REFACT dmrproto

dmrtools/dmrproto/base_fields.py

@@ -0,0 +1,70 @@
+from abc import ABC, abstractmethod
+from typing import Any
+
+from .exceptions import DMRPFieldOutOfRangeException
+
+
+class DMRPFieldBase(ABC):
+    def __init__(self, name: str, offset: int, bytelen: int) -> None:
+        self.name, self.offset, self.bytelen = name, offset, bytelen
+        self.eoffset = offset + bytelen
+        self.typename = f"bytes{self.bytelen}"
+
+    def get(self, obj) -> bytes:
+        return bytes(obj._data[self.offset:self.eoffset])
+
+    def set(self, obj, value: bytes):
+        if not isinstance(value, bytes) or self.bytelen != len(value):
+            raise DMRPFieldOutOfRangeException(self.name, self.typename)
+        obj._data[self.offset:self.eoffset] = value
+
+    @abstractmethod
+    def __get__(self, obj, cls = None) -> Any:
+        pass
+
+    @abstractmethod
+    def __set__(self, obj, value: Any) -> None:
+        pass
+
+
+class DMRPFieldBytes(DMRPFieldBase):
+    def __get__(self, obj, cls = None) -> bytes:
+        return self.get(obj)
+
+    def __set__(self, obj, value: bytes) -> None:
+        self.set(obj, value)
+
+
+class DMRPFieldStr(DMRPFieldBase):
+    def __init__(self, name: str, offset: int, bytelen: int,
+                 pad_with: bytes = b'\x20') -> None:
+        super().__init__(name, offset, bytelen)
+        self.typename = 'str'
+        self.pad_with = pad_with
+
+    def __get__(self, obj, cls = None) -> str:
+        return (self.get(obj).strip(b'\x20\x00')
+                .decode(encoding='ascii', errors='ignore'))
+
+    def __set__(self, obj, value: str) -> None:
+        bvalue = value.encode()
+        if len(bvalue) > self.bytelen:
+            bvalue = bvalue[:self.bytelen]
+        bvalue = bvalue.ljust(self.bytelen, self.pad_with)
+        self.set(obj, bvalue)
+
+
+class DMRPFieldInt(DMRPFieldBase):
+    def __init__(self, name: str, offset: int, bytelen: int) -> None:
+        super().__init__(name, offset, bytelen)
+        self.typename = f"uint{str(bytelen * 8)}"
+
+    def __get__(self, obj, cls = None) -> int:
+        return int.from_bytes(self.get(obj), byteorder="big")
+
+    def __set__(self, obj, value: int) -> None:
+        if not (0 <= value < 1<<(self.bytelen * 8)):
+            raise DMRPFieldOutOfRangeException(self.name, self.typename)
+        self.set(obj, value.to_bytes(self.bytelen, byteorder="big"))
+
+