SOLR-2754: add similarity factories for new ranking algorithms

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1173776 13f79535-47bb-0310-9956-ffa450edef68

lucene/src/java/org/apache/lucene/search/similarities/BM25Similarity.java

@@ -336,4 +336,12 @@ public class BM25Similarity extends Similarity {
   public String toString() {
     return "BM25(k1=" + k1 + ",b=" + b + ")";
   }
+  
+  public float getK1() {
+    return k1;
+  }
+  
+  public float getB() {
+    return b;
+  }
 }

lucene/src/java/org/apache/lucene/search/similarities/DFRSimilarity.java

@@ -83,4 +83,16 @@ public class DFRSimilarity extends SimilarityBase {
     return "DFR " + basicModel.toString() + afterEffect.toString()
                   + normalization.toString();
   }
+  
+  public BasicModel getBasicModel() {
+    return basicModel;
+  }
+  
+  public AfterEffect getAfterEffect() {
+    return afterEffect;
+  }
+  
+  public Normalization getNormalization() {
+    return normalization;
+  }
 }

lucene/src/java/org/apache/lucene/search/similarities/IBSimilarity.java

@@ -91,4 +91,16 @@ public class IBSimilarity extends SimilarityBase {
     return "IB " + distribution.toString() + "-" + lambda.toString()
                  + normalization.toString();
   }
+  
+  public Distribution getDistribution() {
+    return distribution;
+  }
+  
+  public Lambda getLambda() {
+    return lambda;
+  }
+  
+  public Normalization getNormalization() {
+    return normalization;
+  }
 }

lucene/src/java/org/apache/lucene/search/similarities/NormalizationH3.java

@@ -41,4 +41,8 @@ public class NormalizationH3 extends Normalization {
   public String toString() {
     return "3(" + mu + ")";
   }
+  
+  public float getMu() {
+    return mu;
+  }
 }

lucene/src/java/org/apache/lucene/search/similarities/NormalizationZ.java

@@ -41,4 +41,8 @@ public class NormalizationZ extends Normalization {
   public String toString() {
     return "Z(" + z + ")";
   }
+  
+  public float getZ() {
+    return z;
+  }
 }

solr/CHANGES.txt

@@ -171,6 +171,13 @@ New Features
   
 * SOLR-2703: Added support for Lucene's "surround" query parser. (Simon Rosenthal, ehatcher)
 
+* SOLR-2754: Added factories for several ranking algorithms: 
+    BM25SimilarityFactory: Okapi BM25
+    DFRSimilarityFactory: Divergence from Randomness models
+    IBSimilarityFactory: Information-based models
+    LMDirichletSimilarity: LM with Dirichlet smoothing
+    LMJelinekMercerSimilarity: LM with Jelinek-Mercer smoothing
+ (David Mark Nemeskey, Robert Muir)
 
 Optimizations
 ----------------------

solr/core/src/java/org/apache/solr/schema/IndexSchema.java

@@ -470,7 +470,7 @@ public final class IndexSchema {
       };
       log.debug("using default similarityProvider");
     } else {
-      final Object obj = loader.newInstance(((Element) node).getAttribute("class"));
+      final Object obj = loader.newInstance(((Element) node).getAttribute("class"), "search.similarities.");
       // just like always, assume it's a SimilarityProviderFactory and get a ClassCastException - reasonable error handling
       // configure a factory, get a similarity back
       NamedList<?> args = DOMUtil.childNodesToNamedList(node);
@@ -714,7 +714,7 @@ public final class IndexSchema {
       return null;
     } else {
       SimilarityFactory similarityFactory;
-      final Object obj = loader.newInstance(((Element) node).getAttribute("class"));
+      final Object obj = loader.newInstance(((Element) node).getAttribute("class"), "search.similarities.");
       if (obj instanceof SimilarityFactory) {
         // configure a factory, get a similarity back
         SolrParams params = SolrParams.toSolrParams(DOMUtil.childNodesToNamedList(node));

solr/core/src/java/org/apache/solr/search/similarities/BM25SimilarityFactory.java

@@ -0,0 +1,62 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.BM25Similarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.schema.SimilarityFactory;
+
+/**
+ * Factory for {@link BM25Similarity}
+ * <p>
+ * Parameters:
+ * <ul>
+ *   <li>k1 (float): Controls non-linear term frequency normalization (saturation).
+ *                   The default is <code>1.2</code>
+ *   <li>b (float): Controls to what degree document length normalizes tf values.
+ *                  The default is <code>0.75</code>
+ * </ul>
+ * <p>
+ * Optional settings:
+ * <ul>
+ *   <li>discountOverlaps (bool): Sets
+ *       {@link BM25Similarity#setDiscountOverlaps(boolean)}</li>
+ * </ul>
+ * @lucene.experimental
+ */
+public class BM25SimilarityFactory extends SimilarityFactory {
+  private boolean discountOverlaps;
+  private float k1;
+  private float b;
+
+  @Override
+  public void init(SolrParams params) {
+    super.init(params);
+    discountOverlaps = params.getBool("discountOverlaps", true);
+    k1 = params.getFloat("k1", 1.2f);
+    b = params.getFloat("b", 0.75f);
+  }
+
+  @Override
+  public Similarity getSimilarity() {
+    BM25Similarity sim = new BM25Similarity(k1, b);
+    sim.setDiscountOverlaps(discountOverlaps);
+    return sim;
+  }
+}

solr/core/src/java/org/apache/solr/search/similarities/BasicSimilarityProviderFactory.java

