예제 #1
0
		public void  Write(IndexOutput output)
		{
			output.WriteVInt(CURRENT_FORMAT);
			output.WriteVInt(Size());
			for (int i = 0; i < Size(); i++)
			{
				FieldInfo fi = FieldInfo(i);
				var bits = (byte) (0x0);
				if (fi.isIndexed)
					bits |= IS_INDEXED;
				if (fi.storeTermVector)
					bits |= STORE_TERMVECTOR;
				if (fi.storePositionWithTermVector)
					bits |= STORE_POSITIONS_WITH_TERMVECTOR;
				if (fi.storeOffsetWithTermVector)
					bits |= STORE_OFFSET_WITH_TERMVECTOR;
				if (fi.omitNorms)
					bits |= OMIT_NORMS;
				if (fi.storePayloads)
					bits |= STORE_PAYLOADS;
				if (fi.omitTermFreqAndPositions)
					bits |= OMIT_TERM_FREQ_AND_POSITIONS;
				
				output.WriteString(fi.name);
				output.WriteByte(bits);
			}
		}
		protected internal override void  WriteSkipData(int level, IndexOutput skipBuffer)
		{
			// To efficiently store payloads in the posting lists we do not store the length of
			// every payload. Instead we omit the length for a payload if the previous payload had
			// the same length.
			// However, in order to support skipping the payload length at every skip point must be known.
			// So we use the same length encoding that we use for the posting lists for the skip data as well:
			// Case 1: current field does not store payloads
			//           SkipDatum                 --> DocSkip, FreqSkip, ProxSkip
			//           DocSkip,FreqSkip,ProxSkip --> VInt
			//           DocSkip records the document number before every SkipInterval th  document in TermFreqs. 
			//           Document numbers are represented as differences from the previous value in the sequence.
			// Case 2: current field stores payloads
			//           SkipDatum                 --> DocSkip, PayloadLength?, FreqSkip,ProxSkip
			//           DocSkip,FreqSkip,ProxSkip --> VInt
			//           PayloadLength             --> VInt    
			//         In this case DocSkip/2 is the difference between
			//         the current and the previous value. If DocSkip
			//         is odd, then a PayloadLength encoded as VInt follows,
			//         if DocSkip is even, then it is assumed that the
			//         current payload length equals the length at the previous
			//         skip point
			if (curStorePayloads)
			{
				int delta = curDoc - lastSkipDoc[level];
				if (curPayloadLength == lastSkipPayloadLength[level])
				{
					// the current payload length equals the length at the previous skip point,
					// so we don't store the length again
					skipBuffer.WriteVInt(delta * 2);
				}
				else
				{
					// the payload length is different from the previous one. We shift the DocSkip, 
					// set the lowest bit and store the current payload length as VInt.
					skipBuffer.WriteVInt(delta * 2 + 1);
					skipBuffer.WriteVInt(curPayloadLength);
					lastSkipPayloadLength[level] = curPayloadLength;
				}
			}
			else
			{
				// current field does not store payloads
				skipBuffer.WriteVInt(curDoc - lastSkipDoc[level]);
			}
			skipBuffer.WriteVInt((int) (curFreqPointer - lastSkipFreqPointer[level]));
			skipBuffer.WriteVInt((int) (curProxPointer - lastSkipProxPointer[level]));
			
			lastSkipDoc[level] = curDoc;
			//System.out.println("write doc at level " + level + ": " + curDoc);
			
			lastSkipFreqPointer[level] = curFreqPointer;
			lastSkipProxPointer[level] = curProxPointer;
		}
예제 #3
0
		/// <summary>Write as a d-gaps list </summary>
		private void  WriteDgaps(IndexOutput output)
		{
			output.WriteInt(- 1); // mark using d-gaps                         
			output.WriteInt(Size()); // write size
			output.WriteInt(Count()); // write count
			int last = 0;
			int n = Count();
			int m = bits.Length;
			for (int i = 0; i < m && n > 0; i++)
			{
				if (bits[i] != 0)
				{
					output.WriteVInt(i - last);
					output.WriteByte(bits[i]);
					last = i;
					n -= BYTE_COUNTS[bits[i] & 0xFF];
				}
			}
		}