nautilus_common/msgbus/
message.rs

1// -------------------------------------------------------------------------------------------------
2//  Copyright (C) 2015-2026 Nautech Systems Pty Ltd. All rights reserved.
3//  https://nautechsystems.io
4//
5//  Licensed under the GNU Lesser General Public License Version 3.0 (the "License");
6//  You may not use this file except in compliance with the License.
7//  You may obtain a copy of the License at https://www.gnu.org/licenses/lgpl-3.0.en.html
8//
9//  Unless required by applicable law or agreed to in writing, software
10//  distributed under the License is distributed on an "AS IS" BASIS,
11//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12//  See the License for the specific language governing permissions and
13//  limitations under the License.
14// -------------------------------------------------------------------------------------------------
15
16use std::fmt::Display;
17
18use bytes::Bytes;
19use serde::{Deserialize, Serialize};
20use ustr::Ustr;
21
22use super::switchboard::CLOSE_TOPIC;
23
24/// Represents a bus message including a topic and serialized payload.
25#[derive(Clone, Debug, Serialize, Deserialize)]
26#[cfg_attr(
27    feature = "python",
28    pyo3::pyclass(module = "nautilus_trader.core.nautilus_pyo3.common", from_py_object)
29)]
30#[cfg_attr(
31    feature = "python",
32    pyo3_stub_gen::derive::gen_stub_pyclass(module = "nautilus_trader.common")
33)]
34pub struct BusMessage {
35    /// The topic to publish the message on.
36    pub topic: Ustr,
37    /// The serialized payload for the message.
38    pub payload: Bytes,
39}
40
41impl BusMessage {
42    /// Creates a new [`BusMessage`] instance.
43    pub fn new(topic: Ustr, payload: Bytes) -> Self {
44        debug_assert!(!topic.is_empty());
45        Self { topic, payload }
46    }
47
48    /// Creates a new [`BusMessage`] instance with a string-like topic.
49    ///
50    /// This is a convenience constructor that converts any string-like type
51    /// (implementing `AsRef<str>`) into the required `Ustr` type.
52    pub fn with_str_topic<T: AsRef<str>>(topic: T, payload: Bytes) -> Self {
53        Self::new(Ustr::from(topic.as_ref()), payload)
54    }
55
56    /// Creates a new [`BusMessage`] instance with the `CLOSE` topic and empty payload.
57    pub fn new_close() -> Self {
58        Self::with_str_topic(CLOSE_TOPIC, Bytes::new())
59    }
60}
61
62impl Display for BusMessage {
63    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
64        write!(
65            f,
66            "[{}] {}",
67            self.topic,
68            String::from_utf8_lossy(&self.payload)
69        )
70    }
71}
72
73#[cfg(test)]
74mod tests {
75    use bytes::Bytes;
76    use rstest::rstest;
77
78    use super::*;
79
80    #[rstest]
81    #[case("test/topic", "payload data")]
82    #[case("events/trading", "Another payload")]
83    fn test_with_str_topic_str(#[case] topic: &str, #[case] payload_str: &str) {
84        let payload = Bytes::from(payload_str.to_string());
85
86        let message = BusMessage::with_str_topic(topic, payload.clone());
87
88        assert_eq!(message.topic.as_str(), topic);
89        assert_eq!(message.payload, payload);
90    }
91
92    #[rstest]
93    fn test_with_str_topic_string() {
94        let topic_string = String::from("orders/new");
95        let payload = Bytes::from("order payload data");
96
97        let message = BusMessage::with_str_topic(topic_string.clone(), payload.clone());
98
99        assert_eq!(message.topic.as_str(), topic_string);
100        assert_eq!(message.payload, payload);
101    }
102
103    #[rstest]
104    fn test_new_close() {
105        let message = BusMessage::new_close();
106
107        assert_eq!(message.topic.as_str(), "CLOSE");
108        assert!(message.payload.is_empty());
109    }
110}
nautilus_common/msgbus/message.rs

nautilus_common/msgbus/
message.rs
