[Modeling-cvs] ProjectModeling/Modeling DatabaseContext.py,1.22,1.23 ChangeLog,1.8,1.9

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Update of /cvsroot/modeling/ProjectModeling/Modeling
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv18800/Modeling

Modified Files:
	DatabaseContext.py ChangeLog 
Log Message:
* Fixed a serious problem occuring in multi-threaded environment:
  unexpected failures happened when an EC was fetching objects while another
  had a faulted object which was concurrently fetching its own values.


Index: DatabaseContext.py
===================================================================
RCS file: /cvsroot/modeling/ProjectModeling/Modeling/DatabaseContext.py,v
retrieving revision 1.22
retrieving revision 1.23
diff -C2 -d -r1.22 -r1.23
*** DatabaseContext.py	20 Jul 2004 06:21:36 -0000	1.22
--- DatabaseContext.py	25 Feb 2006 13:26:05 -0000	1.23
***************
*** 234,238 ****
        # the userInfo dictionary for this notification is assumed to hold only
        # one row
!       entity_name=aNotification.userInfo().values()[0].entityName()
        from ModelSet import defaultModelSet
        model=defaultModelSet().modelForEntityNamed(entity_name)
--- 234,240 ----
        # the userInfo dictionary for this notification is assumed to hold only
        # one row
!       entity_name=aNotification.userInfo().get('entityName') \
!                    or aNotification.userInfo().values()[0].entityName()
!       # TBD: fix docstring and doc. itself
        from ModelSet import defaultModelSet
        model=defaultModelSet().modelForEntityNamed(entity_name)
***************
*** 321,335 ****
        DatabaseChannel.isFetchInProgress()
      """
!     for channel in self._channels:
!       if not channel.isFetchInProgress():
!         return channel
!     NC.postNotification(DatabaseChannelNeededNotification, self)
!     for channel in self._channels:
!       if not channel.isFetchInProgress():
!         return channel
!     # None registered, let's create one
!     channel=DatabaseChannel(self)
!     self.registerChannel(channel)
!     return channel
    
    def batchFetchRelationship(self, aRelationship, objects, anEditingContext):
--- 323,341 ----
        DatabaseChannel.isFetchInProgress()
      """
!     self.lock()
!     try:
!       for channel in self._channels:
!         if not channel.isFetchInProgress():
!           return channel
!       NC.postNotification(DatabaseChannelNeededNotification, self)
!       for channel in self._channels:
!         if not channel.isFetchInProgress():
!           return channel
!       # None registered, let's create one
!       channel=DatabaseChannel(self)
!       self.registerChannel(channel)
!       return channel
!     finally:
!       self.unlock()
    
    def batchFetchRelationship(self, aRelationship, objects, anEditingContext):
***************
*** 477,485 ****
      See also: DatabaseChannel.isFetchInProgress()
      """
!     for channel in self._channels:
!       if channel.isFetchInProgress():
!         return 1
!     return 0
! 
    def localSnapshotForGlobalID(self, aGlobalID):
      """
--- 483,495 ----
      See also: DatabaseChannel.isFetchInProgress()
      """
!     self.lock()
!     try:
!       for channel in self._channels:
!         if channel.isFetchInProgress():
!           return 1
!       return 0
!     finally:
!       self.unlock()
!   
    def localSnapshotForGlobalID(self, aGlobalID):
      """
***************
*** 859,862 ****
--- 869,886 ----
      return 0
    
+   def ownsEntityName(self, entityName):
+     """
+     Tells whether the DatabaseContext is responsible for the objects of the
+     supplied entity. Namely: if the entity is registered in the entities set
+     managed by the dbContext.database()
+     """
+     try:
+       # will fail if aGlobalID has no method entityName (TemporaryGlobalID)
+       if self._database.entityNamed(entityName):
+         return 1
+     except:
+       pass
+     return 0
+   
    def ownsGlobalID(self, aGlobalID):
      """
***************
*** 907,948 ****
        raise RuntimeError, "Invalid state: DatabaseContext isn't saving changes"
  
