Source code for distributed.utils

from __future__ import annotations

import asyncio
import contextvars
import functools
import importlib
import inspect
import json
import logging
import multiprocessing
import os
import pkgutil
import re
import socket
import sys
import tempfile
import threading
import warnings
import weakref
import xml.etree.ElementTree
from asyncio import TimeoutError
from collections import deque
from collections.abc import Callable, Collection, Container, KeysView, ValuesView
from concurrent.futures import CancelledError, ThreadPoolExecutor  # noqa: F401
from contextlib import contextmanager, suppress
from contextvars import ContextVar
from datetime import timedelta
from functools import wraps
from hashlib import md5
from importlib.util import cache_from_source
from pickle import PickleBuffer
from time import sleep
from types import ModuleType
from typing import TYPE_CHECKING
from typing import Any as AnyType
from typing import ClassVar, Iterator, TypeVar, overload

import click
import tblib.pickling_support

try:
    import resource
except ImportError:
    resource = None  # type: ignore

import tlz as toolz
from tornado import gen
from tornado.ioloop import IOLoop

import dask
from dask import istask
from dask.utils import ensure_bytes as _ensure_bytes
from dask.utils import key_split
from dask.utils import parse_timedelta as _parse_timedelta
from dask.widgets import get_template

from distributed.compatibility import WINDOWS
from distributed.metrics import time

try:
    from dask.context import thread_state
except ImportError:
    thread_state = threading.local()

# For some reason this is required in python >= 3.9
if WINDOWS:
    import multiprocessing.popen_spawn_win32
else:
    import multiprocessing.popen_spawn_posix

logger = _logger = logging.getLogger(__name__)


if TYPE_CHECKING:
    # TODO: import from typing (requires Python >=3.10)
    from typing_extensions import ParamSpec

    P = ParamSpec("P")
    T = TypeVar("T")

no_default = "__no_default__"

_forkserver_preload_set = False


def get_mp_context():
    """Create a multiprocessing context

    The context type is controlled by the
    ``distributed.worker.multiprocessing-method`` configuration key.

    Returns
    -------
    multiprocessing.BaseContext
        The multiprocessing context

    Notes
    -----
    Repeated calls with the same method will return the same object
    (since multiprocessing.get_context returns singleton instances).
    """
    global _forkserver_preload_set
    method = dask.config.get("distributed.worker.multiprocessing-method")
    ctx = multiprocessing.get_context(method)
    if method == "forkserver" and not _forkserver_preload_set:
        # Makes the test suite much faster
        preload = ["distributed"]

        from distributed.versions import optional_packages, required_packages

        for pkg, _ in required_packages + optional_packages:
            try:
                importlib.import_module(pkg)
            except ImportError:
                pass
            else:
                preload.append(pkg)
        ctx.set_forkserver_preload(preload)
        _forkserver_preload_set = True

    return ctx


def has_arg(func, argname):
    """
    Whether the function takes an argument with the given name.
    """
    while True:
        try:
            argspec = inspect.getfullargspec(func)
            if argname in set(argspec.args) | set(argspec.kwonlyargs):
                return True
        except TypeError:
            break
        try:
            # For Tornado coroutines and other decorated functions
            func = func.__wrapped__
        except AttributeError:
            break
    return False


def get_fileno_limit():
    """
    Get the maximum number of open files per process.
    """
    if resource is not None:
        return resource.getrlimit(resource.RLIMIT_NOFILE)[0]
    else:
        # Default ceiling for Windows when using the CRT, though it
        # is settable using _setmaxstdio().
        return 512


@toolz.memoize
def _get_ip(host, port, family):
    # By using a UDP socket, we don't actually try to connect but
    # simply select the local address through which *host* is reachable.
    sock = socket.socket(family, socket.SOCK_DGRAM)
    try:
        sock.connect((host, port))
        ip = sock.getsockname()[0]
        return ip
    except OSError as e:
        warnings.warn(
            "Couldn't detect a suitable IP address for "
            "reaching %r, defaulting to hostname: %s" % (host, e),
            RuntimeWarning,
        )
        addr_info = socket.getaddrinfo(
            socket.gethostname(), port, family, socket.SOCK_DGRAM, socket.IPPROTO_UDP
        )[0]
        return addr_info[4][0]
    finally:
        sock.close()


def get_ip(host="8.8.8.8", port=80):
    """
    Get the local IP address through which the *host* is reachable.

    *host* defaults to a well-known Internet host (one of Google's public
    DNS servers).
    """
    return _get_ip(host, port, family=socket.AF_INET)


def get_ipv6(host="2001:4860:4860::8888", port=80):
    """
    The same as get_ip(), but for IPv6.
    """
    return _get_ip(host, port, family=socket.AF_INET6)


def get_ip_interface(ifname):
    """
    Get the local IPv4 address of a network interface.

    KeyError is raised if the interface doesn't exist.
    ValueError is raised if the interface does no have an IPv4 address
    associated with it.
    """
    import psutil

    net_if_addrs = psutil.net_if_addrs()

    if ifname not in net_if_addrs:
        allowed_ifnames = list(net_if_addrs.keys())
        raise ValueError(
            "{!r} is not a valid network interface. "
            "Valid network interfaces are: {}".format(ifname, allowed_ifnames)
        )

    for info in net_if_addrs[ifname]:
        if info.family == socket.AF_INET:
            return info.address
    raise ValueError(f"interface {ifname!r} doesn't have an IPv4 address")


async def All(args, quiet_exceptions=()):
    """Wait on many tasks at the same time

    Err once any of the tasks err.

