gist.h

此文件包含了在linux下实现tpr-tree索引的源代码

// -*- Mode: C++ -*-
//--------------------------------------------------------------------
//        GiST.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 GIST_H
#define GIST_H

#include "GiSTdefs.h"
#include "GiSTentry.h"
#include "GiSTlist.h"
#include "GiSTnode.h"
#include "GiSTstore.h"
#include "GiSTpredicate.h"
#include "GiSTcursor.h"
#include "GiSTobserver.h"

//--------------------------------------------------------------------
//  GiST
//

class GiST : public GiSTobject
{
public:
  GiST();

  // a likely candidate for overloading
  GiSTobjid IsA() const { return GIST_CLASS; }

  virtual void Create(const char *filename);
  virtual void Open  (const char *filename);
  virtual void Close ();

  virtual GiSTcursor* Search(const GiSTpredicate &query) const;
  virtual GiSTcursor* DebugSearch(const GiSTpredicate &query) const;
  virtual void        Insert(const GiSTentry& entry);
  virtual int         Delete(const GiSTpredicate& pred);
  void        Sync  ();
  GiSTstore*    Store ()   const { return store;    }
  GiSTobserver* Observer() const { return observer; } 

  virtual int IsOpen   ()            { return isOpen; }
  virtual int IsOrdered()      const { return 0; }
  virtual int ForcedReinsert() const { return 0; }
  virtual double m() const { return 0.4; }

// Observer support
  virtual void RegisterObserver(GiSTobserver* obs)
  {
     observer = obs;
     observer->SetGiST(this);
  }
  virtual void UnregisterObserver() { observer = NULL; }
//

#ifdef PRINTING_OBJECTS
  void        DumpNode(ostream& os, GiSTpath path) const;
  void        Print   (ostream& os)                const;
#endif

  ~GiST();

protected:
  // The following must be overriden by descendant classes
  virtual GiSTstore* CreateStore() const = 0;
  virtual GiSTnode*  CreateNode () const = 0;

  // Reads/writes nodes
  GiSTnode* ReadNode (const GiSTpath& path) const;
  void      WriteNode(GiSTnode *node);
  void      DeallocateNode(GiSTnode *node);

  // These are default supports for Forced Reinsert
  virtual GiSTlist<GiSTentry*> RemoveTop  (GiSTnode *node);
  virtual double               RemoveRatio() const { return 0.3; }

// Observer support
  GiSTobserver* observer;
  friend class GiSTobserver;
//
  GiSTnode* InsertHelper (const GiSTentry &entry, int level, GiSTnode* root = NULL);
  GiSTnode* ChooseSubtree(GiSTpage page, const GiSTentry &entry, 
                          int level, GiSTnode* root = NULL);
  void      CorrectTree  (GiSTnode* node);
  void      PropogateUp  (GiSTnode* node, bool* splitvec, 
                          GiSTlist<GiSTentry*>* orphans, GiSTnode*& root);
  void      Split        (GiSTnode *node, bool* splitvec, 
                          GiSTlist<GiSTentry*>* orphans, GiSTnode*& root);
  void      OverflowTreatment(GiSTnode *node, bool* splitvec, 
                          GiSTlist<GiSTentry*>* orphans, GiSTnode*& root);
  void      AdjustKeys   (GiSTnode *node, bool* splitvec, 
                          GiSTlist<GiSTentry*>* orphans, GiSTnode*& root);
  void      CondenseTree (GiSTnode *node, bool* splitvec, 
                          GiSTlist<GiSTentry*>* orphans, GiSTnode*& root);
  void      ShortenTree  (GiSTnode *root);

  GiSTnode *NewNode      (GiST *tree) const
  {
      GiSTnode *retval = CreateNode();
      retval->SetTree(tree);
      return(retval);
  }

  GiSTstore*    store;

private:
  int isOpen;

  int debug;

  friend class GiSTcursor;
};

#endif