79 lines
2.8 KiB
Python

import os
import time
from typing import Generator
from pathlib import Path
from sqlalchemy import create_engine, event
from sqlalchemy.orm import sessionmaker
from sqlalchemy.exc import OperationalError, SQLAlchemyError
from app.core.config import settings, DB_DIR
# Ensure the database directory exists
db_file = DB_DIR / "db.sqlite"
print(f"Database file path: {db_file}")
# Configure SQLite connection with more robust settings
engine = create_engine(
settings.SQLALCHEMY_DATABASE_URL,
connect_args={
"check_same_thread": False,
"timeout": 30, # Wait up to 30 seconds for the lock
},
pool_recycle=3600, # Recycle connections after 1 hour
pool_pre_ping=True, # Verify connections before usage
pool_size=10, # Maximum 10 connections
max_overflow=20, # Allow up to 20 overflow connections
)
# Add SQLite optimizations
@event.listens_for(engine, "connect")
def optimize_sqlite_connection(dbapi_connection, connection_record):
"""Configure SQLite connection for better performance and reliability."""
# Enable WAL journal mode for better concurrency
dbapi_connection.execute("PRAGMA journal_mode=WAL")
# Ensure foreign keys are enforced
dbapi_connection.execute("PRAGMA foreign_keys=ON")
# Synchronous setting for better performance with decent safety
dbapi_connection.execute("PRAGMA synchronous=NORMAL")
# Cache settings
dbapi_connection.execute("PRAGMA cache_size=-64000") # 64MB cache
# Temp storage in memory
dbapi_connection.execute("PRAGMA temp_store=MEMORY")
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
# More robust database access with retry logic
def get_db() -> Generator:
"""
Get a database session with retry logic for transient errors.
Creates the database file and tables if they don't exist.
"""
db = None
retries = 3
retry_delay = 0.5 # Start with 0.5 second delay
for attempt in range(retries):
try:
db = SessionLocal()
# Test connection with a simple query
db.execute("SELECT 1")
# Yield the working connection
yield db
break
except (OperationalError, SQLAlchemyError) as e:
if db:
db.close()
# Only retry transient errors like "database is locked"
if attempt < retries - 1:
print(f"Database connection attempt {attempt+1} failed: {e}")
print(f"Retrying in {retry_delay} seconds...")
time.sleep(retry_delay)
retry_delay *= 2 # Exponential backoff
else:
print(f"All database connection attempts failed: {e}")
raise
finally:
if db:
db.close()