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

		internal bool RegisterMerge(MergePolicy.OneMerge merge)
		{
			lock (this)
			{
				
				if (merge.registerDone)
					return true;
				
				if (stopMerges)
				{
					merge.Abort();
					throw new MergePolicy.MergeAbortedException("merge is aborted: " + merge.SegString(directory));
				}
				
				int count = merge.segments.Count;
				bool isExternal = false;
				for (int i = 0; i < count; i++)
				{
					SegmentInfo info = merge.segments.Info(i);
                    if (mergingSegments.Contains(info))
                    {
                        return false;
                    }
                    if (segmentInfos.IndexOf(info) == -1)
                    {
                        return false;
                    }
                    if (info.dir != directory)
                    {
                        isExternal = true;
                    }
                    if (segmentsToOptimize.Contains(info))
                    {
                        merge.optimize = true;
                        merge.maxNumSegmentsOptimize = optimizeMaxNumSegments;
                    }
				}
				
				EnsureContiguousMerge(merge);
				
				pendingMerges.AddLast(merge);
				
				if (infoStream != null)
					Message("add merge to pendingMerges: " + merge.SegString(directory) + " [total " + pendingMerges.Count + " pending]");
				
				merge.mergeGen = mergeGen;
				merge.isExternal = isExternal;
				
				// OK it does not conflict; now record that this merge
				// is running (while synchronized) to avoid race
				// condition where two conflicting merges from different
				// threads, start
                for (int i = 0; i < count; i++)
                {
                    SegmentInfo si = merge.segments.Info(i);
                    mergingSegments.Add(si);
                }
				
				// Merge is now registered
				merge.registerDone = true;
				return true;
			}
		}