public virtual void writeCompressed(ExtendedDataOutput output)
{
int dataType = (int)this.getDataType();
int unitLength = getUnitLength(this.getDataType());
int elementCount = this.rows();
int maxCompressedLength = this.rows() * sizeof(long) * 8 * 2 + 64 * 3;
ByteBuffer outBuffer = ByteBuffer.Allocate(Math.Max(maxCompressedLength, 65536));
outBuffer.order(output.GetType() == typeof(LittleEndianDataOutputStream));
short flag = (short)((short)DATA_FORM.DF_VECTOR << 8 | (short)DATA_TYPE.DT_COMPRESS & 0xff);
outBuffer.WriteShort(flag);
outBuffer.WriteInt(0); // compressedBytes
outBuffer.WriteInt(1); // cols
outBuffer.WriteByte((byte)0); // version
outBuffer.WriteByte((byte)1); // flag bit0:littleEndian bit1:containChecksum
outBuffer.WriteByte(unchecked ((byte)-1)); // charcode
outBuffer.WriteByte((byte)compressedMethod);
outBuffer.WriteByte((byte)dataType);
outBuffer.WriteByte((byte)unitLength);
outBuffer.WriteByte((byte)0);
outBuffer.WriteByte((byte)0);
outBuffer.WriteInt(-1); //extra
outBuffer.WriteInt(elementCount);
outBuffer.WriteInt(-1); //TODO: checkSum
EncoderFactory.Get(compressedMethod).compress(this, elementCount, unitLength, maxCompressedLength, outBuffer);
int compressedLength = outBuffer.ReadableBytes - 10;
outBuffer.PutInt(compressedLength, 2);
byte[] tmp = new byte[outBuffer.ReadableBytes];
output.write(outBuffer.ToArray());
}