perf: Improve performance and code style for proto_utils.py (#452)

- Pre-compile regular expressions
- Use `cls` instead of `ClassName`
- Change `ToProto.data()` to use `dict_to_struct()`
- Reduce duplication by combining `ToProto.update_event()` and
`ToProto.stream_response()`
- Added missing conversion for type `MutualTlsSecurityScheme`

Author: holtskinner

src/a2a/utils/proto_utils.py

@@ -18,12 +18,34 @@
 
 
 # Regexp patterns for matching
-_TASK_NAME_MATCH = r'tasks/([\w-]+)'
-_TASK_PUSH_CONFIG_NAME_MATCH = (
+_TASK_NAME_MATCH = re.compile(r'tasks/([\w-]+)')
+_TASK_PUSH_CONFIG_NAME_MATCH = re.compile(
     r'tasks/([\w-]+)/pushNotificationConfigs/([\w-]+)'
 )
 
 
+def dict_to_struct(dictionary: dict[str, Any]) -> struct_pb2.Struct:
+    """Converts a Python dict to a Struct proto.
+
+    Unfortunately, using `json_format.ParseDict` does not work because this
+    wants the dictionary to be an exact match of the Struct proto with fields
+    and keys and values, not the traditional Python dict structure.
+
+    Args:
+      dictionary: The Python dict to convert.
+
+    Returns:
+      The Struct proto.
+    """
+    struct = struct_pb2.Struct()
+    for key, val in dictionary.items():
+        if isinstance(val, dict):
+            struct[key] = dict_to_struct(val)
+        else:
+            struct[key] = val
+    return struct
+
+
 class ToProto:
     """Converts Python types to proto types."""
 
@@ -33,11 +55,11 @@ def message(cls, message: types.Message | None) -> a2a_pb2.Message | None:
             return None
         return a2a_pb2.Message(
             message_id=message.message_id,
-            content=[ToProto.part(p) for p in message.parts],
+            content=[cls.part(p) for p in message.parts],
             context_id=message.context_id or '',
             task_id=message.task_id or '',
             role=cls.role(message.role),
-            metadata=ToProto.metadata(message.metadata),
+            metadata=cls.metadata(message.metadata),
         )
 
     @classmethod
@@ -53,20 +75,14 @@ def part(cls, part: types.Part) -> a2a_pb2.Part:
         if isinstance(part.root, types.TextPart):
             return a2a_pb2.Part(text=part.root.text)
         if isinstance(part.root, types.FilePart):
-            return a2a_pb2.Part(file=ToProto.file(part.root.file))
+            return a2a_pb2.Part(file=cls.file(part.root.file))
         if isinstance(part.root, types.DataPart):
-            return a2a_pb2.Part(data=ToProto.data(part.root.data))
+            return a2a_pb2.Part(data=cls.data(part.root.data))
         raise ValueError(f'Unsupported part type: {part.root}')
 
     @classmethod
     def data(cls, data: dict[str, Any]) -> a2a_pb2.DataPart:
-        json_data = json.dumps(data)
-        return a2a_pb2.DataPart(
-            data=json_format.Parse(
-                json_data,
-                struct_pb2.Struct(),
-            )
-        )
+        return a2a_pb2.DataPart(data=dict_to_struct(data))
 
     @classmethod
     def file(
@@ -87,14 +103,14 @@ def task(cls, task: types.Task) -> a2a_pb2.Task:
         return a2a_pb2.Task(
             id=task.id,
             context_id=task.context_id,
-            status=ToProto.task_status(task.status),
+            status=cls.task_status(task.status),
             artifacts=(
-                [ToProto.artifact(a) for a in task.artifacts]
+                [cls.artifact(a) for a in task.artifacts]
                 if task.artifacts
                 else None
             ),
             history=(
-                [ToProto.message(h) for h in task.history]  # type: ignore[misc]
+                [cls.message(h) for h in task.history]  # type: ignore[misc]
                 if task.history
                 else None
             ),
@@ -103,8 +119,8 @@ def task(cls, task: types.Task) -> a2a_pb2.Task:
     @classmethod
     def task_status(cls, status: types.TaskStatus) -> a2a_pb2.TaskStatus:
         return a2a_pb2.TaskStatus(
-            state=ToProto.task_state(status.state),
-            update=ToProto.message(status.message),
+            state=cls.task_state(status.state),
+            update=cls.message(status.message),
         )
 
