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  • Committer: Andrew Bennetts
  • Date: 2010-10-08 08:15:14 UTC
  • mto: This revision was merged to the branch mainline in revision 5498.
  • Revision ID: andrew.bennetts@canonical.com-20101008081514-dviqzrdfwyzsqbz2
Split NEWS into per-release doc/en/release-notes/bzr-*.txt

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# Copyright (C) 2007-2011 Canonical Ltd
 
1
# Copyright (C) 2007-2010 Canonical Ltd
2
2
#
3
3
# This program is free software; you can redistribute it and/or modify
4
4
# it under the terms of the GNU General Public License as published by
14
14
# along with this program; if not, write to the Free Software
15
15
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16
16
 
 
17
 
17
18
"""Support for plugin hooking logic."""
18
 
 
19
 
from __future__ import absolute_import
20
 
 
21
 
from bzrlib import (
22
 
    registry,
23
 
    symbol_versioning,
24
 
    )
 
19
from bzrlib import registry
25
20
from bzrlib.lazy_import import lazy_import
26
21
lazy_import(globals(), """
27
22
import textwrap
28
23
 
29
24
from bzrlib import (
30
 
    _format_version_tuple,
31
 
    errors,
32
 
    pyutils,
33
 
    )
34
 
from bzrlib.i18n import gettext
 
25
        _format_version_tuple,
 
26
        errors,
 
27
        )
 
