1
# Copyright (C) 2007, 2008 Canonical Ltd
3
# This program is free software; you can redistribute it and/or modify
4
# it under the terms of the GNU General Public License as published by
5
# the Free Software Foundation; either version 2 of the License, or
6
# (at your option) any later version.
8
# This program is distributed in the hope that it will be useful,
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11
# GNU General Public License for more details.
13
# You should have received a copy of the GNU General Public License
14
# along with this program; if not, write to the Free Software
15
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18
"""Support for plugin hooking logic."""
19
from bzrlib import registry
20
from bzrlib.lazy_import import lazy_import
21
from bzrlib.symbol_versioning import deprecated_method
22
lazy_import(globals(), """
26
_format_version_tuple,
29
from bzrlib.help_topics import help_as_plain_text
33
known_hooks = registry.Registry()
34
# known_hooks registry contains
35
# tuple of (module, member name) which is the hook point
36
# module where the specific hooks are defined
37
# callable to get the empty specific Hooks for that attribute
38
known_hooks.register_lazy(('bzrlib.branch', 'Branch.hooks'), 'bzrlib.branch',
40
known_hooks.register_lazy(('bzrlib.bzrdir', 'BzrDir.hooks'), 'bzrlib.bzrdir',
42
known_hooks.register_lazy(('bzrlib.commands', 'Command.hooks'),
43
'bzrlib.commands', 'CommandHooks')
44
known_hooks.register_lazy(('bzrlib.lock', 'Lock.hooks'), 'bzrlib.lock',
46
known_hooks.register_lazy(('bzrlib.msgeditor', 'hooks'), 'bzrlib.msgeditor',
48
known_hooks.register_lazy(('bzrlib.mutabletree', 'MutableTree.hooks'),
49
'bzrlib.mutabletree', 'MutableTreeHooks')
50
known_hooks.register_lazy(('bzrlib.smart.client', '_SmartClient.hooks'),
51
'bzrlib.smart.client', 'SmartClientHooks')
52
known_hooks.register_lazy(('bzrlib.smart.server', 'SmartTCPServer.hooks'),
53
'bzrlib.smart.server', 'SmartServerHooks')
56
def known_hooks_key_to_object((module_name, member_name)):
57
"""Convert a known_hooks key to a object.
59
:param key: A tuple (module_name, member_name) as found in the keys of
60
the known_hooks registry.
61
:return: The object this specifies.
63
return registry._LazyObjectGetter(module_name, member_name).get_obj()
66
def known_hooks_key_to_parent_and_attribute((module_name, member_name)):
67
"""Convert a known_hooks key to a object.
69
:param key: A tuple (module_name, member_name) as found in the keys of
70
the known_hooks registry.
71
:return: The object this specifies.
73
member_list = member_name.rsplit('.', 1)
74
if len(member_list) == 2:
75
parent_name, attribute = member_list
78
attribute = member_name
79
parent = known_hooks_key_to_object((module_name, parent_name))
80
return parent, attribute
84
"""A dictionary mapping hook name to a list of callables.
86
e.g. ['FOO'] Is the list of items to be called when the
87
FOO hook is triggered.
92
self._callable_names = {}
94
def create_hook(self, hook):
95
"""Create a hook which can have callbacks registered for it.
97
:param hook: The hook to create. An object meeting the protocol of
98
bzrlib.hooks.HookPoint. It's name is used as the key for future
101
if hook.name in self:
102
raise errors.DuplicateKey(hook.name)
103
self[hook.name] = hook
106
"""Generate the documentation for this Hooks instance.
108
This introspects all the individual hooks and returns their docs as well.
110
hook_names = sorted(self.keys())
112
name = self.__class__.__name__
113
hook_docs.append(name)
114
hook_docs.append("-"*len(name))
116
for hook_name in hook_names:
117
hook = self[hook_name]
119
hook_docs.append(hook.docs())
120
except AttributeError:
123
strings.append(hook_name)
124
strings.append("~" * len(hook_name))
126
strings.append("An old-style hook. For documentation see the __init__ "
127
"method of '%s'\n" % (name,))
128
hook_docs.extend(strings)
129
return "\n".join(hook_docs)
131
def get_hook_name(self, a_callable):
132
"""Get the name for a_callable for UI display.
134
If no name has been registered, the string 'No hook name' is returned.
135
We use a fixed string rather than repr or the callables module because
136
the code names are rarely meaningful for end users and this is not
137
intended for debugging.
