~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005-2011 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.

"""

from __future__ import absolute_import

import os

import sys

import time

from bzrlib.lazy_import import lazy_import

lazy_import(globals(), """

import codecs

import getpass

import warnings

from bzrlib import (

    debug,

    progress,

    osutils,

    trace,

    )

""")

from bzrlib.ui import (

    UIFactory,

    NullProgressView,

    )

class _ChooseUI(object):

    """ Helper class for choose implementation.

    """

    def __init__(self, ui, msg, choices, default):

        self.ui = ui

        self._setup_mode()

        self._build_alternatives(msg, choices, default)

    def _setup_mode(self):

        """Setup input mode (line-based, char-based) and echo-back.

        Line-based input is used if the BZR_TEXTUI_INPUT environment

        variable is set to 'line-based', or if there is no controlling

        terminal.

        """

        if os.environ.get('BZR_TEXTUI_INPUT') != 'line-based' and \

           self.ui.stdin == sys.stdin and self.ui.stdin.isatty():

            self.line_based = False

            self.echo_back = True

        else:

            self.line_based = True

            self.echo_back = not self.ui.stdin.isatty()

    def _build_alternatives(self, msg, choices, default):

        """Parse choices string.

        Setup final prompt and the lists of choices and associated

        shortcuts.

        """

        index = 0

        help_list = []

        self.alternatives = {}

        choices = choices.split('\n')

        if default is not None and default not in range(0, len(choices)):

            raise ValueError("invalid default index")

        for c in choices:

            name = c.replace('&', '').lower()

            choice = (name, index)

            if name in self.alternatives:

                raise ValueError("duplicated choice: %s" % name)

            self.alternatives[name] = choice

            shortcut = c.find('&')

            if -1 != shortcut and (shortcut + 1) < len(c):

                help = c[:shortcut]

                help += '[' + c[shortcut + 1] + ']'

                help += c[(shortcut + 2):]

                shortcut = c[shortcut + 1]

            else:

                c = c.replace('&', '')

                shortcut = c[0]

                help = '[%s]%s' % (shortcut, c[1:])

            shortcut = shortcut.lower()

            if shortcut in self.alternatives:

                raise ValueError("duplicated shortcut: %s" % shortcut)

            self.alternatives[shortcut] = choice

            # Add redirections for default.

            if index == default:

                self.alternatives[''] = choice

                self.alternatives['\r'] = choice

            help_list.append(help)

            index += 1

        self.prompt = u'%s (%s): ' % (msg, ', '.join(help_list))

    def _getline(self):

        line = self.ui.stdin.readline()

        if '' == line:

            raise EOFError

        return line.strip()

    def _getchar(self):

        char = osutils.getchar()

        if char == chr(3): # INTR

            raise KeyboardInterrupt

        if char == chr(4): # EOF (^d, C-d)

            raise EOFError

        return char

    def interact(self):

        """Keep asking the user until a valid choice is made.

        """

        if self.line_based:

            getchoice = self._getline

        else:

            getchoice = self._getchar

        iter = 0

        while True:

            iter += 1

            if 1 == iter or self.line_based:

                self.ui.prompt(self.prompt)

            try:

                choice = getchoice()

            except EOFError:

                self.ui.stderr.write('\n')

                return None

            except KeyboardInterrupt:

                self.ui.stderr.write('\n')

                raise KeyboardInterrupt

            choice = choice.lower()

            if choice not in self.alternatives:

                # Not a valid choice, keep on asking.

                continue

            name, index = self.alternatives[choice]

            if self.echo_back:

                self.ui.stderr.write(name + '\n')

            return index

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 choose(self, msg, choices, default=None):

        """Prompt the user for a list of alternatives.

        Support both line-based and char-based editing.

        In line-based mode, both the shortcut and full choice name are valid

        answers, e.g. for choose('prompt', '&yes\n&no'): 'y', ' Y ', ' yes',

        'YES ' are all valid input lines for choosing 'yes'.

        An empty line, when in line-based mode, or pressing enter in char-based

        mode will select the default choice (if any).

        Choice is echoed back if:

        - input is char-based; which means a controlling terminal is available,

          and osutils.getchar is used

        - input is line-based, and no controlling terminal is available

        """

        choose_ui = _ChooseUI(self, msg, choices, default)

        return choose_ui.interact()

    def be_quiet(self, state):

        if state and not self._quiet:

            self.clear_term()

        UIFactory.be_quiet(self, state)

        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_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=u'', **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.