@@ -0,0 +1,47 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.SimilarityProvider; // javadoc
+import org.apache.solr.schema.IndexSchema;
+import org.apache.solr.schema.SimilarityProviderFactory;
+import org.apache.solr.search.SolrSimilarityProvider;
+
+/**
+ * This class is aimed at non-VSM models, and therefore both the 
+ * {@link SimilarityProvider#coord} and
+ * {@link SimilarityProvider#queryNorm} methods return {@code 1}.
+ * @lucene.experimental
+ */
+public class BasicSimilarityProviderFactory extends SimilarityProviderFactory {
+
+  @Override
+  public SolrSimilarityProvider getSimilarityProvider(IndexSchema schema) {
+    return new SolrSimilarityProvider(schema) {
+      @Override
+      public float coord(int overlap, int maxOverlap) {
+        return 1f;
+      }
+
+      @Override
+      public float queryNorm(float sumOfSquaredWeights) {
+        return 1f;
+      }
+    };
+  }
+}

solr/core/src/java/org/apache/solr/search/similarities/DFRSimilarityFactory.java

@@ -0,0 +1,186 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.AfterEffect;
+import org.apache.lucene.search.similarities.AfterEffect.NoAfterEffect; // javadoc
+import org.apache.lucene.search.similarities.AfterEffectB;
+import org.apache.lucene.search.similarities.AfterEffectL;
+import org.apache.lucene.search.similarities.BasicModel;
+import org.apache.lucene.search.similarities.BasicModelBE;
+import org.apache.lucene.search.similarities.BasicModelD;
+import org.apache.lucene.search.similarities.BasicModelG;
+import org.apache.lucene.search.similarities.BasicModelIF;
+import org.apache.lucene.search.similarities.BasicModelIn;
+import org.apache.lucene.search.similarities.BasicModelIne;
+import org.apache.lucene.search.similarities.BasicModelP;
+import org.apache.lucene.search.similarities.DFRSimilarity;
+import org.apache.lucene.search.similarities.Normalization;
+import org.apache.lucene.search.similarities.Normalization.NoNormalization; // javadoc
+import org.apache.lucene.search.similarities.NormalizationH1;
+import org.apache.lucene.search.similarities.NormalizationH2;
+import org.apache.lucene.search.similarities.NormalizationH3;
+import org.apache.lucene.search.similarities.NormalizationZ;
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.schema.SimilarityFactory;
+
+/**
+ * Factory for {@link DFRSimilarity}
+ * <p>
+ * You must specify the implementations for all three components of
+ * DFR (strings). In general the models are parameter-free, but two of the
+ * normalizations take floating point parameters (see below):
+ * <ol>
+ *    <li>{@link BasicModel basicModel}: Basic model of information content:
+ *        <ul>
+ *           <li>{@link BasicModelBE Be}: Limiting form of Bose-Einstein
+ *           <li>{@link BasicModelG G}: Geometric approximation of Bose-Einstein
+ *           <li>{@link BasicModelP P}: Poisson approximation of the Binomial
+ *           <li>{@link BasicModelD D}: Divergence approximation of the Binomial 
+ *           <li>{@link BasicModelIn I(n)}: Inverse document frequency
+ *           <li>{@link BasicModelIne I(ne)}: Inverse expected document
+ *               frequency [mixture of Poisson and IDF]
+ *           <li>{@link BasicModelIF I(F)}: Inverse term frequency
+ *               [approximation of I(ne)]
+ *        </ul>
+ *    <li>{@link AfterEffect afterEffect}: First normalization of information
+ *        gain:
+ *        <ul>
+ *           <li>{@link AfterEffectL L}: Laplace's law of succession
+ *           <li>{@link AfterEffectB B}: Ratio of two Bernoulli processes
+ *           <li>{@link NoAfterEffect none}: no first normalization
+ *        </ul>
+ *    <li>{@link Normalization normalization}: Second (length) normalization:
+ *        <ul>
+ *           <li>{@link NormalizationH1 H1}: Uniform distribution of term
+ *               frequency
+ *           <li>{@link NormalizationH2 H2}: term frequency density inversely
+ *               related to length
+ *           <li>{@link NormalizationH3 H3}: term frequency normalization
+ *               provided by Dirichlet prior
+ *               <ul>
+ *                  <li>parameter mu (float): smoothing parameter &mu;. The
+ *                      default is <code>800</code>
+ *               </ul>
+ *           <li>{@link NormalizationZ Z}: term frequency normalization provided
+ *                by a Zipfian relation
+ *               <ul>
+ *                  <li>parameter z (float): represents <code>A/(A+1)</code>
+ *                      where A measures the specificity of the language.
+ *                      The default is <code>0.3</code>
+ *               </ul>
+ *           <li>{@link NoNormalization none}: no second normalization
+ *        </ul>
+ * </ol>
+ * <p>
+ * <p>
+ * Optional settings:
+ * <ul>
+ *   <li>discountOverlaps (bool): Sets
+ *       {@link DFRSimilarity#setDiscountOverlaps(boolean)}</li>
+ * </ul>
+ * @lucene.experimental
+ */
+public class DFRSimilarityFactory extends SimilarityFactory {
+  private boolean discountOverlaps;
+  private BasicModel basicModel;
+  private AfterEffect afterEffect;
+  private Normalization normalization;
+
+  @Override
+  public void init(SolrParams params) {
+    super.init(params);
+    discountOverlaps = params.getBool("discountOverlaps", true);
+    basicModel = parseBasicModel(params.get("basicModel"));
+    afterEffect = parseAfterEffect(params.get("afterEffect"));
+    normalization = parseNormalization(
+        params.get("normalization"), params.get("mu"), params.get("z"));
+  }
+  
+  private BasicModel parseBasicModel(String expr) {
+    if ("Be".equals(expr)) {
+      return new BasicModelBE();
+    } else if ("D".equals(expr)) {
+      return new BasicModelD();
+    } else if ("G".equals(expr)) {
+      return new BasicModelG();
+    } else if ("I(F)".equals(expr)) {
+      return new BasicModelIF();
+    } else if ("I(n)".equals(expr)) {
+      return new BasicModelIn();
+    } else if ("I(ne)".equals(expr)) {
+      return new BasicModelIne();
+    } else if ("P".equals(expr)) {
+      return new BasicModelP();
+    } else {
+      throw new RuntimeException("Invalid basicModel: " + expr);
+    }
+  }
+  
+  private AfterEffect parseAfterEffect(String expr) {
+    if ("B".equals(expr)) {
+      return new AfterEffectB();
+    } else if ("L".equals(expr)) {
+      return new AfterEffectL();
+    } else if ("none".equals(expr)) {
+      return new AfterEffect.NoAfterEffect();
+    } else {
+      throw new RuntimeException("Invalid afterEffect: " + expr);
+    }
+  }
+  
+  // also used by IBSimilarityFactory
+  static Normalization parseNormalization(String expr, String mu, String z) {
+    if (mu != null && z != null) {
+      throw new RuntimeException(
+          "specifying mu and z make no sense for: " + expr);
+    }
+    if (mu != null && !"H3".equals(expr)) {
+      throw new RuntimeException(
+          "parameter mu only makes sense for normalization H3");
+    }
+    if (z != null && !"Z".equals(expr)) {
+      throw new RuntimeException(
+          "parameter z only makes sense for normalization Z");
+    }
+    
+    if ("H1".equals(expr)) {
+      return new NormalizationH1();
+    } else if ("H2".equals(expr)) {
+      return new NormalizationH2();
+    } else if ("H3".equals(expr)) {
+      return (mu != null) ? new NormalizationH3(Float.parseFloat(mu))
+                          : new NormalizationH3();
+    } else if ("Z".equals(expr)) {
+      return (z != null) ? new NormalizationZ(Float.parseFloat(z))
+                         : new NormalizationZ();
+    } else if ("none".equals(expr)) {
+      return new Normalization.NoNormalization();
+    } else {
+      throw new RuntimeException("Invalid normalization: " + expr);
+    }
+  }
+
+  @Override
+  public Similarity getSimilarity() {
+    DFRSimilarity sim = new DFRSimilarity(basicModel, afterEffect, normalization);
+    sim.setDiscountOverlaps(discountOverlaps);
+    return sim;
+  }
+}

