Add Online Chat solution
This commit is contained in:
Donne Martin
parent
ae9832c6b7
commit
616710f42e
182
solutions/object_oriented_design/online_chat/online_chat.ipynb
Normal file
182
solutions/object_oriented_design/online_chat/online_chat.ipynb
Normal file
@ -0,0 +1,182 @@
|
||||
{
|
||||
"cells": [
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/system-design-primer-primer)."
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"# Design an online chat"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"## Constraints and assumptions\n",
|
||||
"\n",
|
||||
"* Assume we'll focus on the following workflows:\n",
|
||||
" * Text conversations only\n",
|
||||
" * Users\n",
|
||||
" * Add a user\n",
|
||||
" * Remove a user\n",
|
||||
" * Update a user\n",
|
||||
" * Add to a user's friends list\n",
|
||||
" * Add friend request\n",
|
||||
" * Approve friend request\n",
|
||||
" * Reject friend request\n",
|
||||
" * Remove from a user's friends list\n",
|
||||
" * Create a group chat\n",
|
||||
" * Invite friends to a group chat\n",
|
||||
" * Post a message to a group chat\n",
|
||||
" * Private 1-1 chat\n",
|
||||
" * Invite a friend to a private chat\n",
|
||||
" * Post a meesage to a private chat\n",
|
||||
"* No need to worry about scaling initially"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "markdown",
|
||||
"metadata": {},
|
||||
"source": [
|
||||
"## Solution"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": 1,
|
||||
"metadata": {
|
||||
"collapsed": false
|
||||
},
|
||||
"outputs": [
|
||||
{
|
||||
"name": "stdout",
|
||||
"output_type": "stream",
|
||||
"text": [
|
||||
"Overwriting online_chat.py\n"
|
||||
]
|
||||
}
|
||||
],
|
||||
"source": [
|
||||
"%%writefile online_chat.py\n",
|
||||
"from abc import ABCMeta\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class UserService(object):\n",
|
||||
"\n",
|
||||
" __metaclass__ = Singleton\n",
|
||||
"\n",
|
||||
" def __init__(self):\n",
|
||||
" self.users_by_id = {} # key: user id, value: User\n",
|
||||
"\n",
|
||||
" def add_user(self, user_id, name, pass_hash): # ...\n",
|
||||
" def remove_user(self, user_id): # ...\n",
|
||||
" def add_friend_request(self, from_user_id, to_user_id): # ...\n",
|
||||
" def approve_friend_request(self, from_user_id, to_user_id): # ...\n",
|
||||
" def reject_friend_request(self, from_user_id, to_user_id): # ...\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class User(object):\n",
|
||||
"\n",
|
||||
" def __init__(self, user_id, name, pass_hash):\n",
|
||||
" self.user_id = user_id\n",
|
||||
" self.name = name\n",
|
||||
" self.pass_hash = pass_hash\n",
|
||||
" self.friends_by_id = {} # key: friend id, value: User\n",
|
||||
" self.friend_ids_to_private_chats = {} # key: friend id, value: private chats\n",
|
||||
" self.group_chats_by_id = {} # key: chat id, value: GroupChat\n",
|
||||
" self.received_friend_requests_by_friend_id = {} # key: friend id, value: AddRequest\n",
|
||||
" self.sent_friend_requests_by_friend_id = {} # key: friend id, value: AddRequest\n",
|
||||
"\n",
|
||||
" def message_user(self, friend_id, message): # ...\n",
|
||||
" def message_group(self, group_id, message): # ...\n",
|
||||
" def send_friend_request(self, friend_id): # ...\n",
|
||||
" def receive_friend_request(self, friend_id): # ...\n",
|
||||
" def approve_friend_request(self, friend_id): # ...\n",
|
||||
" def reject_friend_request(self, friend_id): # ...\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class Chat(metaclass=ABCMeta):\n",
|
||||
"\n",
|
||||
" def __init__(self, chat_id):\n",
|
||||
" self.chat_id = chat_id\n",
|
||||
" self.users = []\n",
|
||||
" self.messages = []\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class PrivateChat(Chat):\n",
|
||||
"\n",
|
||||
" def __init__(self, first_user, second_user):\n",
|
||||
" super(PrivateChat, self).__init__()\n",
|
||||
" self.users.append(first_user)\n",
|
||||
" self.users.append(second_user)\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class GroupChat(Chat):\n",
|
||||
"\n",
|
||||
" def add_user(self, user): # ...\n",
|
||||
" def remove_user(self, user): # ... \n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class Message(object):\n",
|
||||
"\n",
|
||||
" def __init__(self, message_id, message, timestamp):\n",
|
||||
" self.message_id = message_id\n",
|
||||
" self.message = message\n",
|
||||
" self.timestamp = timestamp\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class AddRequest(object):\n",
