public virtual void  TestErrorInDocsWriterAdd()
		{
			
			MockRAMDirectory.Failure failure = new AnonymousClassFailure1(this);
			
			// create a couple of files
			
			System.String[] keywords = new System.String[]{"1", "2"};
			System.String[] unindexed = new System.String[]{"Netherlands", "Italy"};
			System.String[] unstored = new System.String[]{"Amsterdam has lots of bridges", "Venice has lots of canals"};
			System.String[] text = new System.String[]{"Amsterdam", "Venice"};
			
			for (int pass = 0; pass < 2; pass++)
			{
				bool autoCommit = (0 == pass);
				MockRAMDirectory dir = new MockRAMDirectory();
				IndexWriter modifier = new IndexWriter(dir, autoCommit, new WhitespaceAnalyzer(), true);
				
				dir.FailOn(failure.Reset());
				
				for (int i = 0; i < keywords.Length; i++)
				{
					Document doc = new Document();
					doc.Add(new Field("id", keywords[i], Field.Store.YES, Field.Index.UN_TOKENIZED));
					doc.Add(new Field("country", unindexed[i], Field.Store.YES, Field.Index.NO));
					doc.Add(new Field("contents", unstored[i], Field.Store.NO, Field.Index.TOKENIZED));
					doc.Add(new Field("city", text[i], Field.Store.YES, Field.Index.TOKENIZED));
					try
					{
						modifier.AddDocument(doc);
					}
					catch (System.IO.IOException)
					{
						break;
					}
				}
				
				System.String[] startFiles = dir.List();
				SegmentInfos infos = new SegmentInfos();
				infos.Read(dir);
				new IndexFileDeleter(dir, new KeepOnlyLastCommitDeletionPolicy(), infos, null, null);
				System.String[] endFiles = dir.List();
				
				if (!SupportClass.Compare.CompareStringArrays(startFiles, endFiles))
				{
					Assert.Fail("docswriter abort() failed to delete unreferenced files:\n  before delete:\n    " + ArrayToString(startFiles) + "\n  after delete:\n    " + ArrayToString(endFiles));
				}
				
				modifier.Close();
			}
		}
		public virtual void  TestOptimizeTempSpaceUsage()
		{
			
			MockRAMDirectory dir = new MockRAMDirectory();
			IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), true);
			for (int j = 0; j < 500; j++)
			{
				AddDocWithIndex(writer, j);
			}
			writer.Close();
			
			long startDiskUsage = 0;
			System.String[] files = dir.List();
			for (int i = 0; i < files.Length; i++)
			{
				startDiskUsage += dir.FileLength(files[i]);
			}
			
			dir.ResetMaxUsedSizeInBytes();
			writer = new IndexWriter(dir, new WhitespaceAnalyzer(), false);
			writer.Optimize();
			writer.Close();
			long maxDiskUsage = dir.GetMaxUsedSizeInBytes();
			
			Assert.IsTrue(
				maxDiskUsage <= 2 * startDiskUsage,
				"optimized used too much temporary space: starting usage was " + startDiskUsage + " bytes; max temp usage was " + maxDiskUsage + " but should have been " + (2 * startDiskUsage) + " (= 2X starting usage)"
			);
			dir.Close();
		}
		/// <summary> Make sure if modifier tries to commit but hits disk full that modifier
		/// remains consistent and usable. Similar to TestIndexReader.testDiskFull().
		/// </summary>
		private void  TestOperationsOnDiskFull(bool updates)
		{
			
			bool debug = false;
			Term searchTerm = new Term("content", "aaa");
			int START_COUNT = 157;
			int END_COUNT = 144;
			
			for (int pass = 0; pass < 2; pass++)
			{
				bool autoCommit = (0 == pass);
				
