internal int docShift; // total # deleted docs that were compacted by this merge public MergeDocIDRemapper(SegmentInfos infos, int[][] docMaps, int[] delCounts, MergePolicy.OneMerge merge, int mergedDocCount) { this.docMaps = docMaps; SegmentInfo firstSegment = merge.segments.Info(0); int i = 0; while (true) { SegmentInfo info = infos.Info(i); if (info.Equals(firstSegment)) { break; } minDocID += info.docCount; i++; } int numDocs = 0; for (int j = 0; j < docMaps.Length; i++, j++) { numDocs += infos.Info(i).docCount; System.Diagnostics.Debug.Assert(infos.Info(i).Equals(merge.segments.Info(j))); } maxDocID = minDocID + numDocs; starts = new int[docMaps.Length]; newStarts = new int[docMaps.Length]; starts[0] = minDocID; newStarts[0] = minDocID; for (i = 1; i < docMaps.Length; i++) { int lastDocCount = merge.segments.Info(i - 1).docCount; starts[i] = starts[i - 1] + lastDocCount; newStarts[i] = newStarts[i - 1] + lastDocCount - delCounts[i - 1]; } docShift = numDocs - mergedDocCount; // There are rare cases when docShift is 0. It happens // if you try to delete a docID that's out of bounds, // because the SegmentReader still allocates deletedDocs // and pretends it has deletions ... so we can't make // this assert here // assert docShift > 0; // Make sure it all adds up: System.Diagnostics.Debug.Assert(docShift == maxDocID - (newStarts [docMaps.Length - 1] + merge.segments.Info(docMaps.Length - 1).docCount - delCounts [docMaps.Length - 1])); }