28
from bzrlib.help_topics import help_as_plain_text
35
29
""")
36
30
 
37
31
 
38
 
class KnownHooksRegistry(registry.Registry):
39
 
    # known_hooks registry contains
40
 
    # tuple of (module, member name) which is the hook point
41
 
    # module where the specific hooks are defined
42
 
    # callable to get the empty specific Hooks for that attribute
43
 
 
44
 
    def register_lazy_hook(self, hook_module_name, hook_member_name,
45
 
            hook_factory_member_name):
46
 
        self.register_lazy((hook_module_name, hook_member_name),
47
 
            hook_module_name, hook_factory_member_name)
48
 
 
49
 
    def iter_parent_objects(self):
50
 
        """Yield (hook_key, (parent_object, attr)) tuples for every registered
51
 
        hook, where 'parent_object' is the object that holds the hook
52
 
        instance.
53
 
 
54
 
        This is useful for resetting/restoring all the hooks to a known state,
55
 
        as is done in bzrlib.tests.TestCase._clear_hooks.
56
 
        """
57
 
        for key in self.keys():
58
 
            yield key, self.key_to_parent_and_attribute(key)
59
 
 
60
 
    def key_to_parent_and_attribute(self, (module_name, member_name)):
61
 
        """Convert a known_hooks key to a (parent_obj, attr) pair.
62
 
 
63
 
        :param key: A tuple (module_name, member_name) as found in the keys of
64
 
            the known_hooks registry.
65
 
        :return: The parent_object of the hook and the name of the attribute on
66
 
            that parent object where the hook is kept.
67
 
        """
68
 
        parent_mod, parent_member, attr = pyutils.calc_parent_name(module_name,
69
 
            member_name)
70
 
        return pyutils.get_named_object(parent_mod, parent_member), attr
71
 
 
72
 
 
73
 
_builtin_known_hooks = (
74
 
    ('bzrlib.branch', 'Branch.hooks', 'BranchHooks'),
75
 
    ('bzrlib.controldir', 'ControlDir.hooks', 'ControlDirHooks'),
76
 
    ('bzrlib.commands', 'Command.hooks', 'CommandHooks'),
77
 
    ('bzrlib.config', 'ConfigHooks', '_ConfigHooks'),
78
 
    ('bzrlib.info', 'hooks', 'InfoHooks'),
79
 
    ('bzrlib.lock', 'Lock.hooks', 'LockHooks'),
80
 
    ('bzrlib.merge', 'Merger.hooks', 'MergeHooks'),
81
 
    ('bzrlib.msgeditor', 'hooks', 'MessageEditorHooks'),
82
 
    ('bzrlib.mutabletree', 'MutableTree.hooks', 'MutableTreeHooks'),
83
 
    ('bzrlib.smart.client', '_SmartClient.hooks', 'SmartClientHooks'),
84
 
    ('bzrlib.smart.server', 'SmartTCPServer.hooks', 'SmartServerHooks'),
85
 
    ('bzrlib.status', 'hooks', 'StatusHooks'),
86
 
    ('bzrlib.transport', 'Transport.hooks', 'TransportHooks'),
87
 
    ('bzrlib.version_info_formats.format_rio', 'RioVersionInfoBuilder.hooks',
88
 
        'RioVersionInfoBuilderHooks'),
89
 
    ('bzrlib.merge_directive', 'BaseMergeDirective.hooks',
90
 
        'MergeDirectiveHooks'),
91
 
    )
92
 
 
93
 
known_hooks = KnownHooksRegistry()
94
 
for (_hook_module, _hook_attribute, _hook_class) in _builtin_known_hooks:
95
 
    known_hooks.register_lazy_hook(_hook_module, _hook_attribute, _hook_class)
96
 
del _builtin_known_hooks, _hook_module, _hook_attribute, _hook_class
 
32
known_hooks = registry.Registry()
 
33
# known_hooks registry contains
 
34
# tuple of (module, member name) which is the hook point
 
35
# module where the specific hooks are defined
 
36
# callable to get the empty specific Hooks for that attribute
 
37
known_hooks.register_lazy(('bzrlib.branch', 'Branch.hooks'), 'bzrlib.branch',
 
38
    'BranchHooks')
 
39
known_hooks.register_lazy(('bzrlib.bzrdir', 'BzrDir.hooks'), 'bzrlib.bzrdir',
 
40
    'BzrDirHooks')
 
41
known_hooks.register_lazy(('bzrlib.commands', 'Command.hooks'),
 
42
    'bzrlib.commands', 'CommandHooks')
 
43
known_hooks.register_lazy(('bzrlib.info', 'hooks'),
 
44
    'bzrlib.info', 'InfoHooks')
 
45
known_hooks.register_lazy(('bzrlib.lock', 'Lock.hooks'), 'bzrlib.lock',
 
46
    'LockHooks')
 
47
known_hooks.register_lazy(('bzrlib.merge', 'Merger.hooks'), 'bzrlib.merge',
 
48
    'MergeHooks')
 
49
known_hooks.register_lazy(('bzrlib.msgeditor', 'hooks'), 'bzrlib.msgeditor',
 
50
    'MessageEditorHooks')
 
51
known_hooks.register_lazy(('bzrlib.mutabletree', 'MutableTree.hooks'),
 
52
    'bzrlib.mutabletree', 'MutableTreeHooks')
 
53
known_hooks.register_lazy(('bzrlib.smart.client', '_SmartClient.hooks'),
 
54
    'bzrlib.smart.client', 'SmartClientHooks')
 
55
known_hooks.register_lazy(('bzrlib.smart.server', 'SmartTCPServer.hooks'),
 
56
    'bzrlib.smart.server', 'SmartServerHooks')
 
57
known_hooks.register_lazy(('bzrlib.status', 'hooks'),
 
58
    'bzrlib.status', 'StatusHooks')
 
59
known_hooks.register_lazy(
 
60
    ('bzrlib.version_info_formats.format_rio', 'RioVersionInfoBuilder.hooks'),
 
61
    'bzrlib.version_info_formats.format_rio', 'RioVersionInfoBuilderHooks')
 
62
known_hooks.register_lazy(
 
63
    ('bzrlib.merge_directive', 'BaseMergeDirective.hooks'),
 
64
    'bzrlib.merge_directive', 'MergeDirectiveHooks')
97
65
 
98
66
 
99
67
def known_hooks_key_to_object((module_name, member_name)):
103
71
        the known_hooks registry.
104
72
    :return: The object this specifies.
105
73
    """
106
 
    return pyutils.get_named_object(module_name, member_name)
 
74
    return registry._LazyObjectGetter(module_name, member_name).get_obj()
 
75
 
 
76
 
 
77
def known_hooks_key_to_parent_and_attribute((module_name, member_name)):
 
78
    """Convert a known_hooks key to a object.
 
