Renames "default" similarity into "classic".

Replaces deprecated DefaultSimilarity by ClassicSimilarity.
Fixes #15102

3 files changed, 108 insertions, 59 deletions

diff --git a/core/src/test/java/org/apache/lucene/queries/BlendedTermQueryTests.java b/core/src/test/java/org/apache/lucene/queries/BlendedTermQueryTests.java
index 0f29ed5a2f..725b1bd440 100644
--- a/core/src/test/java/org/apache/lucene/queries/BlendedTermQueryTests.java
+++ b/core/src/test/java/org/apache/lucene/queries/BlendedTermQueryTests.java
@@ -37,7 +37,7 @@ import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.TopDocs;
 import org.apache.lucene.search.similarities.BM25Similarity;
-import org.apache.lucene.search.similarities.DefaultSimilarity;
+import org.apache.lucene.search.similarities.ClassicSimilarity;
 import org.apache.lucene.search.similarities.Similarity;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.TestUtil;
@@ -214,7 +214,7 @@ public class BlendedTermQueryTests extends ESTestCase {
     }
 
     public IndexSearcher setSimilarity(IndexSearcher searcher) {
-        Similarity similarity = random().nextBoolean() ? new BM25Similarity() : new DefaultSimilarity();
+        Similarity similarity = random().nextBoolean() ? new BM25Similarity() : new ClassicSimilarity();
         searcher.setSimilarity(similarity);
         return searcher;
     }
diff --git a/core/src/test/java/org/elasticsearch/index/similarity/SimilarityTests.java b/core/src/test/java/org/elasticsearch/index/similarity/SimilarityTests.java
index 5b2a368661..dd5ca6bcc5 100644
--- a/core/src/test/java/org/elasticsearch/index/similarity/SimilarityTests.java
+++ b/core/src/test/java/org/elasticsearch/index/similarity/SimilarityTests.java
@@ -19,11 +19,11 @@
 
 package org.elasticsearch.index.similarity;
 
+import org.apache.lucene.search.similarities.ClassicSimilarity;
 import org.apache.lucene.search.similarities.AfterEffectL;
 import org.apache.lucene.search.similarities.BM25Similarity;
 import org.apache.lucene.search.similarities.BasicModelG;
 import org.apache.lucene.search.similarities.DFRSimilarity;
-import org.apache.lucene.search.similarities.DefaultSimilarity;
 import org.apache.lucene.search.similarities.DistributionSPL;
 import org.apache.lucene.search.similarities.IBSimilarity;
 import org.apache.lucene.search.similarities.LMDirichletSimilarity;
@@ -31,11 +31,16 @@ import org.apache.lucene.search.similarities.LMJelinekMercerSimilarity;
 import org.apache.lucene.search.similarities.LambdaTTF;
 import org.apache.lucene.search.similarities.NormalizationH2;
 import org.elasticsearch.common.compress.CompressedXContent;
+import org.elasticsearch.Version;
+import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.mapper.DocumentMapper;
+import org.elasticsearch.index.mapper.DocumentMapperParser;
+import org.elasticsearch.index.mapper.MapperParsingException;
 import org.elasticsearch.test.ESSingleNodeTestCase;
+import org.elasticsearch.test.VersionUtils;
 
 import java.io.IOException;
 
@@ -45,42 +50,43 @@ import static org.hamcrest.CoreMatchers.instanceOf;
 public class SimilarityTests extends ESSingleNodeTestCase {
     public void testResolveDefaultSimilarities() {
         SimilarityService similarityService = createIndex("foo").similarityService();
-        assertThat(similarityService.getSimilarity("default").get(), instanceOf(DefaultSimilarity.class));
+        assertThat(similarityService.getSimilarity("classic").get(), instanceOf(ClassicSimilarity.class));
         assertThat(similarityService.getSimilarity("BM25").get(), instanceOf(BM25Similarity.class));
+        assertThat(similarityService.getSimilarity("default"), equalTo(null));
     }
 
-    public void testResolveSimilaritiesFromMapping_default() throws IOException {
+    public void testResolveSimilaritiesFromMapping_classic() throws IOException {
         String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
-                .startObject("properties")
-                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
-                .endObject()
-                .endObject().endObject().string();
+            .startObject("properties")
+            .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+            .endObject()
+            .endObject().endObject().string();
 
         Settings indexSettings = Settings.settingsBuilder()
-                .put("index.similarity.my_similarity.type", "default")
-                .put("index.similarity.my_similarity.discount_overlaps", false)
-                .build();
+            .put("index.similarity.my_similarity.type", "classic")
+            .put("index.similarity.my_similarity.discount_overlaps", false)
+            .build();
         IndexService indexService = createIndex("foo", indexSettings);
         DocumentMapper documentMapper = indexService.mapperService().documentMapperParser().parse("type", new CompressedXContent(mapping));
-        assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(DefaultSimilarityProvider.class));
+        assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(ClassicSimilarityProvider.class));
 
