Library Management System

A full-stack Library Management System with a C++ backend and web-based frontend. This project demonstrates the integration of data structures and algorithms with modern web technologies.

Table of Contents

• Overview
• Features
• Architecture
• Data Structures Used
• Technologies
• Project Structure
• Installation
• Usage
• API Endpoints
• Command Line Interface
• License

Overview

This Library Management System provides a complete solution for managing books, users, and transactions. The system uses custom-implemented data structures in C++ for efficient data management and provides a RESTful API through Node.js for web-based access.

Features

• Book Management: Add, update, delete, and search books by ISBN, title, or author
• User Management: Register users, update profiles, and track borrowing history
• Transaction Tracking: Record and monitor book borrowing and return transactions
• Sorting Algorithms: Merge sort for books/users, insertion sort for transactions
• Search Functionality: Case-insensitive search across multiple fields
• Data Persistence: CSV-based file storage for all entities
• RESTful API: Express.js server providing HTTP endpoints
• Web Interface: Modern, responsive UI for all operations

Architecture

The system follows a three-tier architecture:

Frontend (HTML/CSS/JS) <-> Node.js Express Server <-> C++ Backend (lms.exe)
                                                            |
                                                      Data Files (CSV)

Data Flow

1. Frontend sends HTTP requests to Express server
2. Express server spawns C++ executable with command-line arguments
3. C++ backend processes the command and outputs JSON to stdout
4. Express server captures the output and returns it as HTTP response
5. Frontend receives and displays the data

Data Structures Used

1. Doubly Linked List (DLL)

Used for: Books and Users

Implementation: DoublyLinkedList<T> in LinkedList.h

Features:

• Bidirectional traversal with next and prev pointers
• O(1) insertion at head/tail
• O(n) search, delete, and update operations
• Merge sort implementation for O(n log n) sorting

Advantages:

• Efficient insertion/deletion at both ends
• Bidirectional traversal for flexible operations
• No fixed size limitation

2. Singly Linked List (SLL)

Used for: Transactions

Implementation: SinglyLinkedList<T> in LinkedList.h

Features:

• Unidirectional traversal with next pointer only
• O(1) insertion at head
• O(n) insertion at tail, search, and delete
• Insertion sort for chronological ordering

Advantages:

• Lower memory overhead (one pointer per node vs two)
• Suitable for append-heavy operations (transactions)
• Simpler implementation for sequential access

3. Node Structures

Doubly Linked List Node: Node<T> in Node.h

template<typename T>
class Node {
    T data;
    Node<T>* next;
    Node<T>* prev;
};

Singly Linked List Node: SLLNode<T> in Node.h

template<typename T>
class SLLNode {
    T data;
    SLLNode<T>* next;
};

4. Specialized Lists

• BookList: Extends DoublyLinkedList<Book> with ISBN-specific operations
• UserList: Extends DoublyLinkedList<User> with user-specific operations
• Transaction List: Uses SinglyLinkedList<Transaction> for chronological records

Technologies

Backend (C++)

• Language: C++11
• Compiler: g++ with -std=c++11 -Wall -Wextra -O2
• Build System: Make
• Data Storage: CSV files

Frontend Server (Node.js)

• Runtime: Node.js
• Framework: Express.js
• Dependencies:
  • express: Web server framework
  • cors: Cross-origin resource sharing
  • body-parser: Request body parsing
  • child_process: Spawn C++ executable

Frontend (Web)

• HTML5: Structure
• CSS3: Styling
• JavaScript: Client-side logic
• Fetch API: HTTP requests

Project Structure

OEL_DSA/
├── cpp_backend/
│   ├── Book.h                 # Book class with JSON serialization
│   ├── User.h                 # User class with borrowing logic
│   ├── Transaction.h          # Transaction class with timestamp
│   ├── Node.h                 # Node structures (DLL and SLL)
│   ├── LinkedList.h           # Generic linked list implementations
│   ├── BookList.h             # Specialized book list
│   ├── UserList.h             # Specialized user list
│   ├── LibrarySystem.cpp      # Main system logic and CLI
│   ├── Makefile               # Build configuration
│   └── lms.exe                # Compiled executable
├── data/
│   ├── books.txt              # Book records (CSV)
│   ├── users.txt              # User records (CSV)
│   └── transactions.txt       # Transaction records (CSV)
├── frontend/
│   ├── server.js              # Express server (API bridge)
│   ├── package.json           # Node.js dependencies
│   └── public/
│       ├── index.html         # Web interface
│       └── styles.css         # Styling
└── README.md                  # This file

Installation

Prerequisites

• C++ Compiler: g++ with C++11 support
• Node.js: Version 14 or higher
• npm: Node package manager
• Make: Build automation tool (optional)

Step 1: Clone the Repository

git clone https://github.com/yourusername/library-management-system.git
cd library-management-system

Step 2: Build C++ Backend

Using Make (Linux/Mac/WSL)

cd cpp_backend
make

Using g++ directly (Windows/Linux/Mac)

cd cpp_backend
g++ -std=c++11 -Wall -Wextra -O2 -o lms LibrarySystem.cpp

On Windows, the output will be lms.exe. On Linux/Mac, it will be lms.