        """

        # with --quiet, never any progress view

        # <https://bugs.launchpad.net/bzr/+bug/320035>.  Otherwise if the

        # user specifically requests either text or no progress bars, always

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

        if self.is_quiet():

            return NullProgressView()

        elif 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 type(prompt) != unicode:

            raise ValueError("prompt %r not a unicode string" % prompt)

        if kwargs:

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

            prompt = prompt % kwargs

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

        self.clear_term()

        self.stdout.flush()

        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 log_transport_activity(self, display=False):

        """See UIFactory.log_transport_activity()"""

        log = getattr(self._progress_view, 'log_transport_activity', None)

        if log is not None:

            log(display=display)

    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()

        if isinstance(msg, unicode):

            te = osutils.get_terminal_encoding()

            msg = msg.encode(te, 'replace')

        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]:

            # We used to check it was the top task, but it's hard to always

            # get this right and it's not necessarily useful: any actual

            # problems will be evident in use

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

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

            pass

        self._progress_view.show_progress(task)

    def _progress_all_finished(self):

        self._progress_view.clear()

    def show_user_warning(self, warning_id, **message_args):

        """Show a text message to the user.

        Explicitly not for warnings about bzr apis, deprecations or internals.

        """

        # eventually trace.warning should migrate here, to avoid logging and

        # be easier to test; that has a lot of test fallout so for now just

        # new code can call this

        if warning_id not in self.suppressed_warnings:

            self.stderr.write(self.format_user_warning(warning_id, message_args) +

                '\n')

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

        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._bytes_by_direction = {'unknown': 0, 'read': 0, 'write': 0}

        self._first_byte_time = None

        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 _avail_width(self):

        # we need one extra space for terminals that wrap on last char

        w = osutils.terminal_width() 

        if w is None:

            return None

        else:

            return w - 1

    def _show_line(self, s):

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

        width = self._avail_width()

        if width is not None:

            s = '%-*.*s' % (width, width, 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 is None) or 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):

        """Format task-specific parts of progress bar.

        :returns: (text_part, counter_part) both unicode strings.

        """

        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_part, counter_part = self._format_task(self._last_task)

        else:

            task_part = counter_part = ''

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

            trans = ''

        else:

            trans = self._last_transport_msg

        # the bar separates the transport activity from the message, so even

        # if there's no bar or spinner, we must show something if both those

        # fields are present

        if (task_part or trans) and not bar_string:

            bar_string = '| '

        # preferentially truncate the task message if we don't have enough

        # space

        avail_width = self._avail_width()

        if avail_width is not None:

            # if terminal avail_width is unknown, don't truncate

            current_len = len(bar_string) + len(trans) + len(task_part) + len(counter_part)

            gap = current_len - avail_width

            if gap > 0:

                task_part = task_part[:-gap-2] + '..'

        s = trans + bar_string + task_part + counter_part

        if avail_width is not None:

            if len(s) < avail_width:

                s = s.ljust(avail_width)

            elif len(s) > avail_width:

                s = s[:avail_width]

        return s

    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: there should be a transport activity model, and that too should

        #      be seen by the progress view, rather than being poked in here.

        self._total_byte_count += byte_count

        self._bytes_since_update += byte_count

        if self._first_byte_time is None:

            # Note that this isn't great, as technically it should be the time

            # when the bytes started transferring, not when they completed.

            # However, we usually start with a small request anyway.

            self._first_byte_time = time.time()

        if direction in self._bytes_by_direction:

            self._bytes_by_direction[direction] += byte_count

        else:

            self._bytes_by_direction['unknown'] += byte_count

        if 'no_activity' in debug.debug_flags:

            # Can be used as a workaround if

            # <https://launchpad.net/bugs/321935> reappears and transport

            # activity is cluttering other output.  However, thanks to

            # TextUIOutputStream this shouldn't be a problem any more.

            return

        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))

            # using base-10 units (see HACKING.txt).

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

                    (self._total_byte_count / 1000, int(rate) / 1000,))

            self._transport_update_time = now

            self._last_repaint = now

            self._bytes_since_update = 0

            self._last_transport_msg = msg

            self._repaint()

    def _format_bytes_by_direction(self):

        if self._first_byte_time is None:

            bps = 0.0

        else:

            transfer_time = time.time() - self._first_byte_time

            if transfer_time < 0.001:

                transfer_time = 0.001

            bps = self._total_byte_count / transfer_time

        # using base-10 units (see HACKING.txt).

        msg = ('Transferred: %.0fkB'

               ' (%.1fkB/s r:%.0fkB w:%.0fkB'

               % (self._total_byte_count / 1000.,

                  bps / 1000.,

                  self._bytes_by_direction['read'] / 1000.,

                  self._bytes_by_direction['write'] / 1000.,

                 ))

        if self._bytes_by_direction['unknown'] > 0:

            msg += ' u:%.0fkB)' % (

                self._bytes_by_direction['unknown'] / 1000.

                )

        else:

            msg += ')'

        return msg

    def log_transport_activity(self, display=False):

        msg = self._format_bytes_by_direction()

        trace.mutter(msg)

        if display and self._total_byte_count > 0:

            self.clear()

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

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)