~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 2008, 2009 Canonical Ltd

#

# 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 2 of the License, or

# (at your option) any later version.

#

# 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, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Text UI, write output to the console.

"""

import codecs

import getpass

import os

import sys

import time

import warnings

from bzrlib.lazy_import import lazy_import

lazy_import(globals(), """

from bzrlib import (

    debug,

    progress,

    osutils,

    symbol_versioning,

    )

""")

from bzrlib.ui import (

    UIFactory,

    NullProgressView,

    )

class TextUIFactory(UIFactory):

    """A UI factory for Text user interefaces."""

    def __init__(self,

                 stdin=None,

                 stdout=None,

                 stderr=None):

        """Create a TextUIFactory.

        """

        super(TextUIFactory, self).__init__()

        # TODO: there's no good reason not to pass all three streams, maybe we

        # should deprecate the default values...

        self.stdin = stdin

        self.stdout = stdout

        self.stderr = stderr

        # paints progress, network activity, etc

        self._progress_view = self.make_progress_view()

    def clear_term(self):

        """Prepare the terminal for output.

        This will, clear any progress bars, and leave the cursor at the

        leftmost position."""

        # XXX: If this is preparing to write to stdout, but that's for example

        # directed into a file rather than to the terminal, and the progress

        # bar _is_ going to the terminal, we shouldn't need

        # to clear it.  We might need to separately check for the case of

        self._progress_view.clear()

    def get_boolean(self, prompt):

        while True:

            self.prompt(prompt + "? [y/n]: ")

            line = self.stdin.readline().lower()

            if line in ('y\n', 'yes\n'):

                return True

            elif line in ('n\n', 'no\n'):

                return False

            elif line in ('', None):

                # end-of-file; possibly should raise an error here instead

                return None

    def get_integer(self, prompt):

        while True:

            self.prompt(prompt)

            line = self.stdin.readline()

            try:

                return int(line)

            except ValueError:

                pass

    def get_non_echoed_password(self):

        isatty = getattr(self.stdin, 'isatty', None)

        if isatty is not None and isatty():

            # getpass() ensure the password is not echoed and other

            # cross-platform niceties

            password = getpass.getpass('')

        else:

            # echo doesn't make sense without a terminal

            password = self.stdin.readline()

            if not password:

                password = None

            elif password[-1] == '\n':

                password = password[:-1]

        return password

    def get_password(self, prompt='', **kwargs):

        """Prompt the user for a password.

        :param prompt: The prompt to present the user

        :param kwargs: Arguments which will be expanded into the prompt.

                       This lets front ends display different things if

                       they so choose.

        :return: The password string, return None if the user

                 canceled the request.

        """

        prompt += ': '

        self.prompt(prompt, **kwargs)

        # There's currently no way to say 'i decline to enter a password'

        # as opposed to 'my password is empty' -- does it matter?

        return self.get_non_echoed_password()

    def get_username(self, prompt, **kwargs):

        """Prompt the user for a username.

        :param prompt: The prompt to present the user

        :param kwargs: Arguments which will be expanded into the prompt.

                       This lets front ends display different things if

                       they so choose.

        :return: The username string, return None if the user

                 canceled the request.

        """

        prompt += ': '

        self.prompt(prompt, **kwargs)

        username = self.stdin.readline()

        if not username:

            username = None

        elif username[-1] == '\n':

            username = username[:-1]

        return username

    def make_progress_view(self):

        """Construct and return a new ProgressView subclass for this UI.

        """

        # if the user specifically requests either text or no progress bars,

        # always do that.  otherwise, guess based on $TERM and tty presence.

        if os.environ.get('BZR_PROGRESS_BAR') == 'text':

            return TextProgressView(self.stderr)

        elif os.environ.get('BZR_PROGRESS_BAR') == 'none':

            return NullProgressView()

        elif progress._supports_progress(self.stderr):

            return TextProgressView(self.stderr)

        else:

            return NullProgressView()

    def _make_output_stream_explicit(self, encoding, encoding_type):

        if encoding_type == 'exact':

            # force sys.stdout to be binary stream on win32; 

            # NB: this leaves the file set in that mode; may cause problems if

            # one process tries to do binary and then text output

            if sys.platform == 'win32':

                fileno = getattr(self.stdout, 'fileno', None)

                if fileno:

                    import msvcrt

                    msvcrt.setmode(fileno(), os.O_BINARY)

            return TextUIOutputStream(self, self.stdout)

        else:

            encoded_stdout = codecs.getwriter(encoding)(self.stdout,

                errors=encoding_type)

