Merge pull request 'Implement Database Connection Pooling' (#31) from 27_pool_db_connections into dev

Reviewed-on: #31

bot/add_character.py

@@ -1,11 +1,12 @@
 import requests
 from misskey.exceptions import MisskeyAPIException
 from client import client_connection
-from db_utils import get_db_connection
+from db_utils import insert_character
 
 def add_character(name: str, rarity: int, weight: float, image_url: str) -> tuple[int, str]:
     """
-    Adds a character to the database, uploading the image from a public URL to the bot's Misskey Drive.
+    Adds a character to the database, uploading the image from a public URL to
+    the bot's Misskey Drive.
 
     Args:
         name (str): Character name.
@@ -20,41 +21,29 @@ def add_character(name: str, rarity: int, weight: float, image_url: str) -> tupl
         ValueError: If inputs are invalid.
         RuntimeError: If image download/upload or database operation fails.
     """
+    # Validate inputs
+    if not name or not name.strip():
+        raise ValueError("Character name cannot be empty.")
+    if not isinstance(rarity, int) or rarity < 1:
+        raise ValueError("Rarity must be a positive integer.")
+    if not isinstance(weight, (int, float)) or weight <= 0:
+        raise ValueError("Weight must be a positive number.")
+    if not image_url:
+        raise ValueError("Image URL must be provided.")
+
+    # Download image
+    response = requests.get(image_url, stream=True, timeout=30)
+    if response.status_code != 200:
+        raise RuntimeError(f"Failed to download image from {image_url}")
+
+    # Upload to bot's Drive
+    mk = client_connection()
     try:
-        # Validate inputs
-        if not name or not name.strip():
-            raise ValueError("Character name cannot be empty.")
-        if not isinstance(rarity, int) or rarity < 1:
-            raise ValueError("Rarity must be a positive integer.")
-        if not isinstance(weight, (int, float)) or weight <= 0:
-            raise ValueError("Weight must be a positive number.")
-        if not image_url:
-            raise ValueError("Image URL must be provided.")
-
-        # Download image
-        response = requests.get(image_url, stream=True, timeout=30)
-        if response.status_code != 200:
-            raise RuntimeError(f"Failed to download image from {image_url}")
-
-        # Upload to bot's Drive
-        mk = client_connection()
-        try:
-            media = mk.drive_files_create(response.raw)
-            file_id = media["id"]
-        except MisskeyAPIException as e:
-            raise RuntimeError(f"Failed to upload image to bot's Drive: {e}") from e
-
-        # Insert into database
-        conn = get_db_connection()
-        cur = conn.cursor()
-        cur.execute(
-            'INSERT INTO characters (name, rarity, weight, file_id) VALUES (?, ?, ?, ?)',
-            (name.strip(), rarity, float(weight), file_id)
-        )
-        conn.commit()
-        character_id = cur.lastrowid
-
-        return character_id, file_id
-    finally:
-        if 'conn' in locals():
-            conn.close()
+        media = mk.drive_files_create(response.raw)
+        file_id = media["id"]
+    except MisskeyAPIException as e:
+        raise RuntimeError(f"Failed to upload image to bot's Drive: {e}") from e
+
+    # Insert into database
+    character_id = insert_character(name.strip(), rarity, float(weight), file_id)
+    return character_id, file_id

bot/bot_app.py

@@ -1,6 +1,7 @@
 import time
 import misskey as misskey
 from client import client_connection
+import db_utils as db
 
 from config import NOTIFICATION_POLL_INTERVAL
 from notification import process_notifications
@@ -8,6 +9,9 @@ from notification import process_notifications
 if __name__ == '__main__':
     # Initialize the Misskey client
     client = client_connection()
+    # Connect to DB
+    db.connect()
+
     print('Listening for notifications...')
     while True:
         if not process_notifications(client):

bot/db_utils.py

@@ -1,68 +1,79 @@
+from random import choices
 import sqlite3
 import config
 
 DB_PATH = config.DB_PATH
+CONNECTION: sqlite3.Connection
+CURSOR: sqlite3.Cursor
 
-def get_db_connection():
+def connect() -> None:
     '''Creates a connection to the database'''
-    conn = sqlite3.connect(DB_PATH)
-    conn.row_factory = sqlite3.Row
-    return conn
+    print('Connecting to the database...')
+    global CONNECTION
+    global CURSOR
+    CONNECTION = sqlite3.connect(DB_PATH, autocommit=True)
+    CONNECTION.row_factory = sqlite3.Row
+    CURSOR = CONNECTION.cursor()
+
+def get_random_character():
+    ''' Gets a random character from the database'''
+    CURSOR.execute('SELECT * FROM characters')
+    characters = CURSOR.fetchall()
+
+    if not characters:
+        return None, None, None, None
+
+    weights = [c['weight'] for c in characters]
+    chosen = choices(characters, weights=weights, k=1)[0]
+
+    return chosen['id'], chosen['name'], chosen['file_id'], chosen['rarity']
 
 def get_or_create_user(username):
     '''Retrieves an ID for a given user, if the user does not exist, it will be
     created.'''
-    conn = get_db_connection()
-    conn.row_factory = sqlite3.Row
-    cur = conn.cursor()
-    cur.execute('SELECT id FROM users WHERE username = ?', (username,))
-    user = cur.fetchone()
+    CURSOR.execute('SELECT id FROM users WHERE username = ?', (username,))
+    user = CURSOR.fetchone()
     if user:
-        conn.close()
         return user[0]
 
