Multireader Support in Searcher Manager

lucene/core/src/java/org/apache/lucene/search/SearcherManager.java

@@ -114,16 +114,15 @@ public SearcherManager(Directory dir, SearcherFactory searcherFactory) throws IO
   }
 
   /**
-   * Creates and returns a new SearcherManager from an existing {@link DirectoryReader}. Note that
+   * Creates and returns a new SearcherManager from an existing {@link IndexReader}.  Note that
    * this steals the incoming reference.
    *
-   * @param reader the DirectoryReader.
+   * @param reader the IndexReader.
    * @param searcherFactory An optional {@link SearcherFactory}. Pass <code>null</code> if you don't
    *     require the searcher to be warmed before going live or other custom behavior.
    * @throws IOException if there is a low-level I/O error
    */
-  public SearcherManager(DirectoryReader reader, SearcherFactory searcherFactory)
-      throws IOException {
+  public SearcherManager(IndexReader reader, SearcherFactory searcherFactory) throws IOException {
     if (searcherFactory == null) {
       searcherFactory = new SearcherFactory();
     }

lucene/core/src/test/org/apache/lucene/search/TestSearcherManager.java

@@ -28,20 +28,13 @@
 import java.util.concurrent.atomic.AtomicReference;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.index.ConcurrentMergeScheduler;
-import org.apache.lucene.index.DirectoryReader;
-import org.apache.lucene.index.FilterDirectoryReader;
-import org.apache.lucene.index.FilterLeafReader;
-import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.index.IndexWriter;
-import org.apache.lucene.index.IndexWriterConfig;
-import org.apache.lucene.index.LeafReader;
-import org.apache.lucene.index.LeafReaderContext;
-import org.apache.lucene.index.Term;
+import org.apache.lucene.document.TextField;
+import org.apache.lucene.index.*;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.tests.analysis.MockAnalyzer;
 import org.apache.lucene.tests.index.RandomIndexWriter;
+import org.apache.lucene.util.English;
 import org.apache.lucene.tests.index.ThreadedIndexingAndSearchingTestCase;
 import org.apache.lucene.tests.util.LuceneTestCase;
 import org.apache.lucene.tests.util.LuceneTestCase.SuppressCodecs;
@@ -546,6 +539,43 @@ public void testCustomDirectoryReader() throws Exception {
     dir.close();
   }
 
+  // LUCENE-13975
+  public void testMultiReaderReader() throws Exception {
+    Directory dir = newDirectory();
+    RandomIndexWriter w = new RandomIndexWriter(random(), dir);
+    DirectoryReader nrtReader = w.getReader();
+
+    Directory dir2 = newDirectory();
+    RandomIndexWriter w2 = new RandomIndexWriter(random(), dir2);
+    DirectoryReader nrtReader2 = w2.getReader();
+
+    MultiReader reader = new MultiReader(nrtReader, nrtReader2);
+
+    SearcherManager mgr = new SearcherManager(reader, null);
+    for(int i=0;i<10;i++) {
+      Document d = new Document();
+      d.add(new TextField("contents", English.intToEnglish(i), Field.Store.NO));
+      w.addDocument(new Document());
+
+      Document d2 = new Document();
+      d2.add(new TextField("contents", English.intToEnglish(i+10), Field.Store.NO));
+      w2.addDocument(new Document());
+    }
+
+    mgr.maybeRefresh();
+    IndexSearcher s = mgr.acquire();
+    try {
+      assertTrue(s.getIndexReader() instanceof MultiReader);
+      assertEquals(s.count(new MatchAllDocsQuery()), 20);
+    } finally {
+      mgr.release(s);
+    }
+
+    mgr.close();
+    w.close();
+    dir.close();
+  }
+
   public void testPreviousReaderIsPassed() throws IOException {
     final Directory dir = newDirectory();
     final IndexWriter w = new IndexWriter(dir, newIndexWriterConfig());