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dynamo_runtime/component/
component.rs

1// SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
2// SPDX-License-Identifier: Apache-2.0
3
4use anyhow::{Context, Result};
5use async_trait::async_trait;
6use futures::stream::StreamExt;
7use futures::{Stream, TryStreamExt};
8use serde::{Deserialize, Serialize};
9
10use crate::component::Component;
11use crate::traits::DistributedRuntimeProvider;
12use crate::traits::events::{EventPublisher, EventSubscriber};
13
14#[async_trait]
15impl EventPublisher for Component {
16    fn subject(&self) -> String {
17        format!("namespace.{}.component.{}", self.namespace.name, self.name)
18    }
19
20    async fn publish(
21        &self,
22        event_name: impl AsRef<str> + Send + Sync,
23        event: &(impl Serialize + Send + Sync),
24    ) -> Result<()> {
25        let bytes = serde_json::to_vec(event)?;
26        self.publish_bytes(event_name, bytes).await
27    }
28
29    async fn publish_bytes(
30        &self,
31        event_name: impl AsRef<str> + Send + Sync,
32        bytes: Vec<u8>,
33    ) -> Result<()> {
34        let subject = format!("{}.{}", self.subject(), event_name.as_ref());
35        self.drt()
36            .kv_router_nats_publish(subject, bytes.into())
37            .await?;
38        Ok(())
39    }
40}
41
42#[async_trait]
43impl EventSubscriber for Component {
44    async fn subscribe(
45        &self,
46        event_name: impl AsRef<str> + Send + Sync,
47    ) -> Result<async_nats::Subscriber> {
48        let subject = format!("{}.{}", self.subject(), event_name.as_ref());
49        Ok(self.drt().kv_router_nats_subscribe(subject).await?)
50    }
51
52    async fn subscribe_with_type<T: for<'de> Deserialize<'de> + Send + 'static>(
53        &self,
54        event_name: impl AsRef<str> + Send + Sync,
55    ) -> Result<impl Stream<Item = Result<T>> + Send> {
56        let subscriber = self.subscribe(event_name).await?;
57
58        // Transform the subscriber into a stream of deserialized events
59        let stream = subscriber.map(move |msg| {
60            serde_json::from_slice::<T>(&msg.payload)
61                .with_context(|| format!("Failed to deserialize event payload: {:?}", msg.payload))
62        });
63
64        Ok(stream)
65    }
66}
67
68#[cfg(feature = "integration")]
69#[cfg(test)]
70mod tests {
71    use crate::{DistributedRuntime, Runtime};
72
73    use super::*;
74
75    // todo - make a distributed runtime fixture
76    // todo - two options - fully mocked or integration test
77    #[tokio::test]
78    async fn test_publish_and_subscribe() {
79        let rt = Runtime::from_current().unwrap();
80        let dtr = DistributedRuntime::from_settings(rt.clone()).await.unwrap();
81        let ns = dtr.namespace("test_component".to_string()).unwrap();
82        let cp = ns.component("test_component".to_string()).unwrap();
83
84        // Create a subscriber on the component
85        let mut subscriber = cp.subscribe("test_event").await.unwrap();
86
87        // Publish a message from the component
88        cp.publish("test_event", &"test_message".to_string())
89            .await
90            .unwrap();
91
92        // Receive the message
93        if let Some(msg) = subscriber.next().await {
94            let received = String::from_utf8(msg.payload.to_vec()).unwrap();
95            assert_eq!(received, "\"test_message\"");
96        }
97
98        rt.shutdown();
99    }
100}