MAJOR: Reworked database to be easier to use and close automatically to prevent resource leaks

web_server/blueprints/authentication.py

@@ -48,7 +48,6 @@ def signup():
 
     # Create a connection to the database
     db = Database()
-    db.create_connection()
 
     try:
         # Check for duplicate email/username, no two users can have the same
@@ -150,7 +149,6 @@ def login():
     
     # Create a connection to the database
     db = Database()
-    db.create_connection()
 
     try:
         # Check if user exists, only existing users can be logged in

web_server/blueprints/chat.py

@@ -51,7 +51,6 @@ def get_past_chat(stream_id: int):
 
     # Connect to the database
     db = Database()
-    db.create_connection()
 
     # fetched in format: [(chatter_id, message, time_sent)]
     all_chats = db.fetchall("""
@@ -103,7 +102,6 @@ def send_chat(data) -> None:
 def save_chat(chatter_id, stream_id, message):
     """Save the chat to the database"""
     db = Database()
-    db.create_connection()
     db.execute("""
                     INSERT INTO chat (chatter_id, stream_id, message)
                     VALUES (?, ?, ?);""", (chatter_id, stream_id, message))

web_server/blueprints/email.py

@@ -1,5 +1,4 @@
 from flask import Blueprint, session
-from database.db_context import get_db
 import smtplib
 from email.mime.text import MIMEText
 from os import getenv
@@ -20,7 +19,6 @@ def send_email() -> None:
 
     # Get the users email address
     db = get_db()
-    db.create_connection()
     user_email = db.fetchone("""
                 SELECT email
                 FROM users

web_server/blueprints/streams.py

@@ -8,7 +8,13 @@ from utils.stream_utils import (
 )
 from utils.user_utils import get_user_id
 from blueprints.utils import login_required
-from utils.recommendation_utils import default_recommendations, recommendations_based_on_category, user_recommendation_category, followed_categories_recommendations
+from utils.recommendation_utils import (
+    default_recommendations, 
+    recommendations_based_on_category, 
+    user_recommendation_category, 
+    followed_categories_recommendations, 
+    category_recommendations
+)
 from utils.utils import most_popular_category
 from database.database import Database
 from datetime import datetime
@@ -42,12 +48,11 @@ def get_recommended_streams() -> list[dict]:
 @stream_bp.route('/get_categories')
 def get_categories() -> list[dict]:
     """
-    Returns a list of most watched categories
+    Returns a list of top 5 most popular categories
     """
 
-    category_data = most_popular_category()
+    category_data = category_recommendations()
-    streams = recommendations_based_on_category(category_data['category_id'])
+    return jsonify(category_data)
-    return jsonify(streams)
 
 @login_required 
 @stream_bp.route('/get_recommended_categories')
@@ -60,7 +65,6 @@ def get_recommended_categories() -> list | list[dict]:
     user_id = get_user_id(username)
 
     db = Database()
-    db.create_connection()
     categories = db.fetchall("""SELECT categories.category_id, categories.category_name, favourability
                                 FROM categories, user_preferences
                                 WHERE user_id = ? AND categories.category_id = user_preferences.category_id,
@@ -166,7 +170,6 @@ def publish_stream():
 
     # Check if stream key is valid
     db = Database()
-    db.create_connection()
     user_info = db.fetchone("""SELECT user_id, username, current_stream_title, current_selected_category_id 
                                FROM users 
                                WHERE stream_key = ?""", (stream_key,))
@@ -190,7 +193,6 @@ def end_stream():
     Ends a stream
     """
     db = Database()
-    db.create_connection()
     user_info = db.fetchone("""SELECT user_id FROM users WHERE stream_key = ?""", (request.form.get("name"),))
 
     if not user_info:

web_server/database/database.py

@@ -6,6 +6,15 @@ class Database:
         self._db = os.path.join(os.path.abspath(os.path.dirname(__file__)), "app.db")
         self._conn = None
         self.cursor = None
+        self.create_connection()
+
+    def __enter__(self):
+        """Returns db on using with clause"""
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        """Closes db connection after with clause"""
+        self.close_connection()
 
     def create_connection(self) -> None:
         """Create a database connection if not already established."""

web_server/utils/recommendation_utils.py

@@ -5,28 +5,28 @@ def user_recommendation_category(user_id: int) -> Optional[int]:
     """
     Queries user_preferences database to find users favourite streaming category and returns the category
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        data = db.fetchone("""
-
+            SELECT category_id 
-    data = db.fetchone(
+            FROM user_preferences 
-        "SELECT category_id FROM user_preferences WHERE user_id = ? ORDER BY favourability DESC LIMIT 1", (user_id,))
+            WHERE user_id = ? 
-    db.close_connection()
+            ORDER BY favourability DESC 
+            LIMIT 1
+        """, (user_id,))
     return data
 
