BarrelTermPositions.h

00001 //
00002 // Copyright(C) 2005--2006 Institute of Computing Tech, Chinese Academy of Sciences. 
00003 // All rights reserved.
00004 // This file is part of FirteX (www.firtex.org)
00005 //
00006 // Use of the FirteX is subject to the terms of the software license set forth in 
00007 // the LICENSE file included with this software, and also available at
00008 // http://www.firtex.org/license.html
00009 //
00010 // Author       : 郭瑞杰(GuoRuijie)
00011 // Email        : ruijieguo@software.ict.ac.cn
00012 // Created      : 2006/1/6
00013 //
00014 
00015 #ifndef _BARRELTERMPOSITIONS_H
00016 #define _BARRELTERMPOSITIONS_H
00017 
00018 #include "TermPositions.h"
00019 #include "BarrelTermDocs.h"
00020 
00021 namespace firtex
00022 {
00023         namespace index
00024         {
00025                 class CBarrelTermPositions : public CBarrelTermDocs,public CTermPositions
00026                 {
00027                 public:
00028                         CBarrelTermPositions(void);
00029                         CBarrelTermPositions(CTermReader* pReader,CIndexInput* pDfiStream,CIndexInput* pPtiStream,CTermInfo& ti,CBitVector* deletedDocs);
00030 
00031                         virtual ~CBarrelTermPositions(void);
00032                 public:
00036                         bool    seek(CTerm* term);
00037 
00041                         docid_t doc();
00042 
00046                         count_t freq();
00047 
00052                         bool    next();
00053 
00061                         count_t next(docid_t*& docs, count_t*& freqs);
00062 
00070                         bool skipTo(docid_t target,docid_t& nearTarget);
00071 
00079                         bool skipToPosition(loc_t target,loc_t& nearTarget);
00080 
00081                         freq_t docFreq(){return CBarrelTermDocs::docFreq();};
00082 
00086                         void    close();
00087 
00091                         loc_t   nextPosition();
00092                         
00098                         count_t nextPositions(loc_t*& positions);
00099                 protected:
00100                         bool    decodePositions();
00101                 protected:
00102                         int                             m_posCount;                             //位置个数,即df
00103                         int                             m_posPointer;                   //在页中的当前位置
00104                         int                             m_posPageSize;                  //页的实际使用大小
00105                         int                             m_posLength;                    //block长度
00106                         int                             m_posPagePosition;              //页在pos中的位置                       
00107                         int                             m_posDecodeCount;               //已经解压的position个数
00108 
00109                         loc_t                   m_posPage[PAGE_SIZE];
00110                         loc_t                   m_posLastPos;                   //记录最后一个pos值
00111 
00112 
00113                         CIndexInput*    m_pPosStream;   
00114 
00115                 };
00116         }
00117 }
00118 
00119 
00120 #endif