/// <summary>Expert: like <see cref="GetReader()" />, except you can
/// specify which termInfosIndexDivisor should be used for
/// any newly opened readers.
/// </summary>
/// <param name="termInfosIndexDivisor">Subsambles which indexed
/// terms are loaded into RAM. This has the same effect as <see cref="IndexWriter.TermIndexInterval" />
/// except that setting
/// must be done at indexing time while this setting can be
/// set per reader. When set to N, then one in every
/// N*termIndexInterval terms in the index is loaded into
/// memory. By setting this to a value > 1 you can reduce
/// memory usage, at the expense of higher latency when
/// loading a TermInfo. The default value is 1. Set this
/// to -1 to skip loading the terms index entirely.
/// </param>
public virtual IndexReader GetReader(int termInfosIndexDivisor)
{
EnsureOpen();
if (infoStream != null)
{
Message("flush at getReader");
}
// Do this up front before flushing so that the readers
// obtained during this flush are pooled, the first time
// this method is called:
poolReaders = true;
// Prevent segmentInfos from changing while opening the
// reader; in theory we could do similar retry logic,
// just like we do when loading segments_N
IndexReader r;
lock (this)
{
Flush(false, true, true);
r = new ReadOnlyDirectoryReader(this, segmentInfos, termInfosIndexDivisor);
}
MaybeMerge();
return r;
}
private DirectoryReader DoReopen(SegmentInfos infos, bool doClone, bool openReadOnly)
{
lock (this)
{
DirectoryReader reader;
if (openReadOnly)
{
reader = new ReadOnlyDirectoryReader(internalDirectory, infos, subReaders, starts, normsCache, doClone, termInfosIndexDivisor);
}
else
{
reader = new DirectoryReader(internalDirectory, infos, subReaders, starts, normsCache, false, doClone, termInfosIndexDivisor);
}
return reader;
}
}
