that this optimization is only available when searching an index
- * whose {@link IndexReader} implements both
- * {@link IndexReader#directory()} and {@link IndexReader#getVersion()}
- * otherwise the optimization is silently disabled regardless of
- * the complement threshold settings.
- * <p>
- * For the default settings see {@link #DEFAULT_COMPLEMENT_THRESHOLD}.
- * <p>
- * To forcing complements in all cases pass {@link #FORCE_COMPLEMENT}.
- * This is mostly useful for testing purposes, as forcing complements when only
- * tiny fraction of available documents match the query does not make sense and
- * would incur performance degradations.
- * <p>
- * To disable complements pass {@link #DISABLE_COMPLEMENT}.
- * @param complementThreshold the complement threshold to set
- */
- public void setComplementThreshold(double complementThreshold) {
- this.complementThreshold = complementThreshold;
- }
-
- /**
- * Check if labeling is allowed for this accumulator.
- * <p>
- * By default labeling is allowed.
- * This allows one accumulator to invoke other accumulators for accumulation
- * but keep to itself the responsibility of labeling.
- * This might br handy since labeling is a costly operation.
- * @return true of labeling is allowed for this accumulator
- * @see #setAllowLabeling(boolean)
- */
- protected boolean isAllowLabeling() {
- return allowLabeling;
- }
-
- /**
- * Set whether labeling is allowed for this accumulator.
- * @param allowLabeling new setting for allow labeling
- * @see #isAllowLabeling()
- */
- protected void setAllowLabeling(boolean allowLabeling) {
- this.allowLabeling = allowLabeling;
- }
-
- /** check if all requests are complementable */
- protected boolean mayComplement() {
- for (FacetRequest freq:searchParams.getFacetRequests()) {
- if (!freq.supportsComplements()) {
- return false;
- }
- }
- return true;
- }
-}
\ No newline at end of file
fnp / pylucene.git / blobdiff