    See https://github.com/tornadoweb/tornado/issues/1546

    Parameters
    ----------
    args: futures to wait for
    quiet_exceptions: tuple, Exception
        Exception types to avoid logging if they fail
    """
    tasks = gen.WaitIterator(*map(asyncio.ensure_future, args))
    results = [None for _ in args]
    while not tasks.done():
        try:
            result = await tasks.next()
        except Exception:

            @gen.coroutine
            def quiet():
                """Watch unfinished tasks

                Otherwise if they err they get logged in a way that is hard to
                control.  They need some other task to watch them so that they
                are not orphaned
                """
                for task in list(tasks._unfinished):
                    try:
                        yield task
                    except quiet_exceptions:
                        pass

            quiet()
            raise
        results[tasks.current_index] = result
    return results


async def Any(args, quiet_exceptions=()):
    """Wait on many tasks at the same time and return when any is finished

    Err once any of the tasks err.

    Parameters
    ----------
    args: futures to wait for
    quiet_exceptions: tuple, Exception
        Exception types to avoid logging if they fail
    """
    tasks = gen.WaitIterator(*map(asyncio.ensure_future, args))
    results = [None for _ in args]
    while not tasks.done():
        try:
            result = await tasks.next()
        except Exception:

            @gen.coroutine
            def quiet():
                """Watch unfinished tasks

                Otherwise if they err they get logged in a way that is hard to
                control.  They need some other task to watch them so that they
                are not orphaned
                """
                for task in list(tasks._unfinished):
                    try:
                        yield task
                    except quiet_exceptions:
                        pass

            quiet()
            raise

        results[tasks.current_index] = result
        break
    return results


class NoOpAwaitable:
    """An awaitable object that always returns None.

    Useful to return from a method that can be called in both asynchronous and
    synchronous contexts"""

    def __await__(self):
        async def f():
            return None

        return f().__await__()


class SyncMethodMixin:
    """
    A mixin for adding an `asynchronous` attribute and `sync` method to a class.

    Subclasses must define a `loop` attribute for an associated
    `tornado.IOLoop`, and may also add a `_asynchronous` attribute indicating
    whether the class should default to asynchronous behavior.
    """

    @property
    def asynchronous(self):
        """Are we running in the event loop?"""
        return in_async_call(self.loop, default=getattr(self, "_asynchronous", False))

    def sync(self, func, *args, asynchronous=None, callback_timeout=None, **kwargs):
        """Call `func` with `args` synchronously or asynchronously depending on
        the calling context"""
        callback_timeout = _parse_timedelta(callback_timeout)
        if asynchronous is None:
            asynchronous = self.asynchronous
        if asynchronous:
            future = func(*args, **kwargs)
            if callback_timeout is not None:
                future = asyncio.wait_for(future, callback_timeout)
            return future
        else:
            return sync(
                self.loop, func, *args, callback_timeout=callback_timeout, **kwargs
            )


def in_async_call(loop, default=False):
    """Whether this call is currently within an async call"""
    try:
        return loop.asyncio_loop is asyncio.get_running_loop()
    except RuntimeError:
        # No *running* loop in thread. If the event loop isn't running, it
        # _could_ be started later in this thread though. Return the default.
        if not loop.asyncio_loop.is_running():
            return default
        return False


def sync(loop, func, *args, callback_timeout=None, **kwargs):
    """
    Run coroutine in loop running in separate thread.
    """
    callback_timeout = _parse_timedelta(callback_timeout, "s")
    if loop.asyncio_loop.is_closed():
        raise RuntimeError("IOLoop is closed")

    e = threading.Event()
    main_tid = threading.get_ident()
    result = error = future = None  # set up non-locals

    @gen.coroutine
    def f():
        nonlocal result, error, future
        try:
            if main_tid == threading.get_ident():
                raise RuntimeError("sync() called from thread of running loop")
            yield gen.moment
            future = func(*args, **kwargs)
            if callback_timeout is not None:
                future = asyncio.wait_for(future, callback_timeout)
            future = asyncio.ensure_future(future)
            result = yield future
        except Exception:
            error = sys.exc_info()
        finally:
            e.set()

    def cancel():
        if future is not None:
            future.cancel()

    def wait(timeout):
        try:
            return e.wait(timeout)
        except KeyboardInterrupt:
            loop.add_callback(cancel)
            raise

    loop.add_callback(f)
    if callback_timeout is not None:
        if not wait(callback_timeout):
            raise TimeoutError(f"timed out after {callback_timeout} s.")
    else:
        while not e.is_set():
            wait(10)

    if error:
        typ, exc, tb = error
        raise exc.with_traceback(tb)
    else:
        return result


class LoopRunner:
    """
    A helper to start and stop an IO loop in a controlled way.
    Several loop runners can associate safely to the same IO loop.

