idsync: write model.json only if updated + unit test #25

Author: loryruta

objectbox/model/idsync.py

@@ -165,10 +165,12 @@ def _validate_matching_prop(self, entity: _Entity, prop: Property, prop_json: Di
         except ValueError as error:
             raise ValueError(f"Property {entity.name}.{prop.name} mismatches property found in JSON file: {error}")
 
-    def _load_or_assign_index(self, entity: _Entity, prop: Property, prop_json: Optional[Dict[str, Any]]):
+    def _load_or_assign_index(self, entity: _Entity, prop: Property, prop_json: Optional[Dict[str, Any]]) -> bool:
         assert prop.index is not None
         index = prop.index
 
+        write_json = False
+
         # Fetch index ID/UID from JSON file
         iduid_json = None
         if (prop_json is not None) and ("indexId" in prop_json):
@@ -187,8 +189,13 @@ def _load_or_assign_index(self, entity: _Entity, prop: Property, prop_json: Opti
         else:  # Assign new ID to new index
             index.iduid = IdUid(self.model.last_index_iduid.id + 1, index.uid)
             self.model.last_index_iduid = index.iduid
+            write_json = True
+
+        return write_json
+
+    def _load_or_assign_property(self, entity: _Entity, prop: Property, entity_json: Optional[Dict[str, Any]]) -> bool:
+        write_json = False
 
-    def _load_or_assign_property(self, entity: _Entity, prop: Property, entity_json: Optional[Dict[str, Any]]):
         prop_json = None
         if prop.has_uid():
             if entity_json is not None:
@@ -197,6 +204,8 @@ def _load_or_assign_property(self, entity: _Entity, prop: Property, entity_json:
                 # User provided a UID not matching any property (within the entity), make sure it's not assigned
                 # elsewhere
                 self._validate_uid_unassigned(prop.uid)
+            else:
+                write_json = prop.name != prop_json["name"]  # If renaming we shall update the JSON
         else:
             if entity_json is not None:
                 prop_json = self._find_property_json_by_name(entity_json, prop.name)
@@ -210,20 +219,31 @@ def _load_or_assign_property(self, entity: _Entity, prop: Property, entity_json:
                 prop.iduid.uid = self._generate_uid()
             prop.iduid = IdUid(entity.last_property_iduid.id + 1, prop.iduid.uid)
             entity.last_property_iduid = prop.iduid
+            write_json = True
 
         if prop.index is not None:
-            self._load_or_assign_index(entity, prop, prop_json)
+            write_json |= self._load_or_assign_index(entity, prop, prop_json)
+
+        return write_json
+
+    def _load_or_assign_entity(self, entity: _Entity) -> bool:
+        write_json = False
 
-    def _load_or_assign_entity(self, entity: _Entity):
         # entity_json = None
         if entity.has_uid():
             entity_json = self._find_entity_json_by_uid(entity.uid)
             if entity_json is None:
                 # User provided a UID not matching any entity, make sure it's not assigned elsewhere
                 self._validate_uid_unassigned(entity.uid)
+            else:
+                write_json = entity.name != entity_json["name"]  # If renaming we shall update the JSON
         else:
             entity_json = self._find_entity_json_by_name(entity.name)
 
+        # Write JSON if the number of properties differs (to handle removed property)
+        if entity_json is not None:
+            write_json |= len(entity.properties) != len(entity_json["properties"])
+
         if entity_json is not None:  # Load existing IDs from JSON
             entity.iduid = IdUid.from_str(entity_json["id"])
             entity.last_property_iduid = IdUid.from_str(entity_json["lastPropertyId"])
@@ -233,27 +253,42 @@ def _load_or_assign_entity(self, entity: _Entity):
             entity.iduid = IdUid(self.model.last_entity_iduid.id + 1, entity.iduid.uid)
             self.model.last_entity_iduid = entity.iduid
             entity.last_property_iduid = IdUid(0, 0)
+            write_json = True
 
         # Load properties
         for prop in entity.properties:
-            self._load_or_assign_property(entity, prop, entity_json)
+            write_json |= self._load_or_assign_property(entity, prop, entity_json)
 
-    def sync(self):
-        """ Syncs the provided model with the model JSON file. """
+        return write_json
+
+    def sync(self) -> bool:
+        """ Syncs the provided model with the model JSON file.
+        Returns True if the model JSON was written. """
 
         if self.model_json is not None:
             self.model.last_entity_iduid = IdUid.from_str(self.model_json["lastEntityId"])
             self.model.last_index_iduid = IdUid.from_str(self.model_json["lastIndexId"])
             # self.model.last_relation_iduid =
 