solr/core/src/java/org/apache/solr/search/similarities/DefaultSimilarityFactory.java

@@ -0,0 +1,55 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.DefaultSimilarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.lucene.search.similarities.TFIDFSimilarity; // javadoc
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.schema.SimilarityFactory;
+
+/**
+ * Factory for {@link DefaultSimilarity}
+ * <p>
+ * DefaultSimilarity is Lucene's default scoring implementation, based
+ * upon the Vector Space Model.
+ * <p>
+ * Optional settings:
+ * <ul>
+ *   <li>discountOverlaps (bool): Sets
+ *       {@link DefaultSimilarity#setDiscountOverlaps(boolean)}</li>
+ * </ul>
+ * @see TFIDFSimilarity
+ * @lucene.experimental
+ */
+public class DefaultSimilarityFactory extends SimilarityFactory {
+  private boolean discountOverlaps;
+
+  @Override
+  public void init(SolrParams params) {
+    super.init(params);
+    discountOverlaps = params.getBool("discountOverlaps", true);
+  }
+
+  @Override
+  public Similarity getSimilarity() {
+    DefaultSimilarity sim = new DefaultSimilarity();
+    sim.setDiscountOverlaps(discountOverlaps);
+    return sim;
+  }
+}

solr/core/src/java/org/apache/solr/search/similarities/IBSimilarityFactory.java

@@ -0,0 +1,111 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.Distribution;
+import org.apache.lucene.search.similarities.DistributionLL;
+import org.apache.lucene.search.similarities.DistributionSPL;
+import org.apache.lucene.search.similarities.IBSimilarity;
+import org.apache.lucene.search.similarities.Lambda;
+import org.apache.lucene.search.similarities.LambdaDF;
+import org.apache.lucene.search.similarities.LambdaTTF;
+import org.apache.lucene.search.similarities.Normalization;
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.schema.SimilarityFactory;
+import org.apache.solr.search.similarities.DFRSimilarityFactory; // javadoc
+
+/**
+ * Factory for {@link IBSimilarity}
+ * <p>
+ * You must specify the implementations for all three components of the
+ * Information-Based model (strings).
+ * <ol>
+ *     <li>{@link Distribution distribution}: Probabilistic distribution used to
+ *         model term occurrence
+ *         <ul>
+ *             <li>{@link DistributionLL LL}: Log-logistic</li>
+ *             <li>{@link DistributionLL SPL}: Smoothed power-law</li>
+ *         </ul>
+ *     </li>
+ *     <li>{@link Lambda lambda}: &lambda;<sub>w</sub> parameter of the
+ *         probability distribution
+ *         <ul>
+ *             <li>{@link LambdaDF DF}: <code>N<sub>w</sub>/N</code> or average
+ *                 number of documents where w occurs</li>
+ *             <li>{@link LambdaTTF TTF}: <code>F<sub>w</sub>/N</code> or
+ *                 average number of occurrences of w in the collection</li>
+ *         </ul>
+ *     </li>
+ *     <li>{@link Normalization normalization}: Term frequency normalization 
+ *         <blockquote>Any supported DFR normalization listed in
+                       {@link DFRSimilarityFactory}</blockquote>
+       </li>
+ * </ol>
+ * <p>
+ * Optional settings:
+ * <ul>
+ *   <li>discountOverlaps (bool): Sets
+ *       {@link IBSimilarity#setDiscountOverlaps(boolean)}</li>
+ * </ul>
+ * @lucene.experimental
+ */
+
+public class IBSimilarityFactory extends SimilarityFactory {
+  private boolean discountOverlaps;
+  private Distribution distribution;
+  private Lambda lambda;
+  private Normalization normalization;
+
+  @Override
+  public void init(SolrParams params) {
+    super.init(params);
+    discountOverlaps = params.getBool("discountOverlaps", true);
+    distribution = parseDistribution(params.get("distribution"));
+    lambda = parseLambda(params.get("lambda"));
+    normalization = DFRSimilarityFactory.parseNormalization(
+        params.get("normalization"), params.get("mu"), params.get("z"));
+  }
+  
+  private Distribution parseDistribution(String expr) {
+    if ("LL".equals(expr)) {
+      return new DistributionLL();
+    } else if ("SPL".equals(expr)) {
+      return new DistributionSPL();
+    } else {
+      throw new RuntimeException("Invalid distribution: " + expr);
+    }
+  }
+  
+  private Lambda parseLambda(String expr) {
+    if ("DF".equals(expr)) {
+      return new LambdaDF();
+    } else if ("TTF".equals(expr)) {
+      return new LambdaTTF();
+    } else {
+      throw new RuntimeException("Invalid lambda: " + expr);
+    }
+  }
+
+  @Override
+  public Similarity getSimilarity() {
+    IBSimilarity sim = new IBSimilarity(distribution, lambda, normalization);
+    sim.setDiscountOverlaps(discountOverlaps);
+    return sim;
+  }
+}

