Source code for clockblocks.utilities

"""
Utility functions, including versions of :func:`wait` and :func:`fork` that implicitly make use of the active clock
on the current thread.
"""

#  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++  #
#  This file is part of SCAMP (Suite for Computer-Assisted Music in Python)                      #
#  Copyright © 2020 Marc Evanstein <marc@marcevanstein.com>.                                     #
#                                                                                                #
#  This program is free software: you can redistribute it and/or modify it under the terms of    #
#  the GNU General Public License as published by the Free Software Foundation, either version   #
#  3 of the License, or (at your option) any later version.                                      #
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#  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;     #
#  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     #
#  See the GNU General Public License for more details.                                          #
#                                                                                                #
#  You should have received a copy of the GNU General Public License along with this program.    #
#  If not, see <http://www.gnu.org/licenses/>.                                                   #
#  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++  #

import threading
import time
from threading import Event
from . import clock as clock_module
from typing import Sequence, Callable, Union


[docs]def sleep_precisely_until(stop_time: float, interruption_event: Event = None) -> None: """ High-precision sleep until stop_time. Sleeps repeatedly by half of the remaining time until there are fewer than 500 microseconds left, at which point it implements a busy wait. :param stop_time: desired stop time in seconds since the epoch (as is returned by :func:`time.time`) :param interruption_event: (optional) an Event used to execute the sleep call. This has the advantage that the sleep can be interrupted by calling `set()` on the event. """ time_remaining = stop_time - time.time() if time_remaining <= 0: return elif time_remaining < 0.0005: # when there's fewer than 500 microseconds left, just burn cpu cycles and hit it exactly while time.time() < stop_time and (interruption_event is None or not interruption_event.is_set()): pass else: if interruption_event is not None: if interruption_event.wait(timeout=time_remaining / 2): return else: time.sleep(time_remaining / 2) sleep_precisely_until(stop_time, interruption_event)
[docs]def sleep_precisely(secs: float, interruption_event: Event = None) -> None: """ High-precision sleep for the given number of seconds. :param secs: sleep duration :param interruption_event: see :func:`sleep_precisely_until` """ sleep_precisely_until(time.time() + secs, interruption_event)
[docs]def current_clock() -> Union['clock_module.Clock', None]: """ Get the :class:`~clockblocks.clock.Clock` active on the current thread (or None if none is active) """ # utility for getting the clock we are currently using (we attach it to the thread when it's started) current_thread = threading.current_thread() if not hasattr(current_thread, '__clock__'): return None return threading.current_thread().__clock__
[docs]def wait(dt: float, units="beats") -> None: """ Calls :func:`~clockblocks.clock.Clock.wait` on the clock that is currently active on the thread. Defaults to :func:`time.sleep` when no clock is active. :param dt: duration to wait :param units: either "beats" or "time" (see :func:`~clockblocks.clock.Clock.wait`) """ c = current_clock() if c is not None: current_clock().wait(dt, units=units) else: time.sleep(dt)
[docs]def wait_forever() -> None: """ Calls :func:`~clockblocks.clock.Clock.wait_forever` on the clock that is currently active on the thread; generally, this is called when there are child clocks running and we want to keep the main script alive while the action takes place on the child clocks. """ c = current_clock() if c is not None: current_clock().wait_forever() else: while True: time.sleep(1)
[docs]def wait_for_children_to_finish() -> None: """ Calls :func:`~clockblocks.clock.Clock.wait_for_children_to_finish` on the clock that is currently active on the thread; generally, this is called when there are child clocks running and we want to keep the main script alive while the action takes place on the child clocks. """ c = current_clock() if c is not None: current_clock().wait_for_children_to_finish()
[docs]def fork(process_function: Callable, args: Sequence = (), kwargs: dict = None, name: str = None, initial_rate: float = None, initial_tempo: float = None, initial_beat_length: float = None) -> 'clock_module.Clock': """ Spawns a parallel process running on a child clock of the currently active clock. :param process_function: see :func:`~clockblocks.clock.Clock.fork` :param name: see :func:`~clockblocks.clock.Clock.fork` :param initial_rate: see :func:`~clockblocks.clock.Clock.fork` :param initial_tempo: see :func:`~clockblocks.clock.Clock.fork` :param initial_beat_length: see :func:`~clockblocks.clock.Clock.fork` :param args: see :func:`~clockblocks.clock.Clock.fork` :param kwargs: see :func:`~clockblocks.clock.Clock.fork` :return: the clock of the newly forked process """ clock = current_clock() if clock is None: raise Exception("Cannot fork function: there is no running clock.") else: return clock.fork(process_function, name=name, initial_rate=initial_rate, initial_tempo=initial_tempo, initial_beat_length=initial_beat_length, args=args, kwargs=kwargs)
[docs]def fork_unsynchronized(process_function: Callable, args: Sequence = (), kwargs: dict = None) -> None: """ Spawns a parallel process, but as an asynchronous thread, not on a child clock. However, this will make use of the ThreadPool of the currently active clock, so it's quicker to spawn than creating a new Thread. :param process_function: the process to be spawned :param args: arguments for that function :param kwargs: keyword arguments for that function """ clock = current_clock() if clock is None: threading.Thread(target=process_function, args=args, kwargs=kwargs).start() else: clock.fork_unsynchronized(process_function, args=args, kwargs=kwargs)
[docs]def snap_float_to_nice_decimal(x: float, order_of_magnitude_difference=7) -> float: """ If x is near to a nice decimal, this rounds it. E.g., given a number like 8.01399999999999214, we want to round it to 8.014. We do this by comparing what we get if we round coarsely to what we get if we round precisely, for where place_difference represents how much more precise the precise round is than the course round. If they're the same, then we should be rounding. :param x: number to snap :param order_of_magnitude_difference: how many orders of magnitude we compare rounding across :return: the rounded value """ for first_place in range(0, 17 - order_of_magnitude_difference): if round(x, first_place) == round(x, first_place + order_of_magnitude_difference): return round(x, first_place) return x
class _PrintColors: PURPLE = '\033[95m' CYAN = '\033[96m' DARKCYAN = '\033[36m' BLUE = '\033[94m' GREEN = '\033[92m' YELLOW = '\033[93m' RED = '\033[91m' BOLD = '\033[1m' UNDERLINE = '\033[4m' END = '\033[0m'