Refactor exc_callback invocation.

Replace _call_exc_callbacks with a function wrapper, which will automatically
call exception callbacks when an exception is raised from the function. This
removes the need to specify the function and its arguments twice (once in the
function call itself and once in _call_exc_callbacks).

Add some extra checks to existing exception callbacks.

6 files changed, 179 insertions, 182 deletions

diff --git a/ipalib/plugins/baseldap.py b/ipalib/plugins/baseldap.py
index f185977e6..7ee5fa1e1 100644
--- a/ipalib/plugins/baseldap.py
+++ b/ipalib/plugins/baseldap.py
@@ -744,26 +744,28 @@ class CallbackInterface(Method):
         else:
             klass.INTERACTIVE_PROMPT_CALLBACKS.append(callback)
 
-    def _call_exc_callbacks(self, args, options, exc, call_func, *call_args, **call_kwargs):
-        rv = None
-        for i in xrange(len(getattr(self, 'EXC_CALLBACKS', []))):
-            callback = self.EXC_CALLBACKS[i]
-            try:
-                if hasattr(callback, 'im_self'):
-                    rv = callback(
-                        args, options, exc, call_func, *call_args, **call_kwargs
-                    )
-                else:
-                    rv = callback(
-                        self, args, options, exc, call_func, *call_args,
-                        **call_kwargs
-                    )
-            except errors.ExecutionError, e:
-                if (i + 1) < len(self.EXC_CALLBACKS):
-                    exc = e
-                    continue
-                raise e
-        return rv
+    def _exc_wrapper(self, keys, options, call_func):
+        """Function wrapper that automatically calls exception callbacks"""
+        def wrapped(*call_args, **call_kwargs):
+            # call call_func first
+            func = call_func
+            callbacks = list(getattr(self, 'EXC_CALLBACKS', []))
+            while True:
+                try:
+                    return func(*call_args, **call_kwargs)
+                except errors.ExecutionError, e:
+                    if not callbacks:
+                        raise
+                    # call exc_callback in the next loop
+                    callback = callbacks.pop(0)
+                    if hasattr(callback, 'im_self'):
+                        def exc_func(*args, **kwargs):
+                            return callback(keys, options, e, call_func, *args, **kwargs)
+                    else:
+                        def exc_func(*args, **kwargs):
+                            return callback(self, keys, options, e, call_func, *args, **kwargs)
+                    func = exc_func
+        return wrapped
 
 
 class BaseLDAPCommand(CallbackInterface, Command):
@@ -883,17 +885,11 @@ last, after all sets and adds."""),
 
         if needldapattrs:
             try:
-                (dn, old_entry) = ldap.get_entry(
+                (dn, old_entry) = self._exc_wrapper(keys, options, ldap.get_entry)(
                     dn, needldapattrs, normalize=self.obj.normalize_dn
                 )
-            except errors.ExecutionError, e:
-                try:
-                    (dn, old_entry) = self._call_exc_callbacks(
-                        keys, options, e, ldap.get_entry, dn, [],
-                        normalize=self.obj.normalize_dn
-                    )
-                except errors.NotFound:
-                    self.obj.handle_not_found(*keys)
+            except errors.NotFound:
+                self.obj.handle_not_found(*keys)
             for attr in needldapattrs:
                 entry_attrs[attr] = old_entry.get(attr, [])
 
@@ -1019,29 +1015,23 @@ class LDAPCreate(BaseLDAPCommand, crud.Create):
         _check_limit_object_class(self.api.Backend.ldap2.schema.attribute_types(self.obj.disallow_object_classes), entry_attrs.keys(), allow_only=False)
 
         try:
-            ldap.add_entry(dn, entry_attrs, normalize=self.obj.normalize_dn)
-        except errors.ExecutionError, e:
-            try:
-                self._call_exc_callbacks(
-                    keys, options, e, ldap.add_entry, dn, entry_attrs,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.NotFound:
-                parent = self.obj.parent_object
-                if parent:
-                    raise errors.NotFound(
-                        reason=self.obj.parent_not_found_msg % {
-                            'parent': keys[-2],
-                            'oname': self.api.Object[parent].object_name,
-                        }
-                    )
+            self._exc_wrapper(keys, options, ldap.add_entry)(dn, entry_attrs, normalize=self.obj.normalize_dn)
+        except errors.NotFound:
+            parent = self.obj.parent_object
+            if parent:
                 raise errors.NotFound(
-                    reason=self.obj.container_not_found_msg % {
-                        'container': self.obj.container_dn,
+                    reason=self.obj.parent_not_found_msg % {
+                        'parent': keys[-2],
+                        'oname': self.api.Object[parent].object_name,
                     }
                 )
-            except errors.DuplicateEntry:
-                self.obj.handle_duplicate_entry(*keys)
+            raise errors.NotFound(
+                reason=self.obj.container_not_found_msg % {
+                    'container': self.obj.container_dn,
+                }
+            )
+        except errors.DuplicateEntry:
+            self.obj.handle_duplicate_entry(*keys)
 