solr/core/src/java/org/apache/solr/search/similarities/LMDirichletSimilarityFactory.java

@@ -0,0 +1,60 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.LMDirichletSimilarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.schema.SimilarityFactory;
+
+/**
+ * Factory for {@link LMDirichletSimilarity}
+ * <p>
+ * Parameters:
+ * <ul>
+ *     <li>parameter mu (float): smoothing parameter &mu;. The default is
+ *         <code>2000</code></li>
+ * </ul>
+ * <p>
+ * Optional settings:
+ * <ul>
+ *   <li>discountOverlaps (bool): Sets
+ *       {@link LMDirichletSimilarity#setDiscountOverlaps(boolean)}</li>
+ * </ul>
+ * @lucene.experimental
+ */
+
+public class LMDirichletSimilarityFactory extends SimilarityFactory {
+  private boolean discountOverlaps;
+  private Float mu;
+
+  @Override
+  public void init(SolrParams params) {
+    super.init(params);
+    discountOverlaps = params.getBool("discountOverlaps", true);
+    mu = params.getFloat("mu");
+  }
+
+  @Override
+  public Similarity getSimilarity() {
+    LMDirichletSimilarity sim = (mu != null) ? new LMDirichletSimilarity(mu)
+                                             : new LMDirichletSimilarity();
+    sim.setDiscountOverlaps(discountOverlaps);
+    return sim;
+  }
+}

solr/core/src/java/org/apache/solr/search/similarities/LMJelinekMercerSimilarityFactory.java

@@ -0,0 +1,59 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.LMJelinekMercerSimilarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.schema.SimilarityFactory;
+
+/**
+ * Factory for {@link LMJelinekMercerSimilarity}
+ * <p>
+ * Parameters:
+ * <ul>
+ *     <li>parameter lambda (float): smoothing parameter &lambda;. The default
+ *         is <code>0.7</code></li>
+ * </ul>
+ * <p>
+ * Optional settings:
+ * <ul>
+ *   <li>discountOverlaps (bool): Sets
+ *       {@link LMJelinekMercerSimilarity#setDiscountOverlaps(boolean)}</li>
+ * </ul>
+ * @lucene.experimental
+ */
+
+public class LMJelinekMercerSimilarityFactory extends SimilarityFactory {
+  private boolean discountOverlaps;
+  private float lambda;
+
+  @Override
+  public void init(SolrParams params) {
+    super.init(params);
+    discountOverlaps = params.getBool("discountOverlaps", true);
+    lambda = params.getFloat("lambda", 0.7f);
+  }
+
+  @Override
+  public Similarity getSimilarity() {
+    LMJelinekMercerSimilarity sim = new LMJelinekMercerSimilarity(lambda);
+    sim.setDiscountOverlaps(discountOverlaps);
+    return sim;
+  }
+}

solr/core/src/test-files/solr/conf/schema-bm25.xml

@@ -0,0 +1,50 @@
+<?xml version="1.0" ?>
+<!--
+ 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.
+-->
+
+<!-- Test schema file for BM25SimilarityFactory -->
+
+<schema name="test" version="1.0">
+  <types>
+    <fieldType name="int" class="solr.TrieIntField" precisionStep="0" omitNorms="true" positionIncrementGap="0"/>
+    
+    <!-- default parameters -->
+    <fieldType name="text" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.BM25SimilarityFactory"/>
+    </fieldType>
+    
+    <!-- with parameters -->
+    <fieldType name="text_params" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.BM25SimilarityFactory">
+        <float name="k1">1.2</float>
+        <float name="b">0.76</float>
+      </similarity>
+    </fieldType>
+   
+  </types>
+
+  <fields>
+    <field name="id" type="int" indexed="true" stored="true" multiValued="false" required="false"/>
+    <field name="text" type="text" indexed="true" stored="false"/>
+    <field name="text_params" type="text_params" indexed="true" stored="false"/>
+  </fields>
+
+  <defaultSearchField>text</defaultSearchField>
+  <uniqueKey>id</uniqueKey>
+</schema>

solr/core/src/test-files/solr/conf/schema-dfr.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" ?>
+<!--
+ 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.
+-->
+
+<!-- Test schema file for DFRSimilarityFactory -->
+
+<schema name="test" version="1.0">
+  <types>
+    <fieldType name="int" class="solr.TrieIntField" precisionStep="0" omitNorms="true" positionIncrementGap="0"/>
+    
+    <!-- default parameters -->
+    <fieldType name="text" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.DFRSimilarityFactory">
+        <str name="basicModel">I(F)</str>
+        <str name="afterEffect">B</str>
+        <str name="normalization">H2</str>
+      </similarity>
+    </fieldType>
+    
+    <!-- with parameters -->
+    <fieldType name="text_params" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.DFRSimilarityFactory">
+        <str name="basicModel">I(F)</str>
+        <str name="afterEffect">B</str>
+        <str name="normalization">H3</str>
+        <float name="mu">900</float>
+      </similarity>
+    </fieldType>
+   
+  </types>
+
+  <fields>
+    <field name="id" type="int" indexed="true" stored="true" multiValued="false" required="false"/>
+    <field name="text" type="text" indexed="true" stored="false"/>
+    <field name="text_params" type="text_params" indexed="true" stored="false"/>
+  </fields>
+
+  <defaultSearchField>text</defaultSearchField>
+  <uniqueKey>id</uniqueKey>
+</schema>