     @classmethod
@@ -132,9 +148,9 @@ def artifact(cls, artifact: types.Artifact) -> a2a_pb2.Artifact:
         return a2a_pb2.Artifact(
             artifact_id=artifact.artifact_id,
             description=artifact.description,
-            metadata=ToProto.metadata(artifact.metadata),
+            metadata=cls.metadata(artifact.metadata),
             name=artifact.name,
-            parts=[ToProto.part(p) for p in artifact.parts],
+            parts=[cls.part(p) for p in artifact.parts],
         )
 
     @classmethod
@@ -151,7 +167,7 @@ def push_notification_config(
         cls, config: types.PushNotificationConfig
     ) -> a2a_pb2.PushNotificationConfig:
         auth_info = (
-            ToProto.authentication_info(config.authentication)
+            cls.authentication_info(config.authentication)
             if config.authentication
             else None
         )
@@ -169,8 +185,8 @@ def task_artifact_update_event(
         return a2a_pb2.TaskArtifactUpdateEvent(
             task_id=event.task_id,
             context_id=event.context_id,
-            artifact=ToProto.artifact(event.artifact),
-            metadata=ToProto.metadata(event.metadata),
+            artifact=cls.artifact(event.artifact),
+            metadata=cls.metadata(event.metadata),
             append=event.append or False,
             last_chunk=event.last_chunk or False,
         )
@@ -182,8 +198,8 @@ def task_status_update_event(
         return a2a_pb2.TaskStatusUpdateEvent(
             task_id=event.task_id,
             context_id=event.context_id,
-            status=ToProto.task_status(event.status),
-            metadata=ToProto.metadata(event.metadata),
+            status=cls.task_status(event.status),
+            metadata=cls.metadata(event.metadata),
             final=event.final,
         )
 
@@ -195,7 +211,7 @@ def message_send_configuration(
             return a2a_pb2.SendMessageConfiguration()
         return a2a_pb2.SendMessageConfiguration(
             accepted_output_modes=config.accepted_output_modes,
-            push_notification=ToProto.push_notification_config(
+            push_notification=cls.push_notification_config(
                 config.push_notification_config
             )
             if config.push_notification_config
@@ -213,19 +229,7 @@ def update_event(
         | types.TaskArtifactUpdateEvent,
     ) -> a2a_pb2.StreamResponse:
         """Converts a task, message, or task update event to a StreamResponse."""
-        if isinstance(event, types.TaskStatusUpdateEvent):
-            return a2a_pb2.StreamResponse(
-                status_update=ToProto.task_status_update_event(event)
-            )
-        if isinstance(event, types.TaskArtifactUpdateEvent):
-            return a2a_pb2.StreamResponse(
-                artifact_update=ToProto.task_artifact_update_event(event)
-            )
-        if isinstance(event, types.Message):
-            return a2a_pb2.StreamResponse(msg=ToProto.message(event))
-        if isinstance(event, types.Task):
-            return a2a_pb2.StreamResponse(task=ToProto.task(event))
-        raise ValueError(f'Unsupported event type: {type(event)}')
+        return cls.stream_response(event)
 
     @classmethod
     def task_or_message(
@@ -257,9 +261,11 @@ def stream_response(
             return a2a_pb2.StreamResponse(
                 status_update=cls.task_status_update_event(event),
             )
-        return a2a_pb2.StreamResponse(
-            artifact_update=cls.task_artifact_update_event(event),
-        )
+        if isinstance(event, types.TaskArtifactUpdateEvent):
+            return a2a_pb2.StreamResponse(
+                artifact_update=cls.task_artifact_update_event(event),
+            )
+        raise ValueError(f'Unsupported event type: {type(event)}')
 
