Tests: Add back BitSetFilterCacheTests which was lost on #13308

core/src/test/java/org/elasticsearch/index/cache/bitset/BitSetFilterCacheTests.java

@@ -0,0 +1,112 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch 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.elasticsearch.index.cache.bitset;
+
+import org.apache.lucene.analysis.standard.StandardAnalyzer;
+import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
+import org.apache.lucene.document.StringField;
+import org.apache.lucene.index.DirectoryReader;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.IndexWriter;
+import org.apache.lucene.index.IndexWriterConfig;
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.index.LogByteSizeMergePolicy;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.QueryWrapperFilter;
+import org.apache.lucene.search.TermQuery;
+import org.apache.lucene.search.join.BitSetProducer;
+import org.apache.lucene.store.RAMDirectory;
+import org.apache.lucene.util.BitSet;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.index.Index;
+import org.elasticsearch.test.ESTestCase;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.equalTo;
+
+public class BitSetFilterCacheTests extends ESTestCase {
+
+    private static int matchCount(BitSetProducer producer, IndexReader reader) throws IOException {
+        int count = 0;
+        for (LeafReaderContext ctx : reader.leaves()) {
+            final BitSet bitSet = producer.getBitSet(ctx);
+            if (bitSet != null) {
+                count += bitSet.cardinality();
+            }
+        }
+        return count;
+    }
+
+    @Test
+    public void testInvalidateEntries() throws Exception {
+        IndexWriter writer = new IndexWriter(
+                new RAMDirectory(),
+                new IndexWriterConfig(new StandardAnalyzer()).setMergePolicy(new LogByteSizeMergePolicy())
+        );
+        Document document = new Document();
+        document.add(new StringField("field", "value", Field.Store.NO));
+        writer.addDocument(document);
+        writer.commit();
+
+        document = new Document();
+        document.add(new StringField("field", "value", Field.Store.NO));
+        writer.addDocument(document);
+        writer.commit();
+
+        document = new Document();
+        document.add(new StringField("field", "value", Field.Store.NO));
+        writer.addDocument(document);
+        writer.commit();
+
+        IndexReader reader = DirectoryReader.open(writer, false);
+        IndexSearcher searcher = new IndexSearcher(reader);
+
+        BitsetFilterCache cache = new BitsetFilterCache(new Index("test"), Settings.EMPTY);
+        BitSetProducer filter = cache.getBitSetProducer(new QueryWrapperFilter(new TermQuery(new Term("field", "value"))));
+        assertThat(matchCount(filter, reader), equalTo(3));
+
+        // now cached
+        assertThat(matchCount(filter, reader), equalTo(3));
+        // There are 3 segments
+        assertThat(cache.getLoadedFilters().size(), equalTo(3l));
+
+        writer.forceMerge(1);
+        reader.close();
+        reader = DirectoryReader.open(writer, false);
+        searcher = new IndexSearcher(reader);
+
+        assertThat(matchCount(filter, reader), equalTo(3));
+
+        // now cached
+        assertThat(matchCount(filter, reader), equalTo(3));
+        // Only one segment now, so the size must be 1
+        assertThat(cache.getLoadedFilters().size(), equalTo(1l));
+
+        reader.close();
+        writer.close();
+        // There is no reference from readers and writer to any segment in the test index, so the size in the fbs cache must be 0
+        assertThat(cache.getLoadedFilters().size(), equalTo(0l));
+    }
+
+}