-        DefaultSimilarity similarity = (DefaultSimilarity) documentMapper.mappers().getMapper("field1").fieldType().similarity().get();
+        ClassicSimilarity similarity = (ClassicSimilarity) documentMapper.mappers().getMapper("field1").fieldType().similarity().get();
         assertThat(similarity.getDiscountOverlaps(), equalTo(false));
     }
 
     public void testResolveSimilaritiesFromMapping_bm25() throws IOException {
         String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
-                .startObject("properties")
-                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
-                .endObject()
-                .endObject().endObject().string();
+            .startObject("properties")
+            .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+            .endObject()
+            .endObject().endObject().string();
 
         Settings indexSettings = Settings.settingsBuilder()
-                .put("index.similarity.my_similarity.type", "BM25")
-                .put("index.similarity.my_similarity.k1", 2.0f)
-                .put("index.similarity.my_similarity.b", 1.5f)
-                .put("index.similarity.my_similarity.discount_overlaps", false)
-                .build();
+            .put("index.similarity.my_similarity.type", "BM25")
+            .put("index.similarity.my_similarity.k1", 2.0f)
+            .put("index.similarity.my_similarity.b", 1.5f)
+            .put("index.similarity.my_similarity.discount_overlaps", false)
+            .build();
         IndexService indexService = createIndex("foo", indexSettings);
         DocumentMapper documentMapper = indexService.mapperService().documentMapperParser().parse("type", new CompressedXContent(mapping));
         assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(BM25SimilarityProvider.class));
@@ -93,18 +99,18 @@ public class SimilarityTests extends ESSingleNodeTestCase {
 
     public void testResolveSimilaritiesFromMapping_DFR() throws IOException {
         String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
-                .startObject("properties")
-                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
-                .endObject()
-                .endObject().endObject().string();
+            .startObject("properties")
+            .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+            .endObject()
+            .endObject().endObject().string();
 
         Settings indexSettings = Settings.settingsBuilder()
-                .put("index.similarity.my_similarity.type", "DFR")
-                .put("index.similarity.my_similarity.basic_model", "g")
-                .put("index.similarity.my_similarity.after_effect", "l")
-                .put("index.similarity.my_similarity.normalization", "h2")
-                .put("index.similarity.my_similarity.normalization.h2.c", 3f)
-                .build();
+            .put("index.similarity.my_similarity.type", "DFR")
+            .put("index.similarity.my_similarity.basic_model", "g")
+            .put("index.similarity.my_similarity.after_effect", "l")
+            .put("index.similarity.my_similarity.normalization", "h2")
+            .put("index.similarity.my_similarity.normalization.h2.c", 3f)
+            .build();
         IndexService indexService = createIndex("foo", indexSettings);
         DocumentMapper documentMapper = indexService.mapperService().documentMapperParser().parse("type", new CompressedXContent(mapping));
         assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(DFRSimilarityProvider.class));
@@ -118,18 +124,18 @@ public class SimilarityTests extends ESSingleNodeTestCase {
 
     public void testResolveSimilaritiesFromMapping_IB() throws IOException {
         String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
-                .startObject("properties")
-                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
-                .endObject()
-                .endObject().endObject().string();
+            .startObject("properties")
+            .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+            .endObject()
+            .endObject().endObject().string();
 
         Settings indexSettings = Settings.settingsBuilder()
-                .put("index.similarity.my_similarity.type", "IB")
-                .put("index.similarity.my_similarity.distribution", "spl")
-                .put("index.similarity.my_similarity.lambda", "ttf")
-                .put("index.similarity.my_similarity.normalization", "h2")
-                .put("index.similarity.my_similarity.normalization.h2.c", 3f)
-                .build();
+            .put("index.similarity.my_similarity.type", "IB")
+            .put("index.similarity.my_similarity.distribution", "spl")
+            .put("index.similarity.my_similarity.lambda", "ttf")
+            .put("index.similarity.my_similarity.normalization", "h2")
+            .put("index.similarity.my_similarity.normalization.h2.c", 3f)
+            .build();
         IndexService indexService = createIndex("foo", indexSettings);
         DocumentMapper documentMapper = indexService.mapperService().documentMapperParser().parse("type", new CompressedXContent(mapping));
         assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(IBSimilarityProvider.class));
@@ -143,15 +149,15 @@ public class SimilarityTests extends ESSingleNodeTestCase {
 
     public void testResolveSimilaritiesFromMapping_LMDirichlet() throws IOException {
         String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
-                .startObject("properties")
-                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
-                .endObject()
-                .endObject().endObject().string();
+            .startObject("properties")
+            .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+            .endObject()
+            .endObject().endObject().string();
 
