public override int Merge(MergeState mergeState)
{
int docCount = 0;
// Used for bulk-reading raw bytes for stored fields
int[] rawDocLengths = new int[MAX_RAW_MERGE_DOCS];
int idx = 0;
foreach (AtomicReader reader in mergeState.Readers)
{
SegmentReader matchingSegmentReader = mergeState.MatchingSegmentReaders[idx++];
Lucene40StoredFieldsReader matchingFieldsReader = null;
if (matchingSegmentReader != null)
{
StoredFieldsReader fieldsReader = matchingSegmentReader.FieldsReader;
// we can only bulk-copy if the matching reader is also a Lucene40FieldsReader
if (fieldsReader != null && fieldsReader is Lucene40StoredFieldsReader)
{
matchingFieldsReader = (Lucene40StoredFieldsReader)fieldsReader;
}
}
if (reader.LiveDocs != null)
{
docCount += CopyFieldsWithDeletions(mergeState, reader, matchingFieldsReader, rawDocLengths);
}
else
{
docCount += CopyFieldsNoDeletions(mergeState, reader, matchingFieldsReader, rawDocLengths);
}
}
Finish(mergeState.FieldInfos, docCount);
return(docCount);
}
private int CopyFieldsNoDeletions(MergeState mergeState, AtomicReader reader, Lucene40StoredFieldsReader matchingFieldsReader, int[] rawDocLengths)
{
int maxDoc = reader.MaxDoc;
int docCount = 0;
if (matchingFieldsReader != null)
{
// We can bulk-copy because the fieldInfos are "congruent"
while (docCount < maxDoc)
{
int len = Math.Min(MAX_RAW_MERGE_DOCS, maxDoc - docCount);
IndexInput stream = matchingFieldsReader.RawDocs(rawDocLengths, docCount, len);
AddRawDocuments(stream, rawDocLengths, len);
docCount += len;
mergeState.CheckAbort.Work(300 * len);
}
}
else
{
for (; docCount < maxDoc; docCount++)
{
// NOTE: it's very important to first assign to doc then pass it to
// fieldsWriter.addDocument; see LUCENE-1282
Document doc = reader.Document(docCount);
AddDocument(doc, mergeState.FieldInfos);
mergeState.CheckAbort.Work(300);
}
}
return(docCount);
}
private int CopyFieldsWithDeletions(MergeState mergeState, AtomicReader reader, Lucene40StoredFieldsReader matchingFieldsReader, int[] rawDocLengths)
{
int docCount = 0;
int maxDoc = reader.MaxDoc;
IBits liveDocs = reader.LiveDocs;
Debug.Assert(liveDocs != null);
if (matchingFieldsReader != null)
{
// We can bulk-copy because the fieldInfos are "congruent"
for (int j = 0; j < maxDoc;)
{
if (!liveDocs.Get(j))
{
// skip deleted docs
++j;
continue;
}
// We can optimize this case (doing a bulk byte copy) since the field
// numbers are identical
int start = j, numDocs = 0;
do
{
j++;
numDocs++;
if (j >= maxDoc)
{
break;
}
if (!liveDocs.Get(j))
{
j++;
break;
}
} while (numDocs < MAX_RAW_MERGE_DOCS);
IndexInput stream = matchingFieldsReader.RawDocs(rawDocLengths, start, numDocs);
AddRawDocuments(stream, rawDocLengths, numDocs);
docCount += numDocs;
mergeState.CheckAbort.Work(300 * numDocs);
}
}
else
{
for (int j = 0; j < maxDoc; j++)
{
if (!liveDocs.Get(j))
{
// skip deleted docs
continue;
}
// TODO: this could be more efficient using
// FieldVisitor instead of loading/writing entire
// doc; ie we just have to renumber the field number
// on the fly?
// NOTE: it's very important to first assign to doc then pass it to
// fieldsWriter.addDocument; see LUCENE-1282
Document doc = reader.Document(j);
AddDocument(doc, mergeState.FieldInfos);
docCount++;
mergeState.CheckAbort.Work(300);
}
}
return(docCount);
}