     @classmethod
     def task_push_notification_config(
@@ -480,11 +486,11 @@ class FromProto:
     def message(cls, message: a2a_pb2.Message) -> types.Message:
         return types.Message(
             message_id=message.message_id,
-            parts=[FromProto.part(p) for p in message.content],
+            parts=[cls.part(p) for p in message.content],
             context_id=message.context_id or None,
             task_id=message.task_id or None,
-            role=FromProto.role(message.role),
-            metadata=FromProto.metadata(message.metadata),
+            role=cls.role(message.role),
+            metadata=cls.metadata(message.metadata),
         )
 
     @classmethod
@@ -498,13 +504,9 @@ def part(cls, part: a2a_pb2.Part) -> types.Part:
         if part.HasField('text'):
             return types.Part(root=types.TextPart(text=part.text))
         if part.HasField('file'):
-            return types.Part(
-                root=types.FilePart(file=FromProto.file(part.file))
-            )
+            return types.Part(root=types.FilePart(file=cls.file(part.file)))
         if part.HasField('data'):
-            return types.Part(
-                root=types.DataPart(data=FromProto.data(part.data))
-            )
+            return types.Part(root=types.DataPart(data=cls.data(part.data)))
         raise ValueError(f'Unsupported part type: {part}')
 
     @classmethod
@@ -543,16 +545,16 @@ def task(cls, task: a2a_pb2.Task) -> types.Task:
         return types.Task(
             id=task.id,
             context_id=task.context_id,
-            status=FromProto.task_status(task.status),
-            artifacts=[FromProto.artifact(a) for a in task.artifacts],
-            history=[FromProto.message(h) for h in task.history],
+            status=cls.task_status(task.status),
+            artifacts=[cls.artifact(a) for a in task.artifacts],
+            history=[cls.message(h) for h in task.history],
         )
 
     @classmethod
     def task_status(cls, status: a2a_pb2.TaskStatus) -> types.TaskStatus:
         return types.TaskStatus(
-            state=FromProto.task_state(status.state),
-            message=FromProto.message(status.update),
+            state=cls.task_state(status.state),
+            message=cls.message(status.update),
         )
 
     @classmethod
@@ -580,9 +582,9 @@ def artifact(cls, artifact: a2a_pb2.Artifact) -> types.Artifact:
         return types.Artifact(
             artifact_id=artifact.artifact_id,
             description=artifact.description,
-            metadata=FromProto.metadata(artifact.metadata),
+            metadata=cls.metadata(artifact.metadata),
             name=artifact.name,
-            parts=[FromProto.part(p) for p in artifact.parts],
+            parts=[cls.part(p) for p in artifact.parts],
         )
 
     @classmethod
@@ -592,8 +594,8 @@ def task_artifact_update_event(
         return types.TaskArtifactUpdateEvent(
             task_id=event.task_id,
             context_id=event.context_id,
-            artifact=FromProto.artifact(event.artifact),
-            metadata=FromProto.metadata(event.metadata),
+            artifact=cls.artifact(event.artifact),
+            metadata=cls.metadata(event.metadata),
             append=event.append,
             last_chunk=event.last_chunk,
         )
@@ -605,8 +607,8 @@ def task_status_update_event(
         return types.TaskStatusUpdateEvent(
             task_id=event.task_id,
             context_id=event.context_id,
-            status=FromProto.task_status(event.status),
-            metadata=FromProto.metadata(event.metadata),
+            status=cls.task_status(event.status),
+            metadata=cls.metadata(event.metadata),
             final=event.final,
         )
 