         try:
             if self.obj.rdn_attribute:
@@ -1050,22 +1040,16 @@ class LDAPCreate(BaseLDAPCommand, crud.Create):
                     object_class = self.obj.object_class
                 else:
                     object_class = None
-                (dn, entry_attrs) = ldap.find_entry_by_attr(
+                (dn, entry_attrs) = self._exc_wrapper(keys, options, ldap.find_entry_by_attr)(
                     self.obj.primary_key.name, keys[-1], object_class, attrs_list,
                     self.obj.container_dn
                 )
             else:
-                (dn, entry_attrs) = ldap.get_entry(
+                (dn, entry_attrs) = self._exc_wrapper(keys, options, ldap.get_entry)(
                     dn, attrs_list, normalize=self.obj.normalize_dn
                 )
-        except errors.ExecutionError, e:
-            try:
-                (dn, entry_attrs) = self._call_exc_callbacks(
-                    keys, options, e, ldap.get_entry, dn, attrs_list,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.NotFound:
-                self.obj.handle_not_found(*keys)
+        except errors.NotFound:
+            self.obj.handle_not_found(*keys)
 
         for callback in self.POST_CALLBACKS:
             if hasattr(callback, 'im_self'):
@@ -1181,17 +1165,11 @@ class LDAPRetrieve(LDAPQuery):
                 dn = callback(self, ldap, dn, attrs_list, *keys, **options)
 
         try:
-            (dn, entry_attrs) = ldap.get_entry(
+            (dn, entry_attrs) = self._exc_wrapper(keys, options, ldap.get_entry)(
                 dn, attrs_list, normalize=self.obj.normalize_dn
             )
-        except errors.ExecutionError, e:
-            try:
-                (dn, entry_attrs) = self._call_exc_callbacks(
-                    keys, options, e, ldap.get_entry, dn, attrs_list,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.NotFound:
-                self.obj.handle_not_found(*keys)
+        except errors.NotFound:
+            self.obj.handle_not_found(*keys)
 
         if options.get('rights', False) and options.get('all', False):
             entry_attrs['attributelevelrights'] = get_effective_rights(ldap, dn)
@@ -1297,7 +1275,7 @@ class LDAPUpdate(LDAPQuery, crud.Update):
 
             if self.obj.rdn_is_primary_key and self.obj.primary_key.name in entry_attrs:
                 # RDN change
-                ldap.update_entry_rdn(dn,
+                self._exc_wrapper(keys, options, ldap.update_entry_rdn)(dn,
                     unicode('%s=%s' % (self.obj.primary_key.name,
                     entry_attrs[self.obj.primary_key.name])))
                 rdnkeys = keys[:-1] + (entry_attrs[self.obj.primary_key.name], )
@@ -1306,37 +1284,25 @@ class LDAPUpdate(LDAPQuery, crud.Update):
                 options['rdnupdate'] = True
                 rdnupdate = True
 
-            ldap.update_entry(dn, entry_attrs, normalize=self.obj.normalize_dn)
-        except errors.ExecutionError, e:
             # Exception callbacks will need to test for options['rdnupdate']
             # to decide what to do. An EmptyModlist in this context doesn't
             # mean an error occurred, just that there were no other updates to
             # perform.
-            try:
-                self._call_exc_callbacks(
-                    keys, options, e, ldap.update_entry, dn, entry_attrs,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.EmptyModlist, e:
-                if not rdnupdate:
-                    raise e
-            except errors.NotFound:
-                self.obj.handle_not_found(*keys)
+            self._exc_wrapper(keys, options, ldap.update_entry)(dn, entry_attrs, normalize=self.obj.normalize_dn)
+        except errors.EmptyModlist, e:
+            if not rdnupdate:
+                raise e
+        except errors.NotFound:
+            self.obj.handle_not_found(*keys)
 
