Feat #58 - fix backpressure logic and update tests

amqp/adapter/data_message_factory.py

@@ -7,10 +7,11 @@ import json
 import re
 from datetime import datetime, timezone
 from io import BytesIO
-from typing import Dict, List
+from typing import Any, Dict, List
 
 import amqp.adapter.file_handler
 from amqp.adapter.file_handler import FileHandler, StreamingFileHandler
+from amqp.adapter.pydantic_serializer import python_type_to_json
 from amqp.adapter.serializer import (
     map_as_string,
     map_with_list_as_string,
@@ -112,6 +113,32 @@ class DataMessageFactory:
             payload,
         )
 
+    def create_rpc_message(
+        self,
+        fq_method_name: str,
+        swarm_id: str,
+        args: Dict[str, Any] = None,
+    ) -> DataMessage:
+        """
+        Create a RPC message with the given parameters.
+        :param fq_method_name: fully qualified method name (e.g. 'com.example.ServiceClass.method_name')
+        :param args: arguments whose serialized form will form the request body
+        :return: DataMessage object
+        """
+        package, class_name, method = fq_method_name.rsplit(".", 2)
+        headers = {"Content-Type": ["application/octet-stream"], "Return-Address": [swarm_id]}
+        trace_info = {}
+        return DataMessage(
+            DataMessageMagicByte.RPC_REQUEST.value,
+            self.generate_snowflake_id(),
+            package,
+            class_name,
+            method,
+            headers,
+            trace_info,
+            python_type_to_json(args) if args else b"",
+        )
+
     @staticmethod
     def amq_message_routing_key(message: DataMessage) -> str:
         """