Step 3: Install Node.js Dependencies

cd ../frontend
npm install

Step 4: Create Data Directory

cd ..
mkdir -p data

The data files will be created automatically on first run.

Usage

Running the Web Application

1. Start the Node.js server:

cd frontend
npm start

The server will start on http://localhost:3001

2. Access the web interface: Open your browser and navigate to http://localhost:3001

Using the C++ Backend Directly

You can also use the C++ backend directly from the command line:

cd cpp_backend
./lms get_books_json

API Endpoints

Books

Method	Endpoint	Description
GET	/api/books	Get all books
POST	/api/books	Add a new book
GET	/api/books/:isbn	Get book by ISBN
PUT	/api/books/:isbn	Update book by ISBN
DELETE	/api/books/:isbn	Delete book by ISBN
GET	/api/books/search/:query	Search books by title
GET	/api/sort/books/:criteria	Sort books (title, author, publicationyear, isbn, availablecopies, totalcopies)

Users

Method	Endpoint	Description
GET	/api/users	Get all users
POST	/api/users	Add a new user
GET	/api/users/:userId	Get user by ID
PUT	/api/users/:userId	Update user by ID
DELETE	/api/users/:userId	Delete user by ID
GET	/api/users/search/:query	Search users by name
GET	/api/sort/users/:criteria	Sort users (name, userid, email, phone)

Transactions

Method	Endpoint	Description
GET	/api/transactions	Get all transactions
POST	/api/transactions/borrow	Borrow a book
POST	/api/transactions/return	Return a book
GET	/api/transactions/user/:userId	Get user transactions
GET	/api/sort/transactions/:criteria	Sort transactions (timestamp, userid, bookisbn, type)

Request/Response Examples

Add a Book

POST /api/books
Content-Type: application/json

{
  "isbn": "978-0134685991",
  "title": "Effective Modern C++",
  "author": "Scott Meyers",
  "publicationYear": 2014,
  "copies": 5
}

Borrow a Book

POST /api/transactions/borrow
Content-Type: application/json

{
  "userId": "U001",
  "bookISBN": "978-0134685991"
}

Command Line Interface

The C++ backend can be used independently via command-line:

Book Commands

# Get all books as JSON
./lms get_books_json

# Add a book
./lms add_book "978-0134685991" "Effective Modern C++" "Scott Meyers" 2014 5

# Delete a book
./lms delete_book "978-0134685991"

# Update a book
./lms update_book "978-0134685991" "New Title" "Author" 2024 10

# Search by ISBN
./lms search_book_isbn "978-0134685991"

# Search by title
./lms search_book_title "Modern C++"

# Search by author
./lms search_book_author "Meyers"

# Display all books
./lms display_books

# Sort books by title
./lms sort_books

User Commands

# Get all users as JSON
./lms get_users_json

# Add a user
./lms add_user "U001" "John Doe" "john@example.com" "1234567890"

# Delete a user
./lms delete_user "U001"

# Update a user
./lms update_user "U001" "Jane Doe" "jane@example.com" "0987654321"

# Search by user ID
./lms search_user "U001"

# Search by name
./lms search_user_name "John"

# Display all users
./lms display_users

# Sort users by name
./lms sort_users

Transaction Commands

# Get all transactions as JSON
./lms get_transactions_json

# Borrow a book
./lms borrow_book "U001" "978-0134685991"

# Return a book
./lms return_book "U001" "978-0134685991"

# Get user transactions
./lms user_transactions "U001"

# Display all transactions
./lms display_transactions

# Sort transactions by date
./lms sort_transactions

Algorithm Complexity

Doubly Linked List Operations

Operation	Time Complexity	Space Complexity
Insert at Head/Tail	O(1)	O(1)
Delete by ID	O(n)	O(1)
Search by ID	O(n)	O(1)
Search by Title/Name	O(n)	O(k) where k = results
Merge Sort	O(n log n)	O(log n)
Display All	O(n)	O(1)

Singly Linked List Operations

Operation	Time Complexity	Space Complexity
Insert at Head	O(1)	O(1)
Insert at Tail	O(n)	O(1)
Delete by ID	O(n)	O(1)
Search by ID	O(n)	O(1)
Insertion Sort	O(n²)	O(1)
Display All	O(n)	O(1)

Data File Format

books.txt

ISBN,Title,Author,PublicationYear,TotalCopies,AvailableCopies
978-0134685991,Effective Modern C++,Scott Meyers,2014,5,3

users.txt

UserID,Name,Email,Phone,BooksBorrowed,BorrowedISBNs
U001,John Doe,john@example.com,1234567890,2,978-0134685991;978-0321563842

transactions.txt

TransactionID,UserID,BookISBN,TransactionType,Timestamp
TXN001,U001,978-0134685991,BORROW,2024-01-15 10:30:00

Development

Building from Source

cd cpp_backend
make clean
make

Running Tests

cd cpp_backend
make test

Development Mode (with auto-reload)

cd frontend
npm run dev

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/new-feature)
3. Commit your changes (git commit -am 'Add new feature')
4. Push to the branch (git push origin feature/new-feature)
5. Create a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Authors

• DSA-LMS Team

Acknowledgments

• Data Structures and Algorithms course project
• C++ Standard Template Library documentation
• Express.js documentation
• Node.js community