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Editing: engines.py
# testing/engines.py # Copyright (C) 2005-2021 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php from __future__ import absolute_import import re import warnings import weakref from . import config from . import uses_deprecated from .util import decorator from .. import event from .. import pool class ConnectionKiller(object): def __init__(self): self.proxy_refs = weakref.WeakKeyDictionary() self.testing_engines = weakref.WeakKeyDictionary() self.conns = set() def add_engine(self, engine): self.testing_engines[engine] = True def connect(self, dbapi_conn, con_record): self.conns.add((dbapi_conn, con_record)) def checkout(self, dbapi_con, con_record, con_proxy): self.proxy_refs[con_proxy] = True def invalidate(self, dbapi_con, con_record, exception): self.conns.discard((dbapi_con, con_record)) def _safe(self, fn): try: fn() except Exception as e: warnings.warn( "testing_reaper couldn't " "rollback/close connection: %s" % e ) def rollback_all(self): for rec in list(self.proxy_refs): if rec is not None and rec.is_valid: self._safe(rec.rollback) def close_all(self): for rec in list(self.proxy_refs): if rec is not None and rec.is_valid: self._safe(rec._close) def _after_test_ctx(self): # this can cause a deadlock with pg8000 - pg8000 acquires # prepared statement lock inside of rollback() - if async gc # is collecting in finalize_fairy, deadlock. # not sure if this should be if pypy/jython only. # note that firebird/fdb definitely needs this though for conn, rec in list(self.conns): if rec.connection is None: # this is a hint that the connection is closed, which # is causing segfaults on mysqlclient due to # https://github.com/PyMySQL/mysqlclient-python/issues/270; # try to work around here continue self._safe(conn.rollback) def _stop_test_ctx(self): if config.options.low_connections: self._stop_test_ctx_minimal() else: self._stop_test_ctx_aggressive() @uses_deprecated() def _stop_test_ctx_minimal(self): self.close_all() self.conns = set() for rec in list(self.testing_engines): if rec is not config.db: rec.dispose() @uses_deprecated() def _stop_test_ctx_aggressive(self): self.close_all() for conn, rec in list(self.conns): self._safe(conn.close) rec.connection = None self.conns = set() for rec in list(self.testing_engines): rec.dispose() def assert_all_closed(self): for rec in self.proxy_refs: if rec.is_valid: assert False testing_reaper = ConnectionKiller() def drop_all_tables(metadata, bind): testing_reaper.close_all() if hasattr(bind, "close"): bind.close() if not config.db.dialect.supports_alter: from . import assertions with assertions.expect_warnings("Can't sort tables", assert_=False): metadata.drop_all(bind) else: metadata.drop_all(bind) @decorator def assert_conns_closed(fn, *args, **kw): try: fn(*args, **kw) finally: testing_reaper.assert_all_closed() @decorator def rollback_open_connections(fn, *args, **kw): """Decorator that rolls back all open connections after fn execution.""" try: fn(*args, **kw) finally: testing_reaper.rollback_all() @decorator def close_first(fn, *args, **kw): """Decorator that closes all connections before fn execution.""" testing_reaper.close_all() fn(*args, **kw) @decorator def close_open_connections(fn, *args, **kw): """Decorator that closes all connections after fn execution.""" try: fn(*args, **kw) finally: testing_reaper.close_all() def all_dialects(exclude=None): import sqlalchemy.databases as d for name in d.__all__: # TEMPORARY if exclude and name in exclude: continue mod = getattr(d, name, None) if not mod: mod = getattr( __import__("sqlalchemy.databases.%s" % name).databases, name ) yield mod.dialect() class ReconnectFixture(object): def __init__(self, dbapi): self.dbapi = dbapi self.connections = [] self.is_stopped = False def __getattr__(self, key): return getattr(self.dbapi, key) def connect(self, *args, **kwargs): conn = self.dbapi.connect(*args, **kwargs) if self.is_stopped: self._safe(conn.close) curs = conn.cursor() # should fail on Oracle etc. # should fail for everything that didn't fail # above, connection is closed curs.execute("select 1") assert False, "simulated connect failure didn't work" else: self.connections.append(conn) return conn def _safe(self, fn): try: fn() except Exception as e: warnings.warn( "ReconnectFixture couldn't " "close connection: %s" % e ) def shutdown(self, stop=False): # TODO: this doesn't cover all cases # as nicely as we'd like, namely MySQLdb. # would need to implement R. Brewer's # proxy server idea to get better # coverage. self.is_stopped = stop for c in list(self.connections): self._safe(c.close) self.connections = [] def restart(self): self.is_stopped = False def reconnecting_engine(url=None, options=None): url = url or config.db.url dbapi = config.db.dialect.dbapi if not options: options = {} options["module"] = ReconnectFixture(dbapi) engine = testing_engine(url, options) _dispose = engine.dispose def dispose(): engine.dialect.dbapi.shutdown() engine.dialect.dbapi.is_stopped = False _dispose() engine.test_shutdown = engine.dialect.dbapi.shutdown engine.test_restart = engine.dialect.dbapi.restart engine.dispose = dispose return engine def testing_engine(url=None, options=None): """Produce an engine configured by --options with optional overrides.""" from sqlalchemy import create_engine from sqlalchemy.engine.url import make_url if not options: use_reaper = True else: use_reaper = options.pop("use_reaper", True) url = url or config.db.url url = make_url(url) if options is None: if config.db is None or url.drivername == config.db.url.drivername: options = config.db_opts else: options = {} elif config.db is not None and url.drivername == config.db.url.drivername: default_opt = config.db_opts.copy() default_opt.update(options) engine = create_engine(url, **options) engine._has_events = True # enable event blocks, helps with profiling if isinstance(engine.pool, pool.QueuePool): engine.pool._timeout = 0 engine.pool._max_overflow = 0 if use_reaper: event.listen(engine.pool, "connect", testing_reaper.connect) event.listen(engine.pool, "checkout", testing_reaper.checkout) event.listen(engine.pool, "invalidate", testing_reaper.invalidate) testing_reaper.add_engine(engine) return engine def mock_engine(dialect_name=None): """Provides a mocking engine based on the current testing.db. This is normally used to test DDL generation flow as emitted by an Engine. It should not be used in other cases, as assert_compile() and assert_sql_execution() are much better choices with fewer moving parts. """ from sqlalchemy import create_engine if not dialect_name: dialect_name = config.db.name buffer = [] def executor(sql, *a, **kw): buffer.append(sql) def assert_sql(stmts): recv = [re.sub(r"[\n\t]", "", str(s)) for s in buffer] assert recv == stmts, recv def print_sql(): d = engine.dialect return "\n".join(str(s.compile(dialect=d)) for s in engine.mock) engine = create_engine( dialect_name + "://", strategy="mock", executor=executor ) assert not hasattr(engine, "mock") engine.mock = buffer engine.assert_sql = assert_sql engine.print_sql = print_sql return engine class DBAPIProxyCursor(object): """Proxy a DBAPI cursor. Tests can provide subclasses of this to intercept DBAPI-level cursor operations. """ def __init__(self, engine, conn, *args, **kwargs): self.engine = engine self.connection = conn self.cursor = conn.cursor(*args, **kwargs) def execute(self, stmt, parameters=None, **kw): if parameters: return self.cursor.execute(stmt, parameters, **kw) else: return self.cursor.execute(stmt, **kw) def executemany(self, stmt, params, **kw): return self.cursor.executemany(stmt, params, **kw) def __getattr__(self, key): return getattr(self.cursor, key) def __enter__(self): return self def __exit__(self, *args): pass class DBAPIProxyConnection(object): """Proxy a DBAPI connection. Tests can provide subclasses of this to intercept DBAPI-level connection operations. """ def __init__(self, engine, cursor_cls): self.conn = self._sqla_unwrap = engine.pool._creator() self.engine = engine self.cursor_cls = cursor_cls def cursor(self, *args, **kwargs): return self.cursor_cls(self.engine, self.conn, *args, **kwargs) def close(self): self.conn.close() def __getattr__(self, key): return getattr(self.conn, key) def proxying_engine( conn_cls=DBAPIProxyConnection, cursor_cls=DBAPIProxyCursor ): """Produce an engine that provides proxy hooks for common methods. """ def mock_conn(): return conn_cls(config.db, cursor_cls) return testing_engine(options={"creator": mock_conn})
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