Removed the Requirement to Install Python and NodeJS (Now Bundled with Borealis)

Dependencies/Python/Lib/concurrent/futures/_base.py

@@ -0,0 +1,654 @@
+# Copyright 2009 Brian Quinlan. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+__author__ = 'Brian Quinlan (brian@sweetapp.com)'
+
+import collections
+import logging
+import threading
+import time
+import types
+
+FIRST_COMPLETED = 'FIRST_COMPLETED'
+FIRST_EXCEPTION = 'FIRST_EXCEPTION'
+ALL_COMPLETED = 'ALL_COMPLETED'
+_AS_COMPLETED = '_AS_COMPLETED'
+
+# Possible future states (for internal use by the futures package).
+PENDING = 'PENDING'
+RUNNING = 'RUNNING'
+# The future was cancelled by the user...
+CANCELLED = 'CANCELLED'
+# ...and _Waiter.add_cancelled() was called by a worker.
+CANCELLED_AND_NOTIFIED = 'CANCELLED_AND_NOTIFIED'
+FINISHED = 'FINISHED'
+
+_FUTURE_STATES = [
+    PENDING,
+    RUNNING,
+    CANCELLED,
+    CANCELLED_AND_NOTIFIED,
+    FINISHED
+]
+
+_STATE_TO_DESCRIPTION_MAP = {
+    PENDING: "pending",
+    RUNNING: "running",
+    CANCELLED: "cancelled",
+    CANCELLED_AND_NOTIFIED: "cancelled",
+    FINISHED: "finished"
+}
+
+# Logger for internal use by the futures package.
+LOGGER = logging.getLogger("concurrent.futures")
+
+class Error(Exception):
+    """Base class for all future-related exceptions."""
+    pass
+
+class CancelledError(Error):
+    """The Future was cancelled."""
+    pass
+
+TimeoutError = TimeoutError  # make local alias for the standard exception
+
+class InvalidStateError(Error):
+    """The operation is not allowed in this state."""
+    pass
+
+class _Waiter(object):
+    """Provides the event that wait() and as_completed() block on."""
+    def __init__(self):
+        self.event = threading.Event()
+        self.finished_futures = []
+
+    def add_result(self, future):
+        self.finished_futures.append(future)
+
+    def add_exception(self, future):
+        self.finished_futures.append(future)
+
+    def add_cancelled(self, future):
+        self.finished_futures.append(future)
+
+class _AsCompletedWaiter(_Waiter):
+    """Used by as_completed()."""
+
+    def __init__(self):
+        super(_AsCompletedWaiter, self).__init__()
+        self.lock = threading.Lock()
+
+    def add_result(self, future):
+        with self.lock:
+            super(_AsCompletedWaiter, self).add_result(future)
+            self.event.set()
+
+    def add_exception(self, future):
+        with self.lock:
+            super(_AsCompletedWaiter, self).add_exception(future)
+            self.event.set()
+
+    def add_cancelled(self, future):
+        with self.lock:
+            super(_AsCompletedWaiter, self).add_cancelled(future)
+            self.event.set()
+
+class _FirstCompletedWaiter(_Waiter):
+    """Used by wait(return_when=FIRST_COMPLETED)."""
+
+    def add_result(self, future):
+        super().add_result(future)
+        self.event.set()
+
+    def add_exception(self, future):
+        super().add_exception(future)
+        self.event.set()
+
+    def add_cancelled(self, future):
+        super().add_cancelled(future)
+        self.event.set()
+
+class _AllCompletedWaiter(_Waiter):
+    """Used by wait(return_when=FIRST_EXCEPTION and ALL_COMPLETED)."""
