Btree2Example

    // ------------------------------- //
    // -------- Start of File -------- //
    // ------------------------------- //
    // ----------------------------------------------------------- //
    // C++ Source Code File Name: gxbtree.cpp
    // Compiler Used: MSVC, BCC32, GCC, HPUX aCC, SOLARIS CC
    // Produced By: DataReel Software Development Team
    // File Creation Date: 08/22/2000
    // Date Last Modified: 06/17/2016
    // Copyright (c) 2001-2016 DataReel Software Development
    // ----------------------------------------------------------- //
    // ------------- Program Description and Details ------------- //
    // ----------------------------------------------------------- //
    /*
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
    USA

    Dictionary example program using the gxBtree class.
    */
    // ----------------------------------------------------------- //
    #include "gxdlcode.h"

    #if defined (__USE_ANSI_CPP__) // Use the ANSI Standard C++ library
    #include <iostream>
    using namespace std; // Use unqualified names for Standard C++ library
    #else // Use the old iostream library by default
    #include <iostream.h>
    #endif // __USE_ANSI_CPP__

    #include <string.h>
    #include <time.h>
    #include "gxbtree.h"
    #include "dfileb.h"
    #include "ustring.h"

    const BtreeNodeOrder_t MyKeyClassOrder = 27;
    const __WORD__ MyKeyNameSize = 26;

    class MyKeyClass : public DatabaseKeyB
    {
    public:
      MyKeyClass();
      MyKeyClass(const char *name);
      void operator=(const char *name);
      ~MyKeyClass() { }

    public: // Base class interface
      size_t KeySize() { return sizeof(key_name); }
      int operator==(const DatabaseKeyB& key) const;
      int operator>(const DatabaseKeyB& key) const;

      // NOTE: This comparison function is only used if the
      // __USE_SINGLE_COMPARE__ preprocessor directive is
      // defined when the program is compiled.
      int CompareKey(const DatabaseKeyB& key) const;

    public: // Persistent data member
      char key_name[MyKeyNameSize];
    };

    MyKeyClass::MyKeyClass() : DatabaseKeyB((char *)key_name)
    {
      for(int i = 0; i < MyKeyNameSize; i++) key_name[i] = 0;
    }

    MyKeyClass::MyKeyClass(const char *name) : DatabaseKeyB((char *)key_name)
    {
      strncpy(key_name, name,  MyKeyNameSize);
      key_name[ MyKeyNameSize-1] = 0; // Ensure null termination
    }

    void MyKeyClass::operator=(const char *name)
    {
      strncpy(key_name, name,  MyKeyNameSize);
      key_name[ MyKeyNameSize-1] = 0; // Ensure null termination
    }

    int MyKeyClass::operator==(const DatabaseKeyB& key) const
    {
      const MyKeyClass *kptr = (const MyKeyClass *)(&key);
      return (strcmp(key_name, (char *)kptr->db_key) == 0);
    }

    int MyKeyClass::operator>(const DatabaseKeyB& key) const
    {
      const MyKeyClass *kptr = (const MyKeyClass *)(&key);
      return (strcmp(key_name, (char *)kptr->db_key) > 0);
    }

    int MyKeyClass::CompareKey(const DatabaseKeyB& key) const
    // NOTE: This comparison function is only used if the
    // __USE_SINGLE_COMPARE__ preprocessor directive is
    // defined when the program is compiled.
    {
      const MyKeyClass *kptr = (const MyKeyClass *)(&key);
      return strcmp(key_name, (char *)kptr->db_key);
    }

    void PausePrg()
    {
      cout << "\n";
      cout << "Press enter to continue..." << "\n";
      cin.get();
    }

    void BtreeStatus(gxBtree &btx)
    {
      UString intbuf;
      cout << "\n";
      intbuf << clear << (FAU_t)btx.Root();
      cout << "Root address =      " << intbuf.c_str() << "\n";
      cout << "Number of trees =   " << btx.NumTrees() << "\n";
      cout << "Number of entries = " << btx.NumKeys() << "\n";
      cout << "Number of nodes =   " << btx.NumNodes() << "\n";
      cout << "B-Tree order =      " << btx.NodeOrder() << "\n";
      cout << "B-Tree height =     " << btx.BtreeHeight() << "\n";
      PausePrg();
    }

    int ParseString(char *str, char words[255][255],
    		int*numwords, char sepchar)
    // General purpose string parser
    {
      int i = 0;
      char newword[255];
      *numwords = 0;

