conduit.Conduit

26 """ 27 Model of a Conduit, which is a one-to-many bridge of DataSources to 28 DataSinks. 29 30 @ivar datasource: The DataSource to synchronize from 31 @type datasource: L{conduit.Module.ModuleWrapper} 32 @ivar datasinks: List of DataSinks to synchronize to 33 @type datasinks: L{conduit.Module.ModuleWrapper}[] 34 """ 35 __gsignals__ = { 36 #Fired when a new instantiatable DP becomes available. It is described via 37 #a wrapper because we do not actually instantiate it till later - to save memory 38 "dataprovider-added" : ( 39 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, [ 40 gobject.TYPE_PYOBJECT]), # The DataProvider that was added to this ConduitModel 41 "dataprovider-removed" : ( 42 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, [ 43 gobject.TYPE_PYOBJECT]), # The DataProvider that was removed from this ConduitModel 44 "dataprovider-changed" : ( 45 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, [ 46 gobject.TYPE_PYOBJECT, # The old DP 47 gobject.TYPE_PYOBJECT]), # The new DP 48 "parameters-changed" : ( 49 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, []), 50 "sync-conflict": ( 51 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, [ 52 gobject.TYPE_PYOBJECT]), #Conflict object 53 "sync-completed": ( 54 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, [ 55 gobject.TYPE_BOOLEAN, #True if there was a fatal error 56 gobject.TYPE_BOOLEAN, #True if there was a non fatal error 57 gobject.TYPE_BOOLEAN]), #True if there was a conflict 58 "sync-started": ( 59 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, []), 60 "sync-progress": ( 61 gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, [ 62 gobject.TYPE_FLOAT, #percent complete 63 gobject.TYPE_PYOBJECT]) #list of successfully completed UIDs 64 } 65

66 - def __init__(self, syncManager, uid=""):

67 """ 68 Makes and empty conduit ready to hold one datasource and many 69 datasinks 70 """ 71 gobject.GObject.__init__(self) 72 73 self.syncManager = syncManager 74 75 if uid == "": 76 self.uid = Utils.uuid_string() 77 else: 78 self.uid = uid 79 80 #a conduit can hold one datasource and many datasinks (wrappers) 81 self.datasource = None 82 self.datasinks = [] 83 self.twoWaySyncEnabled = False 84 self.slowSyncEnabled = False 85 self.autoSyncEnabled = False 86 self.conflictPolicy = "" 87 self.deletedPolicy = "" 88 89 #set conduits to have the default conflict/deleted policy 90 for policyName in CONFLICT_POLICY_NAMES: 91 policyValue = conduit.GLOBALS.settings.get("default_policy_%s" % policyName) 92 self.set_policy(policyName,policyValue) 93 94 self._conflicts = {}

95

96 - def _parameters_changed(self):

97 self.emit("parameters-changed")

98

99 - def _change_detected(self, arg):

100 #Dont trigger a sync if we are already synchronising 101 if not self.is_busy() and self.do_auto_sync(): 102 log.debug("Triggering an auto sync...") 103 self.sync()

104

105 - def emit(self, *args):

106 """ 107 Override the gobject signal emission so that all signals are emitted 108 from the main loop on an idle handler 109 """ 110 gobject.idle_add(gobject.GObject.emit,self,*args)

111

112 - def add_dataprovider(self, dataprovider_wrapper, trySourceFirst=True):