139
return self._callable_names.get(a_callable, "No hook name")
141
def install_named_hook(self, hook_name, a_callable, name):
142
"""Install a_callable in to the hook hook_name, and label it name.
144
:param hook_name: A hook name. See the __init__ method of BranchHooks
145
for the complete list of hooks.
146
:param a_callable: The callable to be invoked when the hook triggers.
147
The exact signature will depend on the hook - see the __init__
148
method of BranchHooks for details on each hook.
149
:param name: A name to associate a_callable with, to show users what is
153
hook = self[hook_name]
155
raise errors.UnknownHook(self.__class__.__name__, hook_name)
157
# list hooks, old-style, not yet deprecated but less useful.
158
hook.append(a_callable)
159
except AttributeError:
160
hook.hook(a_callable, name)
162
self.name_hook(a_callable, name)
164
def name_hook(self, a_callable, name):
165
"""Associate name with a_callable to show users what is running."""
166
self._callable_names[a_callable] = name
169
class HookPoint(object):
170
"""A single hook that clients can register to be called back when it fires.
172
:ivar name: The name of the hook.
173
:ivar introduced: A version tuple specifying what version the hook was
174
introduced in. None indicates an unknown version.
175
:ivar deprecated: A version tuple specifying what version the hook was
176
deprecated or superceded in. None indicates that the hook is not
177
superceded or deprecated. If the hook is superceded then the doc
178
should describe the recommended replacement hook to register for.
179
:ivar doc: The docs for using the hook.
182
def __init__(self, name, doc, introduced, deprecated):
183
"""Create a HookPoint.
185
:param name: The name of the hook, for clients to use when registering.
186
:param doc: The docs for the hook.
187
:param introduced: When the hook was introduced (e.g. (0, 15)).
188
:param deprecated: When the hook was deprecated, None for
193
self.introduced = introduced
194
self.deprecated = deprecated
196
self._callback_names = {}
199
"""Generate the documentation for this HookPoint.
201
:return: A string terminated in \n.
204
strings.append(self.name)
205
strings.append('~'*len(self.name))
208
introduced_string = _format_version_tuple(self.introduced)
210
introduced_string = 'unknown'
211
strings.append('Introduced in: %s' % introduced_string)
213
deprecated_string = _format_version_tuple(self.deprecated)
215
deprecated_string = 'Not deprecated'
216
strings.append('Deprecated in: %s' % deprecated_string)
218
strings.extend(textwrap.wrap(self.__doc__))
220
return '\n'.join(strings)
222
def __eq__(self, other):
223
return (type(other) == type(self) and
224
other.__dict__ == self.__dict__)
226
def hook(self, callback, callback_label):
227
"""Register a callback to be called when this HookPoint fires.
229
:param callback: The callable to use when this HookPoint fires.
230
:param callback_label: A label to show in the UI while this callback is
233
self._callbacks.append(callback)
234
if callback_label is not None:
235
self._callback_names[callback] = callback_label
238
return iter(self._callbacks)
241
return len(self._callbacks)
245
strings.append("<%s(" % type(self).__name__)
246
strings.append(self.name)
247
strings.append("), callbacks=[")
248
for callback in self._callbacks:
249
strings.append(repr(callback))
251
strings.append(self._callback_names[callback])
253
if len(self._callbacks) == 1:
256
return ''.join(strings)
267
A hook of type *xxx* of class *yyy* needs to be registered using::
269
yyy.hooks.install_named_hook("xxx", ...)
271
See `Using hooks`_ in the User Guide for examples.
273
.. _Using hooks: ../user-guide/index.html#using-hooks
275
The class that contains each hook is given before the hooks it supplies. For
276
instance, BranchHooks as the class is the hooks class for
277
`bzrlib.branch.Branch.hooks`.
279
Each description also indicates whether the hook runs on the client (the
280
machine where bzr was invoked) or the server (the machine addressed by
281
the branch URL). These may be, but are not necessarily, the same machine.
283
Plugins (including hooks) are run on the server if all of these is true:
285
* The connection is via a smart server (accessed with a URL starting with
286
"bzr://", "bzr+ssh://" or "bzr+http://", or accessed via a "http://"
287
URL when a smart server is available via HTTP).
289
* The hook is either server specific or part of general infrastructure rather
290
than client specific code (such as commit).
294
def hooks_help_text(topic):
295
segments = [_help_prefix]
296
for hook_key in sorted(known_hooks.keys()):
297
hooks = known_hooks_key_to_object(hook_key)
298
segments.append(hooks.docs())
299
return '\n'.join(segments)
added
removed
bzrlib/hooks.py