      // First skip over leading blanks. Stop if an ASCII NULL is seen
      while (1) {
        if (*str == '\0') return 0;
        if (*str != ' ') break;
        str++;
      }

      while(1) {
        // Check to see if there is room for another word in the array
        if(*numwords == 255) return 1;

        i = 0;
        while(i < 254) {
          if(*str == 0 || *str == sepchar) break;
          newword[i] = *str;
          str++;
          i++;
        }
        newword[i] = 0;   // Ensure an ASCII null at end of newword.
        strcpy (words[*numwords], newword);  // Install into array
        (*numwords)++;

        // If stopped by an ASCII NULL above, exit loop
        if(*str == 0) break;

        str++;
        if(*str == 0) break;
      }
      return 0;
    }

    int ImportTextFile(gxBtree &btx, char *fname)
    {
      cout << "\n";
      cout << "Importing a dictionary file." << "\n";
      cout << "NOTE: Words must be delimited by a space or forward slash (/)"
           << "\n";

      int status, num, key_count = 0;
      char words[255][255];
      char LineBuffer[df_MAX_LINE_LENGTH];
      const char dchar = '/';  // Text delimiter

      cout << "\n";
      cout << "Enter the name of the text file to import" << "\n";

      DiskFileB infile(fname);
      if(!infile) { // Could not open the istream
        cout << "Could not open file: " << fname << "\n";
        return 1;
      }
      cout << "Adding words..." << "\n";

      // Get CPU clock cycles before entering loop
      clock_t begin = clock();

      MyKeyClass key;
      MyKeyClass compare_key;

      while(!infile.df_EOF()) {
        if(infile.df_GetLine(LineBuffer, df_MAX_LINE_LENGTH, '\n', 1) !=
           DiskFileB::df_NO_ERROR) {
          break; // Error reading from the disk file
        }
        if(strcmp(LineBuffer, "") == 0) continue;

        if(ParseString(LineBuffer, words, &num, dchar) == 1) {
          return 1;
        }

        key = LineBuffer;
        status = btx.Insert(key, compare_key, 0);

        if (status != 1) {
          cout << "\n" << "Problem adding " << words[0] << "\n";
          return 1;
        }
        else {
          key_count++;
        }
      }

      // Get CPU clock cycles after loop is completed
      clock_t end =clock();

      // Calculate the elapsed time in seconds.
      double elapsed_time = (double)(end - begin) / CLOCKS_PER_SEC;
      cout.precision(3);
      cout << "Added " << key_count << " words in "
           << elapsed_time << " seconds" << "\n";
      BtreeStatus(btx);

      // Rewind the file
      infile.df_Rewind();

      cout << "Verifying the entries..." << "\n";
      begin = clock();
      key_count = 0;
      double search_time = 0;

      while(!infile.df_EOF()) {
        if(infile.df_GetLine(LineBuffer, df_MAX_LINE_LENGTH, '\n', 1) !=
           DiskFileB::df_NO_ERROR) {
          break; // Error reading from the disk file
        }
        if(strcmp(LineBuffer, "") == 0) continue;

        if(ParseString(LineBuffer, words, &num, dchar) == 1) {
          return 1;
        }

        key = LineBuffer;
        clock_t begin_search = clock();
        status = btx.Find(key, compare_key, 0);
        clock_t end_search = clock();
        search_time += (double)(end_search - begin_search) / CLOCKS_PER_SEC;

        if (status != 1) {
          cout << "\n" << "Problem finding " << words[0] << "\n";
          return 1;
        }
        else {
          key_count++;
        }
      }

      end =clock();
      elapsed_time = (double)(end - begin) / CLOCKS_PER_SEC;
      cout.precision(3);
      cout << "Verified " << key_count << " words in "
           << elapsed_time << " seconds" << "\n";
      double avg_search_time = (search_time/(double)key_count) * 1000;
      cout << "Average search time = " << avg_search_time << " milliseconds"
           << "\n";
      PausePrg();