         try:
-            (dn, entry_attrs) = ldap.get_entry(
+            (dn, entry_attrs) = self._exc_wrapper(keys, options, ldap.get_entry)(
                 dn, attrs_list, normalize=self.obj.normalize_dn
             )
-        except errors.ExecutionError, e:
-            try:
-                (dn, entry_attrs) = self._call_exc_callbacks(
-                    keys, options, e, ldap.get_entry, dn, attrs_list,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.NotFound:
-                raise errors.MidairCollision(
-                    format=_('the entry was deleted while being modified')
-                )
+        except errors.NotFound:
+            raise errors.MidairCollision(
+                format=_('the entry was deleted while being modified')
+            )
 
         if options.get('rights', False) and options.get('all', False):
             entry_attrs['attributelevelrights'] = get_effective_rights(ldap, dn)
@@ -1399,15 +1365,9 @@ class LDAPDelete(LDAPMultiQuery):
                         for (dn_, entry_attrs) in subentries:
                             delete_subtree(dn_)
                 try:
-                    ldap.delete_entry(base_dn, normalize=self.obj.normalize_dn)
-                except errors.ExecutionError, e:
-                    try:
-                        self._call_exc_callbacks(
-                            nkeys, options, e, ldap.delete_entry, base_dn,
-                            normalize=self.obj.normalize_dn
-                        )
-                    except errors.NotFound:
-                        self.obj.handle_not_found(*nkeys)
+                    self._exc_wrapper(nkeys, options, ldap.delete_entry)(base_dn, normalize=self.obj.normalize_dn)
+                except errors.NotFound:
+                    self.obj.handle_not_found(*nkeys)
 
             delete_subtree(dn)
 
@@ -1560,17 +1520,11 @@ class LDAPAddMember(LDAPModMember):
             )
 
         try:
-            (dn, entry_attrs) = ldap.get_entry(
+            (dn, entry_attrs) = self._exc_wrapper(keys, options, ldap.get_entry)(
                 dn, attrs_list, normalize=self.obj.normalize_dn
             )
-        except errors.ExecutionError, e:
-            try:
-                (dn, entry_attrs) = self._call_exc_callbacks(
-                    keys, options, e, ldap.get_entry, dn, attrs_list,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.NotFound:
-                self.obj.handle_not_found(*keys)
+        except errors.NotFound:
+            self.obj.handle_not_found(*keys)
 
         for callback in self.POST_CALLBACKS:
             if hasattr(callback, 'im_self'):
@@ -1668,17 +1622,11 @@ class LDAPRemoveMember(LDAPModMember):
         time.sleep(.3)
 
         try:
-            (dn, entry_attrs) = ldap.get_entry(
+            (dn, entry_attrs) = self._exc_wrapper(keys, options, ldap.get_entry)(
                 dn, attrs_list, normalize=self.obj.normalize_dn
             )
-        except errors.ExecutionError, e:
-            try:
-                (dn, entry_attrs) = self._call_exc_callbacks(
-                    keys, options, e, ldap.get_entry, dn, attrs_list,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.NotFound:
-                self.obj.handle_not_found(*keys)
+        except errors.NotFound:
+            self.obj.handle_not_found(*keys)
 
         for callback in self.POST_CALLBACKS:
             if hasattr(callback, 'im_self'):
@@ -1884,20 +1832,13 @@ class LDAPSearch(BaseLDAPCommand, crud.Search):
                 )
 
         try:
-            (entries, truncated) = ldap.find_entries(
+            (entries, truncated) = self._exc_wrapper(args, options, ldap.find_entries)(
                 filter, attrs_list, base_dn, scope,
                 time_limit=options.get('timelimit', None),
                 size_limit=options.get('sizelimit', None)
             )
-        except errors.ExecutionError, e:
-            try:
-                (entries, truncated) = self._call_exc_callbacks(
-                    args, options, e, ldap.find_entries, filter, attrs_list,
-                    base_dn, scope=ldap.SCOPE_ONELEVEL,
-                    normalize=self.obj.normalize_dn
-                )
-            except errors.NotFound:
-                (entries, truncated) = ([], False)
+        except errors.NotFound:
+            (entries, truncated) = ([], False)
 
