Author: Oluwatimilehin Dayo-Kayode

Title: 'GERP - It's like Grep, but something is Off'

Purpose: This program can be used to search through al the files in a directory 
and look for some sequence of characters, similar to the Unix grep program

4/23/2017

Files: FSTree.h DirNode.h main.cpp database.h database.cpp


-database.h: This header file includes the definition of the dataBase class and 
structs word, and emptyOrNah. It also contains the following functions that
are instrumental to my implementation; a default constructor, a sensitivePrint
function. an insensitivePrint function, an expandAndRehash function, an
addToTable function, a search function. a traverseIndex function, a readFromFile
function, a casePermutations function and a hash function. For further detailed
descriptions of these functions and their behaviors, please see their contracts 
in the database.cpp file.

-database.cpp: This file is the implementation file for database.h. It includes
the implementation of the member functions of the dataBase(the functions
listed above).

-main.cpp: This file receives command line arguments from the user and does
appropriates actions based on the inputs.

Compiling And Running: My program compiles by running the command, "make"
without the quotation marks in the terminal. In order to run the program, the
following command is required; "./gerp filepath" without the quotation
marks in the terminal. Replace filepath with the path of the directory
you would like to run the program on and follow the prompts of the program.

Architectural Overview: The main.cpp file contains an instance of the 
dataBase class and calls the functions in this class on the users input.
The database.cpp file has an instance of the FSTree class in order to use the 
getRoot which helps the program access to root node of the directory being 
traversed. The database.cpp file also has two pointers to an instance of the 
DirNode class; one that points to the current node as the program traverses 
through the tree stemming from the aforementioned root node. It also has a 
pointer to a subdir which is also an instance of the DirNode class, and that 
keeps track of what sub directory the program is at it traverses through 
every level of sub directories that branches off the aformentioned
currnode pointer.


Data Structures and Algorithms:
I implemented this program primarily with a Hashtable. Each index of the 
hashtable contains a struct of structs. So basically the Hashtable has a 
struct of type emptyorNah which has a bool to keep track of whether that
spot has been filled or not, and an instance of the struct word which 
contains the string of word to be saved in that index, and the path index to
access that string of characters. I made my program this way because saving
the path where the string occured rather than the actual line would help save 
memory even though there would be some speed decreases, I felt it was worth it.
I also used a hashtable because not only did I feel more comfortable with it,
but accessing data would take O(n) which would help cover up some of the 
deficiences from saving the path location of strings rather than the actual
line.

Testing:
I tested my hashtable implementation by first testing the add function,
and then testing its ability to resize and rehash properly whenever the hash 
table got filled up.