79
 
 
80
    :param key: A tuple (module_name, member_name) as found in the keys of
 
81
        the known_hooks registry.
 
82
    :return: The object this specifies.
 
83
    """
 
84
    member_list = member_name.rsplit('.', 1)
 
85
    if len(member_list) == 2:
 
86
        parent_name, attribute = member_list
 
87
    else:
 
88
        parent_name = None
 
89
        attribute = member_name
 
90
    parent = known_hooks_key_to_object((module_name, parent_name))
 
91
    return parent, attribute
107
92
 
108
93
 
109
94
class Hooks(dict):
113
98
    FOO hook is triggered.
114
99
    """
115
100
 
116
 
    def __init__(self, module=None, member_name=None):
117
 
        """Create a new hooks dictionary.
118
 
 
119
 
        :param module: The module from which this hooks dictionary should be loaded
120
 
            (used for lazy hooks)
121
 
        :param member_name: Name under which this hooks dictionary should be loaded.
122
 
            (used for lazy hooks)
123
 
        """
 
101
    def __init__(self):
124
102
        dict.__init__(self)
125
103
        self._callable_names = {}
126
 
        self._lazy_callable_names = {}
127
 
        self._module = module
128
 
        self._member_name = member_name
129
 
 
130
 
    def add_hook(self, name, doc, introduced, deprecated=None):
131
 
        """Add a hook point to this dictionary.
132
 
 
133
 
        :param name: The name of the hook, for clients to use when registering.
134
 
        :param doc: The docs for the hook.
135
 
        :param introduced: When the hook was introduced (e.g. (0, 15)).
136
 
        :param deprecated: When the hook was deprecated, None for
137
 
            not-deprecated.
 
104
 
 
105
    def create_hook(self, hook):
 
106
        """Create a hook which can have callbacks registered for it.
 
107
 
 
108
        :param hook: The hook to create. An object meeting the protocol of
 
109
            bzrlib.hooks.HookPoint. It's name is used as the key for future
 
110
            lookups.
138
111
        """
139
 
        if name in self:
140
 
            raise errors.DuplicateKey(name)
141
 
        if self._module:
142
 
            callbacks = _lazy_hooks.setdefault(
143
 
                (self._module, self._member_name, name), [])
144
 
        else:
145
 
            callbacks = None
146
 
        hookpoint = HookPoint(name=name, doc=doc, introduced=introduced,
147
 
                              deprecated=deprecated, callbacks=callbacks)
148
 
        self[name] = hookpoint
 
112
        if hook.name in self:
 
113
            raise errors.DuplicateKey(hook.name)
 
114
        self[hook.name] = hook
149
115
 
150
116
    def docs(self):
151
117
        """Generate the documentation for this Hooks instance.
181
147
        the code names are rarely meaningful for end users and this is not
182
148
        intended for debugging.
183
149
        """
184
 
        name = self._callable_names.get(a_callable, None)
185
 
        if name is None and a_callable is not None:
186
 
            name = self._lazy_callable_names.get((a_callable.__module__,
187
 
                                                  a_callable.__name__),
188
 
                                                 None)
189
 
        if name is None:
190
 
            return 'No hook name'
191
 
        return name
192
 
 
193
 
 
194
 
    def install_named_hook_lazy(self, hook_name, callable_module,
195
 
        callable_member, name):
196
 
        """Install a_callable in to the hook hook_name lazily, and label it.
197
 
 
198
 
        :param hook_name: A hook name. See the __init__ method for the complete
199
 
            list of hooks.
200
 
        :param callable_module: Name of the module in which the callable is
201
 
            present.
202
 
        :param callable_member: Member name of the callable.
203
 
        :param name: A name to associate the callable with, to show users what
204
 
            is running.
205
 
        """
206
 
        try:
207
 
            hook = self[hook_name]
208
 
        except KeyError:
209
 
            raise errors.UnknownHook(self.__class__.__name__, hook_name)
210
 
        try:
211
 
            hook_lazy = getattr(hook, "hook_lazy")
212
 
        except AttributeError:
213
 
            raise errors.UnsupportedOperation(self.install_named_hook_lazy,
214
 
                self)
215
 
        else:
216
 
            hook_lazy(callable_module, callable_member, name)
217
 
        if name is not None:
218
 
            self.name_hook_lazy(callable_module, callable_member, name)
 
