dynamo_runtime/component/
namespace.rs

1// SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
2// SPDX-License-Identifier: Apache-2.0
3
4use anyhow::Context;
5use async_trait::async_trait;
6use futures::stream::StreamExt;
7use futures::{Stream, TryStreamExt};
8
9use super::*;
10use crate::metrics::{MetricsHierarchy, MetricsRegistry};
11use crate::traits::events::{EventPublisher, EventSubscriber};
12
13#[async_trait]
14impl EventPublisher for Namespace {
15    fn subject(&self) -> String {
16        format!("namespace.{}", self.name)
17    }
18
19    async fn publish(
20        &self,
21        event_name: impl AsRef<str> + Send + Sync,
22        event: &(impl Serialize + Send + Sync),
23    ) -> Result<()> {
24        let bytes = serde_json::to_vec(event)?;
25        self.publish_bytes(event_name, bytes).await
26    }
27
28    async fn publish_bytes(
29        &self,
30        event_name: impl AsRef<str> + Send + Sync,
31        bytes: Vec<u8>,
32    ) -> Result<()> {
33        let subject = format!("{}.{}", self.subject(), event_name.as_ref());
34        let Some(nats_client) = self.drt().nats_client() else {
35            anyhow::bail!("KV router's Namespace EventPublisher requires NATS");
36        };
37        nats_client.client().publish(subject, bytes.into()).await?;
38        Ok(())
39    }
40}
41
42#[async_trait]
43impl EventSubscriber for Namespace {
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        let Some(nats_client) = self.drt().nats_client() else {
50            anyhow::bail!("KV router's Namespace EventSubscriber requires NATS");
51        };
52        Ok(nats_client.client().subscribe(subject).await?)
53    }
54
55    async fn subscribe_with_type<T: for<'de> Deserialize<'de> + Send + 'static>(
56        &self,
57        event_name: impl AsRef<str> + Send + Sync,
58    ) -> Result<impl Stream<Item = Result<T>> + Send> {
59        let subscriber = self.subscribe(event_name).await?;
60
61        // Transform the subscriber into a stream of deserialized events
62        let stream = subscriber.map(move |msg| {
63            serde_json::from_slice::<T>(&msg.payload)
64                .with_context(|| format!("Failed to deserialize event payload: {:?}", msg.payload))
65        });
66
67        Ok(stream)
68    }
69}
70
71impl MetricsHierarchy for Namespace {
72    fn basename(&self) -> String {
73        self.name.clone()
74    }
75
76    fn parent_hierarchies(&self) -> Vec<&dyn MetricsHierarchy> {
77        let mut parents = vec![];
78
79        // Walk up the namespace parent chain (grandparents to immediate parent)
80        let parent_chain: Vec<&Namespace> =
81            std::iter::successors(self.parent.as_deref(), |ns| ns.parent.as_deref()).collect();
82
83        // Add DRT first (root)
84        parents.push(&*self.runtime as &dyn MetricsHierarchy);
85
86        // Then add parent namespaces in reverse order (root -> leaf)
87        for parent_ns in parent_chain.iter().rev() {
88            parents.push(*parent_ns as &dyn MetricsHierarchy);
89        }
90
91        parents
92    }
93
94    fn get_metrics_registry(&self) -> &MetricsRegistry {
95        &self.metrics_registry
96    }
97}
98
99#[cfg(feature = "integration")]
100#[cfg(test)]
101mod tests {
102    use super::*;
103
104    // todo - make a distributed runtime fixture
105    // todo - two options - fully mocked or integration test
106    #[tokio::test]
107    async fn test_publish() {
108        let rt = Runtime::from_current().unwrap();
109        let dtr = DistributedRuntime::from_settings(rt.clone()).await.unwrap();
110        let ns = dtr.namespace("test_namespace_publish".to_string()).unwrap();
111        ns.publish("test_event", &"test".to_string()).await.unwrap();
112        rt.shutdown();
113    }
114
115    #[tokio::test]
116    async fn test_subscribe() {
117        let rt = Runtime::from_current().unwrap();
118        let dtr = DistributedRuntime::from_settings(rt.clone()).await.unwrap();
119        let ns = dtr
120            .namespace("test_namespace_subscribe".to_string())
121            .unwrap();
122
123        // Create a subscriber
124        let mut subscriber = ns.subscribe("test_event").await.unwrap();
125
126        // Publish a message
127        ns.publish("test_event", &"test_message".to_string())
128            .await
129            .unwrap();
130
131        // Receive the message
132        if let Some(msg) = subscriber.next().await {
133            let received = String::from_utf8(msg.payload.to_vec()).unwrap();
134            assert_eq!(received, "\"test_message\"");
135        }
136
137        rt.shutdown();
138    }
139}
dynamo_runtime/component/namespace.rs

dynamo_runtime/component/
namespace.rs