     # New user starts with has_rolled = False
-    cur.execute(
+    CURSOR.execute(
         'INSERT INTO users (username, has_rolled) VALUES (?, ?)',
         (username, False)
     )
-    conn.commit()
-    user_id = cur.lastrowid
-    conn.close()
+    user_id = CURSOR.lastrowid
     return user_id
 
-def add_pull(user_id, character_id):
+def insert_character(name: str, rarity: int, weight: float, file_id: str) -> int:
+    '''Inserts a character'''
+    CURSOR.execute(
+        'INSERT INTO characters (name, rarity, weight, file_id) VALUES (?, ?, ?, ?)',
+        (name, rarity, weight, file_id)
+    )
+    character_id = CURSOR.lastrowid
+    return character_id if character_id else 0
+
+def insert_pull(user_id, character_id):
     '''Creates a pull in the database'''
-    conn = get_db_connection()
-    cur = conn.cursor()
-    cur.execute('INSERT INTO pulls (user_id, character_id) VALUES (?, ?)', (user_id, character_id))
-    conn.commit()
-    conn.close()
+    CURSOR.execute(
+        'INSERT INTO pulls (user_id, character_id) VALUES (?, ?)',
+        (user_id, character_id)
+    )
 
 def get_last_rolled_at(user_id):
     '''Gets the timestamp when the user last rolled'''
-    conn = get_db_connection()
-    cur = conn.cursor()
-    cur.execute("SELECT timestamp FROM pulls WHERE user_id = ? ORDER BY timestamp DESC", \
+    CURSOR.execute("SELECT timestamp FROM pulls WHERE user_id = ? ORDER BY timestamp DESC", \
             (user_id,))
-    row = cur.fetchone()
-    conn.close()
+    row = CURSOR.fetchone()
     return row[0] if row else None
 
 
 def get_config(key):
     '''Reads the value for a specified config key from the db'''
-    conn = get_db_connection()
-    cur = conn.cursor()
-    cur.execute("SELECT value FROM config WHERE key = ?", (key,))
-    row = cur.fetchone()
-    conn.close()
+    CURSOR.execute("SELECT value FROM config WHERE key = ?", (key,))
+    row = CURSOR.fetchone()
     return row[0] if row else None
 
 def set_config(key, value):
     '''Writes the value for a specified config key to the db'''
-    conn = get_db_connection()
-    cur = conn.cursor()
-    cur.execute("INSERT OR REPLACE INTO config (key, value) VALUES (?, ?)", (key, value))
-    conn.commit()
-    conn.close()
+    CURSOR.execute("INSERT OR REPLACE INTO config (key, value) VALUES (?, ?)", (key, value))

bot/response.py

@@ -1,25 +1,8 @@
-import random
 from datetime import datetime, timedelta, timezone
-from db_utils import get_or_create_user, add_pull, get_db_connection, get_last_rolled_at
+from db_utils import get_or_create_user, insert_pull, get_last_rolled_at, get_random_character
 from add_character import add_character
 from config import GACHA_ROLL_INTERVAL
 
-def get_character():
-    ''' Gets a random character from the database'''
-    conn = get_db_connection()
-    cur = conn.cursor()
-    cur.execute('SELECT * FROM characters')
-    characters = cur.fetchall()
-    conn.close()
-
-    if not characters:
-        return None, None, None, None
-
-    weights = [c['weight'] for c in characters]
-    chosen = random.choices(characters, weights=weights, k=1)[0]
-
-    return chosen['id'], chosen['name'], chosen['file_id'], chosen['rarity']
-
 def do_roll(full_user):
     '''Determines whether the user can roll, then pulls a random character'''
     user_id = get_or_create_user(full_user)
@@ -50,12 +33,12 @@ def do_roll(full_user):
 
             return f'{full_user} ⏱️ Please wait another {remaining_duration} before rolling again.'
 
-    character_id, character_name, file_id, rarity = get_character()
+    character_id, character_name, file_id, rarity = get_random_character()
 
     if not character_id:
         return f'{full_user} Uwaaa... something went wrong! No characters found. 😿'
 
-    add_pull(user_id,character_id)
+    insert_pull(user_id,character_id)
     stars = '⭐️' * rarity
     return([f"@{full_user} 🎲 Congrats! You rolled {stars} **{character_name}**\n\
             She's all yours now~ 💖✨",[file_id]])