| /* |
| * 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. |
| */ |
| package org.apache.solr.search.similarities; |
| |
| import org.apache.lucene.misc.SweetSpotSimilarity; |
| import org.apache.lucene.search.similarities.ClassicSimilarity; // jdoc |
| import org.apache.lucene.search.similarities.Similarity; |
| import org.apache.solr.common.params.SolrParams; |
| import org.apache.solr.common.SolrException; |
| import static org.apache.solr.common.SolrException.ErrorCode.*; |
| /** |
| * <p>Factory for {@link SweetSpotSimilarity}.</p> |
| * <p> |
| * <code>SweetSpotSimilarity</code> is an extension of |
| * {@link ClassicSimilarity} that provides additional tuning options for |
| * specifying the "sweetspot" of optimal <code>tf</code> and |
| * <code>lengthNorm</code> values in the source data. |
| * </p> |
| * <p> |
| * In addition to the <code>discountOverlaps</code> init param supported by |
| * {@link ClassicSimilarityFactory} The following sets of init params are |
| * supported by this factory: |
| * </p> |
| * <ul> |
| * <li>Length Norm Settings: <ul> |
| * <li><code>lengthNormMin</code> (int)</li> |
| * <li><code>lengthNormMax</code> (int)</li> |
| * <li><code>lengthNormSteepness</code> (float)</li> |
| * </ul></li> |
| * <li>Baseline TF Settings: <ul> |
| * <li><code>baselineTfBase</code> (float)</li> |
| * <li><code>baselineTfMin</code> (float)</li> |
| * </ul></li> |
| * <li>Hyperbolic TF Settings: <ul> |
| * <li><code>hyperbolicTfMin</code> (float)</li> |
| * <li><code>hyperbolicTfMax</code> (float)</li> |
| * <li><code>hyperbolicTfBase</code> (double)</li> |
| * <li><code>hyperbolicTfOffset</code> (float)</li> |
| * </ul></li> |
| * </ul> |
| * <p> |
| * Note: |
| * </p> |
| * <ul> |
| * <li>If any individual settings from one of the above mentioned sets |
| * are specified, then all settings from that set must be specified. |
| * </li> |
| * <li>If Baseline TF settings are specified, then Hyperbolic TF settings |
| * are not permitted, and vice versa. (The settings specified will |
| * determine whether {@link SweetSpotSimilarity#baselineTf} or |
| * {@link SweetSpotSimilarity#hyperbolicTf} will be used. |
| * </li> |
| * </ul> |
| * <p> |
| * Example usage... |
| * </p> |
| * <pre class="prettyprint"> |
| * <!-- using baseline TF --> |
| * <fieldType name="text_baseline" class="solr.TextField" |
| * indexed="true" stored="false"> |
| * <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/> |
| * <similarity class="solr.SweetSpotSimilarityFactory"> |
| * <!-- TF --> |
| * <float name="baselineTfMin">6.0</float> |
| * <float name="baselineTfBase">1.5</float> |
| * <!-- plateau norm --> |
| * <int name="lengthNormMin">3</int> |
| * <int name="lengthNormMax">5</int> |
| * <float name="lengthNormSteepness">0.5</float> |
| * </similarity> |
| * </fieldType> |
| * |
| * <!-- using hyperbolic TF --> |
| * <fieldType name="text_hyperbolic" class="solr.TextField" |
| * indexed="true" stored="false" > |
| * <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/> |
| * <similarity class="solr.SweetSpotSimilarityFactory"> |
| * <float name="hyperbolicTfMin">3.3</float> |
| * <float name="hyperbolicTfMax">7.7</float> |
| * <double name="hyperbolicTfBase">2.718281828459045</double> <!-- e --> |
| * <float name="hyperbolicTfOffset">5.0</float> |
| * <!-- plateau norm, shallower slope --> |
