Cache JSON schema validator for each plugin class.

diff --git a/controlpi/baseplugin.py b/controlpi/baseplugin.py
index 589e1c94e6f26a26668d781b549ae16b26ccdd26..c803462d61dd8bc2108b0ae5739450f99c19143c 100644 (file)
--- a/controlpi/baseplugin.py
+++ b/controlpi/baseplugin.py
@@ -87,7 +87,7 @@ import jsonschema  # type: ignore
 
 from controlpi.messagebus import MessageBus
 
-from typing import Union, Dict, List, Any
+from typing import Union, Dict, List, Any, Optional
 JSONSchema = Union[bool, Dict[str, Union[None, str, int, float, bool,
                                          Dict[str, Any], List[Any]]]]
 # Could be more specific.
@@ -156,26 +156,20 @@ class BasePlugin(ABC):
     overridden by concrete plugins.
     """
 
-    @property
-    @classmethod
-    @abstractmethod
-    def CONF_SCHEMA(cls) -> JSONSchema:
-        """JSON schema for configuration of plugin.
+    CONF_SCHEMA: JSONSchema = False
 
-        Given configurations are validated against this schema in __init__.
-        process_conf and run can assume a valid configuration in self.conf.
-        """
-        raise NotImplementedError
+    _validator: Optional[jsonschema.Draft7Validator] = None
 
     def __init__(self, bus: MessageBus, name: str, conf: PluginConf) -> None:
         # noqa: D107
-        assert isinstance(bus, MessageBus)
         self.bus = bus
-        assert isinstance(name, str)
         self.name = name
-        jsonschema.Draft7Validator.check_schema(type(self).CONF_SCHEMA)
-        validator = jsonschema.Draft7Validator(type(self).CONF_SCHEMA)
-        assert isinstance(conf, dict)
+        if not type(self)._validator:
+            jsonschema.Draft7Validator.check_schema(type(self).CONF_SCHEMA)
+            type(self)._validator = \
+                jsonschema.Draft7Validator(type(self).CONF_SCHEMA)
+        validator = type(self)._validator
+        assert isinstance(validator, jsonschema.Draft7Validator)
         valid = True
         for error in validator.iter_errors(conf):
             print(error)