Sharpen.FilePath.DeleteOnExit C# (CSharp) Method

		public void DeleteOnExit ()
		{
		}

		/// <exception cref="System.IO.IOException"></exception>
		private PackLock RenameAndOpenPack(string lockMessage)
		{
			if (!keepEmpty && GetObjectCount() == 0)
			{
				CleanupTemporaryFiles();
				return null;
			}
			MessageDigest d = Constants.NewMessageDigest();
			byte[] oeBytes = new byte[Constants.OBJECT_ID_LENGTH];
			for (int i = 0; i < GetObjectCount(); i++)
			{
				PackedObjectInfo oe = GetObject(i);
				oe.CopyRawTo(oeBytes, 0);
				d.Update(oeBytes);
			}
			string name = ObjectId.FromRaw(d.Digest()).Name;
			FilePath packDir = new FilePath(db.GetDirectory(), "pack");
			FilePath finalPack = new FilePath(packDir, "pack-" + name + ".pack");
			FilePath finalIdx = new FilePath(packDir, "pack-" + name + ".idx");
			PackLock keep = new PackLock(finalPack, db.GetFS());
			if (!packDir.Exists() && !packDir.Mkdir() && !packDir.Exists())
			{
				// The objects/pack directory isn't present, and we are unable
				// to create it. There is no way to move this pack in.
				//
				CleanupTemporaryFiles();
				throw new IOException(MessageFormat.Format(JGitText.Get().cannotCreateDirectory, 
					packDir.GetAbsolutePath()));
			}
			if (finalPack.Exists())
			{
				// If the pack is already present we should never replace it.
				//
				CleanupTemporaryFiles();
				return null;
			}
			if (lockMessage != null)
			{
				// If we have a reason to create a keep file for this pack, do
				// so, or fail fast and don't put the pack in place.
				//
				try
				{
					if (!keep.Lock(lockMessage))
					{
						throw new IOException(MessageFormat.Format(JGitText.Get().cannotLockPackIn, finalPack
							));
					}
				}
				catch (IOException e)
				{
					CleanupTemporaryFiles();
					throw;
				}
			}
			if (!tmpPack.RenameTo(finalPack))
			{
				CleanupTemporaryFiles();
				keep.Unlock();
				throw new IOException(MessageFormat.Format(JGitText.Get().cannotMovePackTo, finalPack
					));
			}
			if (!tmpIdx.RenameTo(finalIdx))
			{
				CleanupTemporaryFiles();
				keep.Unlock();
				if (!finalPack.Delete())
				{
					finalPack.DeleteOnExit();
				}
				throw new IOException(MessageFormat.Format(JGitText.Get().cannotMoveIndexTo, finalIdx
					));
			}
			try
			{
				newPack = db.OpenPack(finalPack, finalIdx);
			}
			catch (IOException err)
			{
				keep.Unlock();
				if (finalPack.Exists())
				{
					FileUtils.Delete(finalPack);
				}
				if (finalIdx.Exists())
				{
					FileUtils.Delete(finalIdx);
				}
				throw;
			}
			return lockMessage != null ? keep : null;
		}