rt.h

此文件包含了在linux下实现tpr-tree索引的源代码

// -*- Mode: C++ -*-
//--------------------------------------------------------------------
//      RT.h
//      ----
//      Implements the tree
//
//      Class hierarchy:
//      GiSTobject
//        GiST
//          RT
//
//      TPR-tree - Index for continuously moving objects
//      July 2001 release, Aalborg University
//

#ifndef RT_H
#define RT_H

#include "GiST.h"
#include "GiSTfcnt.h"
#include "rtnode.h"
#include "rtpredicate.h"
#include "rtbulksort.h"

const double TPR_UI_FACTOR  = 1.0;   // For the mechanism of auto maintenance of time horizon 

#ifdef RT_DEL_LOOKUP
#define RT_DEF_LOOKUP_SZ   200000
#endif

//------------------------------------------------
//    RT
//

class RT : public GiST
{
   friend class RTnode;   

public:   
   RT ();
   ~RT();

   // !!! Added for RNN testbed to be able to access the tree !!!
   //
   GiSTnode* GetNode (const GiSTpath& path) const { return ReadNode(path); }
   //

   void Create(const char *filename);
   void Open  (const char *filename);
   void Close ();
   void Drop  ();
   void Insert(const GiSTentry& entry);      
   int  Delete(const GiSTpredicate& pred);

   GiSTobjid   IsA() const               { return RT_CLASS;    }

   void        SetAutoHorizon (bool flag){ autoHorizon = flag; }
   bool        GetAutoHorizon () const   { return autoHorizon; }
   void        SetWFactor(double x)      { wfactor = x;        }
   double      GetWFactor() const        { return wfactor;     }
   void        SetHorizon (RTperiod p, RTperiod qw = 0) { param = p; w = qw; }
   RTperiod    GetParam () const         { return param;       }
   RTperiod    GetW     () const         { return w;           }
   void        SetAlpha (double   x)     { alpha = x;          }
   double      GetAlpha () const         { return alpha;       }
   void        SetRefTS (RTtimeStamp x)  { reft = x;           }
   RTtimeStamp GetRefTS () const         { return reft;        }
   RTtimeStamp GetLastCh() const         { return lastChange;  }

   void ResetCounter ()
   { ((GiSTfileCnt*)Store())->ResetCounter(); }
   
   int  GetCounter ()
   { return ((GiSTfileCnt*)Store())->GetCounter(); }
   
   int  PageSize ()
   { return ((GiSTfileCnt *)Store())->PageSize(); }
   
   void SetBufferSize (int size)
   { ((GiSTfileCnt *)Store())->SetBufferSize(size); }
   
   int  GetBufferSize ()
   { return ((GiSTfileCnt *)Store())->GetBufferSize(); }

   void DeleteAll () { Store()->Reset(); }

   // Bulk load
   // Both methods assume that data contains moving points with GiSTpage's
   //
   void LoadTopDownSTR (RTsortArray& data);   
   void LoadBottomUp   (RTsortArray& data);   // STR or Hilbert  

   // Bulk unload
   // Unloads all data of the tree into sortArray, does not change the tree
   //
   RTsortArray* Unload() const; 

#ifdef RT_DEL_LOOKUP
   GiSTpage*   delLookUp0;   
   GiSTpage*   delLookUp;      
   int         numDelLookUp0;
   int         numDelLookUp;
   int         levels;

   void ResetDelLookUp();
   void InitDelLookUp (int numEntries);
#endif

   // Functions for retrieving information relating to a tree-type 
   // FixedKeyLength returns zero if entries are of variable length
   //
   virtual int FixedKeyLength (bool isLeaf) const; 
   virtual int MinKeyLength   (bool isLeaf) const; 
   virtual int MaxKeyLength   (bool isLeaf) const; 
   virtual int MinEntries     (bool isLeaf) const; // in a full node
   virtual int MaxEntries     (bool isLeaf) const; // in a full node
           int HeaderSize     () const { return 3*sizeof(short); }

protected:
   int  leafLength;      
   int  nonleafLength;
   void UpdateKeyLength();     // Updates leafLength and nonleafLength

   GiSTnode*  CreateNode () const { return new RTnode; }
   GiSTstore* CreateStore() const { return new GiSTfileCnt; }

   int       ForcedReinsert() const { return 1; }
   GiSTlist<GiSTentry*> RemoveTop (GiSTnode *node);
   void OldRemoveTop(GiSTnode *node, RTindexArray& out,
                    RTindexArray& remains, int num_rem);
  
   // LoadNodes loads the coresponding tree level, 
   // returning the sortArray of the next level 
   //
   RTsortArray* LoadNodes(RTsortArray& data, int level);
      
private:
   char        file_nm[50];  // The name of the file storing the index 

   bool        autoHorizon;  // Flag whether the horizon is auto-adaptable
   double      wfactor;      // A factor describing how horizon (param) is related to 
                             // average update interval 

   RTperiod    param;        // Horizon length  
   RTperiod    w;            // Querying window length 
   double      alpha;        // a parameter (derived from param) for bulkloading 

   // To automatically maintain the parameter a number of things have to be tracked
   //
   int         numEntries;   // aproximation of the # of live entries in the index  
   RTtimeStamp lastReset;
   int         numOp;        // number of insertions performed since lastReset
   int         horUpdateInt; // when numOp reaches horUpdateInt horizon is updated

   RTtimeStamp reft;         // Reference time-stamp 
   RTtimeStamp lastChange;   // When the tree was changed last
};

#endif