Minor BaseModel code re-organization.

[plomtask] / plomtask / db.py

diff --git a/plomtask/db.py b/plomtask/db.py
index b2f2142c9c6957c19e90674270a1635082050f59..df98dd0f130bbd75553b2e628cd739d793e98616 100644 (file)
--- a/plomtask/db.py
+++ b/plomtask/db.py
@@ -250,14 +250,19 @@ class BaseModel(Generic[BaseModelId]):
             raise HandledException(msg)
         self.id_ = id_
 
+    def __hash__(self) -> int:
+        hashable = [self.id_] + [getattr(self, name) for name in self.to_save]
+        for definition in self.to_save_relations:
+            attr = getattr(self, definition[2])
+            hashable += [tuple(rel.id_ for rel in attr)]
+        for name in self.to_save_versioned:
+            hashable += [hash(getattr(self, name))]
+        return hash(tuple(hashable))
+
     def __eq__(self, other: object) -> bool:
         if not isinstance(other, self.__class__):
             return False
-        to_hash_me = tuple([self.id_] +
-                           [getattr(self, name) for name in self.to_save])
-        to_hash_other = tuple([other.id_] +
-                              [getattr(other, name) for name in other.to_save])
-        return hash(to_hash_me) == hash(to_hash_other)
+        return hash(self) == hash(other)
 
     def __lt__(self, other: Any) -> bool:
         if not isinstance(other, self.__class__):
@@ -267,9 +272,11 @@ class BaseModel(Generic[BaseModelId]):
         assert isinstance(other.id_, int)
         return self.id_ < other.id_
 
+    # cache management
+
     @classmethod
-    def get_cached(cls: type[BaseModelInstance],
-                   id_: BaseModelId) -> BaseModelInstance | None:
+    def _get_cached(cls: type[BaseModelInstance],
+                    id_: BaseModelId) -> BaseModelInstance | None:
         """Get object of id_ from class's cache, or None if not found."""
         # pylint: disable=consider-iterating-dictionary
         cache = cls.get_cache()
@@ -306,6 +313,8 @@ class BaseModel(Generic[BaseModelId]):
         cache = self.__class__.get_cache()
         del cache[self.id_]
 
+    # object retrieval and generation
+
     @classmethod
     def from_table_row(cls: type[BaseModelInstance],
                        # pylint: disable=unused-argument
@@ -330,7 +339,7 @@ class BaseModel(Generic[BaseModelId]):
         """
         obj = None
         if id_ is not None:
-            obj = cls.get_cached(id_)
+            obj = cls._get_cached(id_)
             if not obj:
                 for row in db_conn.row_where(cls.table_name, 'id', id_):
                     obj = cls.from_table_row(db_conn, row)
@@ -408,6 +417,8 @@ class BaseModel(Generic[BaseModelId]):
             return filtered
         return items
 
+    # database writing
+
     def save(self, db_conn: DatabaseConnection) -> None:
         """Write self to DB and cache and ensure .id_.
 
@@ -437,7 +448,9 @@ class BaseModel(Generic[BaseModelId]):
 
     def remove(self, db_conn: DatabaseConnection) -> None:
         """Remove from DB and cache, including dependencies."""
-        if self.id_ is None or self.__class__.get_cached(self.id_) is None:
+        # pylint: disable=protected-access
+        # (since we remain within class)
+        if self.id_ is None or self.__class__._get_cached(self.id_) is None:
             raise HandledException('cannot remove unsaved item')
         for attr_name in self.to_save_versioned:
             getattr(self, attr_name).remove(db_conn)