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# Copyright (C) 2005-2010 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""bzr python plugin support.
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When load_plugins() is invoked, any python module in any directory in
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$BZR_PLUGIN_PATH will be imported. The module will be imported as
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'bzrlib.plugins.$BASENAME(PLUGIN)'. In the plugin's main body, it should
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update any bzrlib registries it wants to extend.
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See the plugin-api developer documentation for information about writing
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BZR_PLUGIN_PATH is also honoured for any plugins imported via
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'import bzrlib.plugins.PLUGINNAME', as long as set_plugins_path has been
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from bzrlib import osutils
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from bzrlib.lazy_import import lazy_import
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lazy_import(globals(), """
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_format_version_tuple,
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from bzrlib import plugins as _mod_plugins
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from bzrlib.symbol_versioning import (
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DEFAULT_PLUGIN_PATH = None
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_plugins_disabled = False
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def are_plugins_disabled():
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return _plugins_disabled
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def disable_plugins():
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"""Disable loading plugins.
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Future calls to load_plugins() will be ignored.
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global _plugins_disabled
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_plugins_disabled = True
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def _strip_trailing_sep(path):
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return path.rstrip("\\/")
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def set_plugins_path(path=None):
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"""Set the path for plugins to be loaded from.
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:param path: The list of paths to search for plugins. By default,
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path will be determined using get_standard_plugins_path.
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if path is [], no plugins can be loaded.
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path = get_standard_plugins_path()
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_mod_plugins.__path__ = path
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PluginImporter.reset()
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# Set up a blacklist for disabled plugins
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disabled_plugins = os.environ.get('BZR_DISABLE_PLUGINS', None)
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if disabled_plugins is not None:
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for name in disabled_plugins.split(os.pathsep):
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PluginImporter.blacklist.add('bzrlib.plugins.' + name)
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# Set up a the specific paths for plugins
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specific_plugins = os.environ.get('BZR_PLUGINS_AT', None)
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if specific_plugins is not None:
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for spec in specific_plugins.split(os.pathsep):
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plugin_name, plugin_path = spec.split('@')
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PluginImporter.specific_paths[
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'bzrlib.plugins.%s' % plugin_name] = plugin_path
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def _append_new_path(paths, new_path):
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"""Append a new path if it set and not already known."""
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if new_path is not None and new_path not in paths:
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paths.append(new_path)
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def get_core_plugin_path():
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bzr_exe = bool(getattr(sys, 'frozen', None))
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if bzr_exe: # expand path for bzr.exe
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# We need to use relative path to system-wide plugin
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# directory because bzrlib from standalone bzr.exe
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# could be imported by another standalone program
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# (e.g. bzr-config; or TortoiseBzr/Olive if/when they
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# will become standalone exe). [bialix 20071123]
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# __file__ typically is
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# C:\Program Files\Bazaar\lib\library.zip\bzrlib\plugin.pyc
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# then plugins directory is
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# C:\Program Files\Bazaar\plugins
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# so relative path is ../../../plugins
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core_path = osutils.abspath(osutils.pathjoin(
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osutils.dirname(__file__), '../../../plugins'))
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else: # don't look inside library.zip
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# search the plugin path before the bzrlib installed dir
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core_path = os.path.dirname(_mod_plugins.__file__)
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def get_site_plugin_path():
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"""Returns the path for the site installed plugins."""
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if sys.platform == 'win32':
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# We don't have (yet) a good answer for windows since that is certainly
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# related to the way we build the installers. -- vila20090821
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from distutils.sysconfig import get_python_lib
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# If distutuils is not available, we just don't know where they are
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site_path = osutils.pathjoin(get_python_lib(), 'bzrlib', 'plugins')
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def get_user_plugin_path():
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return osutils.pathjoin(config.config_dir(), 'plugins')
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def get_standard_plugins_path():
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"""Determine a plugin path suitable for general use."""
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# Ad-Hoc default: core is not overriden by site but user can overrides both
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# The rationale is that:
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# - 'site' comes last, because these plugins should always be available and
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# are supposed to be in sync with the bzr installed on site.