+
+    def __init__(self, num_pending_calls, stop_on_exception):
+        self.num_pending_calls = num_pending_calls
+        self.stop_on_exception = stop_on_exception
+        self.lock = threading.Lock()
+        super().__init__()
+
+    def _decrement_pending_calls(self):
+        with self.lock:
+            self.num_pending_calls -= 1
+            if not self.num_pending_calls:
+                self.event.set()
+
+    def add_result(self, future):
+        super().add_result(future)
+        self._decrement_pending_calls()
+
+    def add_exception(self, future):
+        super().add_exception(future)
+        if self.stop_on_exception:
+            self.event.set()
+        else:
+            self._decrement_pending_calls()
+
+    def add_cancelled(self, future):
+        super().add_cancelled(future)
+        self._decrement_pending_calls()
+
+class _AcquireFutures(object):
+    """A context manager that does an ordered acquire of Future conditions."""
+
+    def __init__(self, futures):
+        self.futures = sorted(futures, key=id)
+
+    def __enter__(self):
+        for future in self.futures:
+            future._condition.acquire()
+
+    def __exit__(self, *args):
+        for future in self.futures:
+            future._condition.release()
+
+def _create_and_install_waiters(fs, return_when):
+    if return_when == _AS_COMPLETED:
+        waiter = _AsCompletedWaiter()
+    elif return_when == FIRST_COMPLETED:
+        waiter = _FirstCompletedWaiter()
+    else:
+        pending_count = sum(
+                f._state not in [CANCELLED_AND_NOTIFIED, FINISHED] for f in fs)
+
+        if return_when == FIRST_EXCEPTION:
+            waiter = _AllCompletedWaiter(pending_count, stop_on_exception=True)
+        elif return_when == ALL_COMPLETED:
+            waiter = _AllCompletedWaiter(pending_count, stop_on_exception=False)
+        else:
+            raise ValueError("Invalid return condition: %r" % return_when)
+
+    for f in fs:
+        f._waiters.append(waiter)
+
+    return waiter
+
+
+def _yield_finished_futures(fs, waiter, ref_collect):
+    """
+    Iterate on the list *fs*, yielding finished futures one by one in
+    reverse order.
+    Before yielding a future, *waiter* is removed from its waiters
+    and the future is removed from each set in the collection of sets
+    *ref_collect*.
+
+    The aim of this function is to avoid keeping stale references after
+    the future is yielded and before the iterator resumes.
+    """
+    while fs:
+        f = fs[-1]
+        for futures_set in ref_collect:
+            futures_set.remove(f)
+        with f._condition:
+            f._waiters.remove(waiter)
+        del f
+        # Careful not to keep a reference to the popped value
+        yield fs.pop()
+
+
+def as_completed(fs, timeout=None):
+    """An iterator over the given futures that yields each as it completes.
+
+    Args:
+        fs: The sequence of Futures (possibly created by different Executors) to
+            iterate over.
+        timeout: The maximum number of seconds to wait. If None, then there
+            is no limit on the wait time.
+
+    Returns:
+        An iterator that yields the given Futures as they complete (finished or
+        cancelled). If any given Futures are duplicated, they will be returned
+        once.
+
+    Raises:
+        TimeoutError: If the entire result iterator could not be generated
+            before the given timeout.
+    """
+    if timeout is not None:
+        end_time = timeout + time.monotonic()
+
+    fs = set(fs)
+    total_futures = len(fs)
+    with _AcquireFutures(fs):
+        finished = set(
+                f for f in fs
+                if f._state in [CANCELLED_AND_NOTIFIED, FINISHED])
+        pending = fs - finished
+        waiter = _create_and_install_waiters(fs, _AS_COMPLETED)
+    finished = list(finished)
+    try:
+        yield from _yield_finished_futures(finished, waiter,
+                                           ref_collect=(fs,))
+
+        while pending:
+            if timeout is None:
+                wait_timeout = None
+            else:
+                wait_timeout = end_time - time.monotonic()
+                if wait_timeout < 0:
+                    raise TimeoutError(
+                            '%d (of %d) futures unfinished' % (
+                            len(pending), total_futures))
+
+            waiter.event.wait(wait_timeout)
+
+            with waiter.lock:
+                finished = waiter.finished_futures
+                waiter.finished_futures = []
+                waiter.event.clear()
+
+            # reverse to keep finishing order
+            finished.reverse()
+            yield from _yield_finished_futures(finished, waiter,
+                                               ref_collect=(fs, pending))
+
+    finally:
+        # Remove waiter from unfinished futures
+        for f in fs:
+            with f._condition:
+                f._waiters.remove(waiter)
+
+DoneAndNotDoneFutures = collections.namedtuple(
+        'DoneAndNotDoneFutures', 'done not_done')
+def wait(fs, timeout=None, return_when=ALL_COMPLETED):
+    """Wait for the futures in the given sequence to complete.
