Current File : //proc/self/root/opt/alt/python37/lib/python3.7/site-packages/pip/_internal/cli/spinners.py
from __future__ import absolute_import, division
import contextlib
import itertools
import logging
import sys
import time
from pip._vendor.progress import HIDE_CURSOR, SHOW_CURSOR
from pip._internal.utils.compat import WINDOWS
from pip._internal.utils.logging import get_indentation
from pip._internal.utils.typing import MYPY_CHECK_RUNNING
if MYPY_CHECK_RUNNING:
from typing import Iterator, IO
logger = logging.getLogger(__name__)
class SpinnerInterface(object):
def spin(self):
# type: () -> None
raise NotImplementedError()
def finish(self, final_status):
# type: (str) -> None
raise NotImplementedError()
class InteractiveSpinner(SpinnerInterface):
def __init__(self, message, file=None, spin_chars="-\\|/",
# Empirically, 8 updates/second looks nice
min_update_interval_seconds=0.125):
# type: (str, IO[str], str, float) -> None
self._message = message
if file is None:
file = sys.stdout
self._file = file
self._rate_limiter = RateLimiter(min_update_interval_seconds)
self._finished = False
self._spin_cycle = itertools.cycle(spin_chars)
self._file.write(" " * get_indentation() + self._message + " ... ")
self._width = 0
def _write(self, status):
# type: (str) -> None
assert not self._finished
# Erase what we wrote before by backspacing to the beginning, writing
# spaces to overwrite the old text, and then backspacing again
backup = "\b" * self._width
self._file.write(backup + " " * self._width + backup)
# Now we have a blank slate to add our status
self._file.write(status)
self._width = len(status)
self._file.flush()
self._rate_limiter.reset()
def spin(self):
# type: () -> None
if self._finished:
return
if not self._rate_limiter.ready():
return
self._write(next(self._spin_cycle))
def finish(self, final_status):
# type: (str) -> None
if self._finished:
return
self._write(final_status)
self._file.write("\n")
self._file.flush()
self._finished = True
# Used for dumb terminals, non-interactive installs (no tty), etc.
# We still print updates occasionally (once every 60 seconds by default) to
# act as a keep-alive for systems like Travis-CI that take lack-of-output as
# an indication that a task has frozen.
class NonInteractiveSpinner(SpinnerInterface):
def __init__(self, message, min_update_interval_seconds=60):
# type: (str, float) -> None
self._message = message
self._finished = False
self._rate_limiter = RateLimiter(min_update_interval_seconds)
self._update("started")
def _update(self, status):
# type: (str) -> None
assert not self._finished
self._rate_limiter.reset()
logger.info("%s: %s", self._message, status)
def spin(self):
# type: () -> None
if self._finished:
return
if not self._rate_limiter.ready():
return
self._update("still running...")
def finish(self, final_status):
# type: (str) -> None
if self._finished:
return
self._update(
"finished with status '{final_status}'".format(**locals()))
self._finished = True
class RateLimiter(object):
def __init__(self, min_update_interval_seconds):
# type: (float) -> None
self._min_update_interval_seconds = min_update_interval_seconds
self._last_update = 0 # type: float
def ready(self):
# type: () -> bool
now = time.time()
delta = now - self._last_update
return delta >= self._min_update_interval_seconds
def reset(self):
# type: () -> None
self._last_update = time.time()
@contextlib.contextmanager
def open_spinner(message):
# type: (str) -> Iterator[SpinnerInterface]
# Interactive spinner goes directly to sys.stdout rather than being routed
# through the logging system, but it acts like it has level INFO,
# i.e. it's only displayed if we're at level INFO or better.
# Non-interactive spinner goes through the logging system, so it is always
# in sync with logging configuration.
if sys.stdout.isatty() and logger.getEffectiveLevel() <= logging.INFO:
spinner = InteractiveSpinner(message) # type: SpinnerInterface
else:
spinner = NonInteractiveSpinner(message)
try:
with hidden_cursor(sys.stdout):
yield spinner
except KeyboardInterrupt:
spinner.finish("canceled")
raise
except Exception:
spinner.finish("error")
raise
else:
spinner.finish("done")
@contextlib.contextmanager
def hidden_cursor(file):
# type: (IO[str]) -> Iterator[None]
# The Windows terminal does not support the hide/show cursor ANSI codes,
# even via colorama. So don't even try.
if WINDOWS:
yield
# We don't want to clutter the output with control characters if we're
# writing to a file, or if the user is running with --quiet.
# See https://github.com/pypa/pip/issues/3418
elif not file.isatty() or logger.getEffectiveLevel() > logging.INFO:
yield
else:
file.write(HIDE_CURSOR)
try:
yield
finally:
file.write(SHOW_CURSOR)
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