Avoid a dict lookup and int conversion to process every packet (#946)

aioesphomeapi/_frame_helper/noise.pxd

@@ -49,7 +49,9 @@ cdef class APINoiseFrameHelper(APIFrameHelper):
     @cython.locals(
         msg=bytes,
         type_high="unsigned char",
-        type_low="unsigned char"
+        type_low="unsigned char",
+        msg_type="unsigned int",
+        payload=bytes
     )
     cdef void _handle_frame(self, bytes frame)
 

aioesphomeapi/_frame_helper/noise.py

@@ -359,7 +359,9 @@ def _handle_frame(self, frame: bytes) -> None:
         # N bytes: message data
         type_high = msg[0]
         type_low = msg[1]
-        self._connection.process_packet((type_high << 8) | type_low, msg[4:])
+        msg_type = (type_high << 8) | type_low
+        payload = msg[4:]
+        self._connection.process_packet(msg_type, payload)
 
     def _handle_closed(self, frame: bytes) -> None:  # pylint: disable=unused-argument
         """Handle a closed frame."""

aioesphomeapi/connection.pxd

@@ -73,6 +73,8 @@ cpdef void handle_complex_message(
 cdef object _handle_timeout
 cdef object _handle_complex_message
 
+cdef tuple MESSAGE_NUMBER_TO_PROTO
+
 
 @cython.dataclasses.dataclass
 cdef class ConnectionParams:
@@ -119,7 +121,7 @@ cdef class APIConnection:
     cdef void send_messages(self, tuple messages)
 
     @cython.locals(handlers=set, handlers_copy=set)
-    cpdef void process_packet(self, object msg_type_proto, object data)
+    cpdef void process_packet(self, unsigned int msg_type_proto, object data)
 
     cdef void _async_cancel_pong_timer(self)
 

aioesphomeapi/connection.py

@@ -63,6 +63,9 @@
 
 _LOGGER = logging.getLogger(__name__)
 
+MESSAGE_NUMBER_TO_PROTO = tuple(MESSAGE_TYPE_TO_PROTO.values())
+
+
 PREFERRED_BUFFER_SIZE = 2097152  # Set buffer limit to 2MB
 MIN_BUFFER_SIZE = 131072  # Minimum buffer size to use
 
@@ -888,22 +891,27 @@ def _set_fatal_exception_if_unset(self, err: Exception) -> None:
     def process_packet(self, msg_type_proto: _int, data: _bytes) -> None:
         """Process an incoming packet."""
         debug_enabled = self._debug_enabled
-        if (klass := MESSAGE_TYPE_TO_PROTO.get(msg_type_proto)) is None:
-            if debug_enabled:
-                _LOGGER.debug(
-                    "%s: Skipping unknown message type %s",
-                    self.log_name,
-                    msg_type_proto,
-                )
-            return
-
         try:
+            # MESSAGE_NUMBER_TO_PROTO is 0-indexed
+            # but the message type is 1-indexed
+            klass = MESSAGE_NUMBER_TO_PROTO[msg_type_proto - 1]
             msg: message.Message = klass()
             # MergeFromString instead of ParseFromString since
             # ParseFromString will clear the message first and
             # the msg is already empty.
             msg.MergeFromString(data)
         except Exception as e:
+            # IndexError will be very rare so we check for it
+            # after the broad exception catch to avoid having
+            # to check the exception type twice for the common case
+            if isinstance(e, IndexError):
+                if debug_enabled:
+                    _LOGGER.debug(
+                        "%s: Skipping unknown message type %s",
+                        self.log_name,
+                        msg_type_proto,
+                    )
+                return
             _LOGGER.error(
                 "%s: Invalid protobuf message: type=%s data=%s: %s",
                 self.log_name,

aioesphomeapi/core.py

@@ -393,3 +393,5 @@ def __init__(self, error: BluetoothGATTError) -> None:
     117: UpdateStateResponse,
     118: UpdateCommandRequest,
 }
+
+MESSAGE_NUMBER_TO_PROTO = tuple(MESSAGE_TYPE_TO_PROTO.values())

tests/test_core.py

@@ -0,0 +1,9 @@
+from __future__ import annotations
+
+from aioesphomeapi.core import MESSAGE_TYPE_TO_PROTO
+
+
+def test_order_and_no_missing_numbers_in_message_type_to_proto():
+    """Test that MESSAGE_TYPE_TO_PROTO has no missing numbers."""
+    for idx, (k, v) in enumerate(MESSAGE_TYPE_TO_PROTO.items()):
+        assert idx + 1 == k