~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

from __future__ import absolute_import

# TODO: Define arguments by objects, rather than just using names.

# Those objects can specify the expected type of the argument, which

# would help with validation and shell completion.  They could also provide

# help/explanation for that argument in a structured way.

# TODO: Specific "examples" property on commands for consistent formatting.

import os

import sys

from bzrlib.lazy_import import lazy_import

lazy_import(globals(), """

import errno

import threading

import bzrlib

from bzrlib import (

    config,

    cleanup,

    cmdline,

    debug,

    errors,

    i18n,

    option,

    osutils,

    trace,

    ui,

    )

""")

from bzrlib.hooks import Hooks

from bzrlib.i18n import gettext

# Compatibility - Option used to be in commands.

from bzrlib.option import Option

from bzrlib.plugin import disable_plugins, load_plugins

from bzrlib import registry

class CommandInfo(object):

    """Information about a command."""

    def __init__(self, aliases):

        """The list of aliases for the command."""

        self.aliases = aliases

    @classmethod

    def from_command(klass, command):

        """Factory to construct a CommandInfo from a command."""

        return klass(command.aliases)

class CommandRegistry(registry.Registry):

    """Special registry mapping command names to command classes.

    :ivar overridden_registry: Look in this registry for commands being

        overridden by this registry.  This can be used to tell plugin commands

        about the builtin they're decorating.

    """

    def __init__(self):

        registry.Registry.__init__(self)

        self.overridden_registry = None

        # map from aliases to the real command that implements the name

        self._alias_dict = {}

    def get(self, command_name):

        real_name = self._alias_dict.get(command_name, command_name)

        return registry.Registry.get(self, real_name)

    @staticmethod

    def _get_name(command_name):

        if command_name.startswith("cmd_"):

            return _unsquish_command_name(command_name)

        else:

            return command_name

    def register(self, cmd, decorate=False):

        """Utility function to help register a command

        :param cmd: Command subclass to register

        :param decorate: If true, allow overriding an existing command

            of the same name; the old command is returned by this function.

            Otherwise it is an error to try to override an existing command.

        """

        k = cmd.__name__

        k_unsquished = self._get_name(k)

        try:

            previous = self.get(k_unsquished)

        except KeyError:

            previous = None

            if self.overridden_registry:

                try:

                    previous = self.overridden_registry.get(k_unsquished)

                except KeyError:

                    pass

        info = CommandInfo.from_command(cmd)

        try:

            registry.Registry.register(self, k_unsquished, cmd,

                                       override_existing=decorate, info=info)

        except KeyError:

            trace.warning('Two plugins defined the same command: %r' % k)

            trace.warning('Not loading the one in %r' %

                sys.modules[cmd.__module__])

            trace.warning('Previously this command was registered from %r' %

                sys.modules[previous.__module__])

        for a in cmd.aliases:

            self._alias_dict[a] = k_unsquished

        return previous

    def register_lazy(self, command_name, aliases, module_name):

        """Register a command without loading its module.

        :param command_name: The primary name of the command.

        :param aliases: A list of aliases for the command.

        :module_name: The module that the command lives in.

        """

        key = self._get_name(command_name)

        registry.Registry.register_lazy(self, key, module_name, command_name,

                                        info=CommandInfo(aliases))

        for a in aliases:

            self._alias_dict[a] = key

plugin_cmds = CommandRegistry()

builtin_command_registry = CommandRegistry()

plugin_cmds.overridden_registry = builtin_command_registry

def register_command(cmd, decorate=False):

    """Register a plugin command.

    Should generally be avoided in favor of lazy registration. 

    """

    global plugin_cmds

    return plugin_cmds.register(cmd, decorate)

def _squish_command_name(cmd):

    return 'cmd_' + cmd.replace('-', '_')

def _unsquish_command_name(cmd):

    return cmd[4:].replace('_','-')

def _register_builtin_commands():

    if builtin_command_registry.keys():

        # only load once

        return

    import bzrlib.builtins

    for cmd_class in _scan_module_for_commands(bzrlib.builtins).values():

        builtin_command_registry.register(cmd_class)

    bzrlib.builtins._register_lazy_builtins()

def _scan_module_for_commands(module):

    r = {}

    for name, obj in module.__dict__.iteritems():

        if name.startswith("cmd_"):

            real_name = _unsquish_command_name(name)

            r[real_name] = obj

    return r

def _list_bzr_commands(names):

    """Find commands from bzr's core and plugins.