+
+    Args:
+        fs: The sequence of Futures (possibly created by different Executors) to
+            wait upon.
+        timeout: The maximum number of seconds to wait. If None, then there
+            is no limit on the wait time.
+        return_when: Indicates when this function should return. The options
+            are:
+
+            FIRST_COMPLETED - Return when any future finishes or is
+                              cancelled.
+            FIRST_EXCEPTION - Return when any future finishes by raising an
+                              exception. If no future raises an exception
+                              then it is equivalent to ALL_COMPLETED.
+            ALL_COMPLETED -   Return when all futures finish or are cancelled.
+
+    Returns:
+        A named 2-tuple of sets. The first set, named 'done', contains the
+        futures that completed (is finished or cancelled) before the wait
+        completed. The second set, named 'not_done', contains uncompleted
+        futures. Duplicate futures given to *fs* are removed and will be
+        returned only once.
+    """
+    fs = set(fs)
+    with _AcquireFutures(fs):
+        done = {f for f in fs
+                   if f._state in [CANCELLED_AND_NOTIFIED, FINISHED]}
+        not_done = fs - done
+        if (return_when == FIRST_COMPLETED) and done:
+            return DoneAndNotDoneFutures(done, not_done)
+        elif (return_when == FIRST_EXCEPTION) and done:
+            if any(f for f in done
+                   if not f.cancelled() and f.exception() is not None):
+                return DoneAndNotDoneFutures(done, not_done)
+
+        if len(done) == len(fs):
+            return DoneAndNotDoneFutures(done, not_done)
+
+        waiter = _create_and_install_waiters(fs, return_when)
+
+    waiter.event.wait(timeout)
+    for f in fs:
+        with f._condition:
+            f._waiters.remove(waiter)
+
+    done.update(waiter.finished_futures)
+    return DoneAndNotDoneFutures(done, fs - done)
+
+
+def _result_or_cancel(fut, timeout=None):
+    try:
+        try:
+            return fut.result(timeout)
+        finally:
+            fut.cancel()
+    finally:
+        # Break a reference cycle with the exception in self._exception
+        del fut
+
+
+class Future(object):
+    """Represents the result of an asynchronous computation."""
+
+    def __init__(self):
+        """Initializes the future. Should not be called by clients."""
+        self._condition = threading.Condition()
+        self._state = PENDING
+        self._result = None
+        self._exception = None
+        self._waiters = []
+        self._done_callbacks = []
+
+    def _invoke_callbacks(self):
+        for callback in self._done_callbacks:
+            try:
+                callback(self)
+            except Exception:
+                LOGGER.exception('exception calling callback for %r', self)
+
+    def __repr__(self):
+        with self._condition:
+            if self._state == FINISHED:
+                if self._exception:
+                    return '<%s at %#x state=%s raised %s>' % (
+                        self.__class__.__name__,
+                        id(self),
+                        _STATE_TO_DESCRIPTION_MAP[self._state],
+                        self._exception.__class__.__name__)
+                else:
+                    return '<%s at %#x state=%s returned %s>' % (
+                        self.__class__.__name__,
+                        id(self),
+                        _STATE_TO_DESCRIPTION_MAP[self._state],
+                        self._result.__class__.__name__)
+            return '<%s at %#x state=%s>' % (
+                    self.__class__.__name__,
+                    id(self),
+                   _STATE_TO_DESCRIPTION_MAP[self._state])
+
+    def cancel(self):
+        """Cancel the future if possible.
+
+        Returns True if the future was cancelled, False otherwise. A future
+        cannot be cancelled if it is running or has already completed.