    Parameters
    ----------
    loop: IOLoop (optional)
        If given, this loop will be re-used, otherwise an appropriate one
        will be looked up or created.
    asynchronous: boolean (optional, default False)
        If false (the default), the loop is meant to run in a separate
        thread and will be started if necessary.
        If true, the loop is meant to run in the thread this
        object is instantiated from, and will not be started automatically.
    """

    # All loops currently associated to loop runners
    _all_loops: ClassVar[
        weakref.WeakKeyDictionary[IOLoop, tuple[int, LoopRunner | None]]
    ] = weakref.WeakKeyDictionary()
    _lock = threading.Lock()

    def __init__(self, loop=None, asynchronous=False):
        if loop is None:
            if asynchronous:
                try:
                    asyncio.get_running_loop()
                except RuntimeError:
                    warnings.warn(
                        "Constructing a LoopRunner(asynchronous=True) without a running loop is deprecated",
                        DeprecationWarning,
                        stacklevel=2,
                    )
                self._loop = IOLoop.current()
            else:
                # We're expecting the loop to run in another thread,
                # avoid re-using this thread's assigned loop
                self._loop = IOLoop()
        else:
            if not loop.asyncio_loop.is_running():
                warnings.warn(
                    "Constructing LoopRunner(loop=loop) without a running loop is deprecated",
                    DeprecationWarning,
                    stacklevel=2,
                )
            self._loop = loop
        self._asynchronous = asynchronous
        self._loop_thread = None
        self._started = False
        with self._lock:
            self._all_loops.setdefault(self._loop, (0, None))

    def start(self):
        """
        Start the IO loop if required.  The loop is run in a dedicated
        thread.

        If the loop is already running, this method does nothing.
        """
        with self._lock:
            self._start_unlocked()

    def _start_unlocked(self):
        assert not self._started

        count, real_runner = self._all_loops[self._loop]
        if self._asynchronous or real_runner is not None or count > 0:
            self._all_loops[self._loop] = count + 1, real_runner
            self._started = True
            return

        assert self._loop_thread is None
        assert count == 0

        loop_evt = threading.Event()
        done_evt = threading.Event()
        in_thread = [None]
        start_exc = [None]

        def loop_cb():
            in_thread[0] = threading.current_thread()
            loop_evt.set()

        def run_loop(loop=self._loop):
            loop.add_callback(loop_cb)
            # run loop forever if it's not running already
            try:
                if not loop.asyncio_loop.is_running():
                    loop.start()
            except Exception as e:
                start_exc[0] = e
            finally:
                done_evt.set()

        thread = threading.Thread(target=run_loop, name="IO loop")
        thread.daemon = True
        thread.start()

        loop_evt.wait(timeout=10)
        self._started = True

        actual_thread = in_thread[0]
        if actual_thread is not thread:
            # Loop already running in other thread (user-launched)
            done_evt.wait(5)
            if start_exc[0] is not None and not isinstance(start_exc[0], RuntimeError):
                if not isinstance(
                    start_exc[0], Exception
                ):  # track down infrequent error
                    raise TypeError(
                        f"not an exception: {start_exc[0]!r}",
                    )
                raise start_exc[0]
            self._all_loops[self._loop] = count + 1, None
        else:
            assert start_exc[0] is None, start_exc
            self._loop_thread = thread
            self._all_loops[self._loop] = count + 1, self

    def stop(self, timeout=10):
        """
        Stop and close the loop if it was created by us.
        Otherwise, just mark this object "stopped".
        """
        with self._lock:
            self._stop_unlocked(timeout)

    def _stop_unlocked(self, timeout):
        if not self._started:
            return

        self._started = False

        count, real_runner = self._all_loops[self._loop]
        if count > 1:
            self._all_loops[self._loop] = count - 1, real_runner
        else:
            assert count == 1
            del self._all_loops[self._loop]
            if real_runner is not None:
                real_runner._real_stop(timeout)

    def _real_stop(self, timeout):
        assert self._loop_thread is not None
        if self._loop_thread is not None:
            try:
                self._loop.add_callback(self._loop.stop)
                self._loop_thread.join(timeout=timeout)
                with suppress(KeyError):  # IOLoop can be missing
                    self._loop.close()
            finally:
                self._loop_thread = None

    def is_started(self):
        """
        Return True between start() and stop() calls, False otherwise.
        """
        return self._started

    def run_sync(self, func, *args, **kwargs):
        """
        Convenience helper: start the loop if needed,
        run sync(func, *args, **kwargs), then stop the loop again.
        """
        if self._started:
            return sync(self.loop, func, *args, **kwargs)
        else:
            self.start()
            try:
                return sync(self.loop, func, *args, **kwargs)
            finally:
                self.stop()

    @property
    def loop(self):
        loop = self._loop
        if not loop.asyncio_loop.is_running():
            warnings.warn(
                "Accessing the loop property while the loop is not running is deprecated",
                DeprecationWarning,
                stacklevel=2,
            )
        return self._loop


@contextmanager
def set_thread_state(**kwargs):
    old = {}
    for k in kwargs:
        try:
            old[k] = getattr(thread_state, k)
        except AttributeError:
            pass
    for k, v in kwargs.items():
        setattr(thread_state, k, v)
    try:
        yield
    finally:
        for k in kwargs:
            try:
                v = old[k]
            except KeyError:
                delattr(thread_state, k)
            else:
                setattr(thread_state, k, v)


@contextmanager
def tmp_text(filename, text):
    fn = os.path.join(tempfile.gettempdir(), filename)
    with open(fn, "w") as f:
        f.write(text)

    try:
        yield fn
    finally:
        if os.path.exists(fn):
            os.remove(fn)


def is_kernel():
    """Determine if we're running within an IPython kernel

    >>> is_kernel()
    False
    """
    # http://stackoverflow.com/questions/34091701/determine-if-were-in-an-ipython-notebook-session
    if "IPython" not in sys.modules:  # IPython hasn't been imported
        return False
    from IPython import get_ipython

    # check for `kernel` attribute on the IPython instance
    return getattr(get_ipython(), "kernel", None) is not None


def key_split_group(x: object) -> str:
    """A more fine-grained version of key_split.