150
        return self._callable_names.get(a_callable, "No hook name")
219
151
 
220
152
    def install_named_hook(self, hook_name, a_callable, name):
221
153
        """Install a_callable in to the hook hook_name, and label it name.
222
154
 
223
 
        :param hook_name: A hook name. See the __init__ method for the complete
224
 
            list of hooks.
 
155
        :param hook_name: A hook name. See the __init__ method of BranchHooks
 
156
            for the complete list of hooks.
225
157
        :param a_callable: The callable to be invoked when the hook triggers.
226
158
            The exact signature will depend on the hook - see the __init__
227
 
            method for details on each hook.
 
159
            method of BranchHooks for details on each hook.
228
160
        :param name: A name to associate a_callable with, to show users what is
229
161
            running.
230
162
        """
240
172
        if name is not None:
241
173
            self.name_hook(a_callable, name)
242
174
 
243
 
    def uninstall_named_hook(self, hook_name, label):
244
 
        """Uninstall named hooks.
245
 
 
246
 
        :param hook_name: Hook point name
247
 
        :param label: Label of the callable to uninstall
248
 
        """
249
 
        try:
250
 
            hook = self[hook_name]
251
 
        except KeyError:
252
 
            raise errors.UnknownHook(self.__class__.__name__, hook_name)
253
 
        try:
254
 
            uninstall = getattr(hook, "uninstall")
255
 
        except AttributeError:
256
 
            raise errors.UnsupportedOperation(self.uninstall_named_hook, self)
257
 
        else:
258
 
            uninstall(label)
259
 
 
260
175
    def name_hook(self, a_callable, name):
261
176
        """Associate name with a_callable to show users what is running."""
262
177
        self._callable_names[a_callable] = name
263
178
 
264
 
    def name_hook_lazy(self, callable_module, callable_member, callable_name):
265
 
        self._lazy_callable_names[(callable_module, callable_member)]= \
266
 
            callable_name
267
 
 
268
179
 
269
180
class HookPoint(object):
270
181
    """A single hook that clients can register to be called back when it fires.
279
190
        should describe the recommended replacement hook to register for.
280
191
    """
281
192
 
282
 
    def __init__(self, name, doc, introduced, deprecated=None, callbacks=None):
 
193
    def __init__(self, name, doc, introduced, deprecated):
283
194
        """Create a HookPoint.
284
195
 
285
196
        :param name: The name of the hook, for clients to use when registering.
292
203
        self.__doc__ = doc
293
204
        self.introduced = introduced
294
205
        self.deprecated = deprecated
295
 
        if callbacks is None:
296
 
            self._callbacks = []
297
 
        else:
298
 
            self._callbacks = callbacks
 
206
        self._callbacks = []
 
207
        self._callback_names = {}
299
208
 
300
209
    def docs(self):
301
210
        """Generate the documentation for this HookPoint.
310
219
            introduced_string = _format_version_tuple(self.introduced)
311
220
        else:
312
221
            introduced_string = 'unknown'
313
 
        strings.append(gettext('Introduced in: %s') % introduced_string)
 
222
        strings.append('Introduced in: %s' % introduced_string)
314
223
        if self.deprecated:
315
224
            deprecated_string = _format_version_tuple(self.deprecated)
316
 
            strings.append(gettext('Deprecated in: %s') % deprecated_string)
 
225
            strings.append('Deprecated in: %s' % deprecated_string)
317
226
        strings.append('')
318
227
        strings.extend(textwrap.wrap(self.__doc__,
319
228
            break_long_words=False))
321
230
        return '\n'.join(strings)
322
231
 