| * <int name="lengthNormMin">1</int> |
| * <int name="lengthNormMax">5</int> |
| * <float name="lengthNormSteepness">0.2</float> |
| * </similarity> |
| * </fieldType> |
| * </pre> |
| * @see SweetSpotSimilarity The javadocs for the individual methods in |
| * <code>SweetSpotSimilarity</code> for SVG diagrams showing how the |
| * each function behaves with various settings/inputs. |
| */ |
| public class SweetSpotSimilarityFactory extends ClassicSimilarityFactory { |
| private SweetSpotSimilarity sim = null; |
| |
| @Override |
| public void init(SolrParams params) { |
| super.init(params); |
| |
| Integer ln_min = params.getInt("lengthNormMin"); |
| Integer ln_max = params.getInt("lengthNormMax"); |
| Float ln_steep = params.getFloat("lengthNormSteepness"); |
| if (! allOrNoneNull(ln_min, ln_max, ln_steep)) { |
| throw new SolrException(SERVER_ERROR, "Overriding default lengthNorm settings requires all to be specified: lengthNormMin, lengthNormMax, lengthNormSteepness"); |
| } |
| |
| Float hyper_min = params.getFloat("hyperbolicTfMin"); |
| Float hyper_max = params.getFloat("hyperbolicTfMax"); |
| Double hyper_base = params.getDouble("hyperbolicTfBase"); |
| Float hyper_offset = params.getFloat("hyperbolicTfOffset"); |
| if (! allOrNoneNull(hyper_min, hyper_max, hyper_base, hyper_offset)) { |
| throw new SolrException(SERVER_ERROR, "Overriding default hyperbolicTf settings requires all to be specified: hyperbolicTfMin, hyperbolicTfMax, hyperbolicTfBase, hyperbolicTfOffset"); |
| } |
| |
| Float baseline_base = params.getFloat("baselineTfBase"); |
| Float baseline_min = params.getFloat("baselineTfMin"); |
| if (! allOrNoneNull(baseline_min, baseline_base)) { |
| throw new SolrException(SERVER_ERROR, "Overriding default baselineTf settings requires all to be specified: baselineTfBase, baselineTfMin"); |
| } |
| |
| // sanity check that they aren't trying to use two diff tf impls |
| if ((null != hyper_min) && (null != baseline_min)) { |
| throw new SolrException(SERVER_ERROR, "Can not mix hyperbolicTf settings with baselineTf settings"); |
| } |
| |
| // pick Similarity impl based on whether hyper tf settings are set |
| sim = (null != hyper_min) ? new HyperbolicSweetSpotSimilarity() |
| : new SweetSpotSimilarity(); |
| |
| if (null != ln_min) { |
| // overlaps already handled by super factory |
| sim.setLengthNormFactors(ln_min, ln_max, ln_steep, this.discountOverlaps); |
| } |
| |
| if (null != hyper_min) { |
| sim.setHyperbolicTfFactors(hyper_min, hyper_max, hyper_base, hyper_offset); |
| } |
| |
| if (null != baseline_min) { |
| sim.setBaselineTfFactors(baseline_base, baseline_min); |
| } |
| } |
| |
| @Override |
| public Similarity getSimilarity() { |
| assert sim != null : "SweetSpotSimilarityFactory was not initialized"; |
| return sim; |
| } |
| |
| /** |
| * Returns true if either: all of the specified arguments are null; |
| * or none of the specified arguments are null |
| */ |
| private static boolean allOrNoneNull(Object... args) { |
| int nulls = 0; |
| int objs = 0; |
| for (Object o : args) { |
| objs++; |
| if (null == o) nulls++; |
| } |
| return (0 == nulls || nulls == objs); |
| } |
| |
| private static final class HyperbolicSweetSpotSimilarity |
| extends SweetSpotSimilarity { |
| @Override |
| public float tf(float freq) { |
| return hyperbolicTf(freq); |
| } |
| } |
| } |
