feat: add cython extension for messages

build.py

@@ -22,6 +22,7 @@ def build(setup_kwargs):
             dict(
                 ext_modules=cythonize(
                     [
+                        "src/dbus_fast/message.py",
                         "src/dbus_fast/signature.py",
                         "src/dbus_fast/unpack.py",
                         "src/dbus_fast/_private/marshaller.py",

src/dbus_fast/message.pxd

@@ -0,0 +1,23 @@
+"""cdefs for message.py"""
+
+import cython
+
+
+cdef class Message:
+
+    cdef public str destination
+    cdef public str path
+    cdef public str interface
+    cdef public str member
+    cdef public object message_type
+    cdef public object flags
+    cdef public str error_name
+    cdef public unsigned int reply_serial
+    cdef public str sender
+    cdef public list unix_fds
+    cdef public str signature
+    cdef public object signature_tree
+    cdef public list body
+    cdef public unsigned int serial
+
+    cpdef _marshall(self, negotiate_unix_fd: bint)

src/dbus_fast/message.py

@@ -121,7 +121,7 @@ def __init__(
         self.error_name = (
             error_name if type(error_name) is not ErrorType else error_name.value
         )
-        self.reply_serial = reply_serial
+        self.reply_serial = reply_serial or 0
         self.sender = sender
         self.unix_fds = unix_fds
         if type(signature) is SignatureTree:
@@ -131,7 +131,7 @@ def __init__(
             self.signature = signature
             self.signature_tree = get_signature_tree(signature)
         self.body = body
-        self.serial = serial
+        self.serial = serial or 0
 
         if not validate:
             return