public CoreFieldIndex(FieldIndexData outerInstance, long indexStart, long termsStart, long packedIndexStart, long packedOffsetsStart,
int numIndexTerms)
{
this.termsStart = termsStart;
termBytesStart = outerInstance.outerInstance.termBytes.GetPointer();
IndexInput clone = (IndexInput)outerInstance.outerInstance.input.Clone();
clone.Seek(indexStart);
// -1 is passed to mean "don't load term index", but
// if we are then later loaded it's overwritten with
// a real value
if (Debugging.AssertsEnabled)
{
Debugging.Assert(outerInstance.outerInstance.indexDivisor > 0);
}
this.numIndexTerms = 1 + (numIndexTerms - 1) / outerInstance.outerInstance.indexDivisor;
if (Debugging.AssertsEnabled)
{
Debugging.Assert(this.numIndexTerms > 0, "numIndexTerms={0} indexDivisor={1}", numIndexTerms, outerInstance.outerInstance.indexDivisor);
}
if (outerInstance.outerInstance.indexDivisor == 1)
{
// Default (load all index terms) is fast -- slurp in the images from disk:
try
{
long numTermBytes = packedIndexStart - indexStart;
outerInstance.outerInstance.termBytes.Copy(clone, numTermBytes);
// records offsets into main terms dict file
termsDictOffsets = PackedInt32s.GetReader(clone);
if (Debugging.AssertsEnabled)
{
Debugging.Assert(termsDictOffsets.Count == numIndexTerms);
}
// records offsets into byte[] term data
termOffsets = PackedInt32s.GetReader(clone);
if (Debugging.AssertsEnabled)
{
Debugging.Assert(termOffsets.Count == 1 + numIndexTerms);
}
}
finally
{
clone.Dispose();
}
}
else
{
// Get packed iterators
IndexInput clone1 = (IndexInput)outerInstance.outerInstance.input.Clone();
IndexInput clone2 = (IndexInput)outerInstance.outerInstance.input.Clone();
try
{
// Subsample the index terms
clone1.Seek(packedIndexStart);
PackedInt32s.IReaderIterator termsDictOffsetsIter = PackedInt32s.GetReaderIterator(clone1, PackedInt32s.DEFAULT_BUFFER_SIZE);
clone2.Seek(packedOffsetsStart);
PackedInt32s.IReaderIterator termOffsetsIter = PackedInt32s.GetReaderIterator(clone2, PackedInt32s.DEFAULT_BUFFER_SIZE);
// TODO: often we can get by w/ fewer bits per
// value, below.. .but this'd be more complex:
// we'd have to try @ fewer bits and then grow
// if we overflowed it.
PackedInt32s.Mutable termsDictOffsetsM = PackedInt32s.GetMutable(this.numIndexTerms, termsDictOffsetsIter.BitsPerValue, PackedInt32s.DEFAULT);
PackedInt32s.Mutable termOffsetsM = PackedInt32s.GetMutable(this.numIndexTerms + 1, termOffsetsIter.BitsPerValue, PackedInt32s.DEFAULT);
termsDictOffsets = termsDictOffsetsM;
termOffsets = termOffsetsM;
int upto = 0;
long termOffsetUpto = 0;
while (upto < this.numIndexTerms)
{
// main file offset copies straight over
termsDictOffsetsM.Set(upto, termsDictOffsetsIter.Next());
termOffsetsM.Set(upto, termOffsetUpto);
long termOffset = termOffsetsIter.Next();
long nextTermOffset = termOffsetsIter.Next();
int numTermBytes = (int)(nextTermOffset - termOffset);
clone.Seek(indexStart + termOffset);
if (Debugging.AssertsEnabled)
{
Debugging.Assert(indexStart + termOffset < clone.Length, "indexStart={0} termOffset={1} len={2}", indexStart, termOffset, clone.Length);
Debugging.Assert(indexStart + termOffset + numTermBytes < clone.Length);
}
outerInstance.outerInstance.termBytes.Copy(clone, numTermBytes);
termOffsetUpto += numTermBytes;
upto++;
if (upto == this.numIndexTerms)
{
break;
}
// skip terms:
termsDictOffsetsIter.Next();
for (int i = 0; i < outerInstance.outerInstance.indexDivisor - 2; i++)
{
termOffsetsIter.Next();
termsDictOffsetsIter.Next();
}
}
termOffsetsM.Set(upto, termOffsetUpto);
}
finally
{
clone1.Dispose();
clone2.Dispose();
clone.Dispose();
}
}
}