first steps

uds/database/abstract_database.py

@@ -0,0 +1,74 @@
+"""Definition of UDS messages database for data encoding and decoding."""
+
+__all__ = ["AbstractService"]
+
+from abc import ABC, abstractmethod
+from typing import Dict, List, Union
+
+from uds.message import RequestSID, ResponseSID, UdsMessage, UdsMessageRecord
+from uds.utilities import RawBytesListAlias
+
+from .services import AbstractService
+
+from .abstract_data_record import DecodedDataRecord
+
+
+class AbstractDatabase(ABC):
+    """Common interface and implementation for UDS message databases."""
+
+    @property
+    @abstractmethod
+    def services(self) -> Dict[int, AbstractService]:
+        """
+        Get mapping of diagnostic services.
+
+        Keys are SID (int) values.
+        Values are diagnostic services with dedicated decoding and encoding implementation.
+        """
+
+    def encode(self,
+               sid: Union[int, RequestSID, ResponseSID],
+               **data_records_values: DataRecordValueAlias) -> RawBytesListAlias:
+        """
+        Encode diagnostic message payload from data records values.
+
+        :param sid: Service Identifier of a diagnostic message.
+        :param data_records_values: Value for each Data Record that is part a service message.
+            Each type represent other data:
+                - int type - raw value of a Data Record
+                - float type - physical value of a Data Record
+                - str type - text value of a Data Record
+                - iterable type - contains values for children Data Records
+                - dict type - values of children Data Records
+
+            .. warning:: Providing physical value as float might sometime cause issues due
+                :ref:`floating-point precision <https://docs.python.org/3/tutorial/floatingpoint.html>`.
+                The closest raw value would be evaluated and put into a payload.
+
+                To avoid rounding, provide raw value (int type).
+
+        :raise TypeError: Provided SID value is neither int, RequestSID nor ResponseSID type.
+        :raise ValueError: This database has no implementation for provided SID value.
+
+        :return: Payload of a diagnostic message.
+        """
+        if isinstance(sid, (RequestSID, ResponseSID)):
+            sid_int = sid.value
+        elif isinstance(sid, int):
+            sid_int = sid
+        else:
+            raise TypeError
+        if sid_int not in self.services:
+            raise ValueError
+        return self.services[sid_int].encode(**data_records_values)
+
+    def decode(self, message: Union[UdsMessage, UdsMessageRecord]) -> List[DecodedDataRecord]:
+        """
+        Decode physical values carried in payload of a diagnostic message.
+
+        :param message: A diagnostic message that is carrying payload to decode.
+
+        :return: Decoded Data Records values from provided diagnostic message.
+        """
+        sid_int = message.payload[0]
+        return self.services[sid_int].decode(message.payload)

uds/database/services/abstract_service.py

@@ -1,6 +1,6 @@
 """Definition of UDS Service data encoding and decoding."""
 
-__all__ = ["AbstractService"]
+__all__ = ["AbstractService", "DataRecordValueAlias"]
 
 from abc import ABC, abstractmethod
 from typing import Dict, Iterable, List, Union
@@ -30,24 +30,25 @@ def response_sid(self) -> ResponseSID:
     @abstractmethod
     def decode(self, payload: RawBytesAlias) -> List[DecodedDataRecord]:
         """
-        Decode physical values carried by a diagnostic message.
+        Decode physical values carried in payload of a diagnostic message.
 
         :param payload: Payload of a diagnostic message.
 
-        :return: Decoded values for all Data Records.
+        :return: Decoded Data Records values from provided diagnostic message.
         """
 
     @abstractmethod
     def encode(self, **data_records_values: DataRecordValueAlias) -> RawBytesListAlias:  # noqa: F841
         """
-        Encode diagnostic message from data records values.
+        Encode diagnostic message payload from data records values.
 
         :param data_records_values: Value for each Data Record that is part a service message.
             Each type represent other data:
                 - int type - raw value of a Data Record
                 - float type - physical value of a Data Record
                 - str type - text value of a Data Record
-                - iterable type - contains values for children Data Records
+                - iterable type - values for children Data Records
+                - dict type - values of children Data Records
 
             .. warning:: Providing physical value as float might sometime cause issues due
                 :ref:`floating-point precision <https://docs.python.org/3/tutorial/floatingpoint.html>`.