    This is not the public interface, just the default hook called by all_command_names.

    """

    # to eliminate duplicates

    names.update(builtin_command_names())

    names.update(plugin_command_names())

    return names

def all_command_names():

    """Return a set of all command names."""

    names = set()

    for hook in Command.hooks['list_commands']:

        names = hook(names)

        if names is None:

            raise AssertionError(

                'hook %s returned None' % Command.hooks.get_hook_name(hook))

    return names

def builtin_command_names():

    """Return list of builtin command names.

    Use of all_command_names() is encouraged rather than builtin_command_names

    and/or plugin_command_names.

    """

    _register_builtin_commands()

    return builtin_command_registry.keys()

def plugin_command_names():

    """Returns command names from commands registered by plugins."""

    return plugin_cmds.keys()

def get_cmd_object(cmd_name, plugins_override=True):

    """Return the command object for a command.

    plugins_override

        If true, plugin commands can override builtins.

    """

    try:

        return _get_cmd_object(cmd_name, plugins_override)

    except KeyError:

        raise errors.BzrCommandError(gettext('unknown command "%s"') % cmd_name)

def _get_cmd_object(cmd_name, plugins_override=True, check_missing=True):

    """Get a command object.

    :param cmd_name: The name of the command.

    :param plugins_override: Allow plugins to override builtins.

    :param check_missing: Look up commands not found in the regular index via

        the get_missing_command hook.

    :return: A Command object instance

    :raises KeyError: If no command is found.

    """

    # We want only 'ascii' command names, but the user may have typed

    # in a Unicode name. In that case, they should just get a

    # 'command not found' error later.

    # In the future, we may actually support Unicode command names.

    cmd = None

    # Get a command

    for hook in Command.hooks['get_command']:

        cmd = hook(cmd, cmd_name)

        if cmd is not None and not plugins_override and not cmd.plugin_name():

            # We've found a non-plugin command, don't permit it to be

            # overridden.

            break

    if cmd is None and check_missing:

        for hook in Command.hooks['get_missing_command']:

            cmd = hook(cmd_name)

            if cmd is not None:

                break

    if cmd is None:

        # No command found.

        raise KeyError

    # Allow plugins to extend commands

    for hook in Command.hooks['extend_command']:

        hook(cmd)

    if getattr(cmd, 'invoked_as', None) is None:

        cmd.invoked_as = cmd_name

    return cmd

def _try_plugin_provider(cmd_name):

    """Probe for a plugin provider having cmd_name."""

    try:

        plugin_metadata, provider = probe_for_provider(cmd_name)

        raise errors.CommandAvailableInPlugin(cmd_name,

            plugin_metadata, provider)

    except errors.NoPluginAvailable:

        pass

def probe_for_provider(cmd_name):

    """Look for a provider for cmd_name.

    :param cmd_name: The command name.

    :return: plugin_metadata, provider for getting cmd_name.

    :raises NoPluginAvailable: When no provider can supply the plugin.

    """

    # look for providers that provide this command but aren't installed

    for provider in command_providers_registry:

        try:

            return provider.plugin_for_command(cmd_name), provider

        except errors.NoPluginAvailable:

            pass

    raise errors.NoPluginAvailable(cmd_name)

def _get_bzr_command(cmd_or_None, cmd_name):

    """Get a command from bzr's core."""

    try:

        cmd_class = builtin_command_registry.get(cmd_name)

    except KeyError:

        pass

    else:

        return cmd_class()

    return cmd_or_None

def _get_external_command(cmd_or_None, cmd_name):

    """Lookup a command that is a shell script."""