solr/core/src/test-files/solr/conf/schema-ib.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" ?>
+<!--
+ 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.
+-->
+
+<!-- Test schema file for IBSimilarityFactory -->
+
+<schema name="test" version="1.0">
+  <types>
+    <fieldType name="int" class="solr.TrieIntField" precisionStep="0" omitNorms="true" positionIncrementGap="0"/>
+    
+    <!-- default parameters -->
+    <fieldType name="text" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.IBSimilarityFactory">
+        <str name="distribution">SPL</str>
+        <str name="lambda">DF</str>
+        <str name="normalization">H2</str>
+      </similarity>
+    </fieldType>
+    
+    <!-- with parameters -->
+    <fieldType name="text_params" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.IBSimilarityFactory">
+        <str name="distribution">LL</str>
+        <str name="lambda">TTF</str>
+        <str name="normalization">H3</str>
+        <float name="mu">900</float>
+      </similarity>
+    </fieldType>
+   
+  </types>
+
+  <fields>
+    <field name="id" type="int" indexed="true" stored="true" multiValued="false" required="false"/>
+    <field name="text" type="text" indexed="true" stored="false"/>
+    <field name="text_params" type="text_params" indexed="true" stored="false"/>
+  </fields>
+
+  <defaultSearchField>text</defaultSearchField>
+  <uniqueKey>id</uniqueKey>
+</schema>

solr/core/src/test-files/solr/conf/schema-lmdirichlet.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" ?>
+<!--
+ 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.
+-->
+
+<!-- Test schema file for LMDirichletSimilarityFactory -->
+
+<schema name="test" version="1.0">
+  <types>
+    <fieldType name="int" class="solr.TrieIntField" precisionStep="0" omitNorms="true" positionIncrementGap="0"/>
+    
+    <!-- default parameters -->
+    <fieldType name="text" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.LMDirichletSimilarityFactory"/>
+    </fieldType>
+    
+    <!-- with parameters -->
+    <fieldType name="text_params" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.LMDirichletSimilarityFactory">
+        <float name="mu">1000</float>
+      </similarity>
+    </fieldType>
+   
+  </types>
+
+  <fields>
+    <field name="id" type="int" indexed="true" stored="true" multiValued="false" required="false"/>
+    <field name="text" type="text" indexed="true" stored="false"/>
+    <field name="text_params" type="text_params" indexed="true" stored="false"/>
+  </fields>
+
+  <defaultSearchField>text</defaultSearchField>
+  <uniqueKey>id</uniqueKey>
+</schema>

solr/core/src/test-files/solr/conf/schema-lmjelinekmercer.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" ?>
+<!--
+ 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.
+-->
+
+<!-- Test schema file for LMJelinekMercerSimilarityFactory -->
+
+<schema name="test" version="1.0">
+  <types>
+    <fieldType name="int" class="solr.TrieIntField" precisionStep="0" omitNorms="true" positionIncrementGap="0"/>
+    
+    <!-- default parameters -->
+    <fieldType name="text" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.LMJelinekMercerSimilarityFactory"/>
+    </fieldType>
+    
+    <!-- with parameters -->
+    <fieldType name="text_params" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.LMJelinekMercerSimilarityFactory">
+        <float name="lambda">0.4</float>
+      </similarity>
+    </fieldType>
+   
+  </types>
+
+  <fields>
+    <field name="id" type="int" indexed="true" stored="true" multiValued="false" required="false"/>
+    <field name="text" type="text" indexed="true" stored="false"/>
+    <field name="text_params" type="text_params" indexed="true" stored="false"/>
+  </fields>
+
+  <defaultSearchField>text</defaultSearchField>
+  <uniqueKey>id</uniqueKey>
+</schema>

solr/core/src/test-files/solr/conf/schema-tfidf.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" ?>
+<!--
+ 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.
+-->
+
+<!-- Test schema file for DefaultSimilarityFactory -->
+
+<schema name="test" version="1.0">
+  <types>
+    <fieldType name="int" class="solr.TrieIntField" precisionStep="0" omitNorms="true" positionIncrementGap="0"/>
+
+    <!-- TF/IDF -->
+    <fieldType name="text" class="solr.TextField">
+      <analyzer class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
+      <similarity class="solr.DefaultSimilarityFactory"/>
+    </fieldType>
+   
+  </types>
+
+  <fields>
+    <field name="id" type="int" indexed="true" stored="true" multiValued="false" required="false"/>
+    <field name="text" type="text" indexed="true" stored="false"/>
+  </fields>
+
+  <defaultSearchField>text</defaultSearchField>
+  <uniqueKey>id</uniqueKey>
+</schema>

solr/core/src/test-files/solr/conf/schema.xml

@@ -406,7 +406,7 @@
     <analyzer>
       <tokenizer class="solr.WhitespaceTokenizerFactory"/>
     </analyzer>
-    <similarity class="org.apache.solr.schema.CustomSimilarityFactory">
+    <similarity class="solr.CustomSimilarityFactory">
       <str name="echo">is there an echo?</str>
     </similarity>
   </fieldType>
@@ -672,13 +672,13 @@
       A custom similarity provider may be specified here, but the default is fine
       for most applications.
  -->
- <similarityProvider class="org.apache.solr.schema.CustomSimilarityProviderFactory">
+ <similarityProvider class="solr.CustomSimilarityProviderFactory">
    <str name="echo">is there an echo?</str>
  </similarityProvider>
 