    >>> key_split_group(('x-2', 1))
    'x-2'
    >>> key_split_group("('x-2', 1)")
    'x-2'
    >>> key_split_group('ae05086432ca935f6eba409a8ecd4896')
    'data'
    >>> key_split_group('<module.submodule.myclass object at 0xdaf372')
    'myclass'
    >>> key_split_group('x')
    'x'
    >>> key_split_group('x-1')
    'x'
    """
    if isinstance(x, tuple):
        return x[0]
    elif isinstance(x, str):
        if x[0] == "(":
            return x.split(",", 1)[0].strip("()\"'")
        elif len(x) == 32 and re.match(r"[a-f0-9]{32}", x):
            return "data"
        elif x[0] == "<":
            return x.strip("<>").split()[0].split(".")[-1]
        else:
            return key_split(x)
    elif isinstance(x, bytes):
        return key_split_group(x.decode())
    else:
        return "Other"


@overload
def log_errors(func: Callable[P, T], /) -> Callable[P, T]:
    ...


@overload
def log_errors(*, pdb: bool = False, unroll_stack: int = 1) -> _LogErrors:
    ...


def log_errors(func=None, /, *, pdb=False, unroll_stack=1):
    """Log any errors and then reraise them.

    This can be used:

    - As a context manager::

        with log_errors(...):
            ...

    - As a bare function decorator::

        @log_errors
        def func(...):
            ...

    - As a function decorator with parameters::

        @log_errors(...)
        def func(...):
            ...

    Parameters
    ----------
    pdb: bool, optional
        Set to True to break into the debugger in case of exception
    unroll_stack: int, optional
        Number of levels of stack to unroll when determining the module's name for the
        purpose of logging. Normally you should omit this. Set to 2 if you are writing a
        helper function, context manager, or decorator.
    """
    le = _LogErrors(pdb=pdb, unroll_stack=unroll_stack)
    return le(func) if func else le


class _LogErrors:
    __slots__ = ("pdb", "unroll_stack")

    pdb: bool
    unroll_stack: int

    def __init__(self, pdb: bool, unroll_stack: int):
        self.pdb = pdb
        self.unroll_stack = unroll_stack

    def __call__(self, func: Callable[P, T], /) -> Callable[P, T]:
        self.unroll_stack += 1

        if inspect.iscoroutinefunction(func):

            async def wrapper(*args, **kwargs):
                with self:
                    return await func(*args, **kwargs)

        else:

            def wrapper(*args, **kwargs):
                with self:
                    return func(*args, **kwargs)

        return wraps(func)(wrapper)

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        from distributed.comm import CommClosedError

        if not exc_type or issubclass(exc_type, (CommClosedError, gen.Return)):
            return

        stack = inspect.stack()
        frame = stack[self.unroll_stack]
        mod = inspect.getmodule(frame[0])
        modname = mod.__name__

        try:
            logger = logging.getLogger(modname)
            logger.exception(exc_value)
        except Exception:  # Interpreter teardown
            pass  # pragma: nocover

        if self.pdb:
            import pdb  # pragma: nocover

            pdb.set_trace()  # pragma: nocover


def silence_logging(level, root="distributed"):
    """
    Change all StreamHandlers for the given logger to the given level
    """
    if isinstance(level, str):
        level = getattr(logging, level.upper())

    old = None
    logger = logging.getLogger(root)
    for handler in logger.handlers:
        if isinstance(handler, logging.StreamHandler):
            old = handler.level
            handler.setLevel(level)

    return old


@toolz.memoize
def ensure_ip(hostname):
    """Ensure that address is an IP address

    Examples
    --------
    >>> ensure_ip('localhost')
    '127.0.0.1'
    >>> ensure_ip('')  # Maps as localhost for binding e.g. 'tcp://:8811'
    '127.0.0.1'
    >>> ensure_ip('123.123.123.123')  # pass through IP addresses
    '123.123.123.123'
    """
    if not hostname:
        hostname = "localhost"

    # Prefer IPv4 over IPv6, for compatibility
    families = [socket.AF_INET, socket.AF_INET6]
    for fam in families:
        try:
            results = socket.getaddrinfo(
                hostname, 1234, fam, socket.SOCK_STREAM  # dummy port number
            )
        except socket.gaierror as e:
            exc = e
        else:
            return results[0][4][0]

    raise exc


tblib.pickling_support.install()


def get_traceback():
    exc_type, exc_value, exc_traceback = sys.exc_info()
    bad = [
        os.path.join("distributed", "worker"),
        os.path.join("distributed", "scheduler"),
        os.path.join("tornado", "gen.py"),
        os.path.join("concurrent", "futures"),
    ]
    while exc_traceback and any(
        b in exc_traceback.tb_frame.f_code.co_filename for b in bad
    ):
        exc_traceback = exc_traceback.tb_next
    return exc_traceback


def truncate_exception(e, n=10000):
    """Truncate exception to be about a certain length"""
    if len(str(e)) > n:
        try:
            return type(e)("Long error message", str(e)[:n])
        except Exception:
            return Exception("Long error message", type(e), str(e)[:n])
    else:
        return e


def validate_key(k):
    """Validate a key as received on a stream."""
    typ = type(k)
    if typ is not str and typ is not bytes:
        raise TypeError(f"Unexpected key type {typ} (value: {k!r})")


def _maybe_complex(task):
    """Possibly contains a nested task"""
    return (
        istask(task)
        or type(task) is list
        and any(map(_maybe_complex, task))
        or type(task) is dict
        and any(map(_maybe_complex, task.values()))
    )


def seek_delimiter(file, delimiter, blocksize):
    """Seek current file to next byte after a delimiter bytestring

    This seeks the file to the next byte following the delimiter.  It does
    not return anything.  Use ``file.tell()`` to see location afterwards.

