/*
    Class declaration for the Index_File class
	The Index_File class can be used independently or as part of the MiniDB project.

    Copyright (C) 2007  Hossein Hakimzadeh

	Comments and bug fixes can be sent to hhakimza@iusb.edu

	This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/
#ifndef INDEX_FILE_H
#define INDEX_FILE_H
//-----------------------------------------------------------------------//
#include "Random_IO.h"

#define ACTIVE         'A'
#define DELETED        'D'

//-----------------------------------------------------------------------//
struct idx_record {
	unsigned long Key;      // Key to search for (alternatively this could be an unsigned long.)
	unsigned long Address;  // physical location of the record in the .DTA file
	char          Flag;     // A = ACTIVE, D=DELETED)
};
//-----------------------------------------------------------------------//
class Index_File
{
	char       FileName[256];                           // *.idx
	Random_IO  RandomFile;
	int        CurrentMaxRecords;                       // Maximum number of index records in the file
	int        Verbose;                                 // ON / OFF

  public:
	Index_File(char *filename);                         //Constructor
	~Index_File();                                      //Destructor, also closes the file
	
	void Initialize(int max_records);                   // set the max records and open the file
	void Expand(int highest_record);                    // Expand the size of the Index_File

	void InsertIndexRecord(idx_record *idx);            // Insert an Index record
	int  SearchIndexRecord(unsigned long Key, idx_record *idx);	// Search and return idx record, -1 if not found

	int  MaximumIndexRecords();                         // Return the maximum number of index records
	void DumpIndexFile(void);
};

#endif