  <!-- default similarity, unless otherwise specified by the fieldType
   -->
- <similarity class="org.apache.solr.schema.CustomSimilarityFactory">
+ <similarity class="solr.CustomSimilarityFactory">
    <str name="echo">I am your default sim</str>
  </similarity>
 </schema>

solr/core/src/test-files/solr/conf/solrconfig-basic.xml

@@ -17,6 +17,8 @@
  limitations under the License.
 -->
 
+<!-- a basic solrconfig that tests can use when they want simple minimal solrconfig/schema
+     DO NOT ADD THINGS TO THIS CONFIG! -->
 <config>
   <luceneMatchVersion>${tests.luceneMatchVersion:LUCENE_CURRENT}</luceneMatchVersion>
   <requestHandler name="standard" class="solr.StandardRequestHandler"></requestHandler>

solr/core/src/test/org/apache/solr/schema/IndexSchemaTest.java

@@ -27,6 +27,7 @@ import org.apache.solr.common.params.MapSolrParams;
 import org.apache.solr.core.SolrCore;
 import org.apache.solr.request.LocalSolrQueryRequest;
 import org.apache.solr.request.SolrQueryRequest;
+import org.apache.solr.search.similarities.MockConfigurableSimilarityProvider;
 import org.apache.lucene.search.similarities.SimilarityProvider;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -79,14 +80,6 @@ public class IndexSchemaTest extends SolrTestCaseJ4 {
             );
     clearIndex();
   }
-
-  @Test
-  public void testSimilarityProviderFactory() {
-    SolrCore core = h.getCore();
-    SimilarityProvider similarityProvider = core.getSchema().getSimilarityProvider();
-    assertTrue("wrong class", similarityProvider instanceof MockConfigurableSimilarityProvider);
-    assertEquals("is there an echo?", ((MockConfigurableSimilarityProvider)similarityProvider).getPassthrough());
-  }
   
   @Test
   public void testRuntimeFieldCreation()

solr/core/src/test/org/apache/solr/schema/TestCollationField.java

@@ -73,7 +73,7 @@ public class TestCollationField extends SolrTestCaseJ4 {
     confDir.mkdir();
     
     // copy over configuration files
-    FileUtils.copyFile(getFile("solr/conf/solrconfig-collate.xml"), new File(confDir, "solrconfig.xml"));
+    FileUtils.copyFile(getFile("solr/conf/solrconfig-basic.xml"), new File(confDir, "solrconfig.xml"));
     FileUtils.copyFile(getFile("solr/conf/schema-collate.xml"), new File(confDir, "schema.xml"));
     
     // generate custom collation rules (DIN 5007-2), saving to customrules.dat

solr/core/src/test/org/apache/solr/search/similarities/BaseSimilarityTestCase.java

@@ -0,0 +1,46 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.lucene.search.similarities.SimilarityProvider;
+import org.apache.solr.SolrTestCaseJ4;
+import org.apache.solr.core.SolrCore;
+import org.apache.solr.search.SolrIndexSearcher;
+import org.apache.solr.util.RefCounted;
+
+public abstract class BaseSimilarityTestCase extends SolrTestCaseJ4 {
+
+  /** returns the similarity in use for the field */
+  protected Similarity getSimilarity(String field) {
+    SolrCore core = h.getCore();
+    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
+    Similarity sim = searcher.get().getSimilarityProvider().get(field);
+    searcher.decref();
+    return sim;
+  }
+  
+  /** returns the (Solr)SimilarityProvider */
+  protected SimilarityProvider getSimilarityProvider() {
+    SolrCore core = h.getCore();
+    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
+    SimilarityProvider prov = searcher.get().getSimilarityProvider();
+    searcher.decref();
+    return prov;
+  }
+}

solr/core/src/test/org/apache/solr/search/similarities/CustomSimilarityFactory.java

@@ -14,9 +14,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.solr.schema;
+package org.apache.solr.search.similarities;
 
 import org.apache.lucene.search.similarities.Similarity;
+import org.apache.solr.schema.SimilarityFactory;
 
 public class CustomSimilarityFactory extends SimilarityFactory {
   @Override

solr/core/src/test/org/apache/solr/search/similarities/CustomSimilarityProviderFactory.java

@@ -14,9 +14,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.solr.schema;
+package org.apache.solr.search.similarities;
 
 import org.apache.solr.common.util.NamedList;
+import org.apache.solr.schema.IndexSchema;
+import org.apache.solr.schema.SimilarityProviderFactory;
 import org.apache.solr.search.SolrSimilarityProvider;
 
 public class CustomSimilarityProviderFactory extends SimilarityProviderFactory {

solr/core/src/test/org/apache/solr/search/similarities/MockConfigurableSimilarity.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.solr.schema;
+package org.apache.solr.search.similarities;
 
 import org.apache.lucene.search.similarities.DefaultSimilarity;
 

solr/core/src/test/org/apache/solr/search/similarities/MockConfigurableSimilarityProvider.java

@@ -14,8 +14,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.solr.schema;
+package org.apache.solr.search.similarities;
 
+import org.apache.solr.schema.IndexSchema;
 import org.apache.solr.search.SolrSimilarityProvider;
 
 public class MockConfigurableSimilarityProvider extends SolrSimilarityProvider {

solr/core/src/test/org/apache/solr/search/similarities/TestBM25SimilarityFactory.java

@@ -0,0 +1,46 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.BM25Similarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.junit.BeforeClass;
+
+/**
+ * Tests {@link BM25SimilarityFactory}
+ */
+public class TestBM25SimilarityFactory extends BaseSimilarityTestCase {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig-basic.xml","schema-bm25.xml");
+  }
+  
+  /** bm25 with default parameters */
+  public void test() throws Exception {
+    assertEquals(BM25Similarity.class, getSimilarity("text").getClass());
+  }
+  
+  /** bm25 with parameters */
+  public void testParameters() throws Exception {
+    Similarity sim = getSimilarity("text_params");
+    assertEquals(BM25Similarity.class, sim.getClass());
+    BM25Similarity bm25 = (BM25Similarity) sim;
+    assertEquals(1.2f, bm25.getK1(), 0.01f);
+    assertEquals(0.76f, bm25.getB(), 0.01f);
+  }
+}

solr/core/src/test/org/apache/solr/search/similarities/TestDFRSimilarityFactory.java

