~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2004, 2005 by 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""bzr python plugin support

Any python module in $BZR_PLUGIN_PATH will be imported upon initialization of

bzrlib. The module will be imported as 'bzrlib.plugins.$BASENAME(PLUGIN)'.

In the plugin's main body, it should update any bzrlib registries it wants to

extend; for example, to add new commands, import bzrlib.commands and add your

new command to the plugin_cmds variable.

"""

# TODO: Refactor this to make it more testable.  The main problem at the

# moment is that loading plugins affects the global process state -- for bzr

# in general use it's a reasonable assumption that all plugins are loaded at

# startup and then stay loaded, but this is less good for testing.

# 

# Several specific issues:

#  - plugins can't be unloaded and will continue to effect later tests

#  - load_plugins does nothing if called a second time

#  - plugin hooks can't be removed

#

# Our options are either to remove these restrictions, or work around them by

# loading the plugins into a different space than the one running the tests.

# That could be either a separate Python interpreter or perhaps a new

# namespace inside this interpreter.

import imp

import os

import sys

import bzrlib

from bzrlib.config import config_dir

from bzrlib.trace import log_error, mutter, log_exception, warning, \

        log_exception_quietly

from bzrlib.errors import BzrError

from bzrlib import plugins

DEFAULT_PLUGIN_PATH = os.path.join(config_dir(), 'plugins')

all_plugins = []

_loaded = False

def load_plugins():

    """Find all python plugins and load them.

    Loading a plugin means importing it into the python interpreter.

    The plugin is expected to make calls to register commands when

    it's loaded (or perhaps access other hooks in future.)

    A list of plugs is stored in bzrlib.plugin.all_plugins for future

    reference.

    The environment variable BZR_PLUGIN_PATH is considered a delimited

    set of paths to look through. Each entry is searched for *.py

    files (and whatever other extensions are used in the platform,

    such as *.pyd).

    """

    global all_plugins, _loaded

    if _loaded:

        # People can make sure plugins are loaded, they just won't be twice

        return

        #raise BzrError("plugins already initialized")

    _loaded = True

    dirs = os.environ.get('BZR_PLUGIN_PATH', DEFAULT_PLUGIN_PATH).split(os.pathsep)

    dirs.insert(0, os.path.dirname(plugins.__file__))

    # The problem with imp.get_suffixes() is that it doesn't include

    # .pyo which is technically valid

    # It also means that "testmodule.so" will show up as both test and testmodule

    # though it is only valid as 'test'

    # but you should be careful, because "testmodule.py" loads as testmodule.

    suffixes = imp.get_suffixes()

    suffixes.append(('.pyo', 'rb', imp.PY_COMPILED))

    package_entries = ['__init__.py', '__init__.pyc', '__init__.pyo']

    for d in dirs:

        # going through them one by one allows different plugins with the same

        # filename in different directories in the path

        mutter('looking for plugins in %s', d)

        if not d:

            continue

        plugin_names = set()

        if not os.path.isdir(d):

            continue

        for f in os.listdir(d):

            path = os.path.join(d, f)

            if os.path.isdir(path):

                for entry in package_entries:

                    # This directory should be a package, and thus added to

                    # the list

                    if os.path.isfile(os.path.join(path, entry)):

                        break

                else: # This directory is not a package

                    continue

            else:

                for suffix_info in suffixes:

                    if f.endswith(suffix_info[0]):

                        f = f[:-len(suffix_info[0])]

                        if suffix_info[2] == imp.C_EXTENSION and f.endswith('module'):

                            f = f[:-len('module')]

                        break

                else:

                    continue

            mutter('add plugin name %s', f)

            plugin_names.add(f)

        plugin_names = list(plugin_names)

        plugin_names.sort()

        for name in plugin_names:

            try:

                plugin_info = imp.find_module(name, [d])

                mutter('load plugin %r', plugin_info)

                try:

                    plugin = imp.load_module('bzrlib.plugins.' + name,

                                             *plugin_info)

                    all_plugins.append(plugin)

                    setattr(bzrlib.plugins, name, plugin)

                finally:

                    if plugin_info[0] is not None:

                        plugin_info[0].close()

                mutter('loaded succesfully')

            except KeyboardInterrupt:

                raise

            except Exception, e:

                ## import pdb; pdb.set_trace()

                warning('Unable to load plugin %r from %r' % (name, d))

                log_exception_quietly()