File size: 8,054 Bytes
8bab08d |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 |
"""
Enterprise-Grade Database Engine with Connection Pooling and Async Support
"""
import os
import logging
from typing import Optional, AsyncGenerator
from contextlib import asynccontextmanager
from sqlalchemy.ext.asyncio import (
create_async_engine,
AsyncSession,
AsyncEngine,
async_sessionmaker
)
from sqlalchemy.pool import NullPool, QueuePool
from sqlalchemy import event, text
from .models import Base
logger = logging.getLogger(__name__)
class DatabaseConfig:
"""Database configuration with environment variable support"""
def __init__(self):
# Database URL (supports SQLite, PostgreSQL, MySQL)
self.database_url = os.getenv(
"DATABASE_URL",
"sqlite+aiosqlite:///./data/cx_agent.db"
)
# Convert postgres:// to postgresql:// for SQLAlchemy
if self.database_url.startswith("postgres://"):
self.database_url = self.database_url.replace(
"postgres://", "postgresql+asyncpg://", 1
)
# Connection pool settings
self.pool_size = int(os.getenv("DB_POOL_SIZE", "20"))
self.max_overflow = int(os.getenv("DB_MAX_OVERFLOW", "10"))
self.pool_timeout = int(os.getenv("DB_POOL_TIMEOUT", "30"))
self.pool_recycle = int(os.getenv("DB_POOL_RECYCLE", "3600"))
self.pool_pre_ping = os.getenv("DB_POOL_PRE_PING", "true").lower() == "true"
# Echo SQL for debugging
self.echo = os.getenv("DB_ECHO", "false").lower() == "true"
# Enable SQLite WAL mode for better concurrency
self.enable_wal = os.getenv("SQLITE_WAL", "true").lower() == "true"
def is_sqlite(self) -> bool:
"""Check if using SQLite"""
return "sqlite" in self.database_url
def is_postgres(self) -> bool:
"""Check if using PostgreSQL"""
return "postgresql" in self.database_url
class DatabaseManager:
"""Singleton database manager with connection pooling"""
_instance: Optional["DatabaseManager"] = None
_engine: Optional[AsyncEngine] = None
_session_factory: Optional[async_sessionmaker[AsyncSession]] = None
def __new__(cls):
if cls._instance is None:
cls._instance = super().__new__(cls)
return cls._instance
def __init__(self):
if self._engine is None:
self._initialize()
def _initialize(self):
"""Initialize database engine and session factory"""
config = DatabaseConfig()
# Engine kwargs
engine_kwargs = {
"echo": config.echo,
"future": True,
}
# Configure connection pool based on database type
if config.is_sqlite():
# SQLite specific settings
logger.info(f"Initializing SQLite database: {config.database_url}")
engine_kwargs.update({
"poolclass": NullPool, # SQLite doesn't need pooling in the same way
"connect_args": {
"check_same_thread": False,
"timeout": 30,
}
})
# Enable WAL mode for better concurrency
if config.enable_wal:
engine_kwargs["connect_args"]["pragmas"] = {
"journal_mode": "WAL",
"synchronous": "NORMAL",
"cache_size": -64000, # 64MB cache
"foreign_keys": 1,
"busy_timeout": 5000,
}
else:
# PostgreSQL/MySQL settings
logger.info(f"Initializing database: {config.database_url}")
engine_kwargs.update({
"poolclass": QueuePool,
"pool_size": config.pool_size,
"max_overflow": config.max_overflow,
"pool_timeout": config.pool_timeout,
"pool_recycle": config.pool_recycle,
"pool_pre_ping": config.pool_pre_ping,
})
# Create async engine
self._engine = create_async_engine(
config.database_url,
**engine_kwargs
)
# Create session factory
self._session_factory = async_sessionmaker(
self._engine,
class_=AsyncSession,
expire_on_commit=False,
autocommit=False,
autoflush=False
)
# Register event listeners
self._register_event_listeners()
logger.info("Database engine initialized successfully")
def _register_event_listeners(self):
"""Register SQLAlchemy event listeners"""
@event.listens_for(self._engine.sync_engine, "connect")
def receive_connect(dbapi_conn, connection_record):
"""Event listener for new connections"""
logger.debug("New database connection established")
@event.listens_for(self._engine.sync_engine, "close")
def receive_close(dbapi_conn, connection_record):
"""Event listener for closed connections"""
logger.debug("Database connection closed")
@property
def engine(self) -> AsyncEngine:
"""Get the database engine"""
if self._engine is None:
raise RuntimeError("Database engine not initialized")
return self._engine
@property
def session_factory(self) -> async_sessionmaker[AsyncSession]:
"""Get the session factory"""
if self._session_factory is None:
raise RuntimeError("Session factory not initialized")
return self._session_factory
async def create_tables(self):
"""Create all database tables"""
logger.info("Creating database tables...")
async with self._engine.begin() as conn:
await conn.run_sync(Base.metadata.create_all)
logger.info("Database tables created successfully")
async def drop_tables(self):
"""Drop all database tables (use with caution!)"""
logger.warning("Dropping all database tables...")
async with self._engine.begin() as conn:
await conn.run_sync(Base.metadata.drop_all)
logger.info("Database tables dropped")
async def health_check(self) -> bool:
"""Check database health"""
try:
async with self.get_session() as session:
await session.execute(text("SELECT 1"))
return True
except Exception as e:
logger.error(f"Database health check failed: {e}")
return False
@asynccontextmanager
async def get_session(self) -> AsyncGenerator[AsyncSession, None]:
"""Get a database session with automatic cleanup"""
session = self.session_factory()
try:
yield session
await session.commit()
except Exception as e:
await session.rollback()
logger.error(f"Database session error: {e}")
raise
finally:
await session.close()
async def close(self):
"""Close database engine and connections"""
if self._engine is not None:
await self._engine.dispose()
logger.info("Database engine closed")
# Global database manager instance
_db_manager: Optional[DatabaseManager] = None
def get_db_manager() -> DatabaseManager:
"""Get or create the global database manager instance"""
global _db_manager
if _db_manager is None:
_db_manager = DatabaseManager()
return _db_manager
async def get_session() -> AsyncGenerator[AsyncSession, None]:
"""Convenience function to get a database session"""
db_manager = get_db_manager()
async with db_manager.get_session() as session:
yield session
async def init_database():
"""Initialize database (create tables if needed)"""
db_manager = get_db_manager()
await db_manager.create_tables()
logger.info("Database initialized")
async def close_database():
"""Close database connections"""
db_manager = get_db_manager()
await db_manager.close()
logger.info("Database closed")
|