    Parameters
    ----------
    file: a file
    delimiter: bytes
        a delimiter like ``b'\n'`` or message sentinel
    blocksize: int
        Number of bytes to read from the file at once.
    """

    if file.tell() == 0:
        return

    last = b""
    while True:
        current = file.read(blocksize)
        if not current:
            return
        full = last + current
        try:
            i = full.index(delimiter)
            file.seek(file.tell() - (len(full) - i) + len(delimiter))
            return
        except ValueError:
            pass
        last = full[-len(delimiter) :]


def read_block(f, offset, length, delimiter=None):
    """Read a block of bytes from a file

    Parameters
    ----------
    f: file
        File-like object supporting seek, read, tell, etc..
    offset: int
        Byte offset to start read
    length: int
        Number of bytes to read
    delimiter: bytes (optional)
        Ensure reading starts and stops at delimiter bytestring

    If using the ``delimiter=`` keyword argument we ensure that the read
    starts and stops at delimiter boundaries that follow the locations
    ``offset`` and ``offset + length``.  If ``offset`` is zero then we
    start at zero.  The bytestring returned WILL include the
    terminating delimiter string.

    Examples
    --------

    >>> from io import BytesIO  # doctest: +SKIP
    >>> f = BytesIO(b'Alice, 100\\nBob, 200\\nCharlie, 300')  # doctest: +SKIP
    >>> read_block(f, 0, 13)  # doctest: +SKIP
    b'Alice, 100\\nBo'

    >>> read_block(f, 0, 13, delimiter=b'\\n')  # doctest: +SKIP
    b'Alice, 100\\nBob, 200\\n'

    >>> read_block(f, 10, 10, delimiter=b'\\n')  # doctest: +SKIP
    b'Bob, 200\\nCharlie, 300'
    """
    if delimiter:
        f.seek(offset)
        seek_delimiter(f, delimiter, 2**16)
        start = f.tell()
        length -= start - offset

        f.seek(start + length)
        seek_delimiter(f, delimiter, 2**16)
        end = f.tell()

        offset = start
        length = end - start

    f.seek(offset)
    bytes = f.read(length)
    return bytes


def ensure_bytes(s):
    """Attempt to turn `s` into bytes.

    Parameters
    ----------
    s : Any
        The object to be converted. Will correctly handled

        * str
        * bytes
        * objects implementing the buffer protocol (memoryview, ndarray, etc.)

    Returns
    -------
    b : bytes

    Raises
    ------
    TypeError
        When `s` cannot be converted

    Examples
    --------
    >>> ensure_bytes('123')
    b'123'
    >>> ensure_bytes(b'123')
    b'123'
    """
    warnings.warn(
        "`distributed.utils.ensure_bytes` is deprecated. "
        "Please switch to `dask.utils.ensure_bytes`. "
        "This will be removed in `2022.6.0`.",
        DeprecationWarning,
        stacklevel=2,
    )
    return _ensure_bytes(s)


def ensure_memoryview(obj):
    """Ensure `obj` is a 1-D contiguous `uint8` `memoryview`"""
    mv: memoryview
    if type(obj) is memoryview:
        mv = obj
    else:
        mv = memoryview(obj)

    if not mv.nbytes:
        # Drop `obj` reference to permit freeing underlying data
        return memoryview(bytearray())
    elif not mv.contiguous:
        # Copy to contiguous form of expected shape & type
        return memoryview(bytearray(mv))
    elif mv.ndim != 1 or mv.format != "B":
        # Perform zero-copy reshape & cast
        # Use `PickleBuffer.raw()` as `memoryview.cast()` fails with F-order
        # xref: https://github.com/python/cpython/issues/91484
        return PickleBuffer(mv).raw()
    else:
        # Return `memoryview` as it already meets requirements
        return mv


def open_port(host: str = "") -> int:
    """Return a probably-open port

    There is a chance that this port will be taken by the operating system soon
    after returning from this function.
    """
    # http://stackoverflow.com/questions/2838244/get-open-tcp-port-in-python
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.bind((host, 0))
        s.listen(1)
        port = s.getsockname()[1]
        return port


def import_file(path: str) -> list[ModuleType]:
    """Loads modules for a file (.py, .zip, .egg)"""
    directory, filename = os.path.split(path)
    name, ext = os.path.splitext(filename)
    names_to_import: list[str] = []
    tmp_python_path: str | None = None

    if ext in (".py",):  # , '.pyc'):
        if directory not in sys.path:
            tmp_python_path = directory
        names_to_import.append(name)
    if ext == ".py":  # Ensure that no pyc file will be reused
        cache_file = cache_from_source(path)
        with suppress(OSError):
            os.remove(cache_file)
    if ext in (".egg", ".zip", ".pyz"):
        if path not in sys.path:
            sys.path.insert(0, path)
        names = (mod_info.name for mod_info in pkgutil.iter_modules([path]))
        names_to_import.extend(names)

    loaded: list[ModuleType] = []
    if not names_to_import:
        logger.warning("Found nothing to import from %s", filename)
    else:
        importlib.invalidate_caches()
        if tmp_python_path is not None:
            sys.path.insert(0, tmp_python_path)
        try:
            for name in names_to_import:
                logger.info("Reload module %s from %s file", name, ext)
                loaded.append(importlib.reload(importlib.import_module(name)))
        finally:
            if tmp_python_path is not None:
                sys.path.remove(tmp_python_path)
    return loaded


def asciitable(columns, rows):
    """Formats an ascii table for given columns and rows.