!     self.__channel=self.availableChannel().adaptorChannel()
!     if self.__channel is None:
!       raise RuntimeError, 'Unable to find an available AdaptorChannel'
!     self.__channel.adaptorContext().beginTransaction()
! 
!     _adaptorOperations=[]
!     trace('performChanges: dbOps: %s'%self._dbOperations)
!     #import pprint
!     #pprint.pprint(self._dbOperations)
! 
!     for dbOp in self._dbOperations:
!       # Simple: No locking, just operations
!       _adOps = self.__databaseOperationToAdaptorOperations(dbOp)
!       if not _adOps:
!         pass
!         # Note: the following statement was initially coded:
!         #self.forgetSnapshotForGlobalID(dbOp.globalID())
!         # meaning: if the object was marked as updated but, in fact, no changes
!         # needs to be forwarded to the database, then we simply discard the
!         # update and forget the snapshots. Seems Ok...
!         # BUT: this leads to a buggy behaviour when an object has been marked
!         # as updated because at least one of its toMany-relationships-related
!         # objects as been removed (and possibly deleted): sure, since the
!         # information about that dropped relationship is stored in the
!         # destination object (in the FK), there is no changes to forward to
!         # the database as far as the source object (=self) is concerned.
!         # However, if we forget the snapshots about that object, the
!         # Database's snapshotForSourceGlobalID() will not be updated and will
!         # be out of sync.
!         # cf. test_EditingContext_Global.test_16_toManySnapshotsUpdated()
!       else:
!         _adaptorOperations += _adOps
!     # order dbOperations NB: __TBD delegate
!     _adaptorOperations.sort()
!     trace("adaptorOperations: %s"%str(_adaptorOperations))
!     #import pdb ; pdb.set_trace()
!     self.__channel.performAdaptorOperations(_adaptorOperations)
!     
    def __databaseOperationToAdaptorOperations(self, databaseOperation):
      """
--- 931,976 ----
        raise RuntimeError, "Invalid state: DatabaseContext isn't saving changes"
  
!     self.lock()
!     try:
!       self.__channel=self.availableChannel().adaptorChannel()
!       if self.__channel is None:
!         raise RuntimeError, 'Unable to find an available AdaptorChannel'
!       self.__channel.adaptorContext().beginTransaction()
!       
!       _adaptorOperations=[]
!       trace('performChanges: dbOps: %s'%self._dbOperations)
!       #import pprint
!       #pprint.pprint(self._dbOperations)
!       
!       for dbOp in self._dbOperations:
!         # Simple: No locking, just operations
!         _adOps = self.__databaseOperationToAdaptorOperations(dbOp)
!         if not _adOps:
!           pass
!           # Note: the following statement was initially coded:
!           #self.forgetSnapshotForGlobalID(dbOp.globalID())
!           # meaning: if the object was marked as updated but, in fact, no changes
!           # needs to be forwarded to the database, then we simply discard the
!           # update and forget the snapshots. Seems Ok...
!           # BUT: this leads to a buggy behaviour when an object has been marked
!           # as updated because at least one of its toMany-relationships-related
!           # objects as been removed (and possibly deleted): sure, since the
!           # information about that dropped relationship is stored in the
!           # destination object (in the FK), there is no changes to forward to
!           # the database as far as the source object (=self) is concerned.
!           # However, if we forget the snapshots about that object, the
!           # Database's snapshotForSourceGlobalID() will not be updated and will
!           # be out of sync.
!           # cf. test_EditingContext_Global.test_16_toManySnapshotsUpdated()
!         else:
!           _adaptorOperations += _adOps
!       # order dbOperations NB: __TBD delegate
!       _adaptorOperations.sort()
!       trace("adaptorOperations: %s"%str(_adaptorOperations))
!       #import pdb ; pdb.set_trace()
!       self.__channel.performAdaptorOperations(_adaptorOperations)
!     finally:
!       self.unlock()
!   
    def __databaseOperationToAdaptorOperations(self, databaseOperation):
      """
***************
*** 1041,1053 ****
      # this could be made more efficient if PKs were asked within a single
      # round-trip to the DB
!     channel=self.availableChannel().adaptorChannel()
!     for gID in self._inserted_gIDs:
!       entity=ec.objectForGlobalID(gID).classDescription().entity()
!       pk=channel.primaryKeysForNewRowsWithEntity(1, entity)
!       self._pks_for_inserted_gIDs[gID]=pk[0]
!       
!       newGid=KeyGlobalID(entity.name(), self._pks_for_inserted_gIDs[gID])
!       self.__temporaryGID_to_KeyGlobalID[gID]=newGid
! 
    def _recordChangesInEditingContext(self, gID, obj, dbOperator):
      """
--- 1069,1085 ----
      # this could be made more efficient if PKs were asked within a single
      # round-trip to the DB
!     self.lock()
!     try:
!       channel=self.availableChannel().adaptorChannel()
!       for gID in self._inserted_gIDs:
!         entity=ec.objectForGlobalID(gID).classDescription().entity()
!         pk=channel.primaryKeysForNewRowsWithEntity(1, entity)
!         self._pks_for_inserted_gIDs[gID]=pk[0]
!         
!         newGid=KeyGlobalID(entity.name(), self._pks_for_inserted_gIDs[gID])
!         self.__temporaryGID_to_KeyGlobalID[gID]=newGid
!     finally:
!       self.unlock()
!   
    def _recordChangesInEditingContext(self, gID, obj, dbOperator):
      """
***************
*** 1741,1745 ****
      See also: DatabaseChannel.selectCountObjectsWithFetchSpecification()
      """
-     channel=self.availableChannel()
      entitiesNames=[aFetchSpec.entityName()]
      if aFetchSpec.isDeep():
--- 1773,1776 ----
***************
*** 1750,1760 ****
        