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# - 'core' comes before 'site' so that running bzr from sources or a user
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# installed version overrides the site version.
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# - 'user' comes first, because... user is always right.
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# - the above rules clearly defines which plugin version will be loaded if
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# several exist. Yet, it is sometimes desirable to disable some directory
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# so that a set of plugins is disabled as once. This can be done via
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# -site, -core, -user.
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env_paths = os.environ.get('BZR_PLUGIN_PATH', '+user').split(os.pathsep)
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defaults = ['+core', '+site']
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# The predefined references
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refs = dict(core=get_core_plugin_path(),
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site=get_site_plugin_path(),
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user=get_user_plugin_path())
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# Unset paths that should be removed
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for k,v in refs.iteritems():
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# defaults can never mention removing paths as that will make it
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# impossible for the user to revoke these removals.
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if removed in env_paths:
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env_paths.remove(removed)
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for p in env_paths + defaults:
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if p.startswith('+'):
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# Resolve references if they are known
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# Leave them untouched so user can still use paths starting
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_append_new_path(paths, p)
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# Get rid of trailing slashes, since Python can't handle them when
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# it tries to import modules.
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paths = map(_strip_trailing_sep, paths)
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def load_plugins(path=None):
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"""Load bzrlib plugins.
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The environment variable BZR_PLUGIN_PATH is considered a delimited
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set of paths to look through. Each entry is searched for *.py
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files (and whatever other extensions are used in the platform,
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load_from_path() provides the underlying mechanism and is called with
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the default directory list to provide the normal behaviour.
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:param path: The list of paths to search for plugins. By default,
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path will be determined using get_standard_plugins_path.
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if path is [], no plugins can be loaded.
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# People can make sure plugins are loaded, they just won't be twice
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# scan for all plugins in the path.
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load_from_path(set_plugins_path(path))
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def load_from_path(dirs):
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"""Load bzrlib plugins found in each dir in dirs.
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Loading a plugin means importing it into the python interpreter.
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The plugin is expected to make calls to register commands when
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it's loaded (or perhaps access other hooks in future.)
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Plugins are loaded into bzrlib.plugins.NAME, and can be found there
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for future reference.
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The python module path for bzrlib.plugins will be modified to be 'dirs'.
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# Explicitly load the plugins with a specific path
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for fullname, path in PluginImporter.specific_paths.iteritems():
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name = fullname[len('bzrlib.plugins.'):]
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_load_plugin_module(name, path)
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# We need to strip the trailing separators here as well as in the
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# set_plugins_path function because calling code can pass anything in to
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# this function, and since it sets plugins.__path__, it should set it to
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# something that will be valid for Python to use (in case people try to
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# run "import bzrlib.plugins.PLUGINNAME" after calling this function).
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_mod_plugins.__path__ = map(_strip_trailing_sep, dirs)
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trace.mutter('looking for plugins in %s', d)
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# backwards compatability: load_from_dirs was the old name
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# This was changed in 0.15
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load_from_dirs = load_from_path
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def _find_plugin_module(dir, name):
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"""Check if there is a valid python module that can be loaded as a plugin.
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:param dir: The directory where the search is performed.
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:param path: An existing file path, either a python file or a package
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:return: (name, path, description) name is the module name, path is the
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file to load and description is the tuple returned by
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path = osutils.pathjoin(dir, name)
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if os.path.isdir(path):
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# Check for a valid __init__.py file, valid suffixes depends on -O and
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# can be .py, .pyc and .pyo
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for suffix, mode, kind in imp.get_suffixes():
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if kind not in (imp.PY_SOURCE, imp.PY_COMPILED):
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# We don't recognize compiled modules (.so, .dll, etc)
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init_path = osutils.pathjoin(path, '__init__' + suffix)
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if os.path.isfile(init_path):
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return name, init_path, (suffix, mode, kind)
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for suffix, mode, kind in imp.get_suffixes():
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if name.endswith(suffix):
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# Clean up the module name
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name = name[:-len(suffix)]
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if kind == imp.C_EXTENSION and name.endswith('module'):
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name = name[:-len('module')]
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return name, path, (suffix, mode, kind)
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# There is no python module here
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return None, None, (None, None, None)
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def _load_plugin_module(name, dir):
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"""Load plugin name from dir.