+        """
+        with self._condition:
+            if self._state in [RUNNING, FINISHED]:
+                return False
+
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                return True
+
+            self._state = CANCELLED
+            self._condition.notify_all()
+
+        self._invoke_callbacks()
+        return True
+
+    def cancelled(self):
+        """Return True if the future was cancelled."""
+        with self._condition:
+            return self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]
+
+    def running(self):
+        """Return True if the future is currently executing."""
+        with self._condition:
+            return self._state == RUNNING
+
+    def done(self):
+        """Return True if the future was cancelled or finished executing."""
+        with self._condition:
+            return self._state in [CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED]
+
+    def __get_result(self):
+        if self._exception:
+            try:
+                raise self._exception
+            finally:
+                # Break a reference cycle with the exception in self._exception
+                self = None
+        else:
+            return self._result
+
+    def add_done_callback(self, fn):
+        """Attaches a callable that will be called when the future finishes.
+
+        Args:
+            fn: A callable that will be called with this future as its only
+                argument when the future completes or is cancelled. The callable
+                will always be called by a thread in the same process in which
+                it was added. If the future has already completed or been
+                cancelled then the callable will be called immediately. These
+                callables are called in the order that they were added.
+        """
+        with self._condition:
+            if self._state not in [CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED]:
+                self._done_callbacks.append(fn)
+                return
+        try:
+            fn(self)
+        except Exception:
+            LOGGER.exception('exception calling callback for %r', self)
+
+    def result(self, timeout=None):
+        """Return the result of the call that the future represents.
+
+        Args:
+            timeout: The number of seconds to wait for the result if the future
+                isn't done. If None, then there is no limit on the wait time.
+
+        Returns:
+            The result of the call that the future represents.
+
+        Raises:
+            CancelledError: If the future was cancelled.
+            TimeoutError: If the future didn't finish executing before the given
+                timeout.
+            Exception: If the call raised then that exception will be raised.
+        """
+        try:
+            with self._condition:
+                if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                    raise CancelledError()
+                elif self._state == FINISHED:
+                    return self.__get_result()
+
+                self._condition.wait(timeout)
+
+                if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                    raise CancelledError()
+                elif self._state == FINISHED:
+                    return self.__get_result()
+                else:
+                    raise TimeoutError()
+        finally:
+            # Break a reference cycle with the exception in self._exception
+            self = None
+
+    def exception(self, timeout=None):
+        """Return the exception raised by the call that the future represents.
+
+        Args:
+            timeout: The number of seconds to wait for the exception if the
+                future isn't done. If None, then there is no limit on the wait
+                time.
+
+        Returns:
+            The exception raised by the call that the future represents or None
+            if the call completed without raising.
+
+        Raises:
+            CancelledError: If the future was cancelled.
+            TimeoutError: If the future didn't finish executing before the given
+                timeout.
+        """
+
+        with self._condition:
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                raise CancelledError()
+            elif self._state == FINISHED:
+                return self._exception
+
+            self._condition.wait(timeout)
+
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                raise CancelledError()
+            elif self._state == FINISHED:
+                return self._exception
+            else:
+                raise TimeoutError()
+
+    # The following methods should only be used by Executors and in tests.
+    def set_running_or_notify_cancel(self):
+        """Mark the future as running or process any cancel notifications.
+
+        Should only be used by Executor implementations and unit tests.
+
+        If the future has been cancelled (cancel() was called and returned
+        True) then any threads waiting on the future completing (though calls
+        to as_completed() or wait()) are notified and False is returned.
+
+        If the future was not cancelled then it is put in the running state
+        (future calls to running() will return True) and True is returned.
+
+        This method should be called by Executor implementations before
+        executing the work associated with this future. If this method returns
+        False then the work should not be executed.
+
+        Returns:
+            False if the Future was cancelled, True otherwise.
+
+        Raises:
+            RuntimeError: if this method was already called or if set_result()
+                or set_exception() was called.
+        """
+        with self._condition:
+            if self._state == CANCELLED:
+                self._state = CANCELLED_AND_NOTIFIED
+                for waiter in self._waiters:
+                    waiter.add_cancelled(self)
+                # self._condition.notify_all() is not necessary because
+                # self.cancel() triggers a notification.
