[2022] Cardiff - CMT202 Distributed and Cloud Computing - Coursework - Distributed data storage system
Assignment
You have been hired by a car rental company to build a distributed data storage system using a remote object paradigm that will allow one to store and access information relating to rental cars, manufacturers of cars and users who rent cars.
Each manufacturer has the following two associated pieces of information which should be stored in the system:
1. Manufacturer name.
2. Manufacturer country which refers to the country in which the manufacturer is based (e.g. BMW is based in Germany).
Each rental car has the following two associated pieces of information which should be stored in the system:
1. Car manufacturer name.
2. Car model.
Note, multiple cars with the same manufacturer and model can exist in the system. You can assume that no two manufacturers will have a car model with the same name.
Each user has the following two associated pieces of information which should be stored in the system:
1. User name.
2. User contact phone number.
Design and implement the above distributed data storage system using a remote object paradigm which allows employees of the car rental company to perform the following twelve tasks:
Task 1
Add a user to the system. Implement this using a method with the following header:
def add_user(self, user_name, user_number)
An example of calling this method is:
rental_object.add_user(“Allen Hatcher”, 123456)
You can assume that each user added to the system has a unique user name.
Task 2
Return all associated pieces of information relating to the set of users currently stored in the system (i.e. a set of user names and contact numbers). Implement this using a method with the following header:
def return_users(self)
An example of calling this method is:
rental_object.return_users()
The information returned by this method should have the property that it can be easily interpreted when displayed using the Python print function. That is, the output from the following print function should be easily interpreted:
print(rental_object.return_users())
Task 3
Add a car manufacturer to the system. Implement this using a method with the following header:
def add_manufacturer(self, manufacturer_name, manufacturer_country)
An example of calling this method is:
rental_object.add_manufacturer(“BMW”, “Germany”)
Task 4
Return all associated pieces of information relating to the set of manufacturers currently stored in the system (i.e. a set of manufacturer names and countries). Implement this using a method with the following header:
def return_manufacturers(self)
An example of calling this method is:
rental_object.return_manufacturers()
The information returned by this method should have the property that it can be easily interpreted when displayed using the Python print function.
Task 5
Add a rental car to the system. Implement this using a method with the following header:
def add_rental_car(self, manufacturer_name, car_model)
An example of calling this method is:
rental_object.add_rental_car(“BMW”, “3 Series”)
When a rental is first added to the system it is initially not rented by any user. Multiple cars with the same manufacturer and model may be added to the system. You can assume that no two manufacturers will have a car model with the same name.
Task 6
Return all associated pieces of information relating to the set of rental cars currently not rented (i.e. a set of car manufacturers and models). Implement this using a method with the following header:
def return_cars_not_rented(self)
An example of calling this method is:
rental_object.return_cars_not_rented()
The information returned by this method should have the property that it can be easily interpreted when displayed using the Python print function.
Task 7
Rent a car of a specified model to a specified user on a specified date. Implement this using a method with the following header:
def rent_car(self, user_name, car_model, year, month, day)
An example of calling this method is:
rental_object.rent_car(“Conor Reilly”, “3 Series”, 2019, 1, 3)
Each rental car can only be rented to a single user at a time. For example, consider the case where there are two rental cars in the system with model equal to “3 Series” and both are currently rented. In this case another car with model equal to “3 Series” cannot be rented until one of the two above cars is returned or an additional car with model equal to “3 Series” is added to the system.
The method rent_car should return a value of 1 if the car in question was successfully rented. Otherwise, the method should return a value of 0.
Task 8
Return all associated pieces of information relating to the set of cars currently rented (i.e. a set of car manufacturers and models). Implement this using a method with the following header:
def return_cars_rented(self)
An example of calling this method is:
rental_object.return_cars_rented()
The information returned by this method should have the property that it can be easily interpreted when displayed using the Python print function.
Task 9
Return a rented car of a specified model by a specified user on a specified date; that is, change the status of the car in question from rented to not rented. Implement this using a method with the following header:
def end_rental(self, user_name, car_model, year, month, day)
An example of calling this method is:
rental_object.end_rental(“Conor Reilly”, “3 Series”, 2019, 2, 4)
You can assume that each user will only rent a single car of each model at any given time. Therefore, when a user returns a car of a specified model there is no confusion with respect to which car they are returning.
Delete from the system all rental cars of a specified model which are currently not rented. Rental cars which are currently rented should not be deleted. Implement this using a method with the following header:
def delete_car(self, car_model)
An example of calling this method is:
rental_object.delete_car(“3 Series”)
Task 11
Delete from the system a specified user. A user should only be deleted if they currently do not rent and have never rented a car. Implement this using a method with the following header:
def delete_user(self, user_name)
An example of calling this method is:
rental_object.delete_user(“Conor Reilly”)
The method delete_user should return a value of 1 if the user in question was successfully deleted. Otherwise, the method should return a value of 0.
Task 12
Return all car models a user previously rented where the corresponding rental and return dates both lie between a specified start and end date inclusive.
Implement this using a method with the following header:
def user_rental_date(self, user_name, start_year, start_month, start_day, end_year, end_month, end_day)
An example of calling this method is:
rental_object.user_rental_date(“Conor Reilly”, 2010, 1, 1, 2029, 2, 1)
Note, the car models returned may contain duplicates if the user rented the model in question more than once.
The information returned by this method should have the property that it can be easily interpreted when displayed using the Python print function.
In your solution to the above assignment, the class in question should be called rental. That is, when defining the class use the expression “class rental(object):”. Also, the class must be contained in a file entitled rental.py.
In the file rental.py you should create an object of type rental and register this object with the name server using the name example.rental. That is, the file rental.py should contain the following code snippet:
daemon = Daemon()
serve({rental: "example.rental"}, daemon=daemon, use_ns=True)
