Refactor radar system

python_app/hardware_full/laser_control/monitoring/session.py

@@ -20,6 +20,8 @@ from dataclasses import asdict, dataclass
 from pathlib import Path
 from typing import Union
 
+from python_app.file_io import atomic_write_json
+
 _PathLike = Union[str, os.PathLike[str]]
 
 # Default IPC locations. Both are overridable via CLI/API so several runs can use
@@ -46,12 +48,7 @@ class LaserVariationSession:
         Writes to a temp file in the same directory then renames, so a concurrent
         checker never observes a half-written file.
         """
-        dest = Path(path)
-        dest.parent.mkdir(parents=True, exist_ok=True)
-        tmp = dest.with_name(f"{dest.name}.{os.getpid()}.tmp")
-        tmp.write_text(json.dumps(asdict(self), indent=2), encoding="utf-8")
-        os.replace(tmp, dest)
-        return dest
+        return atomic_write_json(Path(path), asdict(self))
 
     @classmethod
     def load(cls, path: _PathLike = DEFAULT_SESSION_PATH) -> "LaserVariationSession":

python_app/hardware_full/laser_control/protocol.py

@@ -196,6 +196,8 @@ class Protocol:
         the bus. Note the lock is advisory (``flock``): every program that opens
         this port must also use ``exclusive=True`` for the guarantee to hold.
         """
+        if self.is_connected:
+            return
         port = self._port_name or self._detect_port()
         try:
             self._serial = serial.Serial(
@@ -219,9 +221,10 @@ class Protocol:
 
     def disconnect(self) -> None:
         """Close the serial port if open."""
-        if self._serial and self._serial.is_open:
+        connection, self._serial = self._serial, None
+        if connection is not None and connection.is_open:
             logger.debug("Closing laser serial port")
-            self._serial.close()
+            connection.close()
 
     @property
     def is_connected(self) -> bool:
@@ -246,37 +249,6 @@ class Protocol:
             raise CommunicationError("Serial port is not connected")
         return self._serial.read(length)
 
-    # ---- Static encoding helpers (no connection required) ---------------
-
-    @staticmethod
-    def flipfour(value: int) -> int:
-        """Byte-swap a 16-bit integer (little-endian word swap)."""
-        return ((value & 0xFF) << 8) | ((value >> 8) & 0xFF)
-
-    @staticmethod
-    def pack_float(value: float) -> bytes:
-        return struct.pack('<f', value)
-
-    @staticmethod
-    def pack_uint16(value: int) -> bytes:
-        return struct.pack('<H', value)
-
-    @staticmethod
-    def calculate_crc(data: bytes) -> int:
-        """Return the XOR CRC over all 16-bit words except word 0 and the CRC field.
-
-        The command-code word (word 0) is excluded, matching the firmware's CRC
-        expectation.
-        """
-        hex_str = data.hex()
-        words = [hex_str[i:i+4] for i in range(0, len(hex_str), 4)]
-        # Word 0 (command code) is excluded from the CRC.
-        crc_words = words[1:]
-        result = int(crc_words[0], 16)
-        for w in crc_words[1:]:
-            result ^= int(w, 16)
-        return result
-
     # ---- Command encoders -----------------------------------------------
 
     @staticmethod
@@ -404,11 +376,6 @@ class Protocol:
         """Build DEFAULT_ENABLE command (0x2222) — reset device."""
         return bytearray.fromhex(_flipfour(_int_to_hex4(CMD_DEFAULT_ENABLE)))
 
-    @staticmethod
-    def encode_remove_file() -> bytes:
-        """Build REMOVE_FILE command (0x5555) — delete saved data."""
-        return bytearray.fromhex(_flipfour(_int_to_hex4(CMD_REMOVE_FILE)))
-
     # ---- Response decoders -----------------------------------------------
 
     @staticmethod
@@ -477,4 +444,4 @@ class Protocol:
     @staticmethod
     def state_to_description(state_hex_str: str) -> str:
         """Return human-readable description for a state hex string."""
-        return STATE_DESCRIPTIONS.get(state_hex_str, "Unknown or reserved error.")
+        return STATE_DESCRIPTIONS.get(state_hex_str, "Unknown or reserved error.")