+                return False
+            elif self._state == PENDING:
+                self._state = RUNNING
+                return True
+            else:
+                LOGGER.critical('Future %s in unexpected state: %s',
+                                id(self),
+                                self._state)
+                raise RuntimeError('Future in unexpected state')
+
+    def set_result(self, result):
+        """Sets the return value of work associated with the future.
+
+        Should only be used by Executor implementations and unit tests.
+        """
+        with self._condition:
+            if self._state in {CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED}:
+                raise InvalidStateError('{}: {!r}'.format(self._state, self))
+            self._result = result
+            self._state = FINISHED
+            for waiter in self._waiters:
+                waiter.add_result(self)
+            self._condition.notify_all()
+        self._invoke_callbacks()
+
+    def set_exception(self, exception):
+        """Sets the result of the future as being the given exception.
+
+        Should only be used by Executor implementations and unit tests.
+        """
+        with self._condition:
+            if self._state in {CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED}:
+                raise InvalidStateError('{}: {!r}'.format(self._state, self))
+            self._exception = exception
+            self._state = FINISHED
+            for waiter in self._waiters:
+                waiter.add_exception(self)
+            self._condition.notify_all()
+        self._invoke_callbacks()
+
+    __class_getitem__ = classmethod(types.GenericAlias)
+
+class Executor(object):
+    """This is an abstract base class for concrete asynchronous executors."""
+
+    def submit(self, fn, /, *args, **kwargs):
+        """Submits a callable to be executed with the given arguments.
+
+        Schedules the callable to be executed as fn(*args, **kwargs) and returns
+        a Future instance representing the execution of the callable.
+
+        Returns:
+            A Future representing the given call.
+        """
+        raise NotImplementedError()
+
+    def map(self, fn, *iterables, timeout=None, chunksize=1):
+        """Returns an iterator equivalent to map(fn, iter).
+
+        Args:
+            fn: A callable that will take as many arguments as there are
+                passed iterables.
+            timeout: The maximum number of seconds to wait. If None, then there
+                is no limit on the wait time.
+            chunksize: The size of the chunks the iterable will be broken into
+                before being passed to a child process. This argument is only
+                used by ProcessPoolExecutor; it is ignored by
+                ThreadPoolExecutor.
+
+        Returns:
+            An iterator equivalent to: map(func, *iterables) but the calls may
+            be evaluated out-of-order.
+
+        Raises:
+            TimeoutError: If the entire result iterator could not be generated
+                before the given timeout.
+            Exception: If fn(*args) raises for any values.
+        """
+        if timeout is not None:
+            end_time = timeout + time.monotonic()
+
+        fs = [self.submit(fn, *args) for args in zip(*iterables)]
+
+        # Yield must be hidden in closure so that the futures are submitted
+        # before the first iterator value is required.
+        def result_iterator():
+            try:
+                # reverse to keep finishing order
+                fs.reverse()
+                while fs:
+                    # Careful not to keep a reference to the popped future
+                    if timeout is None:
+                        yield _result_or_cancel(fs.pop())
+                    else:
+                        yield _result_or_cancel(fs.pop(), end_time - time.monotonic())
+            finally:
+                for future in fs:
+                    future.cancel()
+        return result_iterator()
+
+    def shutdown(self, wait=True, *, cancel_futures=False):
+        """Clean-up the resources associated with the Executor.
+
+        It is safe to call this method several times. Otherwise, no other
+        methods can be called after this one.
+
+        Args:
+            wait: If True then shutdown will not return until all running
+                futures have finished executing and the resources used by the
+                executor have been reclaimed.
+            cancel_futures: If True then shutdown will cancel all pending
+                futures. Futures that are completed or running will not be
+                cancelled.
+        """
+        pass
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.shutdown(wait=True)
+        return False
+
+
+class BrokenExecutor(RuntimeError):
+    """
+    Raised when a executor has become non-functional after a severe failure.
+    """