         for callback in self.POST_CALLBACKS:
             if hasattr(callback, 'im_self'):
@@ -2030,21 +1971,15 @@ class LDAPAddReverseMember(LDAPModReverseMember):
             try:
                 options = {'%s' % self.member_attr: keys[-1]}
                 try:
-                    result = self.api.Command[self.member_command](attr, **options)
+                    result = self._exc_wrapper(keys, options, self.api.Command[self.member_command])(attr, **options)
                     if result['completed'] == 1:
                         completed = completed + 1
                     else:
                         failed['member'][self.reverse_attr].append((attr, result['failed']['member'][self.member_attr][0][1]))
-                except errors.ExecutionError, e:
-                    try:
-                        (dn, entry_attrs) = self._call_exc_callbacks(
-                            keys, options, e, self.member_command, dn, attrs_list,
-                            normalize=self.obj.normalize_dn
-                        )
-                    except errors.NotFound, e:
-                        msg = str(e)
-                        (attr, msg) = msg.split(':', 1)
-                        failed['member'][self.reverse_attr].append((attr, unicode(msg.strip())))
+                except errors.NotFound, e:
+                    msg = str(e)
+                    (attr, msg) = msg.split(':', 1)
+                    failed['member'][self.reverse_attr].append((attr, unicode(msg.strip())))
 
             except errors.PublicError, e:
                 failed['member'][self.reverse_attr].append((attr, unicode(msg)))
@@ -2143,21 +2078,15 @@ class LDAPRemoveReverseMember(LDAPModReverseMember):
             try:
                 options = {'%s' % self.member_attr: keys[-1]}
                 try:
-                    result = self.api.Command[self.member_command](attr, **options)
+                    result = self._exc_wrapper(keys, options, self.api.Command[self.member_command])(attr, **options)
                     if result['completed'] == 1:
                         completed = completed + 1
                     else:
                         failed['member'][self.reverse_attr].append((attr, result['failed']['member'][self.member_attr][0][1]))
-                except errors.ExecutionError, e:
-                    try:
-                        (dn, entry_attrs) = self._call_exc_callbacks(
-                            keys, options, e, self.member_command, dn, attrs_list,
-                            normalize=self.obj.normalize_dn
-                        )
-                    except errors.NotFound, e:
-                        msg = str(e)
-                        (attr, msg) = msg.split(':', 1)
-                        failed['member'][self.reverse_attr].append((attr, unicode(msg.strip())))
+                except errors.NotFound, e:
+                    msg = str(e)
+                    (attr, msg) = msg.split(':', 1)
+                    failed['member'][self.reverse_attr].append((attr, unicode(msg.strip())))
 
             except errors.PublicError, e:
                 failed['member'][self.reverse_attr].append((attr, unicode(msg)))
diff --git a/ipalib/plugins/entitle.py b/ipalib/plugins/entitle.py
index 28d2c5dc8..6ade854c3 100644
--- a/ipalib/plugins/entitle.py
+++ b/ipalib/plugins/entitle.py
@@ -642,12 +642,12 @@ class entitle_import(LDAPUpdate):
         If we are adding the first entry there are no updates so EmptyModlist
         will get thrown. Ignore it.
         """
-        if isinstance(exc, errors.EmptyModlist):
-            if not getattr(context, 'entitle_import', False):
-                raise exc
-            return (call_args, {})
-        else:
-            raise exc
+        if call_func.func_name == 'update_entry':
+            if isinstance(exc, errors.EmptyModlist):
+                if not getattr(context, 'entitle_import', False):
+                    raise exc
+                return (call_args, {})
+        raise exc
 
     def execute(self, *keys, **options):
         super(entitle_import, self).execute(*keys, **options)
@@ -729,9 +729,10 @@ class entitle_sync(LDAPUpdate):
         return dn
 
     def exc_callback(self, keys, options, exc, call_func, *call_args, **call_kwargs):
-        if isinstance(exc, errors.EmptyModlist):
-            # If there is nothing to change we are already synchronized.
-            return
+        if call_func.func_name == 'update_entry':
+            if isinstance(exc, errors.EmptyModlist):
+                # If there is nothing to change we are already synchronized.
+                return
         raise exc
 
 api.register(entitle_sync)
diff --git a/ipalib/plugins/group.py b/ipalib/plugins/group.py
index 096cb9eae..13208542c 100644
--- a/ipalib/plugins/group.py
+++ b/ipalib/plugins/group.py
@@ -211,9 +211,10 @@ class group_mod(LDAPUpdate):
     def exc_callback(self, keys, options, exc, call_func, *call_args, **call_kwargs):
         # Check again for GID requirement in case someone tried to clear it
         # using --setattr.
-        if isinstance(exc, errors.ObjectclassViolation):
-            if 'gidNumber' in exc.message and 'posixGroup' in exc.message:
-                raise errors.RequirementError(name='gid')
+        if call_func.func_name == 'update_entry':
+            if isinstance(exc, errors.ObjectclassViolation):
+                if 'gidNumber' in exc.message and 'posixGroup' in exc.message:
+                    raise errors.RequirementError(name='gid')
         raise exc
 
