public override long Get(long index)
{
Debug.Assert(index >= 0 && index < valueCount);
int block = (int)((long)((ulong)index >> blockShift));
int idx = (int)(index & blockMask);
// LUCENENET NOTE: IMPORTANT: The cast to float is critical here for it to work in x86
return(minValues[block] + (long)(float)(idx * averages[block]) + BlockPackedReaderIterator.ZigZagDecode(subReaders[block].Get(idx)));
}
/// <summary>
/// Sole constructor. </summary>
public BlockPackedReader(IndexInput @in, int packedIntsVersion, int blockSize, long valueCount, bool direct)
{
this.valueCount = valueCount;
blockShift = PackedInt32s.CheckBlockSize(blockSize, AbstractBlockPackedWriter.MIN_BLOCK_SIZE, AbstractBlockPackedWriter.MAX_BLOCK_SIZE);
blockMask = blockSize - 1;
int numBlocks = PackedInt32s.NumBlocks(valueCount, blockSize);
long[] minValues = null;
subReaders = new PackedInt32s.Reader[numBlocks];
for (int i = 0; i < numBlocks; ++i)
{
int token = @in.ReadByte() & 0xFF;
int bitsPerValue = token.TripleShift(AbstractBlockPackedWriter.BPV_SHIFT);
if (bitsPerValue > 64)
{
throw new IOException("Corrupted");
}
if ((token & AbstractBlockPackedWriter.MIN_VALUE_EQUALS_0) == 0)
{
if (minValues is null)
{
minValues = new long[numBlocks];
}
minValues[i] = BlockPackedReaderIterator.ZigZagDecode(1L + BlockPackedReaderIterator.ReadVInt64(@in));
}
if (bitsPerValue == 0)
{
subReaders[i] = new PackedInt32s.NullReader(blockSize);
}
else
{
int size = (int)Math.Min(blockSize, valueCount - (long)i * blockSize);
if (direct)
{
long pointer = @in.Position; // LUCENENET specific: Renamed from getFilePointer() to match FileStream
subReaders[i] = PackedInt32s.GetDirectReaderNoHeader(@in, PackedInt32s.Format.PACKED, packedIntsVersion, size, bitsPerValue);
@in.Seek(pointer + PackedInt32s.Format.PACKED.ByteCount(packedIntsVersion, size, bitsPerValue));
}
else
{
subReaders[i] = PackedInt32s.GetReaderNoHeader(@in, PackedInt32s.Format.PACKED, packedIntsVersion, size, bitsPerValue);
}
}
}
this.minValues = minValues;
}
