Lucene.Net.Index.SegmentMerger.MergeFields C# (CSharp) Method

MergeFields() private method

private MergeFields ( ) : int
return int
		private int MergeFields()
		{
			
			if (!mergeDocStores)
			{
				// When we are not merging by doc stores, their field
				// name -> number mapping are the same.  So, we start
				// with the fieldInfos of the last segment in this
				// case, to keep that numbering.
				SegmentReader sr = (SegmentReader) readers[readers.Count - 1];
				fieldInfos = (FieldInfos) sr.core.fieldInfos.Clone();
			}
			else
			{
				fieldInfos = new FieldInfos(); // merge field names
			}
			
			foreach(IndexReader reader in readers)
			{
				if (reader is SegmentReader)
				{
					SegmentReader segmentReader = (SegmentReader) reader;
					FieldInfos readerFieldInfos = segmentReader.FieldInfos();
					int numReaderFieldInfos = readerFieldInfos.Size();
					for (int j = 0; j < numReaderFieldInfos; j++)
					{
						FieldInfo fi = readerFieldInfos.FieldInfo(j);
						fieldInfos.Add(fi.name, fi.isIndexed, fi.storeTermVector, fi.storePositionWithTermVector, fi.storeOffsetWithTermVector, !reader.HasNorms(fi.name), fi.storePayloads, fi.omitTermFreqAndPositions);
					}
				}
				else
				{
					AddIndexed(reader, fieldInfos, reader.GetFieldNames(FieldOption.TERMVECTOR_WITH_POSITION_OFFSET), true, true, true, false, false);
					AddIndexed(reader, fieldInfos, reader.GetFieldNames(FieldOption.TERMVECTOR_WITH_POSITION), true, true, false, false, false);
					AddIndexed(reader, fieldInfos, reader.GetFieldNames(FieldOption.TERMVECTOR_WITH_OFFSET), true, false, true, false, false);
					AddIndexed(reader, fieldInfos, reader.GetFieldNames(FieldOption.TERMVECTOR), true, false, false, false, false);
					AddIndexed(reader, fieldInfos, reader.GetFieldNames(FieldOption.OMIT_TERM_FREQ_AND_POSITIONS), false, false, false, false, true);
					AddIndexed(reader, fieldInfos, reader.GetFieldNames(FieldOption.STORES_PAYLOADS), false, false, false, true, false);
					AddIndexed(reader, fieldInfos, reader.GetFieldNames(FieldOption.INDEXED), false, false, false, false, false);
					fieldInfos.Add(reader.GetFieldNames(FieldOption.UNINDEXED), false);
				}
			}
			fieldInfos.Write(directory, segment + ".fnm");
			
			int docCount = 0;
			
			SetMatchingSegmentReaders();
			
			if (mergeDocStores)
			{
				// merge field values
				FieldsWriter fieldsWriter = new FieldsWriter(directory, segment, fieldInfos);
				
				try
				{
					int idx = 0;
					foreach(IndexReader reader in readers)
					{
						SegmentReader matchingSegmentReader = matchingSegmentReaders[idx++];
						FieldsReader matchingFieldsReader = null;
						if (matchingSegmentReader != null)
						{
							FieldsReader fieldsReader = matchingSegmentReader.GetFieldsReader();
							if (fieldsReader != null && fieldsReader.CanReadRawDocs())
							{
								matchingFieldsReader = fieldsReader;
							}
						}
						if (reader.HasDeletions)
						{
							docCount += CopyFieldsWithDeletions(fieldsWriter, reader, matchingFieldsReader);
						}
						else
						{
							docCount += CopyFieldsNoDeletions(fieldsWriter, reader, matchingFieldsReader);
						}
					}
				}
				finally
				{
					fieldsWriter.Dispose();
				}
				
				System.String fileName = segment + "." + IndexFileNames.FIELDS_INDEX_EXTENSION;
				long fdxFileLength = directory.FileLength(fileName);
				
				if (4 + ((long) docCount) * 8 != fdxFileLength)
				// This is most likely a bug in Sun JRE 1.6.0_04/_05;
				// we detect that the bug has struck, here, and
				// throw an exception to prevent the corruption from
				// entering the index.  See LUCENE-1282 for
				// details.
					throw new System.SystemException("mergeFields produced an invalid result: docCount is " + docCount + " but fdx file size is " + fdxFileLength + " file=" + fileName + " file exists?=" + directory.FileExists(fileName) + "; now aborting this merge to prevent index corruption");
			}
			// If we are skipping the doc stores, that means there
			// are no deletions in any of these segments, so we
			// just sum numDocs() of each segment to get total docCount
			else
			{
				foreach(IndexReader reader in readers)
				{
					docCount += reader.NumDocs();
				}
			}
			
			return docCount;
		}