				// First build up a starting index:
				RAMDirectory startDir = new RAMDirectory();
				IndexWriter writer = new IndexWriter(startDir, autoCommit, new WhitespaceAnalyzer(), true);
				for (int i = 0; i < 157; i++)
				{
					Document d = new Document();
					d.Add(new Field("id", System.Convert.ToString(i), Field.Store.YES, Field.Index.UN_TOKENIZED));
					d.Add(new Field("content", "aaa " + i, Field.Store.NO, Field.Index.TOKENIZED));
					writer.AddDocument(d);
				}
				writer.Close();
				
				long diskUsage = startDir.SizeInBytes();
				long diskFree = diskUsage + 10;
				
				System.IO.IOException err = null;
				
				bool done = false;
				
				// Iterate w/ ever increasing free disk space:
				while (!done)
				{
					MockRAMDirectory dir = new MockRAMDirectory(startDir);
					IndexWriter modifier = new IndexWriter(dir, autoCommit, new WhitespaceAnalyzer());
					
					modifier.SetMaxBufferedDocs(1000); // use flush or close
					modifier.SetMaxBufferedDeleteTerms(1000); // use flush or close
					
					// For each disk size, first try to commit against
					// dir that will hit random IOExceptions & disk
					// full; after, give it infinite disk space & turn
					// off random IOExceptions & retry w/ same reader:
					bool success = false;
					
					for (int x = 0; x < 2; x++)
					{
						
						double rate = 0.1;
						//UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
						double diskRatio = ((double) diskFree) / diskUsage;
						long thisDiskFree;
						System.String testName;
						
						if (0 == x)
						{
							thisDiskFree = diskFree;
							if (diskRatio >= 2.0)
							{
								rate /= 2;
							}
							if (diskRatio >= 4.0)
							{
								rate /= 2;
							}
							if (diskRatio >= 6.0)
							{
								rate = 0.0;
							}
							if (debug)
							{
								System.Console.Out.WriteLine("\ncycle: " + diskFree + " bytes");
							}
							testName = "disk full during reader.close() @ " + thisDiskFree + " bytes";
						}
						else
						{
							thisDiskFree = 0;
							rate = 0.0;
							if (debug)
							{
								System.Console.Out.WriteLine("\ncycle: same writer: unlimited disk space");
							}
							testName = "reader re-use after disk full";
						}
						
						dir.SetMaxSizeInBytes(thisDiskFree);
						dir.SetRandomIOExceptionRate(rate, diskFree);
						
						try
						{
							if (0 == x)
							{
								int docId = 12;
								for (int i = 0; i < 13; i++)
								{
									if (updates)
									{
										Document d = new Document();
										d.Add(new Field("id", System.Convert.ToString(i), Field.Store.YES, Field.Index.UN_TOKENIZED));
										d.Add(new Field("content", "bbb " + i, Field.Store.NO, Field.Index.TOKENIZED));
										modifier.UpdateDocument(new Term("id", System.Convert.ToString(docId)), d);
									}
									else
									{
										// deletes
										modifier.DeleteDocuments(new Term("id", System.Convert.ToString(docId)));
										// modifier.setNorm(docId, "contents", (float)2.0);
									}
									docId += 12;
								}
							}
							modifier.Close();
							success = true;
							if (0 == x)
							{
								done = true;
							}
						}
						catch (System.IO.IOException e)
						{
							if (debug)
							{
								//UPGRADE_TODO: The equivalent in .NET for method 'java.lang.Throwable.toString' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'"
								System.Console.Out.WriteLine("  hit IOException: " + e);
								System.Console.Out.WriteLine(e.StackTrace);
							}
							err = e;
							if (1 == x)
							{
								System.Console.Error.WriteLine(e.StackTrace);
								Assert.Fail(testName + " hit IOException after disk space was freed up");
							}
						}
						
