Do auto translation string matching at database level

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/autotranslate.py

@@ -50,28 +50,31 @@ def auto_translate(user, translation, source, inconsistent, overwrite):
             translation=translation
         )
 
+    # Filter by strings
+    units = units.filter(
+        source__in=sources.values('source')
+    )
+
     translation.commit_pending(None)
 
     for unit in units.iterator():
-        update = sources.filter(source=unit.source)
-        if update.exists():
-            # Get first entry
-            update = update[0]
-            # No save if translation is same
-            if unit.fuzzy == update.fuzzy and unit.target == update.target:
-                continue
-            # Copy translation
-            unit.fuzzy = update.fuzzy
-            unit.target = update.target
-            # Create signle change object for whole merge
-            change = Change.objects.create(
-                action=Change.ACTION_AUTO,
-                unit=unit,
-                user=user,
-                author=user
-            )
-            # Save unit to backend
-            unit.save_backend(None, False, False, user=user)
-            updated += 1
+        # Get first matching entry
+        update = sources.filter(source=unit.source)[0]
+        # No save if translation is same
+        if unit.fuzzy == update.fuzzy and unit.target == update.target:
+            continue
+        # Copy translation
+        unit.fuzzy = update.fuzzy
+        unit.target = update.target
+        # Create signle change object for whole merge
+        change = Change.objects.create(
+            action=Change.ACTION_AUTO,
+            unit=unit,
+            user=user,
+            author=user
+        )
+        # Save unit to backend
+        unit.save_backend(None, False, False, user=user)
+        updated += 1
 
     return updated