@@ -0,0 +1,58 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.AfterEffectB;
+import org.apache.lucene.search.similarities.BasicModelIF;
+import org.apache.lucene.search.similarities.DFRSimilarity;
+import org.apache.lucene.search.similarities.NormalizationH2;
+import org.apache.lucene.search.similarities.NormalizationH3;
+import org.apache.lucene.search.similarities.Similarity;
+import org.junit.BeforeClass;
+
+/**
+ * Tests {@link DFRSimilarityFactory}
+ */
+public class TestDFRSimilarityFactory extends BaseSimilarityTestCase {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig-basic.xml","schema-dfr.xml");
+  }
+  
+  /** dfr with default parameters */
+  public void test() throws Exception {
+    Similarity sim = getSimilarity("text");
+    assertEquals(DFRSimilarity.class, sim.getClass());
+    DFRSimilarity dfr = (DFRSimilarity) sim;
+    assertEquals(BasicModelIF.class, dfr.getBasicModel().getClass());
+    assertEquals(AfterEffectB.class, dfr.getAfterEffect().getClass());
+    assertEquals(NormalizationH2.class, dfr.getNormalization().getClass());
+  }
+  
+  /** dfr with parameterized normalization */
+  public void testParameters() throws Exception {
+    Similarity sim = getSimilarity("text_params");
+    assertEquals(DFRSimilarity.class, sim.getClass());
+    DFRSimilarity dfr = (DFRSimilarity) sim;
+    assertEquals(BasicModelIF.class, dfr.getBasicModel().getClass());
+    assertEquals(AfterEffectB.class, dfr.getAfterEffect().getClass());
+    assertEquals(NormalizationH3.class, dfr.getNormalization().getClass());
+    NormalizationH3 norm = (NormalizationH3) dfr.getNormalization();
+    assertEquals(900f, norm.getMu(), 0.01f);
+  }
+}

solr/core/src/test/org/apache/solr/search/similarities/TestDefaultSimilarityFactory.java

@@ -0,0 +1,36 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.DefaultSimilarity;
+import org.junit.BeforeClass;
+
+/**
+ * Tests {@link DefaultSimilarityFactory}
+ */
+public class TestDefaultSimilarityFactory extends BaseSimilarityTestCase {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig-basic.xml","schema-tfidf.xml");
+  }
+  
+  /** default parameters */
+  public void test() throws Exception {
+    assertEquals(DefaultSimilarity.class, getSimilarity("text").getClass());
+  }
+}

solr/core/src/test/org/apache/solr/search/similarities/TestIBSimilarityFactory.java

@@ -0,0 +1,60 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.DistributionLL;
+import org.apache.lucene.search.similarities.DistributionSPL;
+import org.apache.lucene.search.similarities.IBSimilarity;
+import org.apache.lucene.search.similarities.LambdaDF;
+import org.apache.lucene.search.similarities.LambdaTTF;
+import org.apache.lucene.search.similarities.NormalizationH2;
+import org.apache.lucene.search.similarities.NormalizationH3;
+import org.apache.lucene.search.similarities.Similarity;
+import org.junit.BeforeClass;
+
+/**
+ * Tests {@link IBSimilarityFactory}
+ */
+public class TestIBSimilarityFactory extends BaseSimilarityTestCase {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig-basic.xml","schema-ib.xml");
+  }
+  
+  /** spl/df/h2 with default parameters */
+  public void test() throws Exception {
+    Similarity sim = getSimilarity("text");
+    assertEquals(IBSimilarity.class, sim.getClass());
+    IBSimilarity ib = (IBSimilarity) sim;
+    assertEquals(DistributionSPL.class, ib.getDistribution().getClass());
+    assertEquals(LambdaDF.class, ib.getLambda().getClass());
+    assertEquals(NormalizationH2.class, ib.getNormalization().getClass());
+  }
+  
+  /** ll/ttf/h3 with parameterized normalization */
+  public void testParameters() throws Exception {
+    Similarity sim = getSimilarity("text_params");
+    assertEquals(IBSimilarity.class, sim.getClass());
+    IBSimilarity ib = (IBSimilarity) sim;
+    assertEquals(DistributionLL.class, ib.getDistribution().getClass());
+    assertEquals(LambdaTTF.class, ib.getLambda().getClass());
+    assertEquals(NormalizationH3.class, ib.getNormalization().getClass());
+    NormalizationH3 norm = (NormalizationH3) ib.getNormalization();
+    assertEquals(900f, norm.getMu(), 0.01f);
+  }
+}

solr/core/src/test/org/apache/solr/search/similarities/TestLMDirichletSimilarityFactory.java

@@ -0,0 +1,45 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.LMDirichletSimilarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.junit.BeforeClass;
+
+/**
+ * Tests {@link LMDirichletSimilarityFactory}
+ */
+public class TestLMDirichletSimilarityFactory extends BaseSimilarityTestCase {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig-basic.xml","schema-lmdirichlet.xml");
+  }
+  
+  /** dirichlet with default parameters */
+  public void test() throws Exception {
+    assertEquals(LMDirichletSimilarity.class, getSimilarity("text").getClass());
+  }
+  
+  /** dirichlet with parameters */
+  public void testParameters() throws Exception {
+    Similarity sim = getSimilarity("text_params");
+    assertEquals(LMDirichletSimilarity.class, sim.getClass());
+    LMDirichletSimilarity lm = (LMDirichletSimilarity) sim;
+    assertEquals(1000f, lm.getMu(), 0.01f);
+  }
+}

solr/core/src/test/org/apache/solr/search/similarities/TestLMJelinekMercerSimilarityFactory.java