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:param name: The plugin name in the bzrlib.plugins namespace.
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:param dir: The directory the plugin is loaded from for error messages.
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if ('bzrlib.plugins.%s' % name) in PluginImporter.blacklist:
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exec "import bzrlib.plugins.%s" % name in {}
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except KeyboardInterrupt:
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except errors.IncompatibleAPI, e:
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trace.warning("Unable to load plugin %r. It requested API version "
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"%s of module %s but the minimum exported version is %s, and "
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"the maximum is %s" %
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(name, e.wanted, e.api, e.minimum, e.current))
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trace.warning("%s" % e)
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if re.search('\.|-| ', name):
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sanitised_name = re.sub('[-. ]', '_', name)
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if sanitised_name.startswith('bzr_'):
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sanitised_name = sanitised_name[len('bzr_'):]
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trace.warning("Unable to load %r in %r as a plugin because the "
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"file path isn't a valid module name; try renaming "
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"it to %r." % (name, dir, sanitised_name))
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trace.warning('Unable to load plugin %r from %r' % (name, dir))
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trace.log_exception_quietly()
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if 'error' in debug.debug_flags:
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trace.print_exception(sys.exc_info(), sys.stderr)
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def load_from_dir(d):
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"""Load the plugins in directory d.
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d must be in the plugins module path already.
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This function is called once for each directory in the module path.
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for p in os.listdir(d):
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name, path, desc = _find_plugin_module(d, p)
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if name == '__init__':
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# We do nothing with the __init__.py file in directories from
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# the bzrlib.plugins module path, we may want to, one day
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continue # We don't load __init__.py in the plugins dirs
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elif getattr(_mod_plugins, name, None) is not None:
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# The module has already been loaded from another directory
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# during a previous call.
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# FIXME: There should be a better way to report masked plugins
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trace.mutter('Plugin name %s already loaded', name)
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plugin_names.add(name)
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for name in plugin_names:
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_load_plugin_module(name, d)
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"""Return a dictionary of the plugins.
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Each item in the dictionary is a PlugIn object.
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for name, plugin in _mod_plugins.__dict__.items():
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if isinstance(plugin, types.ModuleType):
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result[name] = PlugIn(name, plugin)
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class PluginsHelpIndex(object):
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"""A help index that returns help topics for plugins."""
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self.prefix = 'plugins/'
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def get_topics(self, topic):
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"""Search for topic in the loaded plugins.
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This will not trigger loading of new plugins.
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:param topic: A topic to search for.
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:return: A list which is either empty or contains a single
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RegisteredTopic entry.
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if topic.startswith(self.prefix):
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topic = topic[len(self.prefix):]
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plugin_module_name = 'bzrlib.plugins.%s' % topic
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module = sys.modules[plugin_module_name]
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return [ModuleHelpTopic(module)]
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class ModuleHelpTopic(object):
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"""A help topic which returns the docstring for a module."""
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def __init__(self, module):
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:param module: The module for which help should be generated.
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def get_help_text(self, additional_see_also=None, verbose=True):
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"""Return a string with the help for this topic.
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:param additional_see_also: Additional help topics to be
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if not self.module.__doc__:
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result = "Plugin '%s' has no docstring.\n" % self.module.__name__
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result = self.module.__doc__
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if result[-1] != '\n':
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# there is code duplicated here and in bzrlib/help_topic.py's
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# matching Topic code. This should probably be factored in
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# to a helper function and a common base class.
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if additional_see_also is not None:
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see_also = sorted(set(additional_see_also))
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result += 'See also: '
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result += ', '.join(see_also)
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def get_help_topic(self):
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"""Return the modules help topic - its __name__ after bzrlib.plugins.."""