    # Only do external command lookups when no command is found so far.

    if cmd_or_None is not None:

        return cmd_or_None

    from bzrlib.externalcommand import ExternalCommand

    cmd_obj = ExternalCommand.find_command(cmd_name)

    if cmd_obj:

        return cmd_obj

def _get_plugin_command(cmd_or_None, cmd_name):

    """Get a command from bzr's plugins."""

    try:

        return plugin_cmds.get(cmd_name)()

    except KeyError:

        pass

    for key in plugin_cmds.keys():

        info = plugin_cmds.get_info(key)

        if cmd_name in info.aliases:

            return plugin_cmds.get(key)()

    return cmd_or_None

class Command(object):

    """Base class for commands.

    Commands are the heart of the command-line bzr interface.

    The command object mostly handles the mapping of command-line

    parameters into one or more bzrlib operations, and of the results

    into textual output.

    Commands normally don't have any state.  All their arguments are

    passed in to the run method.  (Subclasses may take a different

    policy if the behaviour of the instance needs to depend on e.g. a

    shell plugin and not just its Python class.)

    The docstring for an actual command should give a single-line

    summary, then a complete description of the command.  A grammar

    description will be inserted.

    :cvar aliases: Other accepted names for this command.

    :cvar takes_args: List of argument forms, marked with whether they are

        optional, repeated, etc.  Examples::

            ['to_location', 'from_branch?', 'file*']

        * 'to_location' is required

        * 'from_branch' is optional

        * 'file' can be specified 0 or more times

    :cvar takes_options: List of options that may be given for this command.

        These can be either strings, referring to globally-defined options, or

        option objects.  Retrieve through options().

    :cvar hidden: If true, this command isn't advertised.  This is typically

        for commands intended for expert users.

    :cvar encoding_type: Command objects will get a 'outf' attribute, which has

        been setup to properly handle encoding of unicode strings.

        encoding_type determines what will happen when characters cannot be

        encoded:

        * strict - abort if we cannot decode

        * replace - put in a bogus character (typically '?')

        * exact - do not encode sys.stdout

        NOTE: by default on Windows, sys.stdout is opened as a text stream,

        therefore LF line-endings are converted to CRLF.  When a command uses

        encoding_type = 'exact', then sys.stdout is forced to be a binary

        stream, and line-endings will not mangled.

    :cvar invoked_as:

        A string indicating the real name under which this command was

        invoked, before expansion of aliases.

        (This may be None if the command was constructed and run in-process.)

    :cvar hooks: An instance of CommandHooks.

    :cvar __doc__: The help shown by 'bzr help command' for this command.

        This is set by assigning explicitly to __doc__ so that -OO can

        be used::

            class Foo(Command):

                __doc__ = "My help goes here"

    """

    aliases = []

    takes_args = []

    takes_options = []

    encoding_type = 'strict'

    invoked_as = None

    l10n = True

    hidden = False

    def __init__(self):

        """Construct an instance of this command."""

        # List of standard options directly supported

        self.supported_std_options = []

        self._setup_run()

    def add_cleanup(self, cleanup_func, *args, **kwargs):

        """Register a function to call after self.run returns or raises.

        Functions will be called in LIFO order.

        """

        self._operation.add_cleanup(cleanup_func, *args, **kwargs)

    def cleanup_now(self):

        """Execute and empty pending cleanup functions immediately.

        After cleanup_now all registered cleanups are forgotten.  add_cleanup

        may be called again after cleanup_now; these cleanups will be called

        after self.run returns or raises (or when cleanup_now is next called).

        This is useful for releasing expensive or contentious resources (such

        as write locks) before doing further work that does not require those

        resources (such as writing results to self.outf). Note though, that

        as it releases all resources, this may release locks that the command

        wants to hold, so use should be done with care.

        """

        self._operation.cleanup_now()

    def _usage(self):

        """Return single-line grammar for this command.

        Only describes arguments, not options.

        """

        s = 'bzr ' + self.name() + ' '

        for aname in self.takes_args:

            aname = aname.upper()

            if aname[-1] in ['$', '+']:

                aname = aname[:-1] + '...'

            elif aname[-1] == '?':

                aname = '[' + aname[:-1] + ']'

            elif aname[-1] == '*':

                aname = '[' + aname[:-1] + '...]'

            s += aname + ' '

        s = s[:-1]      # remove last space

        return s

    def get_help_text(self, additional_see_also=None, plain=True,

                      see_also_as_links=False, verbose=True):

        """Return a text string with help for this command.