@@ -618,7 +620,7 @@ def push_notification_config(
             id=config.id,
             url=config.url,
             token=config.token,
-            authentication=FromProto.authentication_info(config.authentication)
+            authentication=cls.authentication_info(config.authentication)
             if config.HasField('authentication')
             else None,
         )
@@ -638,7 +640,7 @@ def message_send_configuration(
     ) -> types.MessageSendConfiguration:
         return types.MessageSendConfiguration(
             accepted_output_modes=list(config.accepted_output_modes),
-            push_notification_config=FromProto.push_notification_config(
+            push_notification_config=cls.push_notification_config(
                 config.push_notification
             )
             if config.HasField('push_notification')
@@ -666,18 +668,16 @@ def task_id_params(
             | a2a_pb2.GetTaskPushNotificationConfigRequest
         ),
     ) -> types.TaskIdParams:
-        # This is currently incomplete until the core sdk supports multiple
-        # configs for a single task.
         if isinstance(request, a2a_pb2.GetTaskPushNotificationConfigRequest):
-            m = re.match(_TASK_PUSH_CONFIG_NAME_MATCH, request.name)
+            m = _TASK_PUSH_CONFIG_NAME_MATCH.match(request.name)
             if not m:
                 raise ServerError(
                     error=types.InvalidParamsError(
                         message=f'No task for {request.name}'
                     )
                 )
             return types.TaskIdParams(id=m.group(1))
-        m = re.match(_TASK_NAME_MATCH, request.name)
+        m = _TASK_NAME_MATCH.match(request.name)
         if not m:
             raise ServerError(
                 error=types.InvalidParamsError(
@@ -691,7 +691,7 @@ def task_push_notification_config_request(
         cls,
         request: a2a_pb2.CreateTaskPushNotificationConfigRequest,
     ) -> types.TaskPushNotificationConfig:
-        m = re.match(_TASK_NAME_MATCH, request.parent)
+        m = _TASK_NAME_MATCH.match(request.parent)
         if not m:
             raise ServerError(
                 error=types.InvalidParamsError(
@@ -710,7 +710,7 @@ def task_push_notification_config(
         cls,
         config: a2a_pb2.TaskPushNotificationConfig,
     ) -> types.TaskPushNotificationConfig:
-        m = re.match(_TASK_PUSH_CONFIG_NAME_MATCH, config.name)
+        m = _TASK_PUSH_CONFIG_NAME_MATCH.match(config.name)
         if not m:
             raise ServerError(
                 error=types.InvalidParamsError(
@@ -767,7 +767,7 @@ def task_query_params(
         cls,
         request: a2a_pb2.GetTaskRequest,
     ) -> types.TaskQueryParams:
-        m = re.match(_TASK_NAME_MATCH, request.name)
+        m = _TASK_NAME_MATCH.match(request.name)
         if not m:
             raise ServerError(
                 error=types.InvalidParamsError(
@@ -862,6 +862,12 @@ def security_scheme(
                     flows=cls.oauth2_flows(scheme.oauth2_security_scheme.flows),
                 )
             )
+        if scheme.HasField('mtls_security_scheme'):
+            return types.SecurityScheme(
+                root=types.MutualTLSSecurityScheme(
+                    description=scheme.mtls_security_scheme.description,
+                )
+            )
         return types.SecurityScheme(
             root=types.OpenIdConnectSecurityScheme(
                 description=scheme.open_id_connect_security_scheme.description,
@@ -920,7 +926,9 @@ def stream_response(
             return cls.task(response.task)
         if response.HasField('status_update'):
             return cls.task_status_update_event(response.status_update)
-        return cls.task_artifact_update_event(response.artifact_update)
+        if response.HasField('artifact_update'):
+            return cls.task_artifact_update_event(response.artifact_update)
+        raise ValueError('Unsupported StreamResponse type')
 
     @classmethod
     def skill(cls, skill: a2a_pb2.AgentSkill) -> types.AgentSkill:
@@ -943,25 +951,3 @@ def role(cls, role: a2a_pb2.Role) -> types.Role:
                 return types.Role.agent
             case _:
                 return types.Role.agent
-
-
-def dict_to_struct(dictionary: dict[str, Any]) -> struct_pb2.Struct:
-    """Converts a Python dict to a Struct proto.
-
-    Unfortunately, using `json_format.ParseDict` does not work because this
-    wants the dictionary to be an exact match of the Struct proto with fields
-    and keys and values, not the traditional Python dict structure.
-
-    Args:
-      dictionary: The Python dict to convert.
-
-    Returns:
-      The Struct proto.
-    """
-    struct = struct_pb2.Struct()
-    for key, val in dictionary.items():
-        if isinstance(val, dict):
-            struct[key] = dict_to_struct(val)
-        else:
-            struct[key] = val
-    return struct