/// <summary>Scans within block for matching term. </summary>
private TermInfo ScanEnum(Term term)
{
SegmentTermEnum enumerator = GetEnum();
enumerator.ScanTo(term);
if (enumerator.Term() != null && term.CompareTo(enumerator.Term()) == 0)
{
return(enumerator.TermInfo());
}
else
{
return(null);
}
}
/// <summary>Returns the TermInfo for a Term in the set, or null. </summary>
private TermInfo Get(Term term, bool useCache)
{
if (size == 0)
{
return(null);
}
EnsureIndexIsRead();
TermInfo ti;
ThreadResources resources = GetThreadResources();
Lucene.Net.Util.Cache.Cache cache = null;
if (useCache)
{
cache = resources.termInfoCache;
// check the cache first if the term was recently looked up
ti = (TermInfo)cache.Get(term);
if (ti != null)
{
return(ti);
}
}
// optimize sequential access: first try scanning cached enum w/o seeking
SegmentTermEnum enumerator = resources.termEnum;
if (enumerator.Term() != null && ((enumerator.Prev() != null && term.CompareTo(enumerator.Prev()) > 0) || term.CompareTo(enumerator.Term()) >= 0))
{
int enumOffset = (int)(enumerator.position / totalIndexInterval) + 1;
if (indexTerms.Length == enumOffset || term.CompareTo(indexTerms[enumOffset]) < 0)
{
// no need to seek
int numScans = enumerator.ScanTo(term);
if (enumerator.Term() != null && term.CompareTo(enumerator.Term()) == 0)
{
ti = enumerator.TermInfo();
if (cache != null && numScans > 1)
{
// we only want to put this TermInfo into the cache if
// scanEnum skipped more than one dictionary entry.
// This prevents RangeQueries or WildcardQueries to
// wipe out the cache when they iterate over a large numbers
// of terms in order
cache.Put(term, ti);
}
}
else
{
ti = null;
}
return(ti);
}
}
// random-access: must seek
SeekEnum(enumerator, GetIndexOffset(term));
enumerator.ScanTo(term);
if (enumerator.Term() != null && term.CompareTo(enumerator.Term()) == 0)
{
ti = enumerator.TermInfo();
if (cache != null)
{
cache.Put(term, ti);
}
}
else
{
ti = null;
}
return(ti);
}