 def followed_categories_recommendations(user_id: int):
     """
     Returns top 25 streams given a users category following
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
-
         categories = db.fetchall("""
             SELECT users.user_id, title, username, num_viewers, category_name 
             FROM streams 
             WHERE category_id IN (SELECT category_id FROM categories WHERE user_id = ?)
             ORDER BY num_viewers DESC
-                             LIMIT 25;  """, (user_id,))
+            LIMIT 25;
-    db.close_connection()
+        """, (user_id,))
     return categories
 
 def recommendations_based_on_category(category_id: int) -> Optional[List[Tuple[int, str, int]]]:
@@ -34,9 +34,7 @@ def recommendations_based_on_category(category_id: int) -> Optional[List[Tuple[i
     Queries stream database to get top 25 most viewed streams based on given category and returns 
     (user_id, title, username, num_viewers, category_name)
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
-
         data = db.fetchall("""
             SELECT users.user_id, title, username, num_viewers, category_name
             FROM streams 
@@ -44,8 +42,8 @@ def recommendations_based_on_category(category_id: int) -> Optional[List[Tuple[i
             JOIN categories ON streams.category_id = categories.category_id
             WHERE categories.category_id = ? 
             ORDER BY num_viewers DESC 
-        LIMIT 25""", (category_id,))
+            LIMIT 25
-    db.close_connection()
+        """, (category_id,))
     return data
 
 def default_recommendations():
@@ -53,8 +51,7 @@ def default_recommendations():
     Return a list of 25 recommended live streams by number of viewers
     (user_id, title, username, num_viewers, category_name)
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
         data = db.fetchall("""
             SELECT users.user_id, title, username, num_viewers, category_name
             FROM streams 
@@ -63,6 +60,21 @@ def default_recommendations():
             ORDER BY num_viewers DESC 
             LIMIT 25;
         """)
-    db.close_connection()
     return data
 
+def category_recommendations():
+    """
+    Returns a list of the top 5 most popular categories
+    """
+    with Database() as db:
+        categories = db.fetchall("""
+            SELECT categories.category_id, categories.category_name
+            FROM streams
+            JOIN categories ON streams.category_id = categories.category_id
+            WHERE streams.isLive = 1
+            GROUP BY categories.category_name
+            ORDER BY SUM(streams.num_viewers) DESC
+            LIMIT 5;
+        """)
+    return categories
+

web_server/utils/stream_utils.py

@@ -7,19 +7,19 @@ def streamer_live_status(user_id: int) -> bool:
     """
     Returns boolean on whether the given streamer is live
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        is_live = db.fetchone("""
-    is_live = db.fetchone("""SELECT isLive FROM streams WHERE user_id = ?""", (user_id,))
+            SELECT isLive 
-    db.close_connection()
+            FROM streams 
+            WHERE user_id = ?
+        """, (user_id,))
     return is_live
 
 def followed_live_streams(user_id: int) -> list[dict]:
     """
     Searches for streamers who the user followed which are currently live
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
-
         live_streams = db.fetchall("""
             SELECT user_id, stream_id, title, num_viewers
             FROM streams 
@@ -27,46 +27,40 @@ def followed_live_streams(user_id: int) -> list[dict]:
             AND stream_id = (SELECT MAX(stream_id) FROM streams WHERE user_id = streams.user_id)
             AND isLive = 1;
         """, (user_id,))
-    db.close_connection()
-
     return live_streams
 
 def followed_streamers(user_id: int) -> list[dict]:
     """
     Returns a list of streamers who the user follows
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
-
         followed_streamers = db.fetchall("""
             SELECT user_id, username
             FROM users
             WHERE user_id IN (SELECT followed_id FROM follows WHERE user_id = ?);
         """, (user_id,))
-
-    db.close_connection()
     return followed_streamers
 
 def streamer_most_recent_stream(user_id: int) -> dict:
     """
     Returns data of the most recent stream by a streamer
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        most_recent_stream = db.fetchone("""
-    most_recent_stream = db.fetchone("""SELECT * FROM streams WHERE 
+            SELECT * FROM streams 
-                                        user_id = ? AND 
+            WHERE user_id = ? 
-                                        stream_id = (SELECT MAX(stream_id) FROM
+            AND stream_id = (SELECT MAX(stream_id) FROM streams WHERE user_id = ?)
-                                        streams WHERE user_id = ?)""", (user_id, user_id))
+        """, (user_id, user_id))
-    db.close_connection()
     return most_recent_stream
 
 def user_stream(user_id: int, stream_id: int) -> dict:
     """
     Returns data of a streamers selected stream
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        stream = db.fetchone("""
-    stream = db.fetchone("SELECT * FROM streams WHERE user_id = ? AND stream_id = ?", (user_id, stream_id))
+            SELECT * FROM streams 
-    db.close_connection()
+            WHERE user_id = ? 
-
+            AND stream_id = ?
+        """, (user_id, stream_id))
     return stream

web_server/utils/user_utils.py

@@ -13,138 +13,101 @@ def get_user_id(username: str) -> int:
     """
     Returns user_id associated with given username
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        data = db.fetchone("""
-
+            SELECT user_id 
-    try:
+            FROM users 
-        data = db.fetchone(
+            WHERE username = ?
-            "SELECT user_id FROM users WHERE username = ?", 
+        """, (username,))
-            (username,)
-        )
     return data['user_id'] if data else None
-    except Exception as e:
-        print(f"Error: {e}")
-        return None
-    finally:
-        db.close_connection()
 
