/// <summary> Advances to the first match beyond the current whose document number is
/// greater than or equal to a given target. <br/>
/// The implementation uses {@link TermDocs#SkipTo(int)}.
///
/// </summary>
/// <param name="target">The target document number.
/// </param>
/// <returns> the matching document or -1 if none exist.
/// </returns>
public override int Advance(int target)
{
// first scan in cache
for (pointer++; pointer < pointerMax; pointer++)
{
if (docs[pointer] >= target)
{
return(doc = docs[pointer]);
}
}
// not found in cache, seek underlying stream
bool result = termDocs.SkipTo(target);
if (result)
{
pointerMax = 1;
pointer = 0;
docs[pointer] = doc = termDocs.Doc();
freqs[pointer] = termDocs.Freq();
}
else
{
doc = NO_MORE_DOCS;
}
return(doc);
}