Lucene.Net.Index.IndexWriter.CommitMergedDeletes C# (CSharp) Method

		private void  CommitMergedDeletes(MergePolicy.OneMerge merge, SegmentReader mergeReader)
		{
			lock (this)
			{
				
				System.Diagnostics.Debug.Assert(TestPoint("startCommitMergeDeletes"));
				
				SegmentInfos sourceSegments = merge.segments;
				
				if (infoStream != null)
					Message("commitMergeDeletes " + merge.SegString(directory));
				
				// Carefully merge deletes that occurred after we
				// started merging:
				int docUpto = 0;
				int delCount = 0;
				
				for (int i = 0; i < sourceSegments.Count; i++)
				{
					SegmentInfo info = sourceSegments.Info(i);
					int docCount = info.docCount;
					SegmentReader previousReader = merge.readersClone[i];
					SegmentReader currentReader = merge.readers[i];
					if (previousReader.HasDeletions)
					{
						
						// There were deletes on this segment when the merge
						// started.  The merge has collapsed away those
						// deletes, but, if new deletes were flushed since
						// the merge started, we must now carefully keep any
						// newly flushed deletes but mapping them to the new
						// docIDs.
						
						if (currentReader.NumDeletedDocs > previousReader.NumDeletedDocs)
						{
							// This means this segment has had new deletes
							// committed since we started the merge, so we
							// must merge them:
							for (int j = 0; j < docCount; j++)
							{
								if (previousReader.IsDeleted(j))
								{
									System.Diagnostics.Debug.Assert(currentReader.IsDeleted(j));
                                }
								else
								{
									if (currentReader.IsDeleted(j))
									{
										mergeReader.DoDelete(docUpto);
										delCount++;
									}
									docUpto++;
								}
							}
						}
						else
						{
							docUpto += docCount - previousReader.NumDeletedDocs;
						}
					}
					else if (currentReader.HasDeletions)
					{
						// This segment had no deletes before but now it
						// does:
						for (int j = 0; j < docCount; j++)
						{
							if (currentReader.IsDeleted(j))
							{
								mergeReader.DoDelete(docUpto);
								delCount++;
							}
							docUpto++;
						}
					}
					// No deletes before or after
					else
						docUpto += info.docCount;
				}
				
				System.Diagnostics.Debug.Assert(mergeReader.NumDeletedDocs == delCount);
				
				mergeReader.hasChanges = delCount > 0;
			}
		}