Apache/lucene
1
0
Fork 0
mirror of https://github.com/apache/lucene.git synced 2025-02-08 02:58:58 +00:00
Code Issues Packages Projects Releases Wiki Activity

LUCENE-4447: fixups for .pos

Browse Source 
git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1396622 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Robert Muir 2012-10-10 14:47:11 +00:00
parent 01a284047e
commit 06a4f8a5f6
1 changed files with 24 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
lucene/codecs/src/java/org/apache/lucene/codecs/block/BlockPostingsFormat.java
View File

@ -274,12 +274,12 @@ import org.apache.lucene.util.packed.PackedInts;
* <li>Header --&gt; {@link CodecUtil#writeHeader CodecHeader}</li>
* <li>TermPositions --&gt; &lt;PackedPosDeltaBlock&gt; <sup>PackedPosBlockNum</sup>,
* VIntBlock? </li>
* <li>VIntBlock --&gt; PosVIntCount, &lt;PosDelta[, PayLength?], PayData?,
* OffsetStartDelta?, OffsetLength?&gt;<sup>PosVIntCount</sup>
* <li>VIntBlock --&gt; PosVIntCount, &lt;PositionDelta[, PayloadLength?], PayloadData?,
* OffsetDelta?, OffsetLength?&gt;<sup>PosVIntCount</sup>
* <li>PackedPosDeltaBlock --&gt; {@link PackedInts PackedInts}</li>
* <li>PosVIntCount, PosDelta, OffsetStartDelta, OffsetLength --&gt;
* <li>PosVIntCount, PositionDelta, OffsetDelta, OffsetLength --&gt;
* {@link DataOutput#writeVInt VInt}</li>
* <li>PayData --&gt; {@link DataOutput#writeByte byte}<sup>PayLength</sup></li>
* <li>PayloadData --&gt; {@link DataOutput#writeByte byte}<sup>PayLength</sup></li>
* </ul>
* <p>Notes:</p>
* <ul>
@ -291,13 +291,26 @@ import org.apache.lucene.util.packed.PackedInts;
* PosVIntCount = totalTermFreq - PackedPosBlockNum*PackedBlockSize</li>
* <li>The procedure how PackedPosDeltaBlock is generated is the same as PackedDocDeltaBlock
* in chapter <a href="#Frequencies">Frequencies and Skip Data</a>.</li>
* <li>PosDelta is the same as the format mentioned in
* <a href="{@docRoot}/../core/org/apache/lucene/codecs/lucene40/Lucene40PostingsFormat.html#Positions">Lucene40PostingsFormat:Positions</a>
* </li>
* <li>OffsetStartDelta is the difference between this position's startOffset from the previous
* occurrence (or zero, if this is the first occurrence in this document).</li>
* <li>OffsetLength indicates the length of the current offset (endOffset-startOffset).</li>
* <li>PayloadData is the blob of metadata associated with current position.</li>
* <li>PositionDelta is, if payloads are disabled for the term's field, the
* difference between the position of the current occurrence in the document and
* the previous occurrence (or zero, if this is the first occurrence in this
* document). If payloads are enabled for the term's field, then PositionDelta/2
* is the difference between the current and the previous position. If payloads
* are enabled and PositionDelta is odd, then PayloadLength is stored, indicating
* the length of the payload at the current term position.</li>
* <li>For example, the TermPositions for a term which occurs as the fourth term in
* one document, and as the fifth and ninth term in a subsequent document, would
* be the following sequence of VInts (payloads disabled):
* <p>4, 5, 4</p></li>
* <li>PayloadData is metadata associated with the current term position. If
* PayloadLength is stored at the current position, then it indicates the length
* of this payload. If PayloadLength is not stored, then this payload has the same
* length as the payload at the previous position.</li>
* <li>OffsetDelta is the difference between this position's startOffset from the
* previous occurrence (or zero, if this is the first occurrence in this document).
* OffsetLength follows, encoding the difference between endOffset and startOffset.
* Offset data is only written for
* {@link IndexOptions#DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS}.</li>
* </ul>
* </dd>
* </dl>