         Settings indexSettings = Settings.settingsBuilder()
-                .put("index.similarity.my_similarity.type", "LMDirichlet")
-                .put("index.similarity.my_similarity.mu", 3000f)
-                .build();
+            .put("index.similarity.my_similarity.type", "LMDirichlet")
+            .put("index.similarity.my_similarity.mu", 3000f)
+            .build();
         IndexService indexService = createIndex("foo", indexSettings);
         DocumentMapper documentMapper = indexService.mapperService().documentMapperParser().parse("type", new CompressedXContent(mapping));
         assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(LMDirichletSimilarityProvider.class));
@@ -162,15 +168,15 @@ public class SimilarityTests extends ESSingleNodeTestCase {
 
     public void testResolveSimilaritiesFromMapping_LMJelinekMercer() throws IOException {
         String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
-                .startObject("properties")
-                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
-                .endObject()
-                .endObject().endObject().string();
+            .startObject("properties")
+            .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+            .endObject()
+            .endObject().endObject().string();
 
         Settings indexSettings = Settings.settingsBuilder()
-                .put("index.similarity.my_similarity.type", "LMJelinekMercer")
-                .put("index.similarity.my_similarity.lambda", 0.7f)
-                .build();
+            .put("index.similarity.my_similarity.type", "LMJelinekMercer")
+            .put("index.similarity.my_similarity.lambda", 0.7f)
+            .build();
         IndexService indexService = createIndex("foo", indexSettings);
         DocumentMapper documentMapper = indexService.mapperService().documentMapperParser().parse("type", new CompressedXContent(mapping));
         assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(LMJelinekMercerSimilarityProvider.class));
@@ -178,4 +184,47 @@ public class SimilarityTests extends ESSingleNodeTestCase {
         LMJelinekMercerSimilarity similarity = (LMJelinekMercerSimilarity) documentMapper.mappers().getMapper("field1").fieldType().similarity().get();
         assertThat(similarity.getLambda(), equalTo(0.7f));
     }
+
+    public void testResolveSimilaritiesFromMapping_Unknown() throws IOException {
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
+            .startObject("properties")
+            .startObject("field1").field("type", "string").field("similarity", "unknown_similarity").endObject()
+            .endObject()
+            .endObject().endObject().string();
+
+        IndexService indexService = createIndex("foo");
+        try {
+            indexService.mapperService().documentMapperParser().parse("type", new CompressedXContent(mapping));
+            fail("Expected MappingParsingException");
+        } catch (MapperParsingException e) {
+            assertThat(e.getMessage(), equalTo("Unknown Similarity type [unknown_similarity] for [field1]"));
+        }
+    }
+
+    public void testSimilarityDefaultBackCompat() throws IOException {
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
+            .startObject("properties")
+            .startObject("field1")
+            .field("similarity", "default")
+            .field("type", "string")
+            .endObject()
+            .endObject()
+            .endObject().string();
+        Settings settings = Settings.builder()
+            .put(IndexMetaData.SETTING_VERSION_CREATED, VersionUtils.randomVersionBetween(random(), Version.V_2_0_0, Version.V_2_2_0))
+            .build();
+
+        DocumentMapperParser parser = createIndex("test_v2.x", settings).mapperService().documentMapperParser();
+        DocumentMapper documentMapper = parser.parse("type", new CompressedXContent(mapping));
+        assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity(), instanceOf(ClassicSimilarityProvider.class));
+        assertThat(documentMapper.mappers().getMapper("field1").fieldType().similarity().name(), equalTo("classic"));
+
+        parser = createIndex("test_v3.x").mapperService().documentMapperParser();
+        try {
+            parser.parse("type", new CompressedXContent(mapping));
+            fail("Expected MappingParsingException");
+        } catch (MapperParsingException e) {
+            assertThat(e.getMessage(), equalTo("Unknown Similarity type [default] for [field1]"));
+        }
+    }
 }
diff --git a/core/src/test/java/org/elasticsearch/similarity/SimilarityIT.java b/core/src/test/java/org/elasticsearch/similarity/SimilarityIT.java
index ab6a10f3cd..8912956489 100644
--- a/core/src/test/java/org/elasticsearch/similarity/SimilarityIT.java
+++ b/core/src/test/java/org/elasticsearch/similarity/SimilarityIT.java
@@ -28,7 +28,7 @@ import static org.elasticsearch.index.query.QueryBuilders.matchQuery;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.not;
 
-public class SimilarityIT  extends ESIntegTestCase {
+public class SimilarityIT extends ESIntegTestCase {
     public void testCustomBM25Similarity() throws Exception {
         try {
             client().admin().indices().prepareDelete("test").execute().actionGet();
@@ -45,7 +45,7 @@ public class SimilarityIT  extends ESIntegTestCase {
                                     .field("type", "string")
                                 .endObject()
                                 .startObject("field2")
-                                    .field("similarity", "default")
+                                    .field("similarity", "classic")
                                     .field("type", "string")
                             .endObject()
                         .endObject()