Mercurial > libervia-backend
comparison src/bridge/bridge_constructor/constructors/dbus/dbus_frontend_template.py @ 2085:da4097de5a95
bridge (constructor): refactoring:
- constructors are now in separate modules
- constructors are discovered dynamically
- factorised generation code from D-Bus in base Constructor.
- A generic generation method is now available in base Constructor, using python formatting.
- removed bridge/bridge.py in core as it was useless, may come back in the future if needed
author | Goffi <goffi@goffi.org> |
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date | Sun, 02 Oct 2016 22:44:33 +0200 |
parents | src/bridge/bridge_constructor/dbus_frontend_template.py@2daf7b4c6756 |
children | 4633cfcbcccb |
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2084:e1015a5df6f5 | 2085:da4097de5a95 |
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1 #!/usr/bin/env python2 | |
2 #-*- coding: utf-8 -*- | |
3 | |
4 # SAT communication bridge | |
5 # Copyright (C) 2009-2016 Jérôme Poisson (goffi@goffi.org) | |
6 | |
7 # This program is free software: you can redistribute it and/or modify | |
8 # it under the terms of the GNU Affero General Public License as published by | |
9 # the Free Software Foundation, either version 3 of the License, or | |
10 # (at your option) any later version. | |
11 | |
12 # This program is distributed in the hope that it will be useful, | |
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 # GNU Affero General Public License for more details. | |
16 | |
17 # You should have received a copy of the GNU Affero General Public License | |
18 # along with this program. If not, see <http://www.gnu.org/licenses/>. | |
19 | |
20 from sat.core.i18n import _ | |
21 from bridge_frontend import BridgeFrontend, BridgeException | |
22 import dbus | |
23 from sat.core.log import getLogger | |
24 log = getLogger(__name__) | |
25 from sat.core.exceptions import BridgeExceptionNoService, BridgeInitError | |
26 | |
27 from dbus.mainloop.glib import DBusGMainLoop | |
28 DBusGMainLoop(set_as_default=True) | |
29 | |
30 import ast | |
31 | |
32 const_INT_PREFIX = "org.goffi.SAT" # Interface prefix | |
33 const_ERROR_PREFIX = const_INT_PREFIX + ".error" | |
34 const_OBJ_PATH = '/org/goffi/SAT/bridge' | |
35 const_CORE_SUFFIX = ".core" | |
36 const_PLUGIN_SUFFIX = ".plugin" | |
37 const_TIMEOUT = 120 | |
38 | |
39 | |
40 def dbus_to_bridge_exception(dbus_e): | |
41 """Convert a DBusException to a BridgeException. | |
42 | |
43 @param dbus_e (DBusException) | |
44 @return: BridgeException | |
45 """ | |
46 full_name = dbus_e.get_dbus_name() | |
47 if full_name.startswith(const_ERROR_PREFIX): | |
48 name = dbus_e.get_dbus_name()[len(const_ERROR_PREFIX) + 1:] | |
49 else: | |
50 name = full_name | |
51 # XXX: dbus_e.args doesn't contain the original DBusException args, but we | |
52 # receive its serialized form in dbus_e.args[0]. From that we can rebuild | |
53 # the original arguments list thanks to ast.literal_eval (secure eval). | |
54 message = dbus_e.get_dbus_message() # similar to dbus_e.args[0] | |
55 try: | |
56 message, condition = ast.literal_eval(message) | |
57 except (SyntaxError, ValueError, TypeError): | |
58 condition = '' | |
59 return BridgeException(name, message, condition) | |
60 | |
61 | |
62 class DBusBridgeFrontend(BridgeFrontend): | |
63 def __init__(self): | |
64 try: | |
65 self.sessions_bus = dbus.SessionBus() | |
66 self.db_object = self.sessions_bus.get_object(const_INT_PREFIX, | |
67 const_OBJ_PATH) | |
68 self.db_core_iface = dbus.Interface(self.db_object, | |
69 dbus_interface=const_INT_PREFIX + const_CORE_SUFFIX) | |
70 self.db_plugin_iface = dbus.Interface(self.db_object, | |
71 dbus_interface=const_INT_PREFIX + const_PLUGIN_SUFFIX) | |
72 except dbus.exceptions.DBusException, e: | |
73 if e._dbus_error_name in ('org.freedesktop.DBus.Error.ServiceUnknown', | |
74 'org.freedesktop.DBus.Error.Spawn.ExecFailed'): | |
75 raise BridgeExceptionNoService | |
76 elif e._dbus_error_name == 'org.freedesktop.DBus.Error.NotSupported': | |
77 log.error(_(u"D-Bus is not launched, please see README to see instructions on how to launch it")) | |
78 raise BridgeInitError | |
79 else: | |
80 raise e | |
81 #props = self.db_core_iface.getProperties() | |
82 | |
83 def register(self, functionName, handler, iface="core"): | |
84 if iface == "core": | |
85 self.db_core_iface.connect_to_signal(functionName, handler) | |
86 elif iface == "plugin": | |
87 self.db_plugin_iface.connect_to_signal(functionName, handler) | |
88 else: | |
89 log.error(_('Unknown interface')) | |
90 | |
91 def __getattribute__(self, name): | |
92 """ usual __getattribute__ if the method exists, else try to find a plugin method """ | |
93 try: | |
94 return object.__getattribute__(self, name) | |
95 except AttributeError: | |
96 # The attribute is not found, we try the plugin proxy to find the requested method | |
97 | |
98 def getPluginMethod(*args, **kwargs): | |
99 # We first check if we have an async call. We detect this in two ways: | |
100 # - if we have the 'callback' and 'errback' keyword arguments | |
101 # - or if the last two arguments are callable | |
102 | |
103 async = False | |
104 args = list(args) | |
105 | |
106 if kwargs: | |
107 if 'callback' in kwargs: | |
108 async = True | |
109 _callback = kwargs.pop('callback') | |
110 _errback = kwargs.pop('errback', lambda failure: log.error(unicode(failure))) | |
111 try: | |
112 args.append(kwargs.pop('profile')) | |
113 except KeyError: | |
114 try: | |
115 args.append(kwargs.pop('profile_key')) | |
116 except KeyError: | |
117 pass | |
118 # at this point, kwargs should be empty | |
119 if kwargs: | |
120 log.warnings(u"unexpected keyword arguments, they will be ignored: {}".format(kwargs)) | |
121 elif len(args) >= 2 and callable(args[-1]) and callable(args[-2]): | |
122 async = True | |
123 _errback = args.pop() | |
124 _callback = args.pop() | |
125 | |
126 method = getattr(self.db_plugin_iface, name) | |
127 | |
128 if async: | |
129 kwargs['timeout'] = const_TIMEOUT | |
130 kwargs['reply_handler'] = _callback | |
131 kwargs['error_handler'] = lambda err: _errback(dbus_to_bridge_exception(err)) | |
132 | |
133 return method(*args, **kwargs) | |
134 | |
135 return getPluginMethod | |
136 | |
137 ##METHODS_PART## |