323
232
    def __eq__(self, other):
324
 
        return (type(other) == type(self) and other.__dict__ == self.__dict__)
325
 
 
326
 
    def hook_lazy(self, callback_module, callback_member, callback_label):
327
 
        """Lazily register a callback to be called when this HookPoint fires.
328
 
 
329
 
        :param callback_module: Module of the callable to use when this
330
 
            HookPoint fires.
331
 
        :param callback_member: Member name of the callback.
332
 
        :param callback_label: A label to show in the UI while this callback is
333
 
            processing.
334
 
        """
335
 
        obj_getter = registry._LazyObjectGetter(callback_module,
336
 
            callback_member)
337
 
        self._callbacks.append((obj_getter, callback_label))
 
233
        return (type(other) == type(self) and 
 
234
            other.__dict__ == self.__dict__)
338
235
 
339
236
    def hook(self, callback, callback_label):
340
237
        """Register a callback to be called when this HookPoint fires.
343
240
        :param callback_label: A label to show in the UI while this callback is
344
241
            processing.
345
242
        """
346
 
        obj_getter = registry._ObjectGetter(callback)
347
 
        self._callbacks.append((obj_getter, callback_label))
348
 
 
349
 
    def uninstall(self, label):
350
 
        """Uninstall the callback with the specified label.
351
 
 
352
 
        :param label: Label of the entry to uninstall
353
 
        """
354
 
        entries_to_remove = []
355
 
        for entry in self._callbacks:
356
 
            (entry_callback, entry_label) = entry
357
 
            if entry_label == label:
358
 
                entries_to_remove.append(entry)
359
 
        if entries_to_remove == []:
360
 
            raise KeyError("No entry with label %r" % label)
361
 
        for entry in entries_to_remove:
362
 
            self._callbacks.remove(entry)
 
243
        self._callbacks.append(callback)
 
244
        if callback_label is not None:
 
245
            self._callback_names[callback] = callback_label
363
246
 
364
247
    def __iter__(self):
365
 
        return (callback.get_obj() for callback, name in self._callbacks)
 
248
        return iter(self._callbacks)
366
249
 
367
250
    def __len__(self):
368
251
        return len(self._callbacks)
372
255
        strings.append("<%s(" % type(self).__name__)
373
256
        strings.append(self.name)
374
257
        strings.append("), callbacks=[")
375
 
        callbacks = self._callbacks
376
 
        for (callback, callback_name) in callbacks:
377
 
            strings.append(repr(callback.get_obj()))
 
258
        for callback in self._callbacks:
 
259
            strings.append(repr(callback))
378
260
            strings.append("(")
379
 
            strings.append(callback_name)
 
261
            strings.append(self._callback_names[callback])
380
262
            strings.append("),")
381
 
        if len(callbacks) == 1:
 
263
        if len(self._callbacks) == 1:
382
264
            strings[-1] = ")"
383
265
        strings.append("]>")
384
266
        return ''.join(strings)
423
305
        hooks = known_hooks_key_to_object(hook_key)
424
306
        segments.append(hooks.docs())
425
307
    return '\n'.join(segments)
426
 
 
427
 
 
428
 
# Lazily registered hooks. Maps (module, name, hook_name) tuples
429
 
# to lists of tuples with objectgetters and names
430
 
_lazy_hooks = {}
431
 
 
432
 
 
433
 
def install_lazy_named_hook(hookpoints_module, hookpoints_name, hook_name,
434
 
    a_callable, name):
435
 
    """Install a callable in to a hook lazily, and label it name.
436
 
 
437
 
    :param hookpoints_module: Module name of the hook points.
438
 
    :param hookpoints_name: Name of the hook points.
439
 
    :param hook_name: A hook name.
440
 
    :param callable: a callable to call for the hook.
441
 
    :param name: A name to associate a_callable with, to show users what is
442
 
        running.
443
 
    """
444
 
    key = (hookpoints_module, hookpoints_name, hook_name)
445
 
    obj_getter = registry._ObjectGetter(a_callable)
446
 
    _lazy_hooks.setdefault(key, []).append((obj_getter, name))