        :param additional_see_also: Additional help topics to be

            cross-referenced.

        :param plain: if False, raw help (reStructuredText) is

            returned instead of plain text.

        :param see_also_as_links: if True, convert items in 'See also'

            list to internal links (used by bzr_man rstx generator)

        :param verbose: if True, display the full help, otherwise

            leave out the descriptive sections and just display

            usage help (e.g. Purpose, Usage, Options) with a

            message explaining how to obtain full help.

        """

        if self.l10n:

            i18n.install()  # Install i18n only for get_help_text for now.

        doc = self.help()

        if doc:

            # Note: If self.gettext() translates ':Usage:\n', the section will

            # be shown after "Description" section and we don't want to

            # translate the usage string.

            # Though, bzr export-pot don't exports :Usage: section and it must

            # not be translated.

            doc = self.gettext(doc)

        else:

            doc = gettext("No help for this command.")

        # Extract the summary (purpose) and sections out from the text

        purpose,sections,order = self._get_help_parts(doc)

        # If a custom usage section was provided, use it

        if sections.has_key('Usage'):

            usage = sections.pop('Usage')

        else:

            usage = self._usage()

        # The header is the purpose and usage

        result = ""

        result += gettext(':Purpose: %s\n') % (purpose,)

        if usage.find('\n') >= 0:

            result += gettext(':Usage:\n%s\n') % (usage,)

        else:

            result += gettext(':Usage:   %s\n') % (usage,)

        result += '\n'

        # Add the options

        #

        # XXX: optparse implicitly rewraps the help, and not always perfectly,

        # so we get <https://bugs.launchpad.net/bzr/+bug/249908>.  -- mbp

        # 20090319

        parser = option.get_optparser(self.options())

        options = parser.format_option_help()

        # FIXME: According to the spec, ReST option lists actually don't

        # support options like --1.14 so that causes syntax errors (in Sphinx

        # at least).  As that pattern always appears in the commands that

        # break, we trap on that and then format that block of 'format' options

        # as a literal block. We use the most recent format still listed so we

        # don't have to do that too often -- vila 20110514

        if not plain and options.find('  --1.14  ') != -1:

            options = options.replace(' format:\n', ' format::\n\n', 1)

        if options.startswith('Options:'):

            result += gettext(':Options:%s') % (options[len('options:'):],)

        else:

            result += options

        result += '\n'

        if verbose:

            # Add the description, indenting it 2 spaces

            # to match the indentation of the options

            if sections.has_key(None):

                text = sections.pop(None)

                text = '\n  '.join(text.splitlines())

                result += gettext(':Description:\n  %s\n\n') % (text,)

            # Add the custom sections (e.g. Examples). Note that there's no need

            # to indent these as they must be indented already in the source.

            if sections:

                for label in order:

                    if label in sections:

                        result += ':%s:\n%s\n' % (label, sections[label])

                result += '\n'

        else:

            result += (gettext("See bzr help %s for more details and examples.\n\n")

                % self.name())

        # Add the aliases, source (plug-in) and see also links, if any

        if self.aliases:

            result += gettext(':Aliases:  ')

            result += ', '.join(self.aliases) + '\n'

        plugin_name = self.plugin_name()

        if plugin_name is not None:

            result += gettext(':From:     plugin "%s"\n') % plugin_name

        see_also = self.get_see_also(additional_see_also)

        if see_also:

            if not plain and see_also_as_links:

                see_also_links = []

                for item in see_also:

                    if item == 'topics':

                        # topics doesn't have an independent section

                        # so don't create a real link

                        see_also_links.append(item)

                    else:

                        # Use a Sphinx link for this entry

                        link_text = gettext(":doc:`{0} <{1}-help>`").format(

                                                                    item, item)

                        see_also_links.append(link_text)

                see_also = see_also_links

            result += gettext(':See also: %s') % ', '.join(see_also) + '\n'

        # If this will be rendered as plain text, convert it

        if plain:

            import bzrlib.help_topics

            result = bzrlib.help_topics.help_as_plain_text(result)

        return result

    @staticmethod

    def _get_help_parts(text):

        """Split help text into a summary and named sections.