    Parameters
    ----------
    columns : list
        The column names
    rows : list of tuples
        The rows in the table. Each tuple must be the same length as
        ``columns``.
    """
    rows = [tuple(str(i) for i in r) for r in rows]
    columns = tuple(str(i) for i in columns)
    widths = tuple(max(max(map(len, x)), len(c)) for x, c in zip(zip(*rows), columns))
    row_template = ("|" + (" %%-%ds |" * len(columns))) % widths
    header = row_template % tuple(columns)
    bar = "+%s+" % "+".join("-" * (w + 2) for w in widths)
    data = "\n".join(row_template % r for r in rows)
    return "\n".join([bar, header, bar, data, bar])


def nbytes(frame, _bytes_like=(bytes, bytearray)):
    """Number of bytes of a frame or memoryview"""
    if isinstance(frame, _bytes_like):
        return len(frame)
    else:
        try:
            return frame.nbytes
        except AttributeError:
            return len(frame)


def json_load_robust(fn, load=json.load):
    """Reads a JSON file from disk that may be being written as we read"""
    while not os.path.exists(fn):
        sleep(0.01)
    for _ in range(10):
        try:
            with open(fn) as f:
                cfg = load(f)
            if cfg:
                return cfg
        except (ValueError, KeyError):  # race with writing process
            pass
        sleep(0.1)


class DequeHandler(logging.Handler):
    """A logging.Handler that records records into a deque"""

    _instances: ClassVar[weakref.WeakSet[DequeHandler]] = weakref.WeakSet()

    def __init__(self, *args, n=10000, **kwargs):
        self.deque = deque(maxlen=n)
        super().__init__(*args, **kwargs)
        self._instances.add(self)

    def emit(self, record):
        self.deque.append(record)

    def clear(self):
        """
        Clear internal storage.
        """
        self.deque.clear()

    @classmethod
    def clear_all_instances(cls):
        """
        Clear the internal storage of all live DequeHandlers.
        """
        for inst in list(cls._instances):
            inst.clear()


def reset_logger_locks():
    """Python 2's logger's locks don't survive a fork event

    https://github.com/dask/distributed/issues/1491
    """
    for name in logging.Logger.manager.loggerDict.keys():
        for handler in logging.getLogger(name).handlers:
            handler.createLock()


@functools.lru_cache(1000)
def has_keyword(func, keyword):
    return keyword in inspect.signature(func).parameters


@functools.lru_cache(1000)
def command_has_keyword(cmd, k):
    if cmd is not None:
        if isinstance(cmd, str):
            try:
                from importlib import import_module

                cmd = import_module(cmd)
            except ImportError:
                raise ImportError("Module for command %s is not available" % cmd)

        if isinstance(cmd.main, click.core.Command):
            cmd = cmd.main
        if isinstance(cmd, click.core.Command):
            cmd_params = {
                p.human_readable_name
                for p in cmd.params
                if isinstance(p, click.core.Option)
            }
            return k in cmd_params

    return False


# from bokeh.palettes import viridis
# palette = viridis(18)
palette = [
    "#440154",
    "#471669",
    "#472A79",
    "#433C84",
    "#3C4D8A",
    "#355D8C",
    "#2E6C8E",
    "#287A8E",
    "#23898D",
    "#1E978A",
    "#20A585",
    "#2EB27C",
    "#45BF6F",
    "#64CB5D",
    "#88D547",
    "#AFDC2E",
    "#D7E219",
    "#FDE724",
]


@toolz.memoize
def color_of(x, palette=palette):
    h = md5(str(x).encode())
    n = int(h.hexdigest()[:8], 16)
    return palette[n % len(palette)]


def iscoroutinefunction(f):
    return inspect.iscoroutinefunction(f) or gen.is_coroutine_function(f)


@contextmanager
def warn_on_duration(duration: str | float | timedelta, msg: str) -> Iterator[None]:
    """Generate a UserWarning if the operation in this context takes longer than
    *duration* and print *msg*

    The message may include a format string `{duration}` which will be formatted
    to include the actual duration it took
    """
    start = time()
    yield
    stop = time()
    diff = stop - start
    if diff > _parse_timedelta(duration):
        warnings.warn(msg.format(duration=diff), stacklevel=2)


def format_dashboard_link(host, port):
    template = dask.config.get("distributed.dashboard.link")
    if dask.config.get("distributed.scheduler.dashboard.tls.cert"):
        scheme = "https"
    else:
        scheme = "http"
    return template.format(
        **toolz.merge(os.environ, dict(scheme=scheme, host=host, port=port))
    )


def parse_ports(port: int | str | Collection[int] | None) -> list[int] | list[None]:
    """Parse input port information into list of ports

    Parameters
    ----------
    port : int, str, list[int], None
        Input port or ports. Can be an integer like 8787, a string for a
        single port like "8787", string for a sequential range of ports like
        "8000:8200", a collection of ints, or None.

