gistfcnt.h

此文件包含了在linux下实现tpr-tree索引的源代码

// -*- Mode: C++ -*-
//--------------------------------------------------------------------
//        GiSTfcnt.h
//        ----------
//
//        GiST - Generalized Search Tree 
//        June 2001 release, Aalborg University
//        
//        This file is a revised version of a part of the original 
//        libGiST release (version  0.9beta1)     
//        Copyright (c) 1996, Regents of the University of California
//

#ifndef GISTFCNT_H
#define GISTFCNT_H

#define CACHE_INC (100)
#define DEF_BUFFER_SIZE (100)

#include "GiSTpath.h"
#include "GiSTfileCache.h"

//--------------------------------------------------------------------
//  GiSTcache - stores the numbers and dirty flags of the pages
//              in the simulated cache buffer
//

class GiSTcache
{
public:
  GiSTcache(int size);
  ~GiSTcache();

  void UpdateSize (int size);
  int GetSize () { return len; } 

  int Add(int x, char dirty);  
  int Find(int x) const;
  int FlushDirty();
  void Clear() {num = 0;}

private:
  char*  dirtyFlags;
  int*   array;
  int    num;
  int    len;
};

//--------------------------------------------------------------------
//  GiSTfileCnt - augments GiSTfileCache to count accessed disk pages
//                and simulates the cache buffer of the desired side 
//                (GiSTfileCahce caches real pages to improve the
//                 perfofmance of the experimental testbench itself)
//

class GiSTfileCnt : public  GiSTfileCache
{
public:

  GiSTfileCnt() : GiSTfileCache(), pcount(0), pageSize(DefPageSize)
  { cache = new GiSTcache(DEF_BUFFER_SIZE); }
  ~GiSTfileCnt() { delete cache;          }

  static int DefPageSize;

  void ResetCounter();
  void Write (GiSTpage page, const char *buf);
  void Read  (GiSTpage page, char *buf);
  void DontCountLastOp() { --pcount; }
  int  GetCounter();
  int  PageSize  () const { return pageSize; }

  void  SetBufferSize (int size) { cache->UpdateSize(size); }
  int   GetBufferSize () const   { return cache->GetSize(); } 

private:
  int pageSize;
  int pcount;
  GiSTcache* cache;
};

#endif