def is_psycopg_green():
"""Test whether gevent compatibility layer is installed in psycopg."""
if not hasattr(extensions, 'set_wait_callback'):
raise ImportError(
"support for coroutines not available in this Psycopg version (%s)"
% psycopg2.__version__)
return extensions.get_wait_callback() == gevent_wait_callback
def is_psycopg_green():
"""Test whether gevent compatibility layer is installed in psycopg."""
if not hasattr(extensions, 'set_wait_callback'):
raise ImportError(
"support for coroutines not available in this Psycopg version (%s)"
% psycopg2.__version__)
return extensions.get_wait_callback() == gevent_wait_callback
def _check_wait_callback(self):
# Subclasses may override this method if they have no concept of
# this.
extensions = self._get_extension_module()
callback = extensions.get_wait_callback()
# Truth table:
# callback is not None | Need callback | pass?
# True | True | Pass
# False | False | Pass
# True | False | Fail
# False | True | Fail
#
# This is XNOR, exclusive nor, or iff. Note how it passes
# only when both conditions are the same.
callback_not_none = bool(callback is not None)
need_callback = bool(self._WANT_WAIT_CALLBACK)
if callback_not_none is not need_callback:
raise WaitCallbackStateError(self.__name__, callback_not_none, need_callback)
def is_psycopg_patched():
"""Return True if psycopg is patched, False otherwise"""
if not hasattr(extensions, 'get_wait_callback'):
return False
return extensions.get_wait_callback() == gevent_wait_callback
def _check_wait_callback(self):
from psycopg2 import extensions # pylint:disable=no-name-in-module
if extensions.get_wait_callback() is not None: # pragma: no cover
raise ImportError("Wait callback installed")