      // Rewind the file
      infile.df_Rewind();

      cout << "Deleting the entries..." << "\n";
      begin = clock();
      key_count = 0;

      while(!infile.df_EOF()) {
        if(infile.df_GetLine(LineBuffer, df_MAX_LINE_LENGTH, '\n', 1) !=
           DiskFileB::df_NO_ERROR) {
          break; // Error reading from the disk file
        }
        if(strcmp(LineBuffer, "") == 0) continue;

        if(ParseString(LineBuffer, words, &num, dchar) == 1) {
          return 1;
        }

        if(strcmp(LineBuffer, "") == 0) continue;

        key = LineBuffer;
        status = btx.Delete(key, compare_key, 0);
        // status = btx.LazyDelete(key, compare_key, 0);

        if (status != 1) {
          cout << "\n" << "Problem deleting " << words[0] << "\n";
          return 1;
        }
        else {
          key_count++;
        }
      }

      end =clock();
      cout.precision(3);
      elapsed_time = (double)(end - begin) / CLOCKS_PER_SEC;
      cout << "Deleted " << key_count << " words in "
           << elapsed_time << " seconds" << "\n";
      BtreeStatus(btx);

      // Rewind the file
      infile.df_Rewind();

      cout << "Re-inserting all the words..." << "\n";
      key_count = 0;
      begin = clock();

      while(!infile.df_EOF()) {
        if(infile.df_GetLine(LineBuffer, df_MAX_LINE_LENGTH, '\n', 1) !=
           DiskFileB::df_NO_ERROR) {
          break; // Error reading from the disk file
        }
        if(strcmp(LineBuffer, "") == 0) continue;

        if(ParseString(LineBuffer, words, &num, dchar) == 1) {
          return 1;
        }

        key = LineBuffer;
        status = btx.Insert(key, compare_key, 0);

        if (status != 1) {
          cout << "\n" << "Problem adding " << words[0] << "\n";
          return 1;
        }
        else {
          key_count++;
        }
      }

      end =clock();
      cout.precision(3);
      elapsed_time = (double)(end - begin) / CLOCKS_PER_SEC;
      cout << "Added " << key_count << " words in "
           << elapsed_time << " seconds" << "\n";
      BtreeStatus(btx);

      infile.df_Close();
      return 0;
    }

    int main(int argv, char **argc)
    {
      const char *fname = "testfile.btx"; // File name of this database
      char *dfile = "amerdict.txt"; // Default dictionary file

      char rev_letter = gxDatabaseRevisionLetter; // Set the default rev letter
      if(argv >= 2) { // Set a specified revision letter
        rev_letter = *argc[1];
        if(rev_letter == '0') rev_letter = '\0';
        // Valid rev letters are:
        // Rev 0
        // Rev 'A' or 'a'
        // Rev 'B' or 'b'
        // Rev 'C' or 'c'
        // Rev 'D' or 'd'
        // Rev 'E' or 'e'
        // NOTE: The gxDatabase class will set invalid revision letters
        // to the version set by the gxDatabaseRevisionLetter constant.
      }

      if(argv == 3) dfile = argc[2]; // Use specified dictionary

      MyKeyClass key, kbuf;
      gxBtree btx(key, MyKeyClassOrder);

      // Create a new B-tree index with one tree
      btx.Create(fname, rev_letter);

      ImportTextFile(btx, dfile);

      cout << "Exiting..." << "\n";
      return 0;
    }
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    // ------------------------------- //