[entropy.client] avoid calling close() on cached repositories and make the cache explode, improve constraints on repository objects

libraries/entropy/client/interfaces/client.py

@@ -757,8 +757,9 @@ class Client(Singleton, TextInterface, LoadersMixin, CacheMixin, CalculatorsMixi
         """
         self.__instance_destroyed = True
         if hasattr(self, '_installed_repository'):
-            if self._installed_repository != None:
-                self._installed_repository.close()
+            if self._installed_repository is not None:
+                self._installed_repository.close(
+                    _token = etpConst['clientdbid'])
         if hasattr(self, 'logger'):
             self.logger.close()
         if hasattr(self, '_settings') and \

libraries/entropy/client/interfaces/db.py

@@ -79,8 +79,38 @@ class ClientEntropyRepositoryPlugin(EntropyRepositoryPlugin):
 
         return 0
 
+class CachedRepository(EntropyRepository):
+    """
+    This kind of repository cannot have close() called directly, without
+    a valid token passed. This is because the class object is cached somewhere
+    and calling close() would turn into a software bug.
+    """
+    def setCloseToken(self, token):
+        """
+        Set a token that can be used to validate close() calls. Calling
+        close() on these repos is prohibited and considered a software bug.
+        Only Entropy Client should be able to close them.
+        """
+        self._close_token = token
 
-class InstalledPackagesRepository(EntropyRepository):
+    def close(self, _token = None):
+        """
+        Reimplemented from EntropyRepository
+        """
+        close_token = getattr(self, "_close_token", None)
+        if close_token is not None:
+            if (_token is None) or (_token != close_token):
+                raise PermissionDenied(
+                    "cannot close this repository directly. Software bug!")
+        return EntropyRepository.close(self)
+
+    def __del__(self):
+        """
+        Cannot honor the constraint in this case, sorry!
+        """
+        return EntropyRepository.close(self)
+
+class InstalledPackagesRepository(CachedRepository):
     """
     This class represents the installed packages repository and is a direct
     subclass of EntropyRepository.
@@ -2387,7 +2417,7 @@ class MaskableRepository(EntropyRepositoryBase):
         return -1, myr
 
 
-class AvailablePackagesRepository(EntropyRepository, MaskableRepository):
+class AvailablePackagesRepository(CachedRepository, MaskableRepository):
     """
     This class represents the available packages repository and is a direct
     subclass of EntropyRepository. It implements the update() method in order
@@ -2467,10 +2497,14 @@ class AvailablePackagesRepository(EntropyRepository, MaskableRepository):
         EntropyRepository.clearCache(self)
 
 
-class GenericRepository(EntropyRepository, MaskableRepository):
+class GenericRepository(CachedRepository, MaskableRepository):
     """
     This class represents a generic packages repository and is a direct
     subclass of EntropyRepository.
+    Even GenericRepository is a CachedRepository because its object could
+    get cached by 3rd party. Actually, we require this because our installed
+    packages repository could end up being a GenericRepository, when running
+    in fail-safe mode.
     """
 
     def handlePackage(self, pkg_data, forcedRevision = -1,

libraries/entropy/client/interfaces/methods.py

@@ -62,9 +62,12 @@ class RepositoryMixin:
         def ensure_closed_repo(repoid):
             key = self.__get_repository_cache_key(repoid)
             for cache_obj in (self._repodb_cache, self._memory_db_instances):
+                obj = cache_obj.pop(key, None)
+                if obj is None:
+                    continue
                 try:
-                    cache_obj.pop(key).close()
-                except (KeyError, AttributeError, OperationalError):
+                    obj.close(_token = repoid)
+                except OperationalError:
                     pass
 
         t2 = _("Please update your repositories now in order to remove this message!")
@@ -149,6 +152,7 @@ class RepositoryMixin:
 
     def close_repositories(self, mask_clear = True):
         for item in sorted(self._repodb_cache.keys()):
+            repository_id, root = item
             # in-memory repositories cannot be closed
             # otherwise everything will be lost, to
             # effectively close these repos you
@@ -156,7 +160,7 @@ class RepositoryMixin:
             if item in self._memory_db_instances:
                 continue
             try:
-                self._repodb_cache.pop(item).close()
+                self._repodb_cache.pop(item).close(_token = repository_id)
             except OperationalError as err: # wtf!
                 sys.stderr.write("!!! Cannot close Entropy repos: %s\n" % (
                     err,))
@@ -265,6 +269,7 @@ class RepositoryMixin:
                 xcache = xcache,
                 indexing = indexing
             )
+            conn.setCloseToken(repoid)
             self._add_plugin_to_client_repository(conn)
 
         if (repoid not in self._treeupdates_repos) and \
@@ -788,6 +793,7 @@ class RepositoryMixin:
                     name = etpConst['clientdbid'],
                     xcache = self.xcache, indexing = self.indexing
                 )
+                conn.setCloseToken(etpConst['clientdbid'])
                 self._add_plugin_to_client_repository(conn)
                 # TODO: remove this in future, drop useless data from clientdb
             except (DatabaseError,):
@@ -800,7 +806,7 @@ class RepositoryMixin:
                         conn.validate()
                     except SystemDatabaseError:
                         try:
-                            conn.close()
+                            conn.close(_token = etpConst['clientdbid'])
                         except (RepositoryPluginError, OSError, IOError):
                             pass
                         entropy.tools.print_traceback(f = self.logger)
@@ -810,7 +816,7 @@ class RepositoryMixin:
         return conn
 
     def reopen_installed_repository(self):
-        self._installed_repository.close()
+        self._installed_repository.close(_token = etpConst['clientdbid'])
         self._open_installed_repository()
         # make sure settings are in sync
         self._settings.clear()