Lucene.Net.Index.TestIndexReader.DeleteReaderWriterConflict C# (CSharp) Method

		private void  DeleteReaderWriterConflict(bool optimize)
		{
			//Directory dir = new RAMDirectory();
			Directory dir = GetDirectory();
			
			Term searchTerm = new Term("content", "aaa");
			Term searchTerm2 = new Term("content", "bbb");
			
			//  add 100 documents with term : aaa
			IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED);
			for (int i = 0; i < 100; i++)
			{
				AddDoc(writer, searchTerm.Text);
			}
			writer.Close();
			
			// OPEN READER AT THIS POINT - this should fix the view of the
			// index at the point of having 100 "aaa" documents and 0 "bbb"
			IndexReader reader = IndexReader.Open(dir, false);
			Assert.AreEqual(100, reader.DocFreq(searchTerm), "first docFreq");
			Assert.AreEqual(0, reader.DocFreq(searchTerm2), "first docFreq");
			AssertTermDocsCount("first reader", reader, searchTerm, 100);
			AssertTermDocsCount("first reader", reader, searchTerm2, 0);
			
			// add 100 documents with term : bbb
			writer = new IndexWriter(dir, new WhitespaceAnalyzer(), false, IndexWriter.MaxFieldLength.LIMITED);
			for (int i = 0; i < 100; i++)
			{
				AddDoc(writer, searchTerm2.Text);
			}
			
			// REQUEST OPTIMIZATION
			// This causes a new segment to become current for all subsequent
			// searchers. Because of this, deletions made via a previously open
			// reader, which would be applied to that reader's segment, are lost
			// for subsequent searchers/readers
			if (optimize)
				writer.Optimize();
			writer.Close();
			
			// The reader should not see the new data
			Assert.AreEqual(100, reader.DocFreq(searchTerm), "first docFreq");
			Assert.AreEqual(0, reader.DocFreq(searchTerm2), "first docFreq");
			AssertTermDocsCount("first reader", reader, searchTerm, 100);
			AssertTermDocsCount("first reader", reader, searchTerm2, 0);
			
			
			// DELETE DOCUMENTS CONTAINING TERM: aaa
			// NOTE: the reader was created when only "aaa" documents were in
			int deleted = 0;
		    Assert.Throws<StaleReaderException>(() => reader.DeleteDocuments(searchTerm),
		                                        "Delete allowed on an index reader with stale segment information");
			
			// Re-open index reader and try again. This time it should see
			// the new data.
			reader.Close();
			reader = IndexReader.Open(dir, false);
			Assert.AreEqual(100, reader.DocFreq(searchTerm), "first docFreq");
			Assert.AreEqual(100, reader.DocFreq(searchTerm2), "first docFreq");
			AssertTermDocsCount("first reader", reader, searchTerm, 100);
			AssertTermDocsCount("first reader", reader, searchTerm2, 100);
			
			deleted = reader.DeleteDocuments(searchTerm);
			Assert.AreEqual(100, deleted, "deleted count");
			Assert.AreEqual(100, reader.DocFreq(searchTerm), "deleted docFreq");
			Assert.AreEqual(100, reader.DocFreq(searchTerm2), "deleted docFreq");
			AssertTermDocsCount("deleted termDocs", reader, searchTerm, 0);
			AssertTermDocsCount("deleted termDocs", reader, searchTerm2, 100);
			reader.Close();
			
			// CREATE A NEW READER and re-test
			reader = IndexReader.Open(dir, false);
			Assert.AreEqual(100, reader.DocFreq(searchTerm), "deleted docFreq");
			Assert.AreEqual(100, reader.DocFreq(searchTerm2), "deleted docFreq");
			AssertTermDocsCount("deleted termDocs", reader, searchTerm, 0);
			AssertTermDocsCount("deleted termDocs", reader, searchTerm2, 100);
			reader.Close();
		}