In this programming assignment you are asked to implement an Address Book application with Simple Indexing.
The application should be able to store information for typical address book entries, such as Name, Surname, Address and additional Notes. It must have basic functionality of Add/Update/Delete/Find/List records. Possible user interface for the main menu can be as follows:
- Add New Record
- Update A Record
- Delete A record
- Find A Record
- List Records
- List Index File
- Exit
Enter your choice ==> _
In order to index the file, you must use simple indexing approach. In this approach the records are stored in data file in entry-sequenced order. It means that new records are appended to end of file as they are entered. For record structure you can use whatever method you prefer (i.e., fixed length records, record separators). Additionally, the primary key of the system will be name+surname. Duplicate keys are not allowed, so you must check the presence of the record prior to insertion. Beside, a separate index file must be created with keysorting approach. It means that the index file only keeps primary key field and the pointer to the data file records. Index file is kept in sorted order, and when the application is started the whole file is read into RAM memory. Then all operations are handled through index file in RAM. When the user wants to exit, flush the whole index file into disk. Deletion will simply mark a record to be deleted. Record will not be actually deleted from the data file. However it will actually be deleted from the index file. Search operation is to be done only by the primary key.
“List records” option will prompt the user for one-character-long input and will list the results that are starting with this character. By the way, if the application encounters a run-time error, at that time synchronization between index and data file may fail since last update on index file on RAM not flushed into disk. You should design and implement a solution to overcome this issue. A typical solution can be adding a dirty-flag into index file header. During the program execution, in case of add, update or delete operations index structure in the RAM will change. Subsequent to this change, dirt-flag in the index file must be set. Therefore following a successful flushing of index file, you should re-set the
dirty-flag. When you open the data file in next time, check this flag. If it is set it means the file is not closed properly so it requires reorganization (i.e., re-creation of the index file)