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return self.module.__name__[len('bzrlib.plugins.'):]
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class PlugIn(object):
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"""The bzrlib representation of a plugin.
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The PlugIn object provides a way to manipulate a given plugin module.
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def __init__(self, name, module):
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"""Construct a plugin for module."""
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"""Get the path that this plugin was loaded from."""
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if getattr(self.module, '__path__', None) is not None:
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return os.path.abspath(self.module.__path__[0])
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elif getattr(self.module, '__file__', None) is not None:
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path = os.path.abspath(self.module.__file__)
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if path[-4:] in ('.pyc', '.pyo'):
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pypath = path[:-4] + '.py'
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if os.path.isfile(pypath):
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return repr(self.module)
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return "<%s.%s object at %s, name=%s, module=%s>" % (
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self.__class__.__module__, self.__class__.__name__, id(self),
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self.name, self.module)
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def test_suite(self):
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"""Return the plugin's test suite."""
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if getattr(self.module, 'test_suite', None) is not None:
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return self.module.test_suite()
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def load_plugin_tests(self, loader):
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"""Return the adapted plugin's test suite.
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:param loader: The custom loader that should be used to load additional
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if getattr(self.module, 'load_tests', None) is not None:
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return loader.loadTestsFromModule(self.module)
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def version_info(self):
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"""Return the plugin's version_tuple or None if unknown."""
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version_info = getattr(self.module, 'version_info', None)
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if version_info is not None:
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if isinstance(version_info, types.StringType):
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version_info = version_info.split('.')
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elif len(version_info) == 3:
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version_info = tuple(version_info) + ('final', 0)
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# The given version_info isn't even iteratible
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trace.log_exception_quietly()
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version_info = (version_info,)
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def _get__version__(self):
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version_info = self.version_info()
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if version_info is None or len(version_info) == 0:
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version_string = _format_version_tuple(version_info)
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except (ValueError, TypeError, IndexError), e:
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trace.log_exception_quietly()
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# try to return something usefull for bad plugins, in stead of
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version_string = '.'.join(map(str, version_info))
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return version_string
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__version__ = property(_get__version__)
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class _PluginImporter(object):
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"""An importer tailored to bzr specific needs.
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This is a singleton that takes care of:
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- disabled plugins specified in 'blacklist',
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- plugins that needs to be loaded from specific directories.
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self.blacklist = set()
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self.specific_paths = {}
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def find_module(self, fullname, parent_path=None):
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"""Search a plugin module.
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Disabled plugins raise an import error, plugins with specific paths
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returns a specific loader.
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:return: None if the plugin doesn't need special handling, self
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if not fullname.startswith('bzrlib.plugins.'):
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if fullname in self.blacklist:
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raise ImportError('%s is disabled' % fullname)
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if fullname in self.specific_paths:
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def load_module(self, fullname):
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"""Load a plugin from a specific directory."""
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# We are called only for specific paths
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plugin_path = self.specific_paths[fullname]
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if os.path.isdir(plugin_path):
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for suffix, mode, kind in imp.get_suffixes():
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if kind not in (imp.PY_SOURCE, imp.PY_COMPILED):
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# We don't recognize compiled modules (.so, .dll, etc)
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init_path = osutils.pathjoin(plugin_path, '__init__' + suffix)
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if os.path.isfile(init_path):
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loading_path = init_path
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for suffix, mode, kind in imp.get_suffixes():
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if plugin_path.endswith(suffix):
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loading_path = plugin_path
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if loading_path is None:
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raise ImportError('%s cannot be loaded from %s'
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% (fullname, plugin_path))
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f = open(loading_path, mode)
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mod = imp.load_module(fullname, f, loading_path,
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(suffix, mode, kind))
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# The plugin can contain modules, so be ready
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mod.__path__ = [plugin_path]
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mod.__package__ = fullname
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# Install a dedicated importer for plugins requiring special handling
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PluginImporter = _PluginImporter()
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sys.meta_path.append(PluginImporter)
added
removed
bzrlib/plugin.py