						// Whether we succeeded or failed, check that all
						// un-referenced files were in fact deleted (ie,
						// we did not create garbage). Just create a
						// new IndexFileDeleter, have it delete
						// unreferenced files, then verify that in fact
						// no files were deleted:
						System.String[] startFiles = dir.List();
						SegmentInfos infos = new SegmentInfos();
						infos.Read(dir);
						new IndexFileDeleter(dir, new KeepOnlyLastCommitDeletionPolicy(), infos, null, null);
						System.String[] endFiles = dir.List();
						
						//UPGRADE_TODO: Method 'java.util.Arrays.sort' was converted to 'System.Array.Sort' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilArrayssort_javalangObject[]'"
						System.Array.Sort(startFiles);
						//UPGRADE_TODO: Method 'java.util.Arrays.sort' was converted to 'System.Array.Sort' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilArrayssort_javalangObject[]'"
						System.Array.Sort(endFiles);
						
						// for(int i=0;i<startFiles.length;i++) {
						// System.out.println(" startFiles: " + i + ": " + startFiles[i]);
						// }
						
						if (!SupportClass.Compare.CompareStringArrays(startFiles, endFiles))
						{
							System.String successStr;
							if (success)
							{
								successStr = "success";
							}
							else
							{
								successStr = "IOException";
								System.Console.Error.WriteLine(err.StackTrace);
							}
							Assert.Fail("reader.close() failed to delete unreferenced files after " + successStr + " (" + diskFree + " bytes): before delete:\n    " + ArrayToString(startFiles) + "\n  after delete:\n    " + ArrayToString(endFiles));
						}
						
						// Finally, verify index is not corrupt, and, if
						// we succeeded, we see all docs changed, and if
						// we failed, we see either all docs or no docs
						// changed (transactional semantics):
						IndexReader newReader = null;
						try
						{
							newReader = IndexReader.Open(dir);
						}
						catch (System.IO.IOException e)
						{
							System.Console.Error.WriteLine(e.StackTrace);
							//UPGRADE_TODO: The equivalent in .NET for method 'java.lang.Throwable.toString' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'"
							Assert.Fail(testName + ":exception when creating IndexReader after disk full during close: " + e);
						}
						
						IndexSearcher searcher = new IndexSearcher(newReader);
						Hits hits = null;
						try
						{
							hits = searcher.Search(new TermQuery(searchTerm));
						}
						catch (System.IO.IOException e)
						{
							System.Console.Error.WriteLine(e.StackTrace);
							//UPGRADE_TODO: The equivalent in .NET for method 'java.lang.Throwable.toString' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'"
							Assert.Fail(testName + ": exception when searching: " + e);
						}
						int result2 = hits.Length();
						if (success)
						{
							if (x == 0 && result2 != END_COUNT)
							{
								Assert.Fail(testName + ": method did not throw exception but hits.length for search on term 'aaa' is " + result2 + " instead of expected " + END_COUNT);
							}
							else if (x == 1 && result2 != START_COUNT && result2 != END_COUNT)
							{
								// It's possible that the first exception was
								// "recoverable" wrt pending deletes, in which
								// case the pending deletes are retained and
								// then re-flushing (with plenty of disk
								// space) will succeed in flushing the
								// deletes:
								Assert.Fail(testName + ": method did not throw exception but hits.length for search on term 'aaa' is " + result2 + " instead of expected " + START_COUNT + " or " + END_COUNT);
							}
						}
						else
						{
							// On hitting exception we still may have added
							// all docs:
							if (result2 != START_COUNT && result2 != END_COUNT)
							{
								System.Console.Error.WriteLine(err.StackTrace);
								Assert.Fail(testName + ": method did throw exception but hits.length for search on term 'aaa' is " + result2 + " instead of expected " + START_COUNT + " or " + END_COUNT);
							}
						}
						
						searcher.Close();
						newReader.Close();
						
						if (result2 == END_COUNT)
						{
							break;
						}
					}
					
					dir.Close();
					
					// Try again with 10 more bytes of free space:
					diskFree += 10;
				}
			}
		}