helper functions for bitwise flag setting

modem/arq_session.py

@@ -25,6 +25,14 @@ class ARQSession():
     }
 
 
+    """
+        helpers.set_flag(byte, 'DATA-ACK-NACK', True, FLAG_POSITIONS)
+        helpers.get_flag(byte, 'DATA-ACK-NACK', FLAG_POSITIONS)    
+    """
+    FLAG_POSITIONS = {
+        'DATA-ACK-NACK': 0,  # Bit position for DATA-ACK-NACK
+    }
+
     def __init__(self, config: dict, modem, dxcall: str):
         self.logger = structlog.get_logger(type(self).__name__)
         self.config = config
@@ -83,4 +91,5 @@ class ARQSession():
                 return
         
         self.log(f"Ignoring unknow transition from state {self.state} with frame {frame['frame_type']}")
- 
+
+

modem/helpers.py

@@ -667,4 +667,45 @@ def check_if_file_exists(path):
         log.warning(
             "[Modem] [FILE] Lookup failed", e=e, path=path,
         )
-        return False
+        return False
+
+
+def set_bit(byte, position, value):
+    """Set the bit at 'position' to 'value' in the given byte."""
+    if not 0 <= position <= 7:
+        raise ValueError("Position must be between 0 and 7")
+
+    if value:
+        return byte | (1 << position)
+    else:
+        return byte & ~(1 << position)
+
+def get_bit(byte, position):
+    """Get the boolean value of the bit at 'position' in the given byte."""
+    if not 0 <= position <= 7:
+        raise ValueError("Position must be between 0 and 7")
+
+    return (byte & (1 << position)) != 0
+
+def set_flag(byte, flag_name, value, flag_dict):
+    """Set the flag in the byte according to the flag dictionary.
+
+    # Define a dictionary mapping flag names to their bit positions
+        flag_dict = {
+            'FLAG1': 0,  # Bit position for FLAG1
+            'FLAG2': 1,  # Bit position for FLAG2, etc.
+            'FLAG3': 2
+        }
+
+    """
+    if flag_name not in flag_dict:
+        raise ValueError(f"Unknown flag name: {flag_name}")
+    position = flag_dict[flag_name]
+    return set_bit(byte, position, value)
+
+def get_flag(byte, flag_name, flag_dict):
+    """Get the value of the flag from the byte according to the flag dictionary."""
+    if flag_name not in flag_dict:
+        raise ValueError(f"Unknown flag name: {flag_name}")
+    position = flag_dict[flag_name]
+    return get_bit(byte, position)