            # For whatever reason codecs.getwriter() does not advertise its encoding

            # it just returns the encoding of the wrapped file, which is completely

            # bogus. So set the attribute, so we can find the correct encoding later.

            encoded_stdout.encoding = encoding

            return TextUIOutputStream(self, encoded_stdout)

    def note(self, msg):

        """Write an already-formatted message, clearing the progress bar if necessary."""

        self.clear_term()

        self.stdout.write(msg + '\n')

    def prompt(self, prompt, **kwargs):

        """Emit prompt on the CLI.

        :param kwargs: Dictionary of arguments to insert into the prompt,

            to allow UIs to reformat the prompt.

        """

        if kwargs:

            # See <https://launchpad.net/bugs/365891>

            prompt = prompt % kwargs

        prompt = prompt.encode(osutils.get_terminal_encoding(), 'replace')

        self.clear_term()

        self.stderr.write(prompt)

    def report_transport_activity(self, transport, byte_count, direction):

        """Called by transports as they do IO.

        This may update a progress bar, spinner, or similar display.

        By default it does nothing.

        """

        self._progress_view.show_transport_activity(transport,

            direction, byte_count)

    def show_error(self, msg):

        self.clear_term()

        self.stderr.write("bzr: error: %s\n" % msg)

    def show_message(self, msg):

        self.note(msg)

    def show_warning(self, msg):

        self.clear_term()

        self.stderr.write("bzr: warning: %s\n" % msg)

    def _progress_updated(self, task):

        """A task has been updated and wants to be displayed.

        """

        if not self._task_stack:

            warnings.warn("%r updated but no tasks are active" %

                (task,))

        elif task != self._task_stack[-1]:

            warnings.warn("%r is not the top progress task %r" %

                (task, self._task_stack[-1]))

        self._progress_view.show_progress(task)

    def _progress_all_finished(self):

        self._progress_view.clear()

class TextProgressView(object):

    """Display of progress bar and other information on a tty.

    This shows one line of text, including possibly a network indicator, spinner,

    progress bar, message, etc.

    One instance of this is created and held by the UI, and fed updates when a

    task wants to be painted.

    Transports feed data to this through the ui_factory object.

    The Progress views can comprise a tree with _parent_task pointers, but

    this only prints the stack from the nominated current task up to the root.

    """

    def __init__(self, term_file):

        self._term_file = term_file

        # true when there's output on the screen we may need to clear

        self._have_output = False

        # XXX: We could listen for SIGWINCH and update the terminal width...

        # https://launchpad.net/bugs/316357

        self._width = osutils.terminal_width()

        self._last_transport_msg = ''

        self._spin_pos = 0

        # time we last repainted the screen

        self._last_repaint = 0

        # time we last got information about transport activity

        self._transport_update_time = 0

        self._last_task = None

        self._total_byte_count = 0

        self._bytes_since_update = 0

        self._fraction = 0

        # force the progress bar to be off, as at the moment it doesn't 

        # correspond reliably to overall command progress

        self.enable_bar = False

    def _show_line(self, s):

        # sys.stderr.write("progress %r\n" % s)

        if self._width is not None:

            n = self._width - 1

            s = '%-*.*s' % (n, n, s)

        self._term_file.write('\r' + s + '\r')

    def clear(self):

        if self._have_output:

            self._show_line('')

        self._have_output = False

    def _render_bar(self):

        # return a string for the progress bar itself

        if self.enable_bar and (

            (self._last_task is None) or self._last_task.show_bar):

            # If there's no task object, we show space for the bar anyhow.

            # That's because most invocations of bzr will end showing progress

            # at some point, though perhaps only after doing some initial IO.

            # It looks better to draw the progress bar initially rather than

            # to have what looks like an incomplete progress bar.

            spin_str =  r'/-\|'[self._spin_pos % 4]

            self._spin_pos += 1

            cols = 20

            if self._last_task is None:

                completion_fraction = 0

                self._fraction = 0

            else:

                completion_fraction = \

                    self._last_task._overall_completion_fraction() or 0

            if (completion_fraction < self._fraction and 'progress' in

                debug.debug_flags):

                import pdb;pdb.set_trace()

            self._fraction = completion_fraction

            markers = int(round(float(cols) * completion_fraction)) - 1

            bar_str = '[' + ('#' * markers + spin_str).ljust(cols) + '] '

            return bar_str

        elif self._last_task.show_spinner:

            # The last task wanted just a spinner, no bar

            spin_str =  r'/-\|'[self._spin_pos % 4]

            self._spin_pos += 1

            return spin_str + ' '

        else:

            return ''

    def _format_task(self, task):

        if not task.show_count:

            s = ''

        elif task.current_cnt is not None and task.total_cnt is not None:

            s = ' %d/%d' % (task.current_cnt, task.total_cnt)

        elif task.current_cnt is not None:

            s = ' %d' % (task.current_cnt)

        else:

            s = ''

        # compose all the parent messages

        t = task

        m = task.msg

        while t._parent_task:

            t = t._parent_task

            if t.msg:

                m = t.msg + ':' + m

        return m + s

    def _render_line(self):

        bar_string = self._render_bar()

        if self._last_task:

            task_msg = self._format_task(self._last_task)

        else:

            task_msg = ''

        if self._last_task and not self._last_task.show_transport_activity:

            trans = ''

        else:

            trans = self._last_transport_msg

            if trans:

                trans += ' | '

        return (bar_string + trans + task_msg)

    def _repaint(self):

        s = self._render_line()

        self._show_line(s)

        self._have_output = True

    def show_progress(self, task):

        """Called by the task object when it has changed.

        :param task: The top task object; its parents are also included 

            by following links.

        """

        must_update = task is not self._last_task

        self._last_task = task

        now = time.time()

        if (not must_update) and (now < self._last_repaint + task.update_latency):

            return

        if now > self._transport_update_time + 10:

            # no recent activity; expire it

            self._last_transport_msg = ''

        self._last_repaint = now

        self._repaint()

    def show_transport_activity(self, transport, direction, byte_count):

        """Called by transports via the ui_factory, as they do IO.

        This may update a progress bar, spinner, or similar display.

        By default it does nothing.

        """

        # XXX: Probably there should be a transport activity model, and that

        # too should be seen by the progress view, rather than being poked in

        # here.

        if not self._have_output:

            # As a workaround for <https://launchpad.net/bugs/321935> we only

            # show transport activity when there's already a progress bar

            # shown, which time the application code is expected to know to

            # clear off the progress bar when it's going to send some other

            # output.  Eventually it would be nice to have that automatically

            # synchronized.

            return

        self._total_byte_count += byte_count

        self._bytes_since_update += byte_count

        now = time.time()

        if self._total_byte_count < 2000:

            # a little resistance at first, so it doesn't stay stuck at 0

            # while connecting...

            return

        if self._transport_update_time is None:

            self._transport_update_time = now

        elif now >= (self._transport_update_time + 0.5):

            # guard against clock stepping backwards, and don't update too

            # often

            rate = self._bytes_since_update / (now - self._transport_update_time)

            msg = ("%6dKB %5dKB/s" %

                    (self._total_byte_count>>10, int(rate)>>10,))

            self._transport_update_time = now

            self._last_repaint = now

            self._bytes_since_update = 0

            self._last_transport_msg = msg

            self._repaint()

class TextUIOutputStream(object):

    """Decorates an output stream so that the terminal is cleared before writing.

    This is supposed to ensure that the progress bar does not conflict with bulk

    text output.

    """

    # XXX: this does not handle the case of writing part of a line, then doing

    # progress bar output: the progress bar will probably write over it.

    # one option is just to buffer that text until we have a full line;

    # another is to save and restore it

    # XXX: might need to wrap more methods

    def __init__(self, ui_factory, wrapped_stream):

        self.ui_factory = ui_factory

        self.wrapped_stream = wrapped_stream

        # this does no transcoding, but it must expose the underlying encoding

        # because some callers need to know what can be written - see for

        # example unescape_for_display.

        self.encoding = getattr(wrapped_stream, 'encoding', None)

    def flush(self):

        self.ui_factory.clear_term()

        self.wrapped_stream.flush()

    def write(self, to_write):

        self.ui_factory.clear_term()

        self.wrapped_stream.write(to_write)

    def writelines(self, lines):

        self.ui_factory.clear_term()

        self.wrapped_stream.writelines(lines)