/// <summary>
/// Write a block of data (<code>For</code> format).
/// </summary>
/// <param name="data"> the data to write </param>
/// <param name="encoded"> a buffer to use to encode data </param>
/// <param name="out"> the destination output </param>
/// <exception cref="IOException"> If there is a low-level I/O error </exception>
public void WriteBlock(int[] data, byte[] encoded, IndexOutput @out)
{
if (IsAllEqual(data))
{
@out.WriteByte((byte)(sbyte)ALL_VALUES_EQUAL);
@out.WriteVInt(data[0]);
return;
}
int numBits = BitsRequired(data);
Debug.Assert(numBits > 0 && numBits <= 32, numBits.ToString());
PackedInts.Encoder encoder = Encoders[numBits];
int iters = Iterations[numBits];
Debug.Assert(iters * encoder.ByteValueCount() >= Lucene41PostingsFormat.BLOCK_SIZE);
int encodedSize = EncodedSizes[numBits];
Debug.Assert(iters * encoder.ByteBlockCount() >= encodedSize);
@out.WriteByte((byte)numBits);
encoder.Encode(data, 0, encoded, 0, iters);
@out.WriteBytes(encoded, encodedSize);
}
protected internal void WriteValues(int bitsRequired)
{
PackedInts.Encoder encoder = PackedInts.GetEncoder(PackedInts.Format.PACKED, PackedInts.VERSION_CURRENT, bitsRequired);
int iterations = Values.Length / encoder.ByteValueCount();
int blockSize = encoder.ByteBlockCount() * iterations;
if (Blocks == null || Blocks.Length < blockSize)
{
Blocks = new byte[blockSize];
}
if (Off < Values.Length)
{
Arrays.Fill(Values, Off, Values.Length, 0L);
}
encoder.Encode(Values, 0, Blocks, 0, iterations);
int blockCount = (int)PackedInts.Format.PACKED.ByteCount(PackedInts.VERSION_CURRENT, Off, bitsRequired);
@out.WriteBytes(Blocks, blockCount);
}
internal virtual void PforEncode()
{
if (NumExceptions > 0)
{
int mask = (1 << BitsPerValue) - 1;
int ex = 0;
for (int i = 0; i < BufferSize; ++i)
{
if (Buffer[i] > mask)
{
ExceptionIndices[ex] = i;
Exceptions[ex++] = (int)((uint)Buffer[i] >> BitsPerValue);
Buffer[i] &= mask;
}
}
Debug.Assert(ex == NumExceptions);
Arrays.Fill(Exceptions, NumExceptions, BLOCK_SIZE, 0);
}
if (BitsPerValue > 0)
{
PackedInts.Encoder encoder = PackedInts.GetEncoder(PackedInts.Format.PACKED, PackedInts.VERSION_CURRENT, BitsPerValue);
int numIterations = ITERATIONS[BitsPerValue];
encoder.Encode(Buffer, 0, Data.Bytes, Data.Length, numIterations);
Data.Length += encoder.ByteBlockCount() * numIterations;
}
if (NumExceptions > 0)
{
Debug.Assert(BitsPerException > 0);
Data.WriteByte((sbyte)NumExceptions);
Data.WriteByte((sbyte)BitsPerException);
PackedInts.Encoder encoder = PackedInts.GetEncoder(PackedInts.Format.PACKED, PackedInts.VERSION_CURRENT, BitsPerException);
int numIterations = (NumExceptions + encoder.ByteValueCount() - 1) / encoder.ByteValueCount();
encoder.Encode(Exceptions, 0, Data.Bytes, Data.Length, numIterations);
Data.Length += (int)PackedInts.Format.PACKED.ByteCount(PackedInts.VERSION_CURRENT, NumExceptions, BitsPerException);
for (int i = 0; i < NumExceptions; ++i)
{
Data.WriteByte((sbyte)ExceptionIndices[i]);
}
}
}