    Returns
    -------
    ports : list
        List of ports

    Examples
    --------
    A single port can be specified using an integer:

    >>> parse_ports(8787)
    [8787]

    or a string:

    >>> parse_ports("8787")
    [8787]

    A sequential range of ports can be specified by a string which indicates
    the first and last ports which should be included in the sequence of ports:

    >>> parse_ports("8787:8790")
    [8787, 8788, 8789, 8790]

    An input of ``None`` is also valid and can be used to indicate that no port
    has been specified:

    >>> parse_ports(None)
    [None]

    """
    if isinstance(port, str) and ":" in port:
        port_start, port_stop = map(int, port.split(":"))
        if port_stop <= port_start:
            raise ValueError(
                "When specifying a range of ports like port_start:port_stop, "
                "port_stop must be greater than port_start, but got "
                f"{port_start=} and {port_stop=}"
            )
        return list(range(port_start, port_stop + 1))

    if isinstance(port, str):
        return [int(port)]

    if isinstance(port, int) or port is None:
        return [port]  # type: ignore

    if isinstance(port, Collection):
        if not all(isinstance(p, int) for p in port):
            raise TypeError(port)
        return list(port)  # type: ignore

    raise TypeError(port)


is_coroutine_function = iscoroutinefunction


[docs]class Log(str): """A container for newline-delimited string of log entries""" def _repr_html_(self): return get_template("log.html.j2").render(log=self)
[docs]class Logs(dict): """A container for a dict mapping names to strings of log entries""" def _repr_html_(self): return get_template("logs.html.j2").render(logs=self)
def cli_keywords( d: dict[str, AnyType], cls: Callable | None = None, cmd: str | ModuleType | None = None, ) -> list[str]: """Convert a kwargs dictionary into a list of CLI keywords Parameters ---------- d : dict The keywords to convert cls : callable The callable that consumes these terms to check them for validity cmd : string or object A string with the name of a module, or the module containing a click-generated command with a "main" function, or the function itself. It may be used to parse a module's custom arguments (that is, arguments that are not part of Worker class), such as nworkers from dask-worker CLI or enable_nvlink from dask-cuda-worker CLI. Examples -------- >>> cli_keywords({"x": 123, "save_file": "foo.txt"}) ['--x', '123', '--save-file', 'foo.txt'] >>> from dask.distributed import Worker >>> cli_keywords({"x": 123}, Worker) Traceback (most recent call last): ... ValueError: Class distributed.worker.Worker does not support keyword x """ from dask.utils import typename if cls or cmd: for k in d: if not has_keyword(cls, k) and not command_has_keyword(cmd, k): if cls and cmd: raise ValueError( "Neither class %s or module %s support keyword %s" % (typename(cls), typename(cmd), k) ) elif cls: raise ValueError( f"Class {typename(cls)} does not support keyword {k}" ) else: raise ValueError( f"Module {typename(cmd)} does not support keyword {k}" ) def convert_value(v): out = str(v) if " " in out and "'" not in out and '"' not in out: out = '"' + out + '"' return out return sum( (["--" + k.replace("_", "-"), convert_value(v)] for k, v in d.items()), [] ) def is_valid_xml(text): return xml.etree.ElementTree.fromstring(text) is not None _offload_executor = ThreadPoolExecutor(max_workers=1, thread_name_prefix="Dask-Offload") weakref.finalize(_offload_executor, _offload_executor.shutdown) def import_term(name: str) -> AnyType: """Return the fully qualified term Examples -------- >>> import_term("math.sin") # doctest: +SKIP <function math.sin(x, /)> """ try: module_name, attr_name = name.rsplit(".", 1) except ValueError: return importlib.import_module(name) module = importlib.import_module(module_name) return getattr(module, attr_name) async def offload(fn, *args, **kwargs): loop = asyncio.get_running_loop() # Retain context vars while deserializing; see https://bugs.python.org/issue34014 context = contextvars.copy_context() return await loop.run_in_executor( _offload_executor, lambda: context.run(fn, *args, **kwargs) ) class EmptyContext: def __enter__(self): pass def __exit__(self, exc_type, exc_value, traceback): pass async def __aenter__(self): pass async def __aexit__(self, exc_type, exc_value, traceback): pass empty_context = EmptyContext() def clean_dashboard_address(addrs: AnyType, default_listen_ip: str = "") -> list[dict]: """ Examples -------- >>> clean_dashboard_address(8787) [{'address': '', 'port': 8787}] >>> clean_dashboard_address(":8787") [{'address': '', 'port': 8787}] >>> clean_dashboard_address("8787") [{'address': '', 'port': 8787}] >>> clean_dashboard_address("8787") [{'address': '', 'port': 8787}] >>> clean_dashboard_address("foo:8787") [{'address': 'foo', 'port': 8787}] >>> clean_dashboard_address([8787, 8887]) [{'address': '', 'port': 8787}, {'address': '', 'port': 8887}] >>> clean_dashboard_address(":8787,:8887") [{'address': '', 'port': 8787}, {'address': '', 'port': 8887}] """ if default_listen_ip == "0.0.0.0": default_listen_ip = "" # for IPV6 if isinstance(addrs, str): addrs = addrs.split(",") if not isinstance(addrs, list): addrs = [addrs] addresses = [] for addr in addrs: try: addr = int(addr) except (TypeError, ValueError): pass if isinstance(addr, str): addr = addr.split(":") if isinstance(addr, (tuple, list)): if len(addr) == 2: host, port = (addr[0], int(addr[1])) elif len(addr) == 1: [host], port = addr, 0 else: raise ValueError(addr) elif isinstance(addr, int): host = default_listen_ip port = addr addresses.append({"address": host, "port": port}) return addresses _deprecations = { "deserialize_for_cli": "dask.config.deserialize", "serialize_for_cli": "dask.config.serialize", "format_bytes": "dask.utils.format_bytes", "format_time": "dask.utils.format_time", "funcname": "dask.utils.funcname", "parse_bytes": "dask.utils.parse_bytes", "parse_timedelta": "dask.utils.parse_timedelta", "typename": "dask.utils.typename", "tmpfile": "dask.utils.tmpfile", } def __getattr__(name): if name in _deprecations: use_instead = _deprecations[name] warnings.warn( f"{name} is deprecated and will be removed in a future release. " f"Please use {use_instead} instead.", category=FutureWarning, stacklevel=2, ) return import_term(use_instead) else: raise AttributeError(f"module {__name__} has no attribute {name}") # Used internally by recursive_to_dict to stop infinite recursion. If an object has # already been encountered, a string representation will be returned instead. This is # necessary since we have multiple cyclic referencing data structures. _recursive_to_dict_seen: ContextVar[set[int]] = ContextVar("_recursive_to_dict_seen") _to_dict_no_nest_flag = False def recursive_to_dict( obj: AnyType, *, exclude: Container[str] = (), members: bool = False ) -> AnyType: """Recursively convert arbitrary Python objects to a JSON-serializable representation. This is intended for debugging purposes only. The following objects are supported: list, tuple, set, frozenset, deque, dict, dict_keys, dict_values Descended into these objects recursively. Python-specific collections are converted to JSON-friendly variants. Classes that define ``_to_dict(self, *, exclude: Container[str] = ())``: Call the method and dump its output Classes that define ``_to_dict_no_nest(self, *, exclude: Container[str] = ())``: Like above, but prevents nested calls (see below) Other Python objects Dump the output of ``repr()`` Objects already encountered before, regardless of type Dump the output of ``repr()``. This breaks circular references and shortens the output. Parameters ---------- exclude: A list of attribute names to be excluded from the dump. This will be forwarded to the objects ``_to_dict`` methods and these methods are required to accept this parameter. members: If True, convert the top-level Python object to a dict of its public members **``_to_dict_no_nest`` vs. ``_to_dict``** The presence of the ``_to_dict_no_nest`` method signals ``recursive_to_dict`` to have a mutually exclusive full dict representation with other objects that also have the ``_to_dict_no_nest``, regardless of their class. Only the outermost object in a nested structure has the method invoked; all others are dumped as their string repr instead, even if they were not encountered before. Example: .. code-block:: python >>> class Person: ... def __init__(self, name): ... self.name = name ... self.children = [] ... self.pets = [] ... ... def _to_dict_no_nest(self, exclude=()): ... return recursive_to_dict(self.__dict__, exclude=exclude) ... ... def __repr__(self): ... return self.name >>> class Pet: ... def __init__(self, name): ... self.name = name ... self.owners = [] ... ... def _to_dict_no_nest(self, exclude=()): ... return recursive_to_dict(self.__dict__, exclude=exclude) ... ... def __repr__(self): ... return self.name >>> alice = Person("Alice") >>> bob = Person("Bob") >>> charlie = Pet("Charlie") >>> alice.children.append(bob) >>> alice.pets.append(charlie) >>> bob.pets.append(charlie) >>> charlie.owners[:] = [alice, bob] >>> recursive_to_dict({"people": [alice, bob], "pets": [charlie]}) { "people": [ {"name": "Alice", "children": ["Bob"], "pets": ["Charlie"]}, {"name": "Bob", "children": [], "pets": ["Charlie"]}, ], "pets": [ {"name": "Charlie", "owners": ["Alice", "Bob"]}, ], } If we changed the methods to ``_to_dict``, the output would instead be: .. code-block:: python { "people": [ { "name": "Alice", "children": [ { "name": "Bob", "children": [], "pets": [{"name": "Charlie", "owners": ["Alice", "Bob"]}], }, ], pets: ["Charlie"], ], "Bob", ], "pets": ["Charlie"], } Also notice that, if in the future someone will swap the creation of the ``children`` and ``pets`` attributes inside ``Person.__init__``, the output with ``_to_dict`` will change completely whereas the one with ``_to_dict_no_nest`` won't! """ if isinstance(obj, (int, float, bool, str)) or obj is None: return obj if isinstance(obj, (type, bytes)): return repr(obj) if members: obj = { k: v for k, v in inspect.getmembers(obj) if not k.startswith("_") and k not in exclude and not callable(v) } # Prevent infinite recursion try: seen = _recursive_to_dict_seen.get() except LookupError: seen = set() seen = seen.copy() tok = _recursive_to_dict_seen.set(seen) try: if id(obj) in seen: return repr(obj) if hasattr(obj, "_to_dict_no_nest"): global _to_dict_no_nest_flag if _to_dict_no_nest_flag: return repr(obj) seen.add(id(obj)) _to_dict_no_nest_flag = True try: return obj._to_dict_no_nest(exclude=exclude) finally: _to_dict_no_nest_flag = False seen.add(id(obj)) if hasattr(obj, "_to_dict"): return obj._to_dict(exclude=exclude) if isinstance(obj, (list, tuple, set, frozenset, deque, KeysView, ValuesView)): return [recursive_to_dict(el, exclude=exclude) for el in obj] if isinstance(obj, dict): res = {} for k, v in obj.items(): k = recursive_to_dict(k, exclude=exclude) v = recursive_to_dict(v, exclude=exclude) try: res[k] = v except TypeError: res[str(k)] = v return res return repr(obj) finally: tok.var.reset(tok) def is_python_shutting_down() -> bool: """Is the interpreter shutting down now? This is a variant of ``sys.is_finalizing`` which can return True inside the ``__del__`` method of classes defined inside the distributed package. """ # This import must remain local for the global variable to be # properly evaluated from distributed import _python_shutting_down return _python_shutting_down