|
||||
"\n",
|
||||
" def __init__(self, from_user_id, to_user_id, request_status, timestamp):\n",
|
||||
" self.from_user_id = from_user_id\n",
|
||||
" self.to_user_id = to_user_id\n",
|
||||
" self.request_status = request_status\n",
|
||||
" self.timestamp = timestamp\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class RequestStatus(Enum):\n",
|
||||
"\n",
|
||||
" UNREAD = 0\n",
|
||||
" READ = 1\n",
|
||||
" ACCEPTED = 2\n",
|
||||
" REJECTED = 3\n",
|
||||
"\n",
|
||||
"\n",
|
||||
"class Singleton(type):\n",
|
||||
"\n",
|
||||
" _instances = {}\n",
|
||||
" def __call__(cls, *args, **kwargs):\n",
|
||||
" if cls not in cls._instances:\n",
|
||||
" cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)\n",
|
||||
" return cls._instances[cls]"
|
||||
]
|
||||
}
|
||||
],
|
||||
"metadata": {
|
||||
"kernelspec": {
|
||||
"display_name": "Python 3",
|
||||
"language": "python",
|
||||
"name": "python3"
|
||||
},
|
||||
"language_info": {
|
||||
"codemirror_mode": {
|
||||
"name": "ipython",
|
||||
"version": 3
|
||||
},
|
||||
"file_extension": ".py",
|
||||
"mimetype": "text/x-python",
|
||||
"name": "python",
|
||||
"nbconvert_exporter": "python",
|
||||
"pygments_lexer": "ipython3",
|
||||
"version": "3.4.3"
|
||||
}
|
||||
},
|
||||
"nbformat": 4,
|
||||
"nbformat_minor": 0
|
||||
}
|
||||
91
solutions/object_oriented_design/online_chat/online_chat.py
Normal file
91
solutions/object_oriented_design/online_chat/online_chat.py
Normal file
@ -0,0 +1,91 @@
|
||||
from abc import ABCMeta
|
||||
|
||||
|
||||
class UserService(object):
|
||||
|
||||
__metaclass__ = Singleton
|
||||
|
||||
def __init__(self):
|
||||
self.users_by_id = {} # key: user id, value: User
|
||||
|
||||
def add_user(self, user_id, name, pass_hash): # ...
|
||||
def remove_user(self, user_id): # ...
|
||||
def add_friend_request(self, from_user_id, to_user_id): # ...
|
||||
def approve_friend_request(self, from_user_id, to_user_id): # ...
|
||||
def reject_friend_request(self, from_user_id, to_user_id): # ...
|
||||
|
||||
|
||||
class User(object):
|
||||
|
||||
def __init__(self, user_id, name, pass_hash):
|
||||
self.user_id = user_id
|
||||
self.name = name
|
||||
self.pass_hash = pass_hash
|
||||
self.friends_by_id = {} # key: friend id, value: User
|
||||
self.friend_ids_to_private_chats = {} # key: friend id, value: private chats
|
||||
self.group_chats_by_id = {} # key: chat id, value: GroupChat
|
||||
self.received_friend_requests_by_friend_id = {} # key: friend id, value: AddRequest
|
||||
self.sent_friend_requests_by_friend_id = {} # key: friend id, value: AddRequest
|
||||
|
||||
def message_user(self, friend_id, message): # ...
|
||||
def message_group(self, group_id, message): # ...
|
||||
def send_friend_request(self, friend_id): # ...
|
||||
def receive_friend_request(self, friend_id): # ...
|
||||
def approve_friend_request(self, friend_id): # ...
|
||||
def reject_friend_request(self, friend_id): # ...
|
||||
|
||||
|
||||
class Chat(metaclass=ABCMeta):
|
||||
|
||||
def __init__(self, chat_id):
|
||||
self.users = []
|
||||
self.chat_id = chat_id
|
||||
self.messages = []
|
||||
|
||||
|
||||
class PrivateChat(Chat):
|
||||
|
||||
def __init__(self, first_user, second_user):
|
||||
super(PrivateChat, self).__init__()
|
||||
self.users.append(first_user)
|
||||
self.users.append(second_user)
|
||||
|
||||
|
||||
class GroupChat(Chat):
|
||||
|
||||
def add_user(self, user): # ...
|
||||
def remove_user(self, user): # ...
|
||||
|
||||
|
||||
class Message(object):
|
||||
|
||||
def __init__(self, message_id, message, timestamp):
|
||||
self.message_id = message_id
|
||||
self.message = message
|
||||
self.timestamp = timestamp
|
||||
|
||||
|
||||
class AddRequest(object):
|
||||
|
||||
def __init__(self, from_user_id, to_user_id, request_status, timestamp):
|
||||
self.from_user_id = from_user_id
|
||||
self.to_user_id = to_user_id
|
||||
self.request_status = request_status
|
||||
self.timestamp = timestamp
|
||||
|
||||
|
||||
class RequestStatus(Enum):
|
||||
|
||||
UNREAD = 0
|
||||
READ = 1
|
||||
ACCEPTED = 2
|
||||
REJECTED = 3
|
||||
|
||||
|
||||
class Singleton(type):
|
||||
|
||||
_instances = {}
|
||||
def __call__(cls, *args, **kwargs):
|
||||
if cls not in cls._instances:
|
||||
cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
|
||||
return cls._instances[cls]
|
||||
Loading…
Reference in New Issue
Block a user