from contextlib import asynccontextmanager
from typing import TYPE_CHECKING, Any
from sqlspec.base import SQLSpec
from sqlspec.exceptions import ImproperConfigurationError
from sqlspec.extensions.starlette._state import SQLSpecConfigState
from sqlspec.extensions.starlette._utils import get_or_create_session
from sqlspec.extensions.starlette.middleware import SQLSpecAutocommitMiddleware, SQLSpecManualMiddleware
from sqlspec.utils.logging import get_logger
if TYPE_CHECKING:
from collections.abc import AsyncGenerator
from starlette.applications import Starlette
from starlette.requests import Request
__all__ = ("SQLSpecPlugin",)
logger = get_logger("extensions.starlette")
DEFAULT_COMMIT_MODE = "manual"
DEFAULT_CONNECTION_KEY = "db_connection"
DEFAULT_POOL_KEY = "db_pool"
DEFAULT_SESSION_KEY = "db_session"
[docs]
class SQLSpecPlugin:
"""SQLSpec integration for Starlette applications.
Provides middleware-based session management, automatic transaction handling,
and connection pooling lifecycle management.
Example:
from starlette.applications import Starlette
from sqlspec import SQLSpec
from sqlspec.adapters.asyncpg import AsyncpgConfig
from sqlspec.extensions.starlette import SQLSpecPlugin
sqlspec = SQLSpec()
sqlspec.add_config(AsyncpgConfig(
bind_key="default",
pool_config={"dsn": "postgresql://localhost/mydb"},
extension_config={
"starlette": {
"commit_mode": "autocommit",
"session_key": "db"
}
}
))
app = Starlette()
db_ext = SQLSpecPlugin(sqlspec, app)
@app.route("/users")
async def list_users(request):
db = db_ext.get_session(request)
result = await db.execute("SELECT * FROM users")
return JSONResponse({"users": result.all()})
"""
__slots__ = ("_config_states", "_sqlspec")
[docs]
def __init__(self, sqlspec: SQLSpec, app: "Starlette | None" = None) -> None:
"""Initialize SQLSpec Starlette extension.
Args:
sqlspec: Pre-configured SQLSpec instance with registered configs.
app: Optional Starlette application to initialize immediately.
"""
self._sqlspec = sqlspec
self._config_states: list[SQLSpecConfigState] = []
for cfg in self._sqlspec.configs.values():
settings = self._extract_starlette_settings(cfg)
state = self._create_config_state(cfg, settings)
self._config_states.append(state)
if app is not None:
self.init_app(app)
def _extract_starlette_settings(self, config: Any) -> "dict[str, Any]":
"""Extract Starlette settings from config.extension_config.
Args:
config: Database configuration instance.
Returns:
Dictionary of Starlette-specific settings.
"""
starlette_config = config.extension_config.get("starlette", {})
connection_key = starlette_config.get("connection_key", DEFAULT_CONNECTION_KEY)
pool_key = starlette_config.get("pool_key", DEFAULT_POOL_KEY)
session_key = starlette_config.get("session_key", DEFAULT_SESSION_KEY)
commit_mode = starlette_config.get("commit_mode", DEFAULT_COMMIT_MODE)
if not config.supports_connection_pooling and pool_key == DEFAULT_POOL_KEY:
pool_key = f"_{DEFAULT_POOL_KEY}_{id(config)}"
return {
"connection_key": connection_key,
"pool_key": pool_key,
"session_key": session_key,
"commit_mode": commit_mode,
"extra_commit_statuses": starlette_config.get("extra_commit_statuses"),
"extra_rollback_statuses": starlette_config.get("extra_rollback_statuses"),
"disable_di": starlette_config.get("disable_di", False),
}
def _create_config_state(self, config: Any, settings: "dict[str, Any]") -> SQLSpecConfigState:
"""Create configuration state object.
Args:
config: Database configuration instance.
settings: Extracted Starlette settings.
