Split translations update to more transactions

Generating huge transaction just pushes too much on the database server.
Also we want to commit changes soon as we're already sending
notifications for changes.
Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/models/subproject.py

@@ -18,7 +18,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-from django.db import models
+from django.db import models, transaction
 from django.utils.translation import ugettext as _, ugettext_lazy
 from django.core.mail import mail_admins
 from django.core.exceptions import ValidationError
@@ -966,40 +966,42 @@ class SubProject(models.Model, PercentMixin, URLMixin, PathMixin):
         matches = self.get_mask_matches()
         language_re = re.compile(self.language_regex)
         for pos, path in enumerate(matches):
-            code = self.get_lang_code(path)
-            if langs is not None and code not in langs:
-                self.log_info('skipping %s', path)
-                continue
-            if not language_re.match(code):
-                self.log_info('skipping language %s', code)
-                continue
+            with transaction.atomic():
+                code = self.get_lang_code(path)
+                if langs is not None and code not in langs:
+                    self.log_info('skipping %s', path)
+                    continue
+                if not language_re.match(code):
+                    self.log_info('skipping language %s', code)
+                    continue
 
-            self.log_info(
-                'checking %s (%s) [%d/%d]',
-                path,
-                code,
-                pos + 1,
-                len(matches)
-            )
-            lang = Language.objects.auto_get_or_create(code=code)
-            if lang.code in languages:
-                self.log_error('duplicate language found: %s', lang.code)
-                continue
-            translation = Translation.objects.check_sync(
-                self, lang, code, path, force, request=request
-            )
-            translations.add(translation.id)
-            languages.add(lang.code)
+                self.log_info(
+                    'checking %s (%s) [%d/%d]',
+                    path,
+                    code,
+                    pos + 1,
+                    len(matches)
+                )
+                lang = Language.objects.auto_get_or_create(code=code)
+                if lang.code in languages:
+                    self.log_error('duplicate language found: %s', lang.code)
+                    continue
+                translation = Translation.objects.check_sync(
+                    self, lang, code, path, force, request=request
+                )
+                translations.add(translation.id)
+                languages.add(lang.code)
 
         # Delete possibly no longer existing translations
         if langs is None:
             todelete = self.translation_set.exclude(id__in=translations)
             if todelete.exists():
-                self.log_info(
-                    'removing stale translations: %s',
-                    ','.join([trans.language.code for trans in todelete])
-                )
-                todelete.delete()
+                with transaction.atomic():
+                    self.log_info(
+                        'removing stale translations: %s',
+                        ','.join([trans.language.code for trans in todelete])
+                    )
+                    todelete.delete()
 
         # Process linked repos
         for subproject in self.get_linked_childs():