 api.register(group_mod)
diff --git a/ipalib/plugins/permission.py b/ipalib/plugins/permission.py
index 92203f174..2d300e246 100644
--- a/ipalib/plugins/permission.py
+++ b/ipalib/plugins/permission.py
@@ -374,20 +374,19 @@ class permission_mod(LDAPUpdate):
         return dn
 
     def exc_callback(self, keys, options, exc, call_func, *call_args, **call_kwargs):
-        if isinstance(exc, errors.EmptyModlist):
-            aciupdate = getattr(context, 'aciupdate')
-            opts = copy.copy(options)
-            # Clear the aci attributes out of the permission entry
-            for o in self.obj.aci_attributes + ['all', 'raw', 'rights']:
-                try:
-                    del opts[o]
-                except:
-                    pass
-
-            if len(opts) > 0 and not aciupdate:
-                raise exc
-        else:
-            raise exc
+        if call_func.func_name == 'update_entry':
+            if isinstance(exc, errors.EmptyModlist):
+                aciupdate = getattr(context, 'aciupdate')
+                opts = copy.copy(options)
+                # Clear the aci attributes out of the permission entry
+                for o in self.obj.aci_attributes + ['all', 'raw', 'rights']:
+                    try:
+                        del opts[o]
+                    except:
+                        pass
+                if len(opts) == 0 or aciupdate:
+                    return
+        raise exc
 
     def post_callback(self, ldap, dn, entry_attrs, *keys, **options):
         # rename the underlying ACI after the change to permission
diff --git a/ipalib/plugins/pwpolicy.py b/ipalib/plugins/pwpolicy.py
index 2b586ec54..90a2ea110 100644
--- a/ipalib/plugins/pwpolicy.py
+++ b/ipalib/plugins/pwpolicy.py
@@ -414,11 +414,12 @@ class pwpolicy_mod(LDAPUpdate):
         return dn
 
     def exc_callback(self, keys, options, exc, call_func, *call_args, **call_kwargs):
-        if isinstance(exc, errors.EmptyModlist):
-            entry_attrs = call_args[1]
-            cosupdate = getattr(context, 'cosupdate')
-            if not entry_attrs or cosupdate:
-                return
+        if call_func.func_name == 'update_entry':
+            if isinstance(exc, errors.EmptyModlist):
+                entry_attrs = call_args[1]
+                cosupdate = getattr(context, 'cosupdate')
+                if not entry_attrs or cosupdate:
+                    return
         raise exc
 
 api.register(pwpolicy_mod)
diff --git a/tests/test_xmlrpc/test_baseldap_plugin.py b/tests/test_xmlrpc/test_baseldap_plugin.py
new file mode 100644
index 000000000..0800a5d52
--- /dev/null
+++ b/tests/test_xmlrpc/test_baseldap_plugin.py
@@ -0,0 +1,66 @@
+# Authors:
+#   Petr Viktorin <pviktori@redhat.com>
+#
+# Copyright (C) 2012  Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Test the `ipalib.plugins.baseldap` module.
+"""
+
+from ipalib import errors
+from ipalib.plugins import baseldap
+
+def test_exc_wrapper():
+    """Test the CallbackInterface._exc_wrapper helper method"""
+    handled_exceptions = []
+
+    class test_callback(baseldap.CallbackInterface):
+        """Fake IPA method"""
+        def test_fail(self):
+            self._exc_wrapper([], {}, self.fail)(1, 2, a=1, b=2)
+
+        def fail(self, *args, **kwargs):
+            assert args == (1, 2)
+            assert kwargs == dict(a=1, b=2)
+            raise errors.ExecutionError('failure')
+
+    instance = test_callback()
+
+    # Test with one callback first
+
+    @test_callback.register_exc_callback
+    def handle_exception(self, keys, options, e, call_func, *args, **kwargs):
+        assert args == (1, 2)
+        assert kwargs == dict(a=1, b=2)
+        handled_exceptions.append(type(e))
+
+    instance.test_fail()
+    assert handled_exceptions == [errors.ExecutionError]
+
+    # Test with another callback added
+
+    handled_exceptions = []
+
+    def dont_handle(self, keys, options, e, call_func, *args, **kwargs):
+        assert args == (1, 2)
+        assert kwargs == dict(a=1, b=2)
+        handled_exceptions.append(None)
+        raise e
+    test_callback.register_exc_callback(dont_handle, first=True)
+
+    instance.test_fail()
+    assert handled_exceptions == [None, errors.ExecutionError]