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

		private void  ResolveExternalSegments()
		{
			
			bool any = false;
			
			bool done = false;
			
			while (!done)
			{
				SegmentInfo info = null;
				MergePolicy.OneMerge merge = null;
				lock (this)
				{
					
					if (stopMerges)
						throw new MergePolicy.MergeAbortedException("rollback() was called or addIndexes* hit an unhandled exception");
					
					int numSegments = segmentInfos.Count;
					
					done = true;
					for (int i = 0; i < numSegments; i++)
					{
						info = segmentInfos.Info(i);
						if (info.dir != directory)
						{
							done = false;
							MergePolicy.OneMerge newMerge = new MergePolicy.OneMerge(segmentInfos.Range(i, 1 + i), mergePolicy is LogMergePolicy && UseCompoundFile);
							
							// Returns true if no running merge conflicts
							// with this one (and, records this merge as
							// pending), ie, this segment is not currently
							// being merged:
							if (RegisterMerge(newMerge))
							{
								merge = newMerge;
								
								// If this segment is not currently being
								// merged, then advance it to running & run
								// the merge ourself (below):
                                pendingMerges.Remove(merge);    // {{Aroush-2.9}} From Mike Garski: this is an O(n) op... is that an issue?
								runningMerges.Add(merge);
								break;
							}
						}
					}
					
					if (!done && merge == null)
					// We are not yet done (external segments still
					// exist in segmentInfos), yet, all such segments
					// are currently "covered" by a pending or running
					// merge.  We now try to grab any pending merge
					// that involves external segments:
						merge = GetNextExternalMerge();
					
					if (!done && merge == null)
					// We are not yet done, and, all external segments
					// fall under merges that the merge scheduler is
					// currently running.  So, we now wait and check
					// back to see if the merge has completed.
						DoWait();
				}
				
				if (merge != null)
				{
					any = true;
					Merge(merge);
				}
			}
			
			if (any)
			// Sometimes, on copying an external segment over,
			// more merges may become necessary:
				mergeScheduler.Merge(this);
		}