__all__ = []
import concurrent.futures._base
import reprlib
from . import events
Error = concurrent.futures._base.Error
CancelledError = concurrent.futures.CancelledError
TimeoutError = concurrent.futures.TimeoutError
class InvalidStateError(Error):
"""The operation is not allowed in this state."""
# States for Future.
_PENDING = 'PENDING'
_CANCELLED = 'CANCELLED'
_FINISHED = 'FINISHED'
def isfuture(obj):
"""Check for a Future.
This returns True when obj is a Future instance or is advertising
itself as duck-type compatible by setting _asyncio_future_blocking.
See comment in Future for more details.
"""
return (hasattr(obj.__class__, '_asyncio_future_blocking') and
obj._asyncio_future_blocking is not None)
def _format_callbacks(cb):
"""helper function for Future.__repr__"""
size = len(cb)
if not size:
cb = ''
def format_cb(callback):
return events._format_callback_source(callback, ())
if size == 1:
cb = format_cb(cb[0])
elif size == 2:
cb = '{}, {}'.format(format_cb(cb[0]), format_cb(cb[1]))
elif size > 2:
cb = '{}, <{} more>, {}'.format(format_cb(cb[0]),
size - 2,
format_cb(cb[-1]))
return 'cb=[%s]' % cb
def _future_repr_info(future):
# (Future) -> str
"""helper function for Future.__repr__"""
info = [future._state.lower()]
if future._state == _FINISHED:
if future._exception is not None:
info.append('exception={!r}'.format(future._exception))
else:
# use reprlib to limit the length of the output, especially
# for very long strings
result = reprlib.repr(future._result)
info.append('result={}'.format(result))
if future._callbacks:
info.append(_format_callbacks(future._callbacks))
if future._source_traceback:
frame = future._source_traceback[-1]
info.append('created at %s:%s' % (frame[0], frame[1]))
return info
