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]));
}