public override TermVectorsReader VectorsReader(Directory directory, SegmentInfo segmentInfo, FieldInfos fieldInfos, IOContext context)
{
string fileName = IndexFileNames.SegmentFileName(Lucene3xSegmentInfoFormat.GetDocStoreSegment(segmentInfo), "", Lucene3xTermVectorsReader.VECTORS_FIELDS_EXTENSION);
// Unfortunately, for 3.x indices, each segment's
// FieldInfos can lie about hasVectors (claim it's true
// when really it's false).... so we have to carefully
// check if the files really exist before trying to open
// them (4.x has fixed this):
bool exists;
if (Lucene3xSegmentInfoFormat.GetDocStoreOffset(segmentInfo) != -1 && Lucene3xSegmentInfoFormat.GetDocStoreIsCompoundFile(segmentInfo))
{
string cfxFileName = IndexFileNames.SegmentFileName(Lucene3xSegmentInfoFormat.GetDocStoreSegment(segmentInfo), "", Lucene3xCodec.COMPOUND_FILE_STORE_EXTENSION);
if (segmentInfo.Dir.FileExists(cfxFileName))
{
Directory cfsDir = new CompoundFileDirectory(segmentInfo.Dir, cfxFileName, context, false);
try
{
exists = cfsDir.FileExists(fileName);
}
finally
{
cfsDir.Dispose();
}
}
else
{
exists = false;
}
}
else
{
exists = directory.FileExists(fileName);
}
if (!exists)
{
// 3x's FieldInfos sometimes lies and claims a segment
// has vectors when it doesn't:
return(null);
}
else
{
return(new Lucene3xTermVectorsReader(directory, segmentInfo, fieldInfos, context));
}
}