Returns:
Configuration state instance.
"""
return SQLSpecConfigState(
config=config,
connection_key=settings["connection_key"],
pool_key=settings["pool_key"],
session_key=settings["session_key"],
commit_mode=settings["commit_mode"],
extra_commit_statuses=settings["extra_commit_statuses"],
extra_rollback_statuses=settings["extra_rollback_statuses"],
disable_di=settings["disable_di"],
)
[docs]
def init_app(self, app: "Starlette") -> None:
"""Initialize Starlette application with SQLSpec.
Validates configuration, wraps lifespan, and adds middleware.
Args:
app: Starlette application instance.
"""
self._validate_unique_keys()
original_lifespan = app.router.lifespan_context
@asynccontextmanager
async def combined_lifespan(app: "Starlette") -> "AsyncGenerator[None, None]":
async with self.lifespan(app), original_lifespan(app):
yield
app.router.lifespan_context = combined_lifespan
for config_state in self._config_states:
if not config_state.disable_di:
self._add_middleware(app, config_state)
def _validate_unique_keys(self) -> None:
"""Validate that all state keys are unique across configs.
Raises:
ImproperConfigurationError: If duplicate keys found.
"""
all_keys: set[str] = set()
for state in self._config_states:
keys = {state.connection_key, state.pool_key, state.session_key}
duplicates = all_keys & keys
if duplicates:
msg = f"Duplicate state keys found: {duplicates}"
raise ImproperConfigurationError(msg)
all_keys.update(keys)
def _add_middleware(self, app: "Starlette", config_state: SQLSpecConfigState) -> None:
"""Add transaction middleware for configuration.
Args:
app: Starlette application instance.
config_state: Configuration state.
"""
if config_state.commit_mode == "manual":
app.add_middleware(SQLSpecManualMiddleware, config_state=config_state)
elif config_state.commit_mode == "autocommit":
app.add_middleware(SQLSpecAutocommitMiddleware, config_state=config_state, include_redirect=False)
elif config_state.commit_mode == "autocommit_include_redirect":
app.add_middleware(SQLSpecAutocommitMiddleware, config_state=config_state, include_redirect=True)
[docs]
@asynccontextmanager
async def lifespan(self, app: "Starlette") -> "AsyncGenerator[None, None]":
"""Manage connection pool lifecycle.
Args:
app: Starlette application instance.
Yields:
None
"""
for config_state in self._config_states:
if config_state.config.supports_connection_pooling:
pool = await config_state.config.create_pool()
setattr(app.state, config_state.pool_key, pool)
try:
yield
finally:
for config_state in self._config_states:
if config_state.config.supports_connection_pooling:
close_result = config_state.config.close_pool()
if close_result is not None:
await close_result
[docs]
def get_session(self, request: "Request", key: "str | None" = None) -> Any:
"""Get or create database session for request.
Sessions are cached per request to ensure consistency.
Args:
request: Starlette request instance.
key: Optional session key to retrieve specific database session.
Returns:
Database session (driver instance).
"""
config_state = self._config_states[0] if key is None else self._get_config_state_by_key(key)
return get_or_create_session(request, config_state)
[docs]
def get_connection(self, request: "Request", key: "str | None" = None) -> Any:
"""Get database connection from request state.
Args:
request: Starlette request instance.
key: Optional session key to retrieve specific database connection.
Returns:
Database connection object.
"""
config_state = self._config_states[0] if key is None else self._get_config_state_by_key(key)
return getattr(request.state, config_state.connection_key)
def _get_config_state_by_key(self, key: str) -> SQLSpecConfigState:
"""Get configuration state by session key.
Args:
key: Session key to search for.
Returns:
Configuration state matching the key.
Raises:
ValueError: If no configuration found with the specified key.
"""
for state in self._config_states:
if state.session_key == key:
return state
msg = f"No configuration found with session_key: {key}"
raise ValueError(msg)