 def get_username(user_id: str) -> Optional[str]:
     """
     Returns username associated with given user_id
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        data = db.fetchone("""
-
+            SELECT username 
-    try:
+            FROM user 
-        data = db.fetchone(
+            WHERE user_id = ?
-            "SELECT username FROM user WHERE user_id = ?", 
+        """, (user_id,))
-            (user_id,)
+    return data['username'] if data else None
-        )
-        return data[0] if data else None
-    except Exception as e:
-        print(f"Error: {e}")
-        return None
-    finally:
-        db.close_connection()
     
 def is_user_partner(user_id: int) -> bool:
     """
     Returns True if user is a partner, else False
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        data = db.fetchone("""
-
+            SELECT is_partnered 
-    try:
+            FROM users 
-        data = db.fetchone(
+            WHERE user_id = ?
-            "SELECT is_partnered FROM users WHERE user_id = ?", 
+        """, (user_id,))
-            (user_id,)
-        )
     return bool(data)
-    except Exception as e:
-        print(f"Error: {e}")
-        return False
-    finally:
-        db.close_connection()
 
 def is_subscribed(user_id: int, streamer_id: int) -> bool:
     """
     Returns True if user is subscribed to a streamer, else False
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        result = db.fetchone("""
-
+            SELECT 1 
-    try:
+            FROM subscribes 
-        result = db.fetchone(
+            WHERE user_id = ? 
-            "SELECT 1 FROM subscribes WHERE user_id = ? AND streamer_id = ? AND expires > ?", 
+            AND streamer_id = ? 
-            (user_id, streamer_id, datetime.now())
+            AND expires > ?
-        )
+        """, (user_id, streamer_id, datetime.now()))
     return bool(result)
-    except Exception as e:
-        print(f"Error: {e}")
-        return False
-    finally:
-        db.close_connection()
 
 def is_following(user_id: int, followed_id: int) -> bool:
-    db = Database()
+    """
-    db.create_connection()
+    Returns where a user is following another
-    
+    """
-    try:
+    with Database() as db:
-        result = db.fetchone(
+        result = db.fetchone("""
-            "SELECT 1 FROM follows WHERE user_id = ? AND followed_id = ?", 
+            SELECT 1 
-            (user_id, followed_id)
+            FROM follows 
-        )
+            WHERE user_id = ? 
+            AND followed_id = ?
+        """, (user_id, followed_id))
     return bool(result)
-    except Exception as e:
-        print(f"Error: {e}")
-        return False
-    finally:
-        db.close_connection()
 
 def subscription_expiration(user_id: int, subscribed_id: int) -> int:
     """
     Returns the amount of time left until user subscription to a streamer ends
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        data = db.fetchone("""
-    remaining_time = 0
+            SELECT expires 
-    try:
+            FROM subscriptions 
-        data = db.fetchone(
+            WHERE user_id = ? 
-            "SELECT expires from subscriptions WHERE user_id = ? AND subscribed_id = ? AND expires > since", (user_id,subscribed_id))
+            AND subscribed_id = ? 
+            AND expires > ?
+        """, (user_id, subscribed_id, datetime.now()))
+
     if data:
         expiration_date = data["expires"]
-
         remaining_time = (expiration_date - datetime.now()).seconds
-    except Exception as e:
-        print(f"Error: {e}")
-    finally:
-        db.close_connection()
-
         return remaining_time
 
+    return 0
+
 def verify_token(token: str):
     """
     Given a token verifies token and decodes the token into an email
     """
-    try:
     email = serializer.loads(token, salt='1', max_age=3600)
-        return email
+    return email if email else False
-    except Exception as e:
-        print(f"Error: {e}")
-        return False
 
 def reset_password(new_password: str, email: str):
     """
     Given email and new password reset the password for a given user
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
+        db.execute("""
+            UPDATE users 
+            SET password = ? 
+            WHERE email = ?
+        """, (generate_password_hash(new_password), email))
     
-    try:
-        db.execute("UPDATE users SET password = ? WHERE email = ?", (generate_password_hash(new_password), email))
     return True
-    except Exception as e:
-        print(f"Error: {e}")
-        return False
-    finally:
-        db.close_connection()

web_server/utils/utils.py

@@ -4,27 +4,25 @@ def categories():
     """
     Returns all possible streaming categories
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
         all_categories = db.fetchall("SELECT * FROM categories")
+    
     return all_categories
 
 def tags():
     """
     Returns all possible streaming tags
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
         all_tags = db.fetchall("SELECT * FROM tags")
+    
     return all_tags
 
 def most_popular_category():
     """
     Returns the most popular category based on live stream viewers
     """
-    db = Database()
+    with Database() as db:
-    db.create_connection()
-
         category = db.fetchone("""
             SELECT categories.category_id, categories.category_name
             FROM streams