Source Code for Module flumotion.common.messages

  1  # -*- Mode: Python; test-case-name: flumotion.test.test_common_messages -*- 
  2  # vi:si:et:sw=4:sts=4:ts=4 
  3  # 
  4  # Flumotion - a streaming media server 
  5  # Copyright (C) 2004,2005,2006,2007 Fluendo, S.L. (www.fluendo.com). 
  6  # All rights reserved. 
  7   
  8  # This file may be distributed and/or modified under the terms of 
  9  # the GNU General Public License version 2 as published by 
 10  # the Free Software Foundation. 
 11  # This file is distributed without any warranty; without even the implied 
 12  # warranty of merchantability or fitness for a particular purpose. 
 13  # See "LICENSE.GPL" in the source distribution for more information. 
 14   
 15  # Licensees having purchased or holding a valid Flumotion Advanced 
 16  # Streaming Server license may use this file in accordance with the 
 17  # Flumotion Advanced Streaming Server Commercial License Agreement. 
 18  # See "LICENSE.Flumotion" in the source distribution for more information. 
 19   
 20  # Headers in this file shall remain intact. 
 21   
 22  """serializable translatable messages. 
 23  support for serializable translatable messages from component/manager to admin 
 24  """ 
 25   
 26  import time 
 27   
 28  from twisted.spread import pb 
 29   
 30  from flumotion.common import log 
 31  from flumotion.configure import configure 
 32  from flumotion.common.i18n import FancyEqMixin, Translatable 
 33   
 34  __version__ = "$Rev: 6993 $" 
 35   
 36  (ERROR, 
 37   WARNING, 
 38   INFO) = range(1, 4) 
 39   
 40   
 41  # NOTE: same caveats apply for FancyEqMixin as above 
 42  # this might be a little heavy; we could consider only comparing 
 43  # on id, once we verify that all id's are unique 
 44   
 45 -class Message(pb.Copyable, pb.RemoteCopy, FancyEqMixin): 
 46      """ 
 47      I am a message to be shown in a UI. 
 48   
 49      Projects should subclass this base class to provide default project 
 50      and version class attributes. 
 51   
 52      @ivar  section: name of the section in which the message is described. 
 53      @type  section: str 
 54      @ivar  anchor:  name of the anchor in which the message is described. 
 55      @type  anchor:  str 
 56      @ivar  description: the link text to show 
 57      @type  description: L{flumotion.common.messages.Translatable} 
 58      """ 
 59      project = configure.PACKAGE 
 60      version = configure.version 
 61   
 62      # these properties allow linking to the documentation 
 63      section = None 
 64      anchor = None 
 65      description = None 
 66   
 67      compareAttributes = ["level", "translatables", "debug", "mid", "priority", 
 68          "timestamp"] 
 69   
 70      # F0.8: remove id= in favor of mid= 
 71 -    def __init__(self, level, translatable, debug=None, id=None, priority=50, 
 72          timestamp=None, mid=None): 
 73          """ 
 74          Create a new message. 
 75   
 76          The id identifies this kind of message, and serves two purposes. 
 77   
 78          The first purpose is to serve as a key by which a kind of 
 79          message might be removed from a set of messages. For example, a 
 80          firewire component detecting that a cable has been plugged in 
 81          will remove any message that the cable is unplugged. 
 82   
 83          Secondly it serves so that the message viewers that watch the 
 84          'current state' of some object only see the latest message of a 
 85          given type. For example when messages are stored in persistent 
 86          state objects that can be transferred over the network, it 
 87          becomes inefficient to store the whole history of status 
 88          messages. Message stores can keep only the latest message of a 
 89          given ID. 
 90   
 91          @param level:        ERROR, WARNING or INFO 
 92          @param translatable: a translatable possibly with markup for 
 93                               linking to documentation or running commands. 
 94          @param debug:        further, untranslated, debug information, not 
 95                               always shown 
 96          @param priority:     priority compared to other messages of the same 
 97                               level 
 98          @param timestamp:    time since epoch at which the message was 
 99                               generated, in seconds. 
100          @param mid:          A unique id for this kind of message, as 
101                               discussed above. If not given, will be 
102                               generated from the contents of the 
103                               translatable. 
104          """ 
105          self.level = level 
106          self.translatables = [] 
107          self.debug = debug 
108          if id: 
109              import warnings 
110              warnings.warn('Please use the mid kwarg instead', 
111                  DeprecationWarning, stacklevel=3) 
112              mid = id 
113               
114          # FIXME: untranslated is a really poor choice of id 
115          self.id = mid or translatable.untranslated() 
116          self.priority = priority 
117          self.timestamp = timestamp or time.time() 
118          # -1 is in __init__, -2 is in the subclass __init__, -3 is in the caller 
119          log.doLog(log.DEBUG, None, 'messages', 
120              'creating message %r', self, where=-3) 
121          self.add(translatable) 
122   
123 -    def __repr__(self): 
124          return '<Message %r at %r>' % (self.id, id(self)) 
125   
126 -    def add(self, translatable): 
127          if not isinstance(translatable, Translatable): 
128              raise ValueError('%r is not Translatable' % translatable) 
129          self.translatables.append(translatable) 
130          log.doLog(log.DEBUG, None, 'messages', 
131              'message %r: adding %r', (id(self), translatable.untranslated()), 
132               where=-2) 
133   
134  pb.setUnjellyableForClass(Message, Message) 
135   
136  # these are implemented as factory functions instead of classes because 
137  # properly proxying to the correct subclass is hard with Copyable/RemoteCopy 
138 -def Error(*args, **kwargs): 
139      """ 
140      Create a L{Message} at ERROR level, indicating a failure that needs 
141      intervention to be resolved. 
142      """ 
143      return Message(ERROR, *args, **kwargs) 
144   
145  # FIXME: figure out a way to not be shadowing the Warning builtin without 
146  # breaking all other code 
147  __pychecker__ = 'no-shadowbuiltin' 
148 -def Warning(*args, **kwargs): 
149      """ 
150      Create a L{Message} at WARNING level, indicating a potential problem. 
151      """ 
152      return Message(WARNING, *args, **kwargs) 
153  __pychecker__ = '' 
154   
155 -def Info(*args, **kwargs): 
156      """ 
157      Create a L{Message} at INFO level. 
158      """ 
159      return Message(INFO, *args, **kwargs) 
160   
161 -class Result(pb.Copyable, pb.RemoteCopy): 
162      """ 
163      I am used in worker checks to return a result. 
164   
165      @ivar value:    the result value of the check 
166      @ivar failed:   whether or not the check failed.  Typically triggered 
167                      by adding an ERROR message to the result. 
168      @ivar messages: list of messages 
169      @type messages: list of L{Message} 
170      """ 
171 -    def __init__(self): 
172          self.messages = [] 
173          self.value = None 
174          self.failed = False 
175   
176 -    def succeed(self, value): 
177          """ 
178          Make the result be successful, setting the given result value. 
179          """ 
180          self.value = value 
181   
182 -    def add(self, message): 
183          """ 
184          Add a message to the result. 
185   
186          @type message: L{Message} 
187          """ 
188          self.messages.append(message) 
189          if message.level == ERROR: 
190              self.failed = True 
191              self.value = None 
192  pb.setUnjellyableForClass(Result, Result) 
193