/// <summary>
/// Creates an ordinal map that allows mapping ords to/from a merged
/// space from <c>subs</c>. </summary>
/// <param name="owner"> a cache key </param>
/// <param name="subs"> <see cref="TermsEnum"/>s that support <see cref="TermsEnum.Ord"/>. They need
/// not be dense (e.g. can be FilteredTermsEnums). </param>
/// <exception cref="System.IO.IOException"> if an I/O error occurred. </exception>
public OrdinalMap(object owner, TermsEnum[] subs)
{
// create the ordinal mappings by pulling a termsenum over each sub's
// unique terms, and walking a multitermsenum over those
this.owner = owner;
globalOrdDeltas = new MonotonicAppendingInt64Buffer(PackedInt32s.COMPACT);
firstSegments = new AppendingPackedInt64Buffer(PackedInt32s.COMPACT);
ordDeltas = new MonotonicAppendingInt64Buffer[subs.Length];
for (int i = 0; i < ordDeltas.Length; i++)
{
ordDeltas[i] = new MonotonicAppendingInt64Buffer();
}
long[] segmentOrds = new long[subs.Length];
ReaderSlice[] slices = new ReaderSlice[subs.Length];
TermsEnumIndex[] indexes = new TermsEnumIndex[slices.Length];
for (int i = 0; i < slices.Length; i++)
{
slices[i] = new ReaderSlice(0, 0, i);
indexes[i] = new TermsEnumIndex(subs[i], i);
}
MultiTermsEnum mte = new MultiTermsEnum(slices);
mte.Reset(indexes);
long globalOrd = 0;
while (mte.Next() != null)
{
TermsEnumWithSlice[] matches = mte.MatchArray;
for (int i = 0; i < mte.MatchCount; i++)
{
int segmentIndex = matches[i].Index;
long segmentOrd = matches[i].Terms.Ord;
long delta = globalOrd - segmentOrd;
// for each unique term, just mark the first segment index/delta where it occurs
if (i == 0)
{
firstSegments.Add(segmentIndex);
globalOrdDeltas.Add(delta);
}
// for each per-segment ord, map it back to the global term.
while (segmentOrds[segmentIndex] <= segmentOrd)
{
ordDeltas[segmentIndex].Add(delta);
segmentOrds[segmentIndex]++;
}
}
globalOrd++;
}
firstSegments.Freeze();
globalOrdDeltas.Freeze();
for (int i = 0; i < ordDeltas.Length; ++i)
{
ordDeltas[i].Freeze();
}
}
/// <summary>
/// Returns {@code true} if this instance can be reused by
/// the provided <seealso cref="MultiTermsEnum"/>.
/// </summary>
public bool CanReuse(MultiTermsEnum parent)
{
return(this.parent == parent);
}
/// <summary>
/// Sole constructor. </summary>
public MultiDocsAndPositionsEnum(MultiTermsEnum parent, int subReaderCount)
{
this.parent = parent;
subDocsAndPositionsEnum = new DocsAndPositionsEnum[subReaderCount];
}
/// <summary>
/// Sole constructor </summary>
/// <param name="parent"> The <seealso cref="MultiTermsEnum"/> that created us. </param>
/// <param name="subReaderCount"> How many sub-readers are being merged. </param>
public MultiDocsEnum(MultiTermsEnum parent, int subReaderCount)
{
this.Parent = parent;
SubDocsEnum = new DocsEnum[subReaderCount];
}