+        write_json = False
+
+        # Write JSON if the number of entities differs (to handle removed entity)
+        if self.model_json is not None:
+            write_json |= len(self.model_json["entities"]) != len(self.model.entities)
+
         for entity in self.model.entities:
-            self._load_or_assign_entity(entity)
+            write_json |= self._load_or_assign_entity(entity)
+
+        if write_json:
+            logger.info(f"Model changed, writing model.json: {self.model_filepath}")
+            self._save_model_json()
 
-        self._save_model_json()
+        return write_json
 
 
-def sync_model(model: Model, model_filepath: str = "objectbox-model.json"):
-    """ Syncs the provided model with the model JSON file. """
+def sync_model(model: Model, model_filepath: str = "objectbox-model.json") -> bool:
+    """ Syncs the provided model with the model JSON file.
+    Returns True if the model JSON was written. """
 
     id_sync = IdSync(model, model_filepath)
-    id_sync.sync()
+    return id_sync.sync()

tests/test_idsync.py

@@ -1,3 +1,4 @@
+from typing import *
 from objectbox import *
 from objectbox.model import *
 from objectbox.model.entity import _Entity
@@ -18,14 +19,19 @@ def __init__(self):
         self.model_path = 'test.json'
         if os.path.exists(self.model_path):
             os.remove(self.model_path)
+        self.model = None
         self.db_path = 'testdb'
         Store.remove_db_files(self.db_path)
-    def sync(self, model):
+
+    def sync(self, model: Model) -> bool:
         self.model = model
-        sync_model(self.model, self.model_path)
+        return sync_model(self.model, self.model_path)
+
     def json(self):
         return json.load(open(self.model_path))
+
     def store(self):
+        assert self.model is not None
         return Store(model=self.model, directory=self.db_path)
 
 
@@ -367,3 +373,98 @@ class EntityA:
     assert box.count() == 1
     assert not hasattr(box.get(1), "name")
     assert box.get(1).renamed_name == "Luca"
+
+
+def test_model_json_updates(env):
+    """ Tests situations where the model JSON should be written/should not be written. """
+
+    def assert_model_json_written(value: bool, *entities: _Entity):
+        model = Model()
+        for entity in entities:
+            model.entity(entity)
+        assert env.sync(model) == value
+
+    # Init
+    @Entity()
+    class EntityA:
+        id = Id()
+        name = String()
+    assert_model_json_written(True, EntityA)
+
+    # Add entity
+    @Entity()
+    class EntityB:
+        id = Id()
+        name = String()
+    assert_model_json_written(True, EntityB)
+
+    entityb_uid = EntityB.uid
+
+    # Rename entity
+    @Entity(uid=entityb_uid)
+    class EntityC:
+        id = Id()
+        name = String()
+    assert_model_json_written(True, EntityC)
+
+    # Noop
+    model = Model()
+    model.entity(EntityC)
+    assert not env.sync(model)
+
+    # Add entity
+    @Entity()
+    class EntityD:
+        id = Id()
+        name = String()
+        age = Int8()
+    assert_model_json_written(True, EntityC, EntityD)
+
+    # Noop
+    assert_model_json_written(False, EntityC, EntityD)
+
+    # Replace entity
+    @Entity()
+    class EntityE:
+        id = Id()
+    assert_model_json_written(True, EntityD, EntityE)
+
+    # Noop
+    assert_model_json_written(False, EntityD, EntityE)
+
+    # Remove entity
+    assert_model_json_written(True, EntityD)
+
+    # Noop
+    assert_model_json_written(False, EntityD)
+
+    # Add property
+    @Entity()
+    class EntityD:
+        id = Id()
+        name = String()
+        age = Int8()
+        my_prop = String()
+    assert_model_json_written(True, EntityD)
+
+    my_prop_uid = EntityD.get_property("my_prop").uid
+
+    # Rename property
+    @Entity()
+    class EntityD:
+        id = Id()
+        name = String()
+        age = Int8()
+        my_prop_renamed = String(uid=my_prop_uid)
+    assert_model_json_written(True, EntityD)
+
+    # Noop
+    assert_model_json_written(False, EntityD)
+
+    # Remove property
+    @Entity()
+    class EntityD:
+        id = Id()
+        name = String()
+        age = Int8()
+    assert_model_json_written(True, EntityD)