~bzr-pqm/bzr/bzr.dev

2370.4.1 by Robert Collins
New SmartServer hooks facility. There are two initial hooks documented
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# Copyright (C) 2007 Canonical Ltd
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#
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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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#
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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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#
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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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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"""Support for plugin hooking logic."""
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from bzrlib.lazy_import import lazy_import
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lazy_import(globals(), """
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from bzrlib import (
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        errors,
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        )
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""")
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class Hooks(dict):
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    """A dictionary mapping hook name to a list of callables.
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    e.g. ['FOO'] Is the list of items to be called when the
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    FOO hook is triggered.
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    """
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    def install_hook(self, hook_name, a_callable):
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        """Install a_callable in to the hook hook_name.
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        :param hook_name: A hook name. See the __init__ method of BranchHooks
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            for the complete list of hooks.
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        :param a_callable: The callable to be invoked when the hook triggers.
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            The exact signature will depend on the hook - see the __init__ 
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            method of BranchHooks for details on each hook.
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        """
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        try:
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            self[hook_name].append(a_callable)
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        except KeyError:
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            raise errors.UnknownHook(self.__class__.__name__, hook_name)