@@ -0,0 +1,45 @@
+package org.apache.solr.search.similarities;
+
+/**
+ * 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.
+ */
+
+import org.apache.lucene.search.similarities.LMJelinekMercerSimilarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.junit.BeforeClass;
+
+/**
+ * Tests {@link LMJelinekMercerSimilarityFactory}
+ */
+public class TestLMJelinekMercerSimilarityFactory extends BaseSimilarityTestCase {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig-basic.xml","schema-lmjelinekmercer.xml");
+  }
+  
+  /** jelinek-mercer with default parameters */
+  public void test() throws Exception {
+    assertEquals(LMJelinekMercerSimilarity.class, getSimilarity("text").getClass());
+  }
+  
+  /** jelinek-mercer with parameters */
+  public void testParameters() throws Exception {
+    Similarity sim = getSimilarity("text_params");
+    assertEquals(LMJelinekMercerSimilarity.class, sim.getClass());
+    LMJelinekMercerSimilarity lm = (LMJelinekMercerSimilarity) sim;
+    assertEquals(0.4f, lm.getLambda(), 0.01f);
+  }
+}

solr/core/src/test/org/apache/solr/search/similarities/TestPerFieldSimilarity.java

@@ -1,4 +1,4 @@
-package org.apache.solr.schema;
+package org.apache.solr.search.similarities;
 
 /**
  * Licensed to the Apache Software Foundation (ASF) under one or more
@@ -18,18 +18,16 @@ package org.apache.solr.schema;
  */
 
 import org.apache.lucene.misc.SweetSpotSimilarity;
-import org.apache.lucene.search.similarities.DefaultSimilarity;
 import org.apache.lucene.search.similarities.Similarity;
-import org.apache.solr.SolrTestCaseJ4;
+import org.apache.lucene.search.similarities.SimilarityProvider;
 import org.apache.solr.core.SolrCore;
-import org.apache.solr.search.SolrIndexSearcher;
-import org.apache.solr.util.RefCounted;
 import org.junit.BeforeClass;
+import org.junit.Test;
 
 /**
  * Tests per-field similarity support in the schema
  */
-public class TestPerFieldSimilarity extends SolrTestCaseJ4 {
+public class TestPerFieldSimilarity extends BaseSimilarityTestCase {
 
   @BeforeClass
   public static void beforeClass() throws Exception {
@@ -38,69 +36,54 @@ public class TestPerFieldSimilarity extends SolrTestCaseJ4 {
   
   /** test a field where the sim is specified directly */
   public void testDirect() throws Exception {
-    SolrCore core = h.getCore();
-    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
-    Similarity sim = searcher.get().getSimilarityProvider().get("sim1text");
-    assertEquals(SweetSpotSimilarity.class, sim.getClass());
-    searcher.decref();
+    assertEquals(SweetSpotSimilarity.class, getSimilarity("sim1text").getClass());
   }
   
   /** ... and for a dynamic field */
   public void testDirectDynamic() throws Exception {
-    SolrCore core = h.getCore();
-    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
-    Similarity sim = searcher.get().getSimilarityProvider().get("text_sim1");
-    assertEquals(SweetSpotSimilarity.class, sim.getClass());
-    searcher.decref();
+    assertEquals(SweetSpotSimilarity.class, getSimilarity("text_sim1").getClass());
   }
   
   /** test a field where a configurable sim factory is defined */
   public void testFactory() throws Exception {
-    SolrCore core = h.getCore();
-    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
-    Similarity sim = searcher.get().getSimilarityProvider().get("sim2text");
+    Similarity sim = getSimilarity("sim2text");
     assertEquals(MockConfigurableSimilarity.class, sim.getClass());
     assertEquals("is there an echo?", ((MockConfigurableSimilarity)sim).getPassthrough());
-    searcher.decref();
   }
   
   /** ... and for a dynamic field */
   public void testFactoryDynamic() throws Exception {
-    SolrCore core = h.getCore();
-    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
-    Similarity sim = searcher.get().getSimilarityProvider().get("text_sim2");
+    Similarity sim = getSimilarity("text_sim2");
     assertEquals(MockConfigurableSimilarity.class, sim.getClass());
     assertEquals("is there an echo?", ((MockConfigurableSimilarity)sim).getPassthrough());
-    searcher.decref();
   }
   
   /** test a field where no similarity is specified */
   public void testDefaults() throws Exception {
-    SolrCore core = h.getCore();
-    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
-    Similarity sim = searcher.get().getSimilarityProvider().get("sim3text");
+    Similarity sim = getSimilarity("sim3text");
     assertEquals(MockConfigurableSimilarity.class, sim.getClass());
     assertEquals("I am your default sim", ((MockConfigurableSimilarity)sim).getPassthrough());
-    searcher.decref();
   }
   
   /** ... and for a dynamic field */
   public void testDefaultsDynamic() throws Exception {
-    SolrCore core = h.getCore();
-    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
-    Similarity sim = searcher.get().getSimilarityProvider().get("text_sim3");
+    Similarity sim = getSimilarity("text_sim3");
     assertEquals(MockConfigurableSimilarity.class, sim.getClass());
     assertEquals("I am your default sim", ((MockConfigurableSimilarity)sim).getPassthrough());
-    searcher.decref();
   }
   
   /** test a field that does not exist */
   public void testNonexistent() throws Exception {
-    SolrCore core = h.getCore();
-    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
-    Similarity sim = searcher.get().getSimilarityProvider().get("sdfdsfdsfdswr5fsdfdsfdsfs");
+    Similarity sim = getSimilarity("sdfdsfdsfdswr5fsdfdsfdsfs");
     assertEquals(MockConfigurableSimilarity.class, sim.getClass());
     assertEquals("I am your default sim", ((MockConfigurableSimilarity)sim).getPassthrough());
-    searcher.decref();
+  }
+  
+  @Test
+  public void testSimilarityProviderFactory() {
+    SolrCore core = h.getCore();
+    SimilarityProvider similarityProvider = core.getSchema().getSimilarityProvider();
+    assertTrue("wrong class", similarityProvider instanceof MockConfigurableSimilarityProvider);
+    assertEquals("is there an echo?", ((MockConfigurableSimilarityProvider)similarityProvider).getPassthrough());
   }
 }