        :return: (summary,sections,order) where summary is the top line and

            sections is a dictionary of the rest indexed by section name.

            order is the order the section appear in the text.

            A section starts with a heading line of the form ":xxx:".

            Indented text on following lines is the section value.

            All text found outside a named section is assigned to the

            default section which is given the key of None.

        """

        def save_section(sections, order, label, section):

            if len(section) > 0:

                if sections.has_key(label):

                    sections[label] += '\n' + section

                else:

                    order.append(label)

                    sections[label] = section

        lines = text.rstrip().splitlines()

        summary = lines.pop(0)

        sections = {}

        order = []

        label,section = None,''

        for line in lines:

            if line.startswith(':') and line.endswith(':') and len(line) > 2:

                save_section(sections, order, label, section)

                label,section = line[1:-1],''

            elif (label is not None) and len(line) > 1 and not line[0].isspace():

                save_section(sections, order, label, section)

                label,section = None,line

            else:

                if len(section) > 0:

                    section += '\n' + line

                else:

                    section = line

        save_section(sections, order, label, section)

        return summary, sections, order

    def get_help_topic(self):

        """Return the commands help topic - its name."""

        return self.name()

    def get_see_also(self, additional_terms=None):

        """Return a list of help topics that are related to this command.

        The list is derived from the content of the _see_also attribute. Any

        duplicates are removed and the result is in lexical order.

        :param additional_terms: Additional help topics to cross-reference.

        :return: A list of help topics.

        """

        see_also = set(getattr(self, '_see_also', []))

        if additional_terms:

            see_also.update(additional_terms)

        return sorted(see_also)

    def options(self):

        """Return dict of valid options for this command.

        Maps from long option name to option object."""

        r = Option.STD_OPTIONS.copy()

        std_names = r.keys()

        for o in self.takes_options:

            if isinstance(o, basestring):

                o = option.Option.OPTIONS[o]

            r[o.name] = o

            if o.name in std_names:

                self.supported_std_options.append(o.name)

        return r

    def _setup_outf(self):

        """Return a file linked to stdout, which has proper encoding."""

        self.outf = ui.ui_factory.make_output_stream(

            encoding_type=self.encoding_type)

    def run_argv_aliases(self, argv, alias_argv=None):

        """Parse the command line and run with extra aliases in alias_argv."""

        args, opts = parse_args(self, argv, alias_argv)

        self._setup_outf()

        # Process the standard options

        if 'help' in opts:  # e.g. bzr add --help

            self.outf.write(self.get_help_text())

            return 0

        if 'usage' in opts:  # e.g. bzr add --usage

            self.outf.write(self.get_help_text(verbose=False))

            return 0

        trace.set_verbosity_level(option._verbosity_level)

        if 'verbose' in self.supported_std_options:

            opts['verbose'] = trace.is_verbose()

        elif opts.has_key('verbose'):

            del opts['verbose']

        if 'quiet' in self.supported_std_options:

            opts['quiet'] = trace.is_quiet()

        elif opts.has_key('quiet'):

            del opts['quiet']

        # mix arguments and options into one dictionary

        cmdargs = _match_argform(self.name(), self.takes_args, args)

        cmdopts = {}

        for k, v in opts.items():

            cmdopts[k.replace('-', '_')] = v

        all_cmd_args = cmdargs.copy()

        all_cmd_args.update(cmdopts)

        try:

            return self.run(**all_cmd_args)

        finally:

            # reset it, so that other commands run in the same process won't

            # inherit state. Before we reset it, log any activity, so that it

            # gets properly tracked.

            ui.ui_factory.log_transport_activity(

                display=('bytes' in debug.debug_flags))

            trace.set_verbosity_level(0)

    def _setup_run(self):

        """Wrap the defined run method on self with a cleanup.

        This is called by __init__ to make the Command be able to be run

        by just calling run(), as it could be before cleanups were added.

        If a different form of cleanups are in use by your Command subclass,

        you can override this method.