113 """ 114 Adds a dataprovider to the conduit. 115 116 @param dataprovider_wrapper: The L{conduit.Module.ModuleWrapper} 117 containing a L{conduit.DataProvider.DataProviderBase} to add 118 @type dataprovider_wrapper: L{conduit.Module.ModuleWrapper} 119 """ 120 if dataprovider_wrapper.module_type == "source": 121 #only one source is allowed 122 if self.datasource == None: 123 self.datasource = dataprovider_wrapper 124 else: 125 log.warn("Only one datasource allowed per conduit") 126 return False 127 128 elif dataprovider_wrapper.module_type == "sink": 129 #only one sink of each kind is allowed 130 if dataprovider_wrapper in self.datasinks: 131 log.warn("This datasink already present in this conduit") 132 return False 133 else: 134 #temp reference for drawing the connector line 135 self.datasinks.append(dataprovider_wrapper) 136 137 elif dataprovider_wrapper.module_type == "twoway": 138 if self.datasource == None: 139 if trySourceFirst: 140 log.debug("Adding twoway dataprovider into source position") 141 self.datasource = dataprovider_wrapper 142 else: 143 log.debug("Adding twoway dataprovider into sink position") 144 self.datasinks.append(dataprovider_wrapper) 145 else: 146 log.debug("Adding twoway dataprovider into sink position") 147 self.datasinks.append(dataprovider_wrapper) 148 #Datasinks go on the right 149 else: 150 log.warn("Only sinks, sources or twoway dataproviders may be added") 151 return False 152 153 if dataprovider_wrapper.module != None: 154 dataprovider_wrapper.module.connect("change-detected", self._change_detected) 155 156 self.emit("dataprovider-added", dataprovider_wrapper) 157 return True

158

159 - def get_dataprovider_position(self, dataproviderWrapper):

160 """ 161 Returns the dp position, 162 Source = 0,0 163 Sink = 1, index 164 """ 165 if dataproviderWrapper == self.datasource: 166 return 0, 0 167 elif dataproviderWrapper in self.datasinks: 168 return 1, self.datasinks.index(dataproviderWrapper) 169 else: 170 return -1, -1

171

172 - def is_busy(self):

173 """ 174 Returns True if the conduit is currenlty performing a synchronisation 175 operaton on one or more of its contained DataProviders 176 """ 177 return self.syncManager.sync_in_progress(self)

178

179 - def can_sync(self):

180 """ 181 Returns True if this conduit can be synchronized. It must have a 182 source and a sync, that are not pending 183 """ 184 return self.datasource != None \ 185 and len(self.datasinks) > 0 \ 186 and not self.datasource.is_pending() \ 187 and not self.datasinks[0].is_pending()

188

189 - def get_dataproviders_by_key(self, key):

190 """ 191 Use list comprehension to return all dp's with a given key 192 193 @returns: A list of dataproviders with a given key 194 """ 195 return [dp for dp in [self.datasource] + self.datasinks if dp != None and dp.get_key()==key]

196

197 - def get_all_dataproviders(self):

198 """ 199 @returns: A list of dataproviders with a given key 200 """ 201 return [dp for dp in [self.datasource] + self.datasinks if dp != None]

202

203 - def is_empty(self):

204 """ 205 @returns: True if the conduit contains no dataproviders 206 """ 207 return self.datasource == None and len(self.datasinks) == 0

208

209 - def delete_dataprovider(self, dataprovider):

210 """ 211 Deletes dataprovider 212 """ 213 self.emit("dataprovider-removed", dataprovider) 214 215 #needed to close the db in file dataproviders 216 if dataprovider.module != None: 217 dataprovider.module.uninitialize() 218 219 #Sources and sinks are stored seperately so must be deleted from different 220 #places. Lucky there is only one source or this would be harder.... 221 if dataprovider == self.datasource: 222 del(self.datasource) 223 self.datasource = None 224 return True 225 elif dataprovider in self.datasinks: 226 i = self.datasinks.index(dataprovider) 227 del(self.datasinks[i]) 228 return True 229 else: 230 log.warn("Could not remove %s" % dataprovider) 231 return False

232

233 - def can_do_two_way_sync(self):

234 """ 235 Checks if the conduit is eleigable for two way sync, which is true 236 if it has one source and once sink. Two way doesnt make sense in 237 any other case 238 """ 239 if self.datasource != None and len(self.datasinks) == 1: 240 return self.datasource.module_type == "twoway" and self.datasinks[0].module_type == "twoway" 241 return False

242

243 - def enable_two_way_sync(self):

244

Source Code for Module conduit.Conduit