      objects=[]
!     count=0
      for entityName in entitiesNames:
        aFetchSpec.setEntityName(entityName)
-       c=channel.selectCountObjectsWithFetchSpecification(aFetchSpec,
-                                                               anEditingContext)
-       count+=int(c) # SQLite
  
      return count
  
--- 1781,1797 ----
        
      objects=[]
!     count=c=0
      for entityName in entitiesNames:
        aFetchSpec.setEntityName(entityName)
  
+       self.lock()
+       try:
+         channel=self.availableChannel()
+         c=channel.selectCountObjectsWithFetchSpecification(aFetchSpec,
+                                                            anEditingContext)
+       finally:
+         self.unlock()
+       count+=int(c) # SQLite
+     
      return count
  
***************
*** 1789,1793 ****
  
      """
-     channel=self.availableChannel()
      entitiesNames=[aFetchSpec.entityName()]
      if aFetchSpec.isDeep():
--- 1826,1829 ----
***************
*** 1802,1807 ****
        for entityName in entitiesNames:
          aFetchSpec.setEntityName(entityName)
!         channel.selectObjectsWithFetchSpecification(aFetchSpec,
!                                                     anEditingContext)
          object=channel.fetchObject()
          while object:
--- 1838,1850 ----
        for entityName in entitiesNames:
          aFetchSpec.setEntityName(entityName)
! 
!         self.lock()
!         try:
!           channel=self.availableChannel()
!           channel.selectObjectsWithFetchSpecification(aFetchSpec,
!                                                       anEditingContext)
!         finally:
!           self.unlock()
!           
          object=channel.fetchObject()
          while object:
***************
*** 1812,1816 ****
        aFetchSpec.setEntityName(original_entity_name)
      return objects
! 
    def refaultObject(self, aDatabaseObject, aGlobalID, anEditingContext):
      """
--- 1855,1859 ----
        aFetchSpec.setEntityName(original_entity_name)
      return objects
!   
    def refaultObject(self, aDatabaseObject, aGlobalID, anEditingContext):
      """

Index: ChangeLog
===================================================================
RCS file: /cvsroot/modeling/ProjectModeling/Modeling/ChangeLog,v
retrieving revision 1.8
retrieving revision 1.9
diff -C2 -d -r1.8 -r1.9
*** ChangeLog	25 Feb 2006 13:08:08 -0000	1.8
--- ChangeLog	25 Feb 2006 13:26:05 -0000	1.9
***************
*** 1,4 ****
--- 1,12 ----
  2006-02-25  Sebastien Bigaret  <Seb...@en...>
  
+ 	* DatabaseContext (DatabaseContext methods: availableChannel,
+ 	hasBusyChannels, performChanges, prepareForSaveWithCoordinator,
+ 	objectsCountWithFetchSpecification,
+ 	objectsWithFetchSpecification):
+ 	modified to fix "random" failures when EC.fetch() and clearing
+ 	fault were concurrently fetching values (MT environment only)
+ 
+ 	* DatabaseContext.py (DatabaseContext.ownsEntityName): added
  	* ObjectStoreCoordinator.py
  	(ObjectStoreCoordinator.objectStoreForEntityName): added