[haiz] haiz

backend/db/models/guid.py

@@ -0,0 +1,56 @@
+import uuid
+from typing import Any
+
+from sqlalchemy import Dialect
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.types import CHAR, TypeDecorator
+
+
+class GUID(TypeDecorator):
+    """Platform-independent GUID type.
+    Uses PostgreSQL's UUID type, otherwise uses
+    CHAR(32), storing as stringified hex values.
+    """
+
+    impl = CHAR
+    cache_ok = True
+
+    @staticmethod
+    def generate():
+        return uuid.uuid4()
+
+    @staticmethod
+    def convert_value_to_guid(value: Any, dialect: Dialect) -> str | None:
+        if value is None:
+            return value
+        elif dialect.name == "postgresql":
+            return str(value)
+        else:
+            if not isinstance(value, uuid.UUID):
+                return "%.32x" % uuid.UUID(value).int
+            else:
+                # hexstring
+                return "%.32x" % value.int
+
+    def load_dialect_impl(self, dialect):
+        if dialect.name == "postgresql":
+            return dialect.type_descriptor(UUID())
+        else:
+            return dialect.type_descriptor(CHAR(32))
+
+    def process_bind_param(self, value, dialect):
+        return self.convert_value_to_guid(value, dialect)
+
+    def _uuid_value(self, value):
+        if value is None:
+            return value
+        else:
+            if not isinstance(value, uuid.UUID):
+                value = uuid.UUID(value)
+            return value
+
+    def process_result_value(self, value, dialect):
+        return self._uuid_value(value)
+
+    def sort_key_function(self, value):
+        return self._uuid_value(value)