split platform

lib/python3.5/site-packages/pip/utils/ui.py

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+from __future__ import absolute_import
+from __future__ import division
+
+import itertools
+import sys
+from signal import signal, SIGINT, default_int_handler
+
+from pip.compat import WINDOWS
+from pip.utils import format_size
+from pip.utils.logging import get_indentation
+from pip._vendor import six
+from pip._vendor.progress.bar import Bar, IncrementalBar
+from pip._vendor.progress.helpers import WritelnMixin
+from pip._vendor.progress.spinner import Spinner
+
+try:
+    from pip._vendor import colorama
+# Lots of different errors can come from this, including SystemError and
+# ImportError.
+except Exception:
+    colorama = None
+
+
+def _select_progress_class(preferred, fallback):
+    encoding = getattr(preferred.file, "encoding", None)
+
+    # If we don't know what encoding this file is in, then we'll just assume
+    # that it doesn't support unicode and use the ASCII bar.
+    if not encoding:
+        return fallback
+
+    # Collect all of the possible characters we want to use with the preferred
+    # bar.
+    characters = [
+        getattr(preferred, "empty_fill", six.text_type()),
+        getattr(preferred, "fill", six.text_type()),
+    ]
+    characters += list(getattr(preferred, "phases", []))
+
+    # Try to decode the characters we're using for the bar using the encoding
+    # of the given file, if this works then we'll assume that we can use the
+    # fancier bar and if not we'll fall back to the plaintext bar.
+    try:
+        six.text_type().join(characters).encode(encoding)
+    except UnicodeEncodeError:
+        return fallback
+    else:
+        return preferred
+
+
+_BaseBar = _select_progress_class(IncrementalBar, Bar)
+
+
+class InterruptibleMixin(object):
+    """
+    Helper to ensure that self.finish() gets called on keyboard interrupt.
+
+    This allows downloads to be interrupted without leaving temporary state
+    (like hidden cursors) behind.
+
+    This class is similar to the progress library's existing SigIntMixin
+    helper, but as of version 1.2, that helper has the following problems:
+
+    1. It calls sys.exit().
+    2. It discards the existing SIGINT handler completely.
+    3. It leaves its own handler in place even after an uninterrupted finish,
+       which will have unexpected delayed effects if the user triggers an
+       unrelated keyboard interrupt some time after a progress-displaying
+       download has already completed, for example.
+    """
+
+    def __init__(self, *args, **kwargs):
+        """
+        Save the original SIGINT handler for later.
+        """
+        super(InterruptibleMixin, self).__init__(*args, **kwargs)
+
+        self.original_handler = signal(SIGINT, self.handle_sigint)
+
+        # If signal() returns None, the previous handler was not installed from
+        # Python, and we cannot restore it. This probably should not happen,
+        # but if it does, we must restore something sensible instead, at least.
+        # The least bad option should be Python's default SIGINT handler, which
+        # just raises KeyboardInterrupt.
+        if self.original_handler is None:
+            self.original_handler = default_int_handler
+
+    def finish(self):
+        """
+        Restore the original SIGINT handler after finishing.
+
+        This should happen regardless of whether the progress display finishes
+        normally, or gets interrupted.
+        """
+        super(InterruptibleMixin, self).finish()
+        signal(SIGINT, self.original_handler)
+
+    def handle_sigint(self, signum, frame):
+        """
+        Call self.finish() before delegating to the original SIGINT handler.
+
+        This handler should only be in place while the progress display is
+        active.
+        """
+        self.finish()
+        self.original_handler(signum, frame)
+
+
+class DownloadProgressMixin(object):
+
+    def __init__(self, *args, **kwargs):
+        super(DownloadProgressMixin, self).__init__(*args, **kwargs)
+        self.message = (" " * (get_indentation() + 2)) + self.message
+
+    @property
+    def downloaded(self):
+        return format_size(self.index)
+
+    @property
+    def download_speed(self):
+        # Avoid zero division errors...
+        if self.avg == 0.0:
+            return "..."
+        return format_size(1 / self.avg) + "/s"
+
+    @property
+    def pretty_eta(self):
+        if self.eta:
+            return "eta %s" % self.eta_td
+        return ""
+
+    def iter(self, it, n=1):
+        for x in it:
+            yield x
+            self.next(n)
+        self.finish()
+
+
+class WindowsMixin(object):
+
+    def __init__(self, *args, **kwargs):
+        # The Windows terminal does not support the hide/show cursor ANSI codes
+        # even with colorama. So we'll ensure that hide_cursor is False on
+        # Windows.
+        # This call neds to go before the super() call, so that hide_cursor
+        # is set in time. The base progress bar class writes the "hide cursor"
+        # code to the terminal in its init, so if we don't set this soon
+        # enough, we get a "hide" with no corresponding "show"...
+        if WINDOWS and self.hide_cursor:
+            self.hide_cursor = False
+
+        super(WindowsMixin, self).__init__(*args, **kwargs)
+
+        # Check if we are running on Windows and we have the colorama module,
+        # if we do then wrap our file with it.
+        if WINDOWS and colorama:
+            self.file = colorama.AnsiToWin32(self.file)
+            # The progress code expects to be able to call self.file.isatty()
+            # but the colorama.AnsiToWin32() object doesn't have that, so we'll
+            # add it.
+            self.file.isatty = lambda: self.file.wrapped.isatty()
+            # The progress code expects to be able to call self.file.flush()
+            # but the colorama.AnsiToWin32() object doesn't have that, so we'll
+            # add it.
+            self.file.flush = lambda: self.file.wrapped.flush()
+
+
+class DownloadProgressBar(WindowsMixin, InterruptibleMixin,
+                          DownloadProgressMixin, _BaseBar):
+
+    file = sys.stdout
+    message = "%(percent)d%%"
+    suffix = "%(downloaded)s %(download_speed)s %(pretty_eta)s"
+
+
+class DownloadProgressSpinner(WindowsMixin, InterruptibleMixin,
+                              DownloadProgressMixin, WritelnMixin, Spinner):
+
+    file = sys.stdout
+    suffix = "%(downloaded)s %(download_speed)s"
+
+    def next_phase(self):
+        if not hasattr(self, "_phaser"):
+            self._phaser = itertools.cycle(self.phases)
+        return next(self._phaser)
+
+    def update(self):
+        message = self.message % self
+        phase = self.next_phase()
+        suffix = self.suffix % self
+        line = ''.join([
+            message,
+            " " if message else "",
+            phase,
+            " " if suffix else "